1/* 2** 2001-09-15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef SQLITE3_H 34#define SQLITE3_H 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Facilitate override of interface linkage and calling conventions. 47** Be aware that these macros may not be used within this particular 48** translation of the amalgamation and its associated header file. 49** 50** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the 51** compiler that the target identifier should have external linkage. 52** 53** The SQLITE_CDECL macro is used to set the calling convention for 54** public functions that accept a variable number of arguments. 55** 56** The SQLITE_APICALL macro is used to set the calling convention for 57** public functions that accept a fixed number of arguments. 58** 59** The SQLITE_STDCALL macro is no longer used and is now deprecated. 60** 61** The SQLITE_CALLBACK macro is used to set the calling convention for 62** function pointers. 63** 64** The SQLITE_SYSAPI macro is used to set the calling convention for 65** functions provided by the operating system. 66** 67** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and 68** SQLITE_SYSAPI macros are used only when building for environments 69** that require non-default calling conventions. 70*/ 71#ifndef SQLITE_EXTERN 72# define SQLITE_EXTERN extern 73#endif 74#ifndef SQLITE_API 75# define SQLITE_API 76#endif 77#ifndef SQLITE_CDECL 78# define SQLITE_CDECL 79#endif 80#ifndef SQLITE_APICALL 81# define SQLITE_APICALL 82#endif 83#ifndef SQLITE_STDCALL 84# define SQLITE_STDCALL SQLITE_APICALL 85#endif 86#ifndef SQLITE_CALLBACK 87# define SQLITE_CALLBACK 88#endif 89#ifndef SQLITE_SYSAPI 90# define SQLITE_SYSAPI 91#endif 92 93/* 94** These no-op macros are used in front of interfaces to mark those 95** interfaces as either deprecated or experimental. New applications 96** should not use deprecated interfaces - they are supported for backwards 97** compatibility only. Application writers should be aware that 98** experimental interfaces are subject to change in point releases. 99** 100** These macros used to resolve to various kinds of compiler magic that 101** would generate warning messages when they were used. But that 102** compiler magic ended up generating such a flurry of bug reports 103** that we have taken it all out and gone back to using simple 104** noop macros. 105*/ 106#define SQLITE_DEPRECATED 107#define SQLITE_EXPERIMENTAL 108 109/* 110** Ensure these symbols were not defined by some previous header file. 111*/ 112#ifdef SQLITE_VERSION 113# undef SQLITE_VERSION 114#endif 115#ifdef SQLITE_VERSION_NUMBER 116# undef SQLITE_VERSION_NUMBER 117#endif 118 119/* 120** CAPI3REF: Compile-Time Library Version Numbers 121** 122** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 123** evaluates to a string literal that is the SQLite version in the 124** format "X.Y.Z" where X is the major version number (always 3 for 125** SQLite3) and Y is the minor version number and Z is the release number.)^ 126** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 127** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 128** numbers used in [SQLITE_VERSION].)^ 129** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 130** be larger than the release from which it is derived. Either Y will 131** be held constant and Z will be incremented or else Y will be incremented 132** and Z will be reset to zero. 133** 134** Since [version 3.6.18] ([dateof:3.6.18]), 135** SQLite source code has been stored in the 136** <a href="http://www.fossil-scm.org/">Fossil configuration management 137** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 138** a string which identifies a particular check-in of SQLite 139** within its configuration management system. ^The SQLITE_SOURCE_ID 140** string contains the date and time of the check-in (UTC) and a SHA1 141** or SHA3-256 hash of the entire source tree. If the source code has 142** been edited in any way since it was last checked in, then the last 143** four hexadecimal digits of the hash may be modified. 144** 145** See also: [sqlite3_libversion()], 146** [sqlite3_libversion_number()], [sqlite3_sourceid()], 147** [sqlite_version()] and [sqlite_source_id()]. 148*/ 149#define SQLITE_VERSION "--VERS--" 150#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 151#define SQLITE_SOURCE_ID "--SOURCE-ID--" 152 153/* 154** CAPI3REF: Run-Time Library Version Numbers 155** KEYWORDS: sqlite3_version sqlite3_sourceid 156** 157** These interfaces provide the same information as the [SQLITE_VERSION], 158** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 159** but are associated with the library instead of the header file. ^(Cautious 160** programmers might include assert() statements in their application to 161** verify that values returned by these interfaces match the macros in 162** the header, and thus ensure that the application is 163** compiled with matching library and header files. 164** 165** <blockquote><pre> 166** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 167** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 168** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 169** </pre></blockquote>)^ 170** 171** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 172** macro. ^The sqlite3_libversion() function returns a pointer to the 173** to the sqlite3_version[] string constant. The sqlite3_libversion() 174** function is provided for use in DLLs since DLL users usually do not have 175** direct access to string constants within the DLL. ^The 176** sqlite3_libversion_number() function returns an integer equal to 177** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 178** a pointer to a string constant whose value is the same as the 179** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 180** using an edited copy of [the amalgamation], then the last four characters 181** of the hash might be different from [SQLITE_SOURCE_ID].)^ 182** 183** See also: [sqlite_version()] and [sqlite_source_id()]. 184*/ 185SQLITE_EXTERN const char sqlite3_version[]; 186const char *sqlite3_libversion(void); 187const char *sqlite3_sourceid(void); 188int sqlite3_libversion_number(void); 189 190/* 191** CAPI3REF: Run-Time Library Compilation Options Diagnostics 192** 193** ^The sqlite3_compileoption_used() function returns 0 or 1 194** indicating whether the specified option was defined at 195** compile time. ^The SQLITE_ prefix may be omitted from the 196** option name passed to sqlite3_compileoption_used(). 197** 198** ^The sqlite3_compileoption_get() function allows iterating 199** over the list of options that were defined at compile time by 200** returning the N-th compile time option string. ^If N is out of range, 201** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 202** prefix is omitted from any strings returned by 203** sqlite3_compileoption_get(). 204** 205** ^Support for the diagnostic functions sqlite3_compileoption_used() 206** and sqlite3_compileoption_get() may be omitted by specifying the 207** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 208** 209** See also: SQL functions [sqlite_compileoption_used()] and 210** [sqlite_compileoption_get()] and the [compile_options pragma]. 211*/ 212#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 213int sqlite3_compileoption_used(const char *zOptName); 214const char *sqlite3_compileoption_get(int N); 215#else 216# define sqlite3_compileoption_used(X) 0 217# define sqlite3_compileoption_get(X) ((void*)0) 218#endif 219 220/* 221** CAPI3REF: Test To See If The Library Is Threadsafe 222** 223** ^The sqlite3_threadsafe() function returns zero if and only if 224** SQLite was compiled with mutexing code omitted due to the 225** [SQLITE_THREADSAFE] compile-time option being set to 0. 226** 227** SQLite can be compiled with or without mutexes. When 228** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 229** are enabled and SQLite is threadsafe. When the 230** [SQLITE_THREADSAFE] macro is 0, 231** the mutexes are omitted. Without the mutexes, it is not safe 232** to use SQLite concurrently from more than one thread. 233** 234** Enabling mutexes incurs a measurable performance penalty. 235** So if speed is of utmost importance, it makes sense to disable 236** the mutexes. But for maximum safety, mutexes should be enabled. 237** ^The default behavior is for mutexes to be enabled. 238** 239** This interface can be used by an application to make sure that the 240** version of SQLite that it is linking against was compiled with 241** the desired setting of the [SQLITE_THREADSAFE] macro. 242** 243** This interface only reports on the compile-time mutex setting 244** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 245** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 246** can be fully or partially disabled using a call to [sqlite3_config()] 247** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 248** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 249** sqlite3_threadsafe() function shows only the compile-time setting of 250** thread safety, not any run-time changes to that setting made by 251** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 252** is unchanged by calls to sqlite3_config().)^ 253** 254** See the [threading mode] documentation for additional information. 255*/ 256int sqlite3_threadsafe(void); 257 258/* 259** CAPI3REF: Database Connection Handle 260** KEYWORDS: {database connection} {database connections} 261** 262** Each open SQLite database is represented by a pointer to an instance of 263** the opaque structure named "sqlite3". It is useful to think of an sqlite3 264** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 265** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 266** and [sqlite3_close_v2()] are its destructors. There are many other 267** interfaces (such as 268** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 269** [sqlite3_busy_timeout()] to name but three) that are methods on an 270** sqlite3 object. 271*/ 272typedef struct sqlite3 sqlite3; 273 274/* 275** CAPI3REF: 64-Bit Integer Types 276** KEYWORDS: sqlite_int64 sqlite_uint64 277** 278** Because there is no cross-platform way to specify 64-bit integer types 279** SQLite includes typedefs for 64-bit signed and unsigned integers. 280** 281** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 282** The sqlite_int64 and sqlite_uint64 types are supported for backwards 283** compatibility only. 284** 285** ^The sqlite3_int64 and sqlite_int64 types can store integer values 286** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 287** sqlite3_uint64 and sqlite_uint64 types can store integer values 288** between 0 and +18446744073709551615 inclusive. 289*/ 290#ifdef SQLITE_INT64_TYPE 291 typedef SQLITE_INT64_TYPE sqlite_int64; 292# ifdef SQLITE_UINT64_TYPE 293 typedef SQLITE_UINT64_TYPE sqlite_uint64; 294# else 295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 296# endif 297#elif defined(_MSC_VER) || defined(__BORLANDC__) 298 typedef __int64 sqlite_int64; 299 typedef unsigned __int64 sqlite_uint64; 300#else 301 typedef long long int sqlite_int64; 302 typedef unsigned long long int sqlite_uint64; 303#endif 304typedef sqlite_int64 sqlite3_int64; 305typedef sqlite_uint64 sqlite3_uint64; 306 307/* 308** If compiling for a processor that lacks floating point support, 309** substitute integer for floating-point. 310*/ 311#ifdef SQLITE_OMIT_FLOATING_POINT 312# define double sqlite3_int64 313#endif 314 315/* 316** CAPI3REF: Closing A Database Connection 317** DESTRUCTOR: sqlite3 318** 319** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 320** for the [sqlite3] object. 321** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 322** the [sqlite3] object is successfully destroyed and all associated 323** resources are deallocated. 324** 325** Ideally, applications should [sqlite3_finalize | finalize] all 326** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 327** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 328** with the [sqlite3] object prior to attempting to close the object. 329** ^If the database connection is associated with unfinalized prepared 330** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 331** sqlite3_close() will leave the database connection open and return 332** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 333** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 334** it returns [SQLITE_OK] regardless, but instead of deallocating the database 335** connection immediately, it marks the database connection as an unusable 336** "zombie" and makes arrangements to automatically deallocate the database 337** connection after all prepared statements are finalized, all BLOB handles 338** are closed, and all backups have finished. The sqlite3_close_v2() interface 339** is intended for use with host languages that are garbage collected, and 340** where the order in which destructors are called is arbitrary. 341** 342** ^If an [sqlite3] object is destroyed while a transaction is open, 343** the transaction is automatically rolled back. 344** 345** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 346** must be either a NULL 347** pointer or an [sqlite3] object pointer obtained 348** from [sqlite3_open()], [sqlite3_open16()], or 349** [sqlite3_open_v2()], and not previously closed. 350** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 351** argument is a harmless no-op. 352*/ 353int sqlite3_close(sqlite3*); 354int sqlite3_close_v2(sqlite3*); 355 356/* 357** The type for a callback function. 358** This is legacy and deprecated. It is included for historical 359** compatibility and is not documented. 360*/ 361typedef int (*sqlite3_callback)(void*,int,char**, char**); 362 363/* 364** CAPI3REF: One-Step Query Execution Interface 365** METHOD: sqlite3 366** 367** The sqlite3_exec() interface is a convenience wrapper around 368** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 369** that allows an application to run multiple statements of SQL 370** without having to use a lot of C code. 371** 372** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 373** semicolon-separate SQL statements passed into its 2nd argument, 374** in the context of the [database connection] passed in as its 1st 375** argument. ^If the callback function of the 3rd argument to 376** sqlite3_exec() is not NULL, then it is invoked for each result row 377** coming out of the evaluated SQL statements. ^The 4th argument to 378** sqlite3_exec() is relayed through to the 1st argument of each 379** callback invocation. ^If the callback pointer to sqlite3_exec() 380** is NULL, then no callback is ever invoked and result rows are 381** ignored. 382** 383** ^If an error occurs while evaluating the SQL statements passed into 384** sqlite3_exec(), then execution of the current statement stops and 385** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 386** is not NULL then any error message is written into memory obtained 387** from [sqlite3_malloc()] and passed back through the 5th parameter. 388** To avoid memory leaks, the application should invoke [sqlite3_free()] 389** on error message strings returned through the 5th parameter of 390** sqlite3_exec() after the error message string is no longer needed. 391** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 392** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 393** NULL before returning. 394** 395** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 396** routine returns SQLITE_ABORT without invoking the callback again and 397** without running any subsequent SQL statements. 398** 399** ^The 2nd argument to the sqlite3_exec() callback function is the 400** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 401** callback is an array of pointers to strings obtained as if from 402** [sqlite3_column_text()], one for each column. ^If an element of a 403** result row is NULL then the corresponding string pointer for the 404** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 405** sqlite3_exec() callback is an array of pointers to strings where each 406** entry represents the name of corresponding result column as obtained 407** from [sqlite3_column_name()]. 408** 409** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 410** to an empty string, or a pointer that contains only whitespace and/or 411** SQL comments, then no SQL statements are evaluated and the database 412** is not changed. 413** 414** Restrictions: 415** 416** <ul> 417** <li> The application must ensure that the 1st parameter to sqlite3_exec() 418** is a valid and open [database connection]. 419** <li> The application must not close the [database connection] specified by 420** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 421** <li> The application must not modify the SQL statement text passed into 422** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 423** </ul> 424*/ 425int sqlite3_exec( 426 sqlite3*, /* An open database */ 427 const char *sql, /* SQL to be evaluated */ 428 int (*callback)(void*,int,char**,char**), /* Callback function */ 429 void *, /* 1st argument to callback */ 430 char **errmsg /* Error msg written here */ 431); 432 433/* 434** CAPI3REF: Result Codes 435** KEYWORDS: {result code definitions} 436** 437** Many SQLite functions return an integer result code from the set shown 438** here in order to indicate success or failure. 439** 440** New error codes may be added in future versions of SQLite. 441** 442** See also: [extended result code definitions] 443*/ 444#define SQLITE_OK 0 /* Successful result */ 445/* beginning-of-error-codes */ 446#define SQLITE_ERROR 1 /* Generic error */ 447#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 448#define SQLITE_PERM 3 /* Access permission denied */ 449#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 450#define SQLITE_BUSY 5 /* The database file is locked */ 451#define SQLITE_LOCKED 6 /* A table in the database is locked */ 452#define SQLITE_NOMEM 7 /* A malloc() failed */ 453#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 454#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 455#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 456#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 457#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 458#define SQLITE_FULL 13 /* Insertion failed because database is full */ 459#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 460#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 461#define SQLITE_EMPTY 16 /* Internal use only */ 462#define SQLITE_SCHEMA 17 /* The database schema changed */ 463#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 464#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 465#define SQLITE_MISMATCH 20 /* Data type mismatch */ 466#define SQLITE_MISUSE 21 /* Library used incorrectly */ 467#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 468#define SQLITE_AUTH 23 /* Authorization denied */ 469#define SQLITE_FORMAT 24 /* Not used */ 470#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 471#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 472#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 473#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 474#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 475#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 476/* end-of-error-codes */ 477 478/* 479** CAPI3REF: Extended Result Codes 480** KEYWORDS: {extended result code definitions} 481** 482** In its default configuration, SQLite API routines return one of 30 integer 483** [result codes]. However, experience has shown that many of 484** these result codes are too coarse-grained. They do not provide as 485** much information about problems as programmers might like. In an effort to 486** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 487** and later) include 488** support for additional result codes that provide more detailed information 489** about errors. These [extended result codes] are enabled or disabled 490** on a per database connection basis using the 491** [sqlite3_extended_result_codes()] API. Or, the extended code for 492** the most recent error can be obtained using 493** [sqlite3_extended_errcode()]. 494*/ 495#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 496#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 497#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 498#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 499#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 500#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 501#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 502#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 503#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 504#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 505#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 506#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 507#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 508#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 509#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 510#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 511#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 512#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 513#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 514#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 515#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 516#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 517#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 518#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 519#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 520#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 521#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 522#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 523#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 524#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 525#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 526#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 527#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 528#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 529#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 530#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 531#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 532#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 533#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 534#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 535#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 536#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 537#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 538#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 539#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 540#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 541#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 542#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 543#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 544#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 545#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 546#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 547#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 548#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 549#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 550#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 551#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 552#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 553#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 554#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 555#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 556#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 557#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 558#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 559#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 560#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 561#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 562#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 563#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 564#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 565#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 566#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 567#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 568#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 569#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 570 571/* 572** CAPI3REF: Flags For File Open Operations 573** 574** These bit values are intended for use in the 575** 3rd parameter to the [sqlite3_open_v2()] interface and 576** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 577** 578** Only those flags marked as "Ok for sqlite3_open_v2()" may be 579** used as the third argument to the [sqlite3_open_v2()] interface. 580** The other flags have historically been ignored by sqlite3_open_v2(), 581** though future versions of SQLite might change so that an error is 582** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 583** Applications should not depend on the historical behavior. 584** 585** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 586** [sqlite3_open_v2()] does *not* cause the underlying database file 587** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 588** [sqlite3_open_v2()] has historically be a no-op and might become an 589** error in future versions of SQLite. 590*/ 591#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 592#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 593#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 594#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 595#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 596#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 597#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 598#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 599#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 600#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 601#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 602#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 603#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 604#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 605#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 606#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 607#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 608#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 609#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 610#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 611#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 612#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 613 614/* Reserved: 0x00F00000 */ 615/* Legacy compatibility: */ 616#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 617 618 619/* 620** CAPI3REF: Device Characteristics 621** 622** The xDeviceCharacteristics method of the [sqlite3_io_methods] 623** object returns an integer which is a vector of these 624** bit values expressing I/O characteristics of the mass storage 625** device that holds the file that the [sqlite3_io_methods] 626** refers to. 627** 628** The SQLITE_IOCAP_ATOMIC property means that all writes of 629** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 630** mean that writes of blocks that are nnn bytes in size and 631** are aligned to an address which is an integer multiple of 632** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 633** that when data is appended to a file, the data is appended 634** first then the size of the file is extended, never the other 635** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 636** information is written to disk in the same order as calls 637** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 638** after reboot following a crash or power loss, the only bytes in a 639** file that were written at the application level might have changed 640** and that adjacent bytes, even bytes within the same sector are 641** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 642** flag indicates that a file cannot be deleted when open. The 643** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 644** read-only media and cannot be changed even by processes with 645** elevated privileges. 646** 647** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 648** filesystem supports doing multiple write operations atomically when those 649** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 650** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 651*/ 652#define SQLITE_IOCAP_ATOMIC 0x00000001 653#define SQLITE_IOCAP_ATOMIC512 0x00000002 654#define SQLITE_IOCAP_ATOMIC1K 0x00000004 655#define SQLITE_IOCAP_ATOMIC2K 0x00000008 656#define SQLITE_IOCAP_ATOMIC4K 0x00000010 657#define SQLITE_IOCAP_ATOMIC8K 0x00000020 658#define SQLITE_IOCAP_ATOMIC16K 0x00000040 659#define SQLITE_IOCAP_ATOMIC32K 0x00000080 660#define SQLITE_IOCAP_ATOMIC64K 0x00000100 661#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 662#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 663#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 664#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 665#define SQLITE_IOCAP_IMMUTABLE 0x00002000 666#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 667 668/* 669** CAPI3REF: File Locking Levels 670** 671** SQLite uses one of these integer values as the second 672** argument to calls it makes to the xLock() and xUnlock() methods 673** of an [sqlite3_io_methods] object. 674*/ 675#define SQLITE_LOCK_NONE 0 676#define SQLITE_LOCK_SHARED 1 677#define SQLITE_LOCK_RESERVED 2 678#define SQLITE_LOCK_PENDING 3 679#define SQLITE_LOCK_EXCLUSIVE 4 680 681/* 682** CAPI3REF: Synchronization Type Flags 683** 684** When SQLite invokes the xSync() method of an 685** [sqlite3_io_methods] object it uses a combination of 686** these integer values as the second argument. 687** 688** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 689** sync operation only needs to flush data to mass storage. Inode 690** information need not be flushed. If the lower four bits of the flag 691** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 692** If the lower four bits equal SQLITE_SYNC_FULL, that means 693** to use Mac OS X style fullsync instead of fsync(). 694** 695** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 696** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 697** settings. The [synchronous pragma] determines when calls to the 698** xSync VFS method occur and applies uniformly across all platforms. 699** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 700** energetic or rigorous or forceful the sync operations are and 701** only make a difference on Mac OSX for the default SQLite code. 702** (Third-party VFS implementations might also make the distinction 703** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 704** operating systems natively supported by SQLite, only Mac OSX 705** cares about the difference.) 706*/ 707#define SQLITE_SYNC_NORMAL 0x00002 708#define SQLITE_SYNC_FULL 0x00003 709#define SQLITE_SYNC_DATAONLY 0x00010 710 711/* 712** CAPI3REF: OS Interface Open File Handle 713** 714** An [sqlite3_file] object represents an open file in the 715** [sqlite3_vfs | OS interface layer]. Individual OS interface 716** implementations will 717** want to subclass this object by appending additional fields 718** for their own use. The pMethods entry is a pointer to an 719** [sqlite3_io_methods] object that defines methods for performing 720** I/O operations on the open file. 721*/ 722typedef struct sqlite3_file sqlite3_file; 723struct sqlite3_file { 724 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 725}; 726 727/* 728** CAPI3REF: OS Interface File Virtual Methods Object 729** 730** Every file opened by the [sqlite3_vfs.xOpen] method populates an 731** [sqlite3_file] object (or, more commonly, a subclass of the 732** [sqlite3_file] object) with a pointer to an instance of this object. 733** This object defines the methods used to perform various operations 734** against the open file represented by the [sqlite3_file] object. 735** 736** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 737** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 738** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 739** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 740** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 741** to NULL. 742** 743** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 744** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 745** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 746** flag may be ORed in to indicate that only the data of the file 747** and not its inode needs to be synced. 748** 749** The integer values to xLock() and xUnlock() are one of 750** <ul> 751** <li> [SQLITE_LOCK_NONE], 752** <li> [SQLITE_LOCK_SHARED], 753** <li> [SQLITE_LOCK_RESERVED], 754** <li> [SQLITE_LOCK_PENDING], or 755** <li> [SQLITE_LOCK_EXCLUSIVE]. 756** </ul> 757** xLock() increases the lock. xUnlock() decreases the lock. 758** The xCheckReservedLock() method checks whether any database connection, 759** either in this process or in some other process, is holding a RESERVED, 760** PENDING, or EXCLUSIVE lock on the file. It returns true 761** if such a lock exists and false otherwise. 762** 763** The xFileControl() method is a generic interface that allows custom 764** VFS implementations to directly control an open file using the 765** [sqlite3_file_control()] interface. The second "op" argument is an 766** integer opcode. The third argument is a generic pointer intended to 767** point to a structure that may contain arguments or space in which to 768** write return values. Potential uses for xFileControl() might be 769** functions to enable blocking locks with timeouts, to change the 770** locking strategy (for example to use dot-file locks), to inquire 771** about the status of a lock, or to break stale locks. The SQLite 772** core reserves all opcodes less than 100 for its own use. 773** A [file control opcodes | list of opcodes] less than 100 is available. 774** Applications that define a custom xFileControl method should use opcodes 775** greater than 100 to avoid conflicts. VFS implementations should 776** return [SQLITE_NOTFOUND] for file control opcodes that they do not 777** recognize. 778** 779** The xSectorSize() method returns the sector size of the 780** device that underlies the file. The sector size is the 781** minimum write that can be performed without disturbing 782** other bytes in the file. The xDeviceCharacteristics() 783** method returns a bit vector describing behaviors of the 784** underlying device: 785** 786** <ul> 787** <li> [SQLITE_IOCAP_ATOMIC] 788** <li> [SQLITE_IOCAP_ATOMIC512] 789** <li> [SQLITE_IOCAP_ATOMIC1K] 790** <li> [SQLITE_IOCAP_ATOMIC2K] 791** <li> [SQLITE_IOCAP_ATOMIC4K] 792** <li> [SQLITE_IOCAP_ATOMIC8K] 793** <li> [SQLITE_IOCAP_ATOMIC16K] 794** <li> [SQLITE_IOCAP_ATOMIC32K] 795** <li> [SQLITE_IOCAP_ATOMIC64K] 796** <li> [SQLITE_IOCAP_SAFE_APPEND] 797** <li> [SQLITE_IOCAP_SEQUENTIAL] 798** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 799** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 800** <li> [SQLITE_IOCAP_IMMUTABLE] 801** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 802** </ul> 803** 804** The SQLITE_IOCAP_ATOMIC property means that all writes of 805** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 806** mean that writes of blocks that are nnn bytes in size and 807** are aligned to an address which is an integer multiple of 808** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 809** that when data is appended to a file, the data is appended 810** first then the size of the file is extended, never the other 811** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 812** information is written to disk in the same order as calls 813** to xWrite(). 814** 815** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 816** in the unread portions of the buffer with zeros. A VFS that 817** fails to zero-fill short reads might seem to work. However, 818** failure to zero-fill short reads will eventually lead to 819** database corruption. 820*/ 821typedef struct sqlite3_io_methods sqlite3_io_methods; 822struct sqlite3_io_methods { 823 int iVersion; 824 int (*xClose)(sqlite3_file*); 825 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 826 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 827 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 828 int (*xSync)(sqlite3_file*, int flags); 829 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 830 int (*xLock)(sqlite3_file*, int); 831 int (*xUnlock)(sqlite3_file*, int); 832 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 833 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 834 int (*xSectorSize)(sqlite3_file*); 835 int (*xDeviceCharacteristics)(sqlite3_file*); 836 /* Methods above are valid for version 1 */ 837 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 838 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 839 void (*xShmBarrier)(sqlite3_file*); 840 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 841 /* Methods above are valid for version 2 */ 842 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 843 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 844 /* Methods above are valid for version 3 */ 845 /* Additional methods may be added in future releases */ 846}; 847 848/* 849** CAPI3REF: Standard File Control Opcodes 850** KEYWORDS: {file control opcodes} {file control opcode} 851** 852** These integer constants are opcodes for the xFileControl method 853** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 854** interface. 855** 856** <ul> 857** <li>[[SQLITE_FCNTL_LOCKSTATE]] 858** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 859** opcode causes the xFileControl method to write the current state of 860** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 861** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 862** into an integer that the pArg argument points to. This capability 863** is used during testing and is only available when the SQLITE_TEST 864** compile-time option is used. 865** 866** <li>[[SQLITE_FCNTL_SIZE_HINT]] 867** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 868** layer a hint of how large the database file will grow to be during the 869** current transaction. This hint is not guaranteed to be accurate but it 870** is often close. The underlying VFS might choose to preallocate database 871** file space based on this hint in order to help writes to the database 872** file run faster. 873** 874** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 875** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 876** implements [sqlite3_deserialize()] to set an upper bound on the size 877** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 878** If the integer pointed to is negative, then it is filled in with the 879** current limit. Otherwise the limit is set to the larger of the value 880** of the integer pointed to and the current database size. The integer 881** pointed to is set to the new limit. 882** 883** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 884** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 885** extends and truncates the database file in chunks of a size specified 886** by the user. The fourth argument to [sqlite3_file_control()] should 887** point to an integer (type int) containing the new chunk-size to use 888** for the nominated database. Allocating database file space in large 889** chunks (say 1MB at a time), may reduce file-system fragmentation and 890** improve performance on some systems. 891** 892** <li>[[SQLITE_FCNTL_FILE_POINTER]] 893** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 894** to the [sqlite3_file] object associated with a particular database 895** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 896** 897** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 898** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 899** to the [sqlite3_file] object associated with the journal file (either 900** the [rollback journal] or the [write-ahead log]) for a particular database 901** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 902** 903** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 904** No longer in use. 905** 906** <li>[[SQLITE_FCNTL_SYNC]] 907** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 908** sent to the VFS immediately before the xSync method is invoked on a 909** database file descriptor. Or, if the xSync method is not invoked 910** because the user has configured SQLite with 911** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 912** of the xSync method. In most cases, the pointer argument passed with 913** this file-control is NULL. However, if the database file is being synced 914** as part of a multi-database commit, the argument points to a nul-terminated 915** string containing the transactions super-journal file name. VFSes that 916** do not need this signal should silently ignore this opcode. Applications 917** should not call [sqlite3_file_control()] with this opcode as doing so may 918** disrupt the operation of the specialized VFSes that do require it. 919** 920** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 921** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 922** and sent to the VFS after a transaction has been committed immediately 923** but before the database is unlocked. VFSes that do not need this signal 924** should silently ignore this opcode. Applications should not call 925** [sqlite3_file_control()] with this opcode as doing so may disrupt the 926** operation of the specialized VFSes that do require it. 927** 928** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 929** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 930** retry counts and intervals for certain disk I/O operations for the 931** windows [VFS] in order to provide robustness in the presence of 932** anti-virus programs. By default, the windows VFS will retry file read, 933** file write, and file delete operations up to 10 times, with a delay 934** of 25 milliseconds before the first retry and with the delay increasing 935** by an additional 25 milliseconds with each subsequent retry. This 936** opcode allows these two values (10 retries and 25 milliseconds of delay) 937** to be adjusted. The values are changed for all database connections 938** within the same process. The argument is a pointer to an array of two 939** integers where the first integer is the new retry count and the second 940** integer is the delay. If either integer is negative, then the setting 941** is not changed but instead the prior value of that setting is written 942** into the array entry, allowing the current retry settings to be 943** interrogated. The zDbName parameter is ignored. 944** 945** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 946** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 947** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 948** write ahead log ([WAL file]) and shared memory 949** files used for transaction control 950** are automatically deleted when the latest connection to the database 951** closes. Setting persistent WAL mode causes those files to persist after 952** close. Persisting the files is useful when other processes that do not 953** have write permission on the directory containing the database file want 954** to read the database file, as the WAL and shared memory files must exist 955** in order for the database to be readable. The fourth parameter to 956** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 957** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 958** WAL mode. If the integer is -1, then it is overwritten with the current 959** WAL persistence setting. 960** 961** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 962** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 963** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 964** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 965** xDeviceCharacteristics methods. The fourth parameter to 966** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 967** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 968** mode. If the integer is -1, then it is overwritten with the current 969** zero-damage mode setting. 970** 971** <li>[[SQLITE_FCNTL_OVERWRITE]] 972** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 973** a write transaction to indicate that, unless it is rolled back for some 974** reason, the entire database file will be overwritten by the current 975** transaction. This is used by VACUUM operations. 976** 977** <li>[[SQLITE_FCNTL_VFSNAME]] 978** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 979** all [VFSes] in the VFS stack. The names are of all VFS shims and the 980** final bottom-level VFS are written into memory obtained from 981** [sqlite3_malloc()] and the result is stored in the char* variable 982** that the fourth parameter of [sqlite3_file_control()] points to. 983** The caller is responsible for freeing the memory when done. As with 984** all file-control actions, there is no guarantee that this will actually 985** do anything. Callers should initialize the char* variable to a NULL 986** pointer in case this file-control is not implemented. This file-control 987** is intended for diagnostic use only. 988** 989** <li>[[SQLITE_FCNTL_VFS_POINTER]] 990** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 991** [VFSes] currently in use. ^(The argument X in 992** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 993** of type "[sqlite3_vfs] **". This opcodes will set *X 994** to a pointer to the top-level VFS.)^ 995** ^When there are multiple VFS shims in the stack, this opcode finds the 996** upper-most shim only. 997** 998** <li>[[SQLITE_FCNTL_PRAGMA]] 999** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1000** file control is sent to the open [sqlite3_file] object corresponding 1001** to the database file to which the pragma statement refers. ^The argument 1002** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1003** pointers to strings (char**) in which the second element of the array 1004** is the name of the pragma and the third element is the argument to the 1005** pragma or NULL if the pragma has no argument. ^The handler for an 1006** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1007** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1008** or the equivalent and that string will become the result of the pragma or 1009** the error message if the pragma fails. ^If the 1010** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1011** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1012** file control returns [SQLITE_OK], then the parser assumes that the 1013** VFS has handled the PRAGMA itself and the parser generates a no-op 1014** prepared statement if result string is NULL, or that returns a copy 1015** of the result string if the string is non-NULL. 1016** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1017** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1018** that the VFS encountered an error while handling the [PRAGMA] and the 1019** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1020** file control occurs at the beginning of pragma statement analysis and so 1021** it is able to override built-in [PRAGMA] statements. 1022** 1023** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1024** ^The [SQLITE_FCNTL_BUSYHANDLER] 1025** file-control may be invoked by SQLite on the database file handle 1026** shortly after it is opened in order to provide a custom VFS with access 1027** to the connection's busy-handler callback. The argument is of type (void**) 1028** - an array of two (void *) values. The first (void *) actually points 1029** to a function of type (int (*)(void *)). In order to invoke the connection's 1030** busy-handler, this function should be invoked with the second (void *) in 1031** the array as the only argument. If it returns non-zero, then the operation 1032** should be retried. If it returns zero, the custom VFS should abandon the 1033** current operation. 1034** 1035** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1036** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1037** to have SQLite generate a 1038** temporary filename using the same algorithm that is followed to generate 1039** temporary filenames for TEMP tables and other internal uses. The 1040** argument should be a char** which will be filled with the filename 1041** written into memory obtained from [sqlite3_malloc()]. The caller should 1042** invoke [sqlite3_free()] on the result to avoid a memory leak. 1043** 1044** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1045** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1046** maximum number of bytes that will be used for memory-mapped I/O. 1047** The argument is a pointer to a value of type sqlite3_int64 that 1048** is an advisory maximum number of bytes in the file to memory map. The 1049** pointer is overwritten with the old value. The limit is not changed if 1050** the value originally pointed to is negative, and so the current limit 1051** can be queried by passing in a pointer to a negative number. This 1052** file-control is used internally to implement [PRAGMA mmap_size]. 1053** 1054** <li>[[SQLITE_FCNTL_TRACE]] 1055** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1056** to the VFS about what the higher layers of the SQLite stack are doing. 1057** This file control is used by some VFS activity tracing [shims]. 1058** The argument is a zero-terminated string. Higher layers in the 1059** SQLite stack may generate instances of this file control if 1060** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1061** 1062** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1063** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1064** pointer to an integer and it writes a boolean into that integer depending 1065** on whether or not the file has been renamed, moved, or deleted since it 1066** was first opened. 1067** 1068** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1069** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1070** underlying native file handle associated with a file handle. This file 1071** control interprets its argument as a pointer to a native file handle and 1072** writes the resulting value there. 1073** 1074** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1075** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1076** opcode causes the xFileControl method to swap the file handle with the one 1077** pointed to by the pArg argument. This capability is used during testing 1078** and only needs to be supported when SQLITE_TEST is defined. 1079** 1080** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1081** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1082** be advantageous to block on the next WAL lock if the lock is not immediately 1083** available. The WAL subsystem issues this signal during rare 1084** circumstances in order to fix a problem with priority inversion. 1085** Applications should <em>not</em> use this file-control. 1086** 1087** <li>[[SQLITE_FCNTL_ZIPVFS]] 1088** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1089** VFS should return SQLITE_NOTFOUND for this opcode. 1090** 1091** <li>[[SQLITE_FCNTL_RBU]] 1092** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1093** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1094** this opcode. 1095** 1096** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1097** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1098** the file descriptor is placed in "batch write mode", which 1099** means all subsequent write operations will be deferred and done 1100** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1101** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1102** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1103** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1104** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1105** no VFS interface calls on the same [sqlite3_file] file descriptor 1106** except for calls to the xWrite method and the xFileControl method 1107** with [SQLITE_FCNTL_SIZE_HINT]. 1108** 1109** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1110** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1111** operations since the previous successful call to 1112** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1113** This file control returns [SQLITE_OK] if and only if the writes were 1114** all performed successfully and have been committed to persistent storage. 1115** ^Regardless of whether or not it is successful, this file control takes 1116** the file descriptor out of batch write mode so that all subsequent 1117** write operations are independent. 1118** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1119** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1120** 1121** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1122** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1123** operations since the previous successful call to 1124** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1125** ^This file control takes the file descriptor out of batch write mode 1126** so that all subsequent write operations are independent. 1127** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1128** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1129** 1130** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1131** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1132** to block for up to M milliseconds before failing when attempting to 1133** obtain a file lock using the xLock or xShmLock methods of the VFS. 1134** The parameter is a pointer to a 32-bit signed integer that contains 1135** the value that M is to be set to. Before returning, the 32-bit signed 1136** integer is overwritten with the previous value of M. 1137** 1138** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1139** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1140** a database file. The argument is a pointer to a 32-bit unsigned integer. 1141** The "data version" for the pager is written into the pointer. The 1142** "data version" changes whenever any change occurs to the corresponding 1143** database file, either through SQL statements on the same database 1144** connection or through transactions committed by separate database 1145** connections possibly in other processes. The [sqlite3_total_changes()] 1146** interface can be used to find if any database on the connection has changed, 1147** but that interface responds to changes on TEMP as well as MAIN and does 1148** not provide a mechanism to detect changes to MAIN only. Also, the 1149** [sqlite3_total_changes()] interface responds to internal changes only and 1150** omits changes made by other database connections. The 1151** [PRAGMA data_version] command provides a mechanism to detect changes to 1152** a single attached database that occur due to other database connections, 1153** but omits changes implemented by the database connection on which it is 1154** called. This file control is the only mechanism to detect changes that 1155** happen either internally or externally and that are associated with 1156** a particular attached database. 1157** 1158** <li>[[SQLITE_FCNTL_CKPT_START]] 1159** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1160** in wal mode before the client starts to copy pages from the wal 1161** file to the database file. 1162** 1163** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1164** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1165** in wal mode after the client has finished copying pages from the wal 1166** file to the database file, but before the *-shm file is updated to 1167** record the fact that the pages have been checkpointed. 1168** </ul> 1169** 1170** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1171** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1172** whether or not there is a database client in another process with a wal-mode 1173** transaction open on the database or not. It is only available on unix.The 1174** (void*) argument passed with this file-control should be a pointer to a 1175** value of type (int). The integer value is set to 1 if the database is a wal 1176** mode database and there exists at least one client in another process that 1177** currently has an SQL transaction open on the database. It is set to 0 if 1178** the database is not a wal-mode db, or if there is no such connection in any 1179** other process. This opcode cannot be used to detect transactions opened 1180** by clients within the current process, only within other processes. 1181** </ul> 1182** 1183** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1184** Used by the cksmvfs VFS module only. 1185** </ul> 1186*/ 1187#define SQLITE_FCNTL_LOCKSTATE 1 1188#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1189#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1190#define SQLITE_FCNTL_LAST_ERRNO 4 1191#define SQLITE_FCNTL_SIZE_HINT 5 1192#define SQLITE_FCNTL_CHUNK_SIZE 6 1193#define SQLITE_FCNTL_FILE_POINTER 7 1194#define SQLITE_FCNTL_SYNC_OMITTED 8 1195#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1196#define SQLITE_FCNTL_PERSIST_WAL 10 1197#define SQLITE_FCNTL_OVERWRITE 11 1198#define SQLITE_FCNTL_VFSNAME 12 1199#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1200#define SQLITE_FCNTL_PRAGMA 14 1201#define SQLITE_FCNTL_BUSYHANDLER 15 1202#define SQLITE_FCNTL_TEMPFILENAME 16 1203#define SQLITE_FCNTL_MMAP_SIZE 18 1204#define SQLITE_FCNTL_TRACE 19 1205#define SQLITE_FCNTL_HAS_MOVED 20 1206#define SQLITE_FCNTL_SYNC 21 1207#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1208#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1209#define SQLITE_FCNTL_WAL_BLOCK 24 1210#define SQLITE_FCNTL_ZIPVFS 25 1211#define SQLITE_FCNTL_RBU 26 1212#define SQLITE_FCNTL_VFS_POINTER 27 1213#define SQLITE_FCNTL_JOURNAL_POINTER 28 1214#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1215#define SQLITE_FCNTL_PDB 30 1216#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1217#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1218#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1219#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1220#define SQLITE_FCNTL_DATA_VERSION 35 1221#define SQLITE_FCNTL_SIZE_LIMIT 36 1222#define SQLITE_FCNTL_CKPT_DONE 37 1223#define SQLITE_FCNTL_RESERVE_BYTES 38 1224#define SQLITE_FCNTL_CKPT_START 39 1225#define SQLITE_FCNTL_EXTERNAL_READER 40 1226#define SQLITE_FCNTL_CKSM_FILE 41 1227 1228/* deprecated names */ 1229#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1230#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1231#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1232 1233 1234/* 1235** CAPI3REF: Mutex Handle 1236** 1237** The mutex module within SQLite defines [sqlite3_mutex] to be an 1238** abstract type for a mutex object. The SQLite core never looks 1239** at the internal representation of an [sqlite3_mutex]. It only 1240** deals with pointers to the [sqlite3_mutex] object. 1241** 1242** Mutexes are created using [sqlite3_mutex_alloc()]. 1243*/ 1244typedef struct sqlite3_mutex sqlite3_mutex; 1245 1246/* 1247** CAPI3REF: Loadable Extension Thunk 1248** 1249** A pointer to the opaque sqlite3_api_routines structure is passed as 1250** the third parameter to entry points of [loadable extensions]. This 1251** structure must be typedefed in order to work around compiler warnings 1252** on some platforms. 1253*/ 1254typedef struct sqlite3_api_routines sqlite3_api_routines; 1255 1256/* 1257** CAPI3REF: OS Interface Object 1258** 1259** An instance of the sqlite3_vfs object defines the interface between 1260** the SQLite core and the underlying operating system. The "vfs" 1261** in the name of the object stands for "virtual file system". See 1262** the [VFS | VFS documentation] for further information. 1263** 1264** The VFS interface is sometimes extended by adding new methods onto 1265** the end. Each time such an extension occurs, the iVersion field 1266** is incremented. The iVersion value started out as 1 in 1267** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1268** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1269** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1270** may be appended to the sqlite3_vfs object and the iVersion value 1271** may increase again in future versions of SQLite. 1272** Note that due to an oversight, the structure 1273** of the sqlite3_vfs object changed in the transition from 1274** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1275** and yet the iVersion field was not increased. 1276** 1277** The szOsFile field is the size of the subclassed [sqlite3_file] 1278** structure used by this VFS. mxPathname is the maximum length of 1279** a pathname in this VFS. 1280** 1281** Registered sqlite3_vfs objects are kept on a linked list formed by 1282** the pNext pointer. The [sqlite3_vfs_register()] 1283** and [sqlite3_vfs_unregister()] interfaces manage this list 1284** in a thread-safe way. The [sqlite3_vfs_find()] interface 1285** searches the list. Neither the application code nor the VFS 1286** implementation should use the pNext pointer. 1287** 1288** The pNext field is the only field in the sqlite3_vfs 1289** structure that SQLite will ever modify. SQLite will only access 1290** or modify this field while holding a particular static mutex. 1291** The application should never modify anything within the sqlite3_vfs 1292** object once the object has been registered. 1293** 1294** The zName field holds the name of the VFS module. The name must 1295** be unique across all VFS modules. 1296** 1297** [[sqlite3_vfs.xOpen]] 1298** ^SQLite guarantees that the zFilename parameter to xOpen 1299** is either a NULL pointer or string obtained 1300** from xFullPathname() with an optional suffix added. 1301** ^If a suffix is added to the zFilename parameter, it will 1302** consist of a single "-" character followed by no more than 1303** 11 alphanumeric and/or "-" characters. 1304** ^SQLite further guarantees that 1305** the string will be valid and unchanged until xClose() is 1306** called. Because of the previous sentence, 1307** the [sqlite3_file] can safely store a pointer to the 1308** filename if it needs to remember the filename for some reason. 1309** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1310** must invent its own temporary name for the file. ^Whenever the 1311** xFilename parameter is NULL it will also be the case that the 1312** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1313** 1314** The flags argument to xOpen() includes all bits set in 1315** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1316** or [sqlite3_open16()] is used, then flags includes at least 1317** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1318** If xOpen() opens a file read-only then it sets *pOutFlags to 1319** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1320** 1321** ^(SQLite will also add one of the following flags to the xOpen() 1322** call, depending on the object being opened: 1323** 1324** <ul> 1325** <li> [SQLITE_OPEN_MAIN_DB] 1326** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1327** <li> [SQLITE_OPEN_TEMP_DB] 1328** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1329** <li> [SQLITE_OPEN_TRANSIENT_DB] 1330** <li> [SQLITE_OPEN_SUBJOURNAL] 1331** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1332** <li> [SQLITE_OPEN_WAL] 1333** </ul>)^ 1334** 1335** The file I/O implementation can use the object type flags to 1336** change the way it deals with files. For example, an application 1337** that does not care about crash recovery or rollback might make 1338** the open of a journal file a no-op. Writes to this journal would 1339** also be no-ops, and any attempt to read the journal would return 1340** SQLITE_IOERR. Or the implementation might recognize that a database 1341** file will be doing page-aligned sector reads and writes in a random 1342** order and set up its I/O subsystem accordingly. 1343** 1344** SQLite might also add one of the following flags to the xOpen method: 1345** 1346** <ul> 1347** <li> [SQLITE_OPEN_DELETEONCLOSE] 1348** <li> [SQLITE_OPEN_EXCLUSIVE] 1349** </ul> 1350** 1351** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1352** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1353** will be set for TEMP databases and their journals, transient 1354** databases, and subjournals. 1355** 1356** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1357** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1358** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1359** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1360** SQLITE_OPEN_CREATE, is used to indicate that file should always 1361** be created, and that it is an error if it already exists. 1362** It is <i>not</i> used to indicate the file should be opened 1363** for exclusive access. 1364** 1365** ^At least szOsFile bytes of memory are allocated by SQLite 1366** to hold the [sqlite3_file] structure passed as the third 1367** argument to xOpen. The xOpen method does not have to 1368** allocate the structure; it should just fill it in. Note that 1369** the xOpen method must set the sqlite3_file.pMethods to either 1370** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1371** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1372** element will be valid after xOpen returns regardless of the success 1373** or failure of the xOpen call. 1374** 1375** [[sqlite3_vfs.xAccess]] 1376** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1377** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1378** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1379** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1380** flag is never actually used and is not implemented in the built-in 1381** VFSes of SQLite. The file is named by the second argument and can be a 1382** directory. The xAccess method returns [SQLITE_OK] on success or some 1383** non-zero error code if there is an I/O error or if the name of 1384** the file given in the second argument is illegal. If SQLITE_OK 1385** is returned, then non-zero or zero is written into *pResOut to indicate 1386** whether or not the file is accessible. 1387** 1388** ^SQLite will always allocate at least mxPathname+1 bytes for the 1389** output buffer xFullPathname. The exact size of the output buffer 1390** is also passed as a parameter to both methods. If the output buffer 1391** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1392** handled as a fatal error by SQLite, vfs implementations should endeavor 1393** to prevent this by setting mxPathname to a sufficiently large value. 1394** 1395** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1396** interfaces are not strictly a part of the filesystem, but they are 1397** included in the VFS structure for completeness. 1398** The xRandomness() function attempts to return nBytes bytes 1399** of good-quality randomness into zOut. The return value is 1400** the actual number of bytes of randomness obtained. 1401** The xSleep() method causes the calling thread to sleep for at 1402** least the number of microseconds given. ^The xCurrentTime() 1403** method returns a Julian Day Number for the current date and time as 1404** a floating point value. 1405** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1406** Day Number multiplied by 86400000 (the number of milliseconds in 1407** a 24-hour day). 1408** ^SQLite will use the xCurrentTimeInt64() method to get the current 1409** date and time if that method is available (if iVersion is 2 or 1410** greater and the function pointer is not NULL) and will fall back 1411** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1412** 1413** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1414** are not used by the SQLite core. These optional interfaces are provided 1415** by some VFSes to facilitate testing of the VFS code. By overriding 1416** system calls with functions under its control, a test program can 1417** simulate faults and error conditions that would otherwise be difficult 1418** or impossible to induce. The set of system calls that can be overridden 1419** varies from one VFS to another, and from one version of the same VFS to the 1420** next. Applications that use these interfaces must be prepared for any 1421** or all of these interfaces to be NULL or for their behavior to change 1422** from one release to the next. Applications must not attempt to access 1423** any of these methods if the iVersion of the VFS is less than 3. 1424*/ 1425typedef struct sqlite3_vfs sqlite3_vfs; 1426typedef void (*sqlite3_syscall_ptr)(void); 1427struct sqlite3_vfs { 1428 int iVersion; /* Structure version number (currently 3) */ 1429 int szOsFile; /* Size of subclassed sqlite3_file */ 1430 int mxPathname; /* Maximum file pathname length */ 1431 sqlite3_vfs *pNext; /* Next registered VFS */ 1432 const char *zName; /* Name of this virtual file system */ 1433 void *pAppData; /* Pointer to application-specific data */ 1434 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1435 int flags, int *pOutFlags); 1436 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1437 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1438 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1439 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1440 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1441 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1442 void (*xDlClose)(sqlite3_vfs*, void*); 1443 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1444 int (*xSleep)(sqlite3_vfs*, int microseconds); 1445 int (*xCurrentTime)(sqlite3_vfs*, double*); 1446 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1447 /* 1448 ** The methods above are in version 1 of the sqlite_vfs object 1449 ** definition. Those that follow are added in version 2 or later 1450 */ 1451 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1452 /* 1453 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1454 ** Those below are for version 3 and greater. 1455 */ 1456 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1457 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1458 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1459 /* 1460 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1461 ** New fields may be appended in future versions. The iVersion 1462 ** value will increment whenever this happens. 1463 */ 1464}; 1465 1466/* 1467** CAPI3REF: Flags for the xAccess VFS method 1468** 1469** These integer constants can be used as the third parameter to 1470** the xAccess method of an [sqlite3_vfs] object. They determine 1471** what kind of permissions the xAccess method is looking for. 1472** With SQLITE_ACCESS_EXISTS, the xAccess method 1473** simply checks whether the file exists. 1474** With SQLITE_ACCESS_READWRITE, the xAccess method 1475** checks whether the named directory is both readable and writable 1476** (in other words, if files can be added, removed, and renamed within 1477** the directory). 1478** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1479** [temp_store_directory pragma], though this could change in a future 1480** release of SQLite. 1481** With SQLITE_ACCESS_READ, the xAccess method 1482** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1483** currently unused, though it might be used in a future release of 1484** SQLite. 1485*/ 1486#define SQLITE_ACCESS_EXISTS 0 1487#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1488#define SQLITE_ACCESS_READ 2 /* Unused */ 1489 1490/* 1491** CAPI3REF: Flags for the xShmLock VFS method 1492** 1493** These integer constants define the various locking operations 1494** allowed by the xShmLock method of [sqlite3_io_methods]. The 1495** following are the only legal combinations of flags to the 1496** xShmLock method: 1497** 1498** <ul> 1499** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1500** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1501** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1502** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1503** </ul> 1504** 1505** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1506** was given on the corresponding lock. 1507** 1508** The xShmLock method can transition between unlocked and SHARED or 1509** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1510** and EXCLUSIVE. 1511*/ 1512#define SQLITE_SHM_UNLOCK 1 1513#define SQLITE_SHM_LOCK 2 1514#define SQLITE_SHM_SHARED 4 1515#define SQLITE_SHM_EXCLUSIVE 8 1516 1517/* 1518** CAPI3REF: Maximum xShmLock index 1519** 1520** The xShmLock method on [sqlite3_io_methods] may use values 1521** between 0 and this upper bound as its "offset" argument. 1522** The SQLite core will never attempt to acquire or release a 1523** lock outside of this range 1524*/ 1525#define SQLITE_SHM_NLOCK 8 1526 1527 1528/* 1529** CAPI3REF: Initialize The SQLite Library 1530** 1531** ^The sqlite3_initialize() routine initializes the 1532** SQLite library. ^The sqlite3_shutdown() routine 1533** deallocates any resources that were allocated by sqlite3_initialize(). 1534** These routines are designed to aid in process initialization and 1535** shutdown on embedded systems. Workstation applications using 1536** SQLite normally do not need to invoke either of these routines. 1537** 1538** A call to sqlite3_initialize() is an "effective" call if it is 1539** the first time sqlite3_initialize() is invoked during the lifetime of 1540** the process, or if it is the first time sqlite3_initialize() is invoked 1541** following a call to sqlite3_shutdown(). ^(Only an effective call 1542** of sqlite3_initialize() does any initialization. All other calls 1543** are harmless no-ops.)^ 1544** 1545** A call to sqlite3_shutdown() is an "effective" call if it is the first 1546** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1547** an effective call to sqlite3_shutdown() does any deinitialization. 1548** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1549** 1550** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1551** is not. The sqlite3_shutdown() interface must only be called from a 1552** single thread. All open [database connections] must be closed and all 1553** other SQLite resources must be deallocated prior to invoking 1554** sqlite3_shutdown(). 1555** 1556** Among other things, ^sqlite3_initialize() will invoke 1557** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1558** will invoke sqlite3_os_end(). 1559** 1560** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1561** ^If for some reason, sqlite3_initialize() is unable to initialize 1562** the library (perhaps it is unable to allocate a needed resource such 1563** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1564** 1565** ^The sqlite3_initialize() routine is called internally by many other 1566** SQLite interfaces so that an application usually does not need to 1567** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1568** calls sqlite3_initialize() so the SQLite library will be automatically 1569** initialized when [sqlite3_open()] is called if it has not be initialized 1570** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1571** compile-time option, then the automatic calls to sqlite3_initialize() 1572** are omitted and the application must call sqlite3_initialize() directly 1573** prior to using any other SQLite interface. For maximum portability, 1574** it is recommended that applications always invoke sqlite3_initialize() 1575** directly prior to using any other SQLite interface. Future releases 1576** of SQLite may require this. In other words, the behavior exhibited 1577** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1578** default behavior in some future release of SQLite. 1579** 1580** The sqlite3_os_init() routine does operating-system specific 1581** initialization of the SQLite library. The sqlite3_os_end() 1582** routine undoes the effect of sqlite3_os_init(). Typical tasks 1583** performed by these routines include allocation or deallocation 1584** of static resources, initialization of global variables, 1585** setting up a default [sqlite3_vfs] module, or setting up 1586** a default configuration using [sqlite3_config()]. 1587** 1588** The application should never invoke either sqlite3_os_init() 1589** or sqlite3_os_end() directly. The application should only invoke 1590** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1591** interface is called automatically by sqlite3_initialize() and 1592** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1593** implementations for sqlite3_os_init() and sqlite3_os_end() 1594** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1595** When [custom builds | built for other platforms] 1596** (using the [SQLITE_OS_OTHER=1] compile-time 1597** option) the application must supply a suitable implementation for 1598** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1599** implementation of sqlite3_os_init() or sqlite3_os_end() 1600** must return [SQLITE_OK] on success and some other [error code] upon 1601** failure. 1602*/ 1603int sqlite3_initialize(void); 1604int sqlite3_shutdown(void); 1605int sqlite3_os_init(void); 1606int sqlite3_os_end(void); 1607 1608/* 1609** CAPI3REF: Configuring The SQLite Library 1610** 1611** The sqlite3_config() interface is used to make global configuration 1612** changes to SQLite in order to tune SQLite to the specific needs of 1613** the application. The default configuration is recommended for most 1614** applications and so this routine is usually not necessary. It is 1615** provided to support rare applications with unusual needs. 1616** 1617** <b>The sqlite3_config() interface is not threadsafe. The application 1618** must ensure that no other SQLite interfaces are invoked by other 1619** threads while sqlite3_config() is running.</b> 1620** 1621** The sqlite3_config() interface 1622** may only be invoked prior to library initialization using 1623** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1624** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1625** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1626** Note, however, that ^sqlite3_config() can be called as part of the 1627** implementation of an application-defined [sqlite3_os_init()]. 1628** 1629** The first argument to sqlite3_config() is an integer 1630** [configuration option] that determines 1631** what property of SQLite is to be configured. Subsequent arguments 1632** vary depending on the [configuration option] 1633** in the first argument. 1634** 1635** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1636** ^If the option is unknown or SQLite is unable to set the option 1637** then this routine returns a non-zero [error code]. 1638*/ 1639int sqlite3_config(int, ...); 1640 1641/* 1642** CAPI3REF: Configure database connections 1643** METHOD: sqlite3 1644** 1645** The sqlite3_db_config() interface is used to make configuration 1646** changes to a [database connection]. The interface is similar to 1647** [sqlite3_config()] except that the changes apply to a single 1648** [database connection] (specified in the first argument). 1649** 1650** The second argument to sqlite3_db_config(D,V,...) is the 1651** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1652** that indicates what aspect of the [database connection] is being configured. 1653** Subsequent arguments vary depending on the configuration verb. 1654** 1655** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1656** the call is considered successful. 1657*/ 1658int sqlite3_db_config(sqlite3*, int op, ...); 1659 1660/* 1661** CAPI3REF: Memory Allocation Routines 1662** 1663** An instance of this object defines the interface between SQLite 1664** and low-level memory allocation routines. 1665** 1666** This object is used in only one place in the SQLite interface. 1667** A pointer to an instance of this object is the argument to 1668** [sqlite3_config()] when the configuration option is 1669** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1670** By creating an instance of this object 1671** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1672** during configuration, an application can specify an alternative 1673** memory allocation subsystem for SQLite to use for all of its 1674** dynamic memory needs. 1675** 1676** Note that SQLite comes with several [built-in memory allocators] 1677** that are perfectly adequate for the overwhelming majority of applications 1678** and that this object is only useful to a tiny minority of applications 1679** with specialized memory allocation requirements. This object is 1680** also used during testing of SQLite in order to specify an alternative 1681** memory allocator that simulates memory out-of-memory conditions in 1682** order to verify that SQLite recovers gracefully from such 1683** conditions. 1684** 1685** The xMalloc, xRealloc, and xFree methods must work like the 1686** malloc(), realloc() and free() functions from the standard C library. 1687** ^SQLite guarantees that the second argument to 1688** xRealloc is always a value returned by a prior call to xRoundup. 1689** 1690** xSize should return the allocated size of a memory allocation 1691** previously obtained from xMalloc or xRealloc. The allocated size 1692** is always at least as big as the requested size but may be larger. 1693** 1694** The xRoundup method returns what would be the allocated size of 1695** a memory allocation given a particular requested size. Most memory 1696** allocators round up memory allocations at least to the next multiple 1697** of 8. Some allocators round up to a larger multiple or to a power of 2. 1698** Every memory allocation request coming in through [sqlite3_malloc()] 1699** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1700** that causes the corresponding memory allocation to fail. 1701** 1702** The xInit method initializes the memory allocator. For example, 1703** it might allocate any required mutexes or initialize internal data 1704** structures. The xShutdown method is invoked (indirectly) by 1705** [sqlite3_shutdown()] and should deallocate any resources acquired 1706** by xInit. The pAppData pointer is used as the only parameter to 1707** xInit and xShutdown. 1708** 1709** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1710** the xInit method, so the xInit method need not be threadsafe. The 1711** xShutdown method is only called from [sqlite3_shutdown()] so it does 1712** not need to be threadsafe either. For all other methods, SQLite 1713** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1714** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1715** it is by default) and so the methods are automatically serialized. 1716** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1717** methods must be threadsafe or else make their own arrangements for 1718** serialization. 1719** 1720** SQLite will never invoke xInit() more than once without an intervening 1721** call to xShutdown(). 1722*/ 1723typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1724struct sqlite3_mem_methods { 1725 void *(*xMalloc)(int); /* Memory allocation function */ 1726 void (*xFree)(void*); /* Free a prior allocation */ 1727 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1728 int (*xSize)(void*); /* Return the size of an allocation */ 1729 int (*xRoundup)(int); /* Round up request size to allocation size */ 1730 int (*xInit)(void*); /* Initialize the memory allocator */ 1731 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1732 void *pAppData; /* Argument to xInit() and xShutdown() */ 1733}; 1734 1735/* 1736** CAPI3REF: Configuration Options 1737** KEYWORDS: {configuration option} 1738** 1739** These constants are the available integer configuration options that 1740** can be passed as the first argument to the [sqlite3_config()] interface. 1741** 1742** New configuration options may be added in future releases of SQLite. 1743** Existing configuration options might be discontinued. Applications 1744** should check the return code from [sqlite3_config()] to make sure that 1745** the call worked. The [sqlite3_config()] interface will return a 1746** non-zero [error code] if a discontinued or unsupported configuration option 1747** is invoked. 1748** 1749** <dl> 1750** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1751** <dd>There are no arguments to this option. ^This option sets the 1752** [threading mode] to Single-thread. In other words, it disables 1753** all mutexing and puts SQLite into a mode where it can only be used 1754** by a single thread. ^If SQLite is compiled with 1755** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1756** it is not possible to change the [threading mode] from its default 1757** value of Single-thread and so [sqlite3_config()] will return 1758** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1759** configuration option.</dd> 1760** 1761** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1762** <dd>There are no arguments to this option. ^This option sets the 1763** [threading mode] to Multi-thread. In other words, it disables 1764** mutexing on [database connection] and [prepared statement] objects. 1765** The application is responsible for serializing access to 1766** [database connections] and [prepared statements]. But other mutexes 1767** are enabled so that SQLite will be safe to use in a multi-threaded 1768** environment as long as no two threads attempt to use the same 1769** [database connection] at the same time. ^If SQLite is compiled with 1770** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1771** it is not possible to set the Multi-thread [threading mode] and 1772** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1773** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1774** 1775** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1776** <dd>There are no arguments to this option. ^This option sets the 1777** [threading mode] to Serialized. In other words, this option enables 1778** all mutexes including the recursive 1779** mutexes on [database connection] and [prepared statement] objects. 1780** In this mode (which is the default when SQLite is compiled with 1781** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1782** to [database connections] and [prepared statements] so that the 1783** application is free to use the same [database connection] or the 1784** same [prepared statement] in different threads at the same time. 1785** ^If SQLite is compiled with 1786** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1787** it is not possible to set the Serialized [threading mode] and 1788** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1789** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1790** 1791** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1792** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1793** a pointer to an instance of the [sqlite3_mem_methods] structure. 1794** The argument specifies 1795** alternative low-level memory allocation routines to be used in place of 1796** the memory allocation routines built into SQLite.)^ ^SQLite makes 1797** its own private copy of the content of the [sqlite3_mem_methods] structure 1798** before the [sqlite3_config()] call returns.</dd> 1799** 1800** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1801** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1802** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1803** The [sqlite3_mem_methods] 1804** structure is filled with the currently defined memory allocation routines.)^ 1805** This option can be used to overload the default memory allocation 1806** routines with a wrapper that simulations memory allocation failure or 1807** tracks memory usage, for example. </dd> 1808** 1809** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1810** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1811** type int, interpreted as a boolean, which if true provides a hint to 1812** SQLite that it should avoid large memory allocations if possible. 1813** SQLite will run faster if it is free to make large memory allocations, 1814** but some application might prefer to run slower in exchange for 1815** guarantees about memory fragmentation that are possible if large 1816** allocations are avoided. This hint is normally off. 1817** </dd> 1818** 1819** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1820** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1821** interpreted as a boolean, which enables or disables the collection of 1822** memory allocation statistics. ^(When memory allocation statistics are 1823** disabled, the following SQLite interfaces become non-operational: 1824** <ul> 1825** <li> [sqlite3_hard_heap_limit64()] 1826** <li> [sqlite3_memory_used()] 1827** <li> [sqlite3_memory_highwater()] 1828** <li> [sqlite3_soft_heap_limit64()] 1829** <li> [sqlite3_status64()] 1830** </ul>)^ 1831** ^Memory allocation statistics are enabled by default unless SQLite is 1832** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1833** allocation statistics are disabled by default. 1834** </dd> 1835** 1836** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1837** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1838** </dd> 1839** 1840** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1841** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1842** that SQLite can use for the database page cache with the default page 1843** cache implementation. 1844** This configuration option is a no-op if an application-defined page 1845** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1846** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1847** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1848** and the number of cache lines (N). 1849** The sz argument should be the size of the largest database page 1850** (a power of two between 512 and 65536) plus some extra bytes for each 1851** page header. ^The number of extra bytes needed by the page header 1852** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1853** ^It is harmless, apart from the wasted memory, 1854** for the sz parameter to be larger than necessary. The pMem 1855** argument must be either a NULL pointer or a pointer to an 8-byte 1856** aligned block of memory of at least sz*N bytes, otherwise 1857** subsequent behavior is undefined. 1858** ^When pMem is not NULL, SQLite will strive to use the memory provided 1859** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1860** a page cache line is larger than sz bytes or if all of the pMem buffer 1861** is exhausted. 1862** ^If pMem is NULL and N is non-zero, then each database connection 1863** does an initial bulk allocation for page cache memory 1864** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1865** of -1024*N bytes if N is negative, . ^If additional 1866** page cache memory is needed beyond what is provided by the initial 1867** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1868** additional cache line. </dd> 1869** 1870** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1871** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1872** that SQLite will use for all of its dynamic memory allocation needs 1873** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1874** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1875** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1876** [SQLITE_ERROR] if invoked otherwise. 1877** ^There are three arguments to SQLITE_CONFIG_HEAP: 1878** An 8-byte aligned pointer to the memory, 1879** the number of bytes in the memory buffer, and the minimum allocation size. 1880** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1881** to using its default memory allocator (the system malloc() implementation), 1882** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1883** memory pointer is not NULL then the alternative memory 1884** allocator is engaged to handle all of SQLites memory allocation needs. 1885** The first pointer (the memory pointer) must be aligned to an 8-byte 1886** boundary or subsequent behavior of SQLite will be undefined. 1887** The minimum allocation size is capped at 2**12. Reasonable values 1888** for the minimum allocation size are 2**5 through 2**8.</dd> 1889** 1890** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1891** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1892** pointer to an instance of the [sqlite3_mutex_methods] structure. 1893** The argument specifies alternative low-level mutex routines to be used 1894** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1895** the content of the [sqlite3_mutex_methods] structure before the call to 1896** [sqlite3_config()] returns. ^If SQLite is compiled with 1897** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1898** the entire mutexing subsystem is omitted from the build and hence calls to 1899** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1900** return [SQLITE_ERROR].</dd> 1901** 1902** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1903** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1904** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1905** [sqlite3_mutex_methods] 1906** structure is filled with the currently defined mutex routines.)^ 1907** This option can be used to overload the default mutex allocation 1908** routines with a wrapper used to track mutex usage for performance 1909** profiling or testing, for example. ^If SQLite is compiled with 1910** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1911** the entire mutexing subsystem is omitted from the build and hence calls to 1912** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1913** return [SQLITE_ERROR].</dd> 1914** 1915** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1916** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1917** the default size of lookaside memory on each [database connection]. 1918** The first argument is the 1919** size of each lookaside buffer slot and the second is the number of 1920** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1921** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1922** option to [sqlite3_db_config()] can be used to change the lookaside 1923** configuration on individual connections.)^ </dd> 1924** 1925** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1926** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1927** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1928** the interface to a custom page cache implementation.)^ 1929** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1930** 1931** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1932** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1933** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1934** the current page cache implementation into that object.)^ </dd> 1935** 1936** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1937** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1938** global [error log]. 1939** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1940** function with a call signature of void(*)(void*,int,const char*), 1941** and a pointer to void. ^If the function pointer is not NULL, it is 1942** invoked by [sqlite3_log()] to process each logging event. ^If the 1943** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1944** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1945** passed through as the first parameter to the application-defined logger 1946** function whenever that function is invoked. ^The second parameter to 1947** the logger function is a copy of the first parameter to the corresponding 1948** [sqlite3_log()] call and is intended to be a [result code] or an 1949** [extended result code]. ^The third parameter passed to the logger is 1950** log message after formatting via [sqlite3_snprintf()]. 1951** The SQLite logging interface is not reentrant; the logger function 1952** supplied by the application must not invoke any SQLite interface. 1953** In a multi-threaded application, the application-defined logger 1954** function must be threadsafe. </dd> 1955** 1956** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1957** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1958** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1959** then URI handling is globally disabled.)^ ^If URI handling is globally 1960** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1961** [sqlite3_open16()] or 1962** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1963** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1964** connection is opened. ^If it is globally disabled, filenames are 1965** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1966** database connection is opened. ^(By default, URI handling is globally 1967** disabled. The default value may be changed by compiling with the 1968** [SQLITE_USE_URI] symbol defined.)^ 1969** 1970** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1971** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1972** argument which is interpreted as a boolean in order to enable or disable 1973** the use of covering indices for full table scans in the query optimizer. 1974** ^The default setting is determined 1975** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1976** if that compile-time option is omitted. 1977** The ability to disable the use of covering indices for full table scans 1978** is because some incorrectly coded legacy applications might malfunction 1979** when the optimization is enabled. Providing the ability to 1980** disable the optimization allows the older, buggy application code to work 1981** without change even with newer versions of SQLite. 1982** 1983** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1984** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1985** <dd> These options are obsolete and should not be used by new code. 1986** They are retained for backwards compatibility but are now no-ops. 1987** </dd> 1988** 1989** [[SQLITE_CONFIG_SQLLOG]] 1990** <dt>SQLITE_CONFIG_SQLLOG 1991** <dd>This option is only available if sqlite is compiled with the 1992** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1993** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1994** The second should be of type (void*). The callback is invoked by the library 1995** in three separate circumstances, identified by the value passed as the 1996** fourth parameter. If the fourth parameter is 0, then the database connection 1997** passed as the second argument has just been opened. The third argument 1998** points to a buffer containing the name of the main database file. If the 1999** fourth parameter is 1, then the SQL statement that the third parameter 2000** points to has just been executed. Or, if the fourth parameter is 2, then 2001** the connection being passed as the second parameter is being closed. The 2002** third parameter is passed NULL In this case. An example of using this 2003** configuration option can be seen in the "test_sqllog.c" source file in 2004** the canonical SQLite source tree.</dd> 2005** 2006** [[SQLITE_CONFIG_MMAP_SIZE]] 2007** <dt>SQLITE_CONFIG_MMAP_SIZE 2008** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2009** that are the default mmap size limit (the default setting for 2010** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2011** ^The default setting can be overridden by each database connection using 2012** either the [PRAGMA mmap_size] command, or by using the 2013** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2014** will be silently truncated if necessary so that it does not exceed the 2015** compile-time maximum mmap size set by the 2016** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2017** ^If either argument to this option is negative, then that argument is 2018** changed to its compile-time default. 2019** 2020** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2021** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2022** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2023** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2024** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2025** that specifies the maximum size of the created heap. 2026** 2027** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2028** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2029** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2030** is a pointer to an integer and writes into that integer the number of extra 2031** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2032** The amount of extra space required can change depending on the compiler, 2033** target platform, and SQLite version. 2034** 2035** [[SQLITE_CONFIG_PMASZ]] 2036** <dt>SQLITE_CONFIG_PMASZ 2037** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2038** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2039** sorter to that integer. The default minimum PMA Size is set by the 2040** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2041** to help with sort operations when multithreaded sorting 2042** is enabled (using the [PRAGMA threads] command) and the amount of content 2043** to be sorted exceeds the page size times the minimum of the 2044** [PRAGMA cache_size] setting and this value. 2045** 2046** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2047** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2048** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2049** becomes the [statement journal] spill-to-disk threshold. 2050** [Statement journals] are held in memory until their size (in bytes) 2051** exceeds this threshold, at which point they are written to disk. 2052** Or if the threshold is -1, statement journals are always held 2053** exclusively in memory. 2054** Since many statement journals never become large, setting the spill 2055** threshold to a value such as 64KiB can greatly reduce the amount of 2056** I/O required to support statement rollback. 2057** The default value for this setting is controlled by the 2058** [SQLITE_STMTJRNL_SPILL] compile-time option. 2059** 2060** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2061** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2062** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2063** of type (int) - the new value of the sorter-reference size threshold. 2064** Usually, when SQLite uses an external sort to order records according 2065** to an ORDER BY clause, all fields required by the caller are present in the 2066** sorted records. However, if SQLite determines based on the declared type 2067** of a table column that its values are likely to be very large - larger 2068** than the configured sorter-reference size threshold - then a reference 2069** is stored in each sorted record and the required column values loaded 2070** from the database as records are returned in sorted order. The default 2071** value for this option is to never use this optimization. Specifying a 2072** negative value for this option restores the default behaviour. 2073** This option is only available if SQLite is compiled with the 2074** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2075** 2076** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2077** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2078** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2079** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2080** database created using [sqlite3_deserialize()]. This default maximum 2081** size can be adjusted up or down for individual databases using the 2082** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2083** configuration setting is never used, then the default maximum is determined 2084** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2085** compile-time option is not set, then the default maximum is 1073741824. 2086** </dl> 2087*/ 2088#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2089#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2090#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2091#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2092#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2093#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2094#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2095#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2096#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2097#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2098#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2099/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2100#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2101#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2102#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2103#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2104#define SQLITE_CONFIG_URI 17 /* int */ 2105#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2106#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2107#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2108#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2109#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2110#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2111#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2112#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2113#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2114#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2115#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2116#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2117 2118/* 2119** CAPI3REF: Database Connection Configuration Options 2120** 2121** These constants are the available integer configuration options that 2122** can be passed as the second argument to the [sqlite3_db_config()] interface. 2123** 2124** New configuration options may be added in future releases of SQLite. 2125** Existing configuration options might be discontinued. Applications 2126** should check the return code from [sqlite3_db_config()] to make sure that 2127** the call worked. ^The [sqlite3_db_config()] interface will return a 2128** non-zero [error code] if a discontinued or unsupported configuration option 2129** is invoked. 2130** 2131** <dl> 2132** [[SQLITE_DBCONFIG_LOOKASIDE]] 2133** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2134** <dd> ^This option takes three additional arguments that determine the 2135** [lookaside memory allocator] configuration for the [database connection]. 2136** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2137** pointer to a memory buffer to use for lookaside memory. 2138** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2139** may be NULL in which case SQLite will allocate the 2140** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2141** size of each lookaside buffer slot. ^The third argument is the number of 2142** slots. The size of the buffer in the first argument must be greater than 2143** or equal to the product of the second and third arguments. The buffer 2144** must be aligned to an 8-byte boundary. ^If the second argument to 2145** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2146** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2147** configuration for a database connection can only be changed when that 2148** connection is not currently using lookaside memory, or in other words 2149** when the "current value" returned by 2150** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2151** Any attempt to change the lookaside memory configuration when lookaside 2152** memory is in use leaves the configuration unchanged and returns 2153** [SQLITE_BUSY].)^</dd> 2154** 2155** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2156** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2157** <dd> ^This option is used to enable or disable the enforcement of 2158** [foreign key constraints]. There should be two additional arguments. 2159** The first argument is an integer which is 0 to disable FK enforcement, 2160** positive to enable FK enforcement or negative to leave FK enforcement 2161** unchanged. The second parameter is a pointer to an integer into which 2162** is written 0 or 1 to indicate whether FK enforcement is off or on 2163** following this call. The second parameter may be a NULL pointer, in 2164** which case the FK enforcement setting is not reported back. </dd> 2165** 2166** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2167** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2168** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2169** There should be two additional arguments. 2170** The first argument is an integer which is 0 to disable triggers, 2171** positive to enable triggers or negative to leave the setting unchanged. 2172** The second parameter is a pointer to an integer into which 2173** is written 0 or 1 to indicate whether triggers are disabled or enabled 2174** following this call. The second parameter may be a NULL pointer, in 2175** which case the trigger setting is not reported back. 2176** 2177** <p>Originally this option disabled all triggers. ^(However, since 2178** SQLite version 3.35.0, TEMP triggers are still allowed even if 2179** this option is off. So, in other words, this option now only disables 2180** triggers in the main database schema or in the schemas of ATTACH-ed 2181** databases.)^ </dd> 2182** 2183** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2184** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2185** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2186** There should be two additional arguments. 2187** The first argument is an integer which is 0 to disable views, 2188** positive to enable views or negative to leave the setting unchanged. 2189** The second parameter is a pointer to an integer into which 2190** is written 0 or 1 to indicate whether views are disabled or enabled 2191** following this call. The second parameter may be a NULL pointer, in 2192** which case the view setting is not reported back. 2193** 2194** <p>Originally this option disabled all views. ^(However, since 2195** SQLite version 3.35.0, TEMP views are still allowed even if 2196** this option is off. So, in other words, this option now only disables 2197** views in the main database schema or in the schemas of ATTACH-ed 2198** databases.)^ </dd> 2199** 2200** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2201** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2202** <dd> ^This option is used to enable or disable the 2203** [fts3_tokenizer()] function which is part of the 2204** [FTS3] full-text search engine extension. 2205** There should be two additional arguments. 2206** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2207** positive to enable fts3_tokenizer() or negative to leave the setting 2208** unchanged. 2209** The second parameter is a pointer to an integer into which 2210** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2211** following this call. The second parameter may be a NULL pointer, in 2212** which case the new setting is not reported back. </dd> 2213** 2214** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2215** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2216** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2217** interface independently of the [load_extension()] SQL function. 2218** The [sqlite3_enable_load_extension()] API enables or disables both the 2219** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2220** There should be two additional arguments. 2221** When the first argument to this interface is 1, then only the C-API is 2222** enabled and the SQL function remains disabled. If the first argument to 2223** this interface is 0, then both the C-API and the SQL function are disabled. 2224** If the first argument is -1, then no changes are made to state of either the 2225** C-API or the SQL function. 2226** The second parameter is a pointer to an integer into which 2227** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2228** is disabled or enabled following this call. The second parameter may 2229** be a NULL pointer, in which case the new setting is not reported back. 2230** </dd> 2231** 2232** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2233** <dd> ^This option is used to change the name of the "main" database 2234** schema. ^The sole argument is a pointer to a constant UTF8 string 2235** which will become the new schema name in place of "main". ^SQLite 2236** does not make a copy of the new main schema name string, so the application 2237** must ensure that the argument passed into this DBCONFIG option is unchanged 2238** until after the database connection closes. 2239** </dd> 2240** 2241** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2242** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2243** <dd> Usually, when a database in wal mode is closed or detached from a 2244** database handle, SQLite checks if this will mean that there are now no 2245** connections at all to the database. If so, it performs a checkpoint 2246** operation before closing the connection. This option may be used to 2247** override this behaviour. The first parameter passed to this operation 2248** is an integer - positive to disable checkpoints-on-close, or zero (the 2249** default) to enable them, and negative to leave the setting unchanged. 2250** The second parameter is a pointer to an integer 2251** into which is written 0 or 1 to indicate whether checkpoints-on-close 2252** have been disabled - 0 if they are not disabled, 1 if they are. 2253** </dd> 2254** 2255** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2256** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2257** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2258** a single SQL query statement will always use the same algorithm regardless 2259** of values of [bound parameters].)^ The QPSG disables some query optimizations 2260** that look at the values of bound parameters, which can make some queries 2261** slower. But the QPSG has the advantage of more predictable behavior. With 2262** the QPSG active, SQLite will always use the same query plan in the field as 2263** was used during testing in the lab. 2264** The first argument to this setting is an integer which is 0 to disable 2265** the QPSG, positive to enable QPSG, or negative to leave the setting 2266** unchanged. The second parameter is a pointer to an integer into which 2267** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2268** following this call. 2269** </dd> 2270** 2271** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2272** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2273** include output for any operations performed by trigger programs. This 2274** option is used to set or clear (the default) a flag that governs this 2275** behavior. The first parameter passed to this operation is an integer - 2276** positive to enable output for trigger programs, or zero to disable it, 2277** or negative to leave the setting unchanged. 2278** The second parameter is a pointer to an integer into which is written 2279** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2280** it is not disabled, 1 if it is. 2281** </dd> 2282** 2283** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2284** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2285** [VACUUM] in order to reset a database back to an empty database 2286** with no schema and no content. The following process works even for 2287** a badly corrupted database file: 2288** <ol> 2289** <li> If the database connection is newly opened, make sure it has read the 2290** database schema by preparing then discarding some query against the 2291** database, or calling sqlite3_table_column_metadata(), ignoring any 2292** errors. This step is only necessary if the application desires to keep 2293** the database in WAL mode after the reset if it was in WAL mode before 2294** the reset. 2295** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2296** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2297** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2298** </ol> 2299** Because resetting a database is destructive and irreversible, the 2300** process requires the use of this obscure API and multiple steps to help 2301** ensure that it does not happen by accident. 2302** 2303** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2304** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2305** "defensive" flag for a database connection. When the defensive 2306** flag is enabled, language features that allow ordinary SQL to 2307** deliberately corrupt the database file are disabled. The disabled 2308** features include but are not limited to the following: 2309** <ul> 2310** <li> The [PRAGMA writable_schema=ON] statement. 2311** <li> The [PRAGMA journal_mode=OFF] statement. 2312** <li> Writes to the [sqlite_dbpage] virtual table. 2313** <li> Direct writes to [shadow tables]. 2314** </ul> 2315** </dd> 2316** 2317** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2318** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2319** "writable_schema" flag. This has the same effect and is logically equivalent 2320** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2321** The first argument to this setting is an integer which is 0 to disable 2322** the writable_schema, positive to enable writable_schema, or negative to 2323** leave the setting unchanged. The second parameter is a pointer to an 2324** integer into which is written 0 or 1 to indicate whether the writable_schema 2325** is enabled or disabled following this call. 2326** </dd> 2327** 2328** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2329** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2330** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2331** the legacy behavior of the [ALTER TABLE RENAME] command such it 2332** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2333** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2334** additional information. This feature can also be turned on and off 2335** using the [PRAGMA legacy_alter_table] statement. 2336** </dd> 2337** 2338** [[SQLITE_DBCONFIG_DQS_DML]] 2339** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2340** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2341** the legacy [double-quoted string literal] misfeature for DML statements 2342** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2343** default value of this setting is determined by the [-DSQLITE_DQS] 2344** compile-time option. 2345** </dd> 2346** 2347** [[SQLITE_DBCONFIG_DQS_DDL]] 2348** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2349** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2350** the legacy [double-quoted string literal] misfeature for DDL statements, 2351** such as CREATE TABLE and CREATE INDEX. The 2352** default value of this setting is determined by the [-DSQLITE_DQS] 2353** compile-time option. 2354** </dd> 2355** 2356** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2357** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2358** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2359** assume that database schemas are untainted by malicious content. 2360** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2361** takes additional defensive steps to protect the application from harm 2362** including: 2363** <ul> 2364** <li> Prohibit the use of SQL functions inside triggers, views, 2365** CHECK constraints, DEFAULT clauses, expression indexes, 2366** partial indexes, or generated columns 2367** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2368** <li> Prohibit the use of virtual tables inside of triggers or views 2369** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2370** </ul> 2371** This setting defaults to "on" for legacy compatibility, however 2372** all applications are advised to turn it off if possible. This setting 2373** can also be controlled using the [PRAGMA trusted_schema] statement. 2374** </dd> 2375** 2376** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2377** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2378** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2379** the legacy file format flag. When activated, this flag causes all newly 2380** created database file to have a schema format version number (the 4-byte 2381** integer found at offset 44 into the database header) of 1. This in turn 2382** means that the resulting database file will be readable and writable by 2383** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2384** newly created databases are generally not understandable by SQLite versions 2385** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2386** is now scarcely any need to generated database files that are compatible 2387** all the way back to version 3.0.0, and so this setting is of little 2388** practical use, but is provided so that SQLite can continue to claim the 2389** ability to generate new database files that are compatible with version 2390** 3.0.0. 2391** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2392** the [VACUUM] command will fail with an obscure error when attempting to 2393** process a table with generated columns and a descending index. This is 2394** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2395** either generated columns or decending indexes. 2396** </dd> 2397** </dl> 2398*/ 2399#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2400#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2401#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2402#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2403#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2404#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2405#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2406#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2407#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2408#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2409#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2410#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2411#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2412#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2413#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2414#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2415#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2416#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2417#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2418 2419/* 2420** CAPI3REF: Enable Or Disable Extended Result Codes 2421** METHOD: sqlite3 2422** 2423** ^The sqlite3_extended_result_codes() routine enables or disables the 2424** [extended result codes] feature of SQLite. ^The extended result 2425** codes are disabled by default for historical compatibility. 2426*/ 2427int sqlite3_extended_result_codes(sqlite3*, int onoff); 2428 2429/* 2430** CAPI3REF: Last Insert Rowid 2431** METHOD: sqlite3 2432** 2433** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2434** has a unique 64-bit signed 2435** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2436** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2437** names are not also used by explicitly declared columns. ^If 2438** the table has a column of type [INTEGER PRIMARY KEY] then that column 2439** is another alias for the rowid. 2440** 2441** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2442** the most recent successful [INSERT] into a rowid table or [virtual table] 2443** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2444** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2445** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2446** zero. 2447** 2448** As well as being set automatically as rows are inserted into database 2449** tables, the value returned by this function may be set explicitly by 2450** [sqlite3_set_last_insert_rowid()] 2451** 2452** Some virtual table implementations may INSERT rows into rowid tables as 2453** part of committing a transaction (e.g. to flush data accumulated in memory 2454** to disk). In this case subsequent calls to this function return the rowid 2455** associated with these internal INSERT operations, which leads to 2456** unintuitive results. Virtual table implementations that do write to rowid 2457** tables in this way can avoid this problem by restoring the original 2458** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2459** control to the user. 2460** 2461** ^(If an [INSERT] occurs within a trigger then this routine will 2462** return the [rowid] of the inserted row as long as the trigger is 2463** running. Once the trigger program ends, the value returned 2464** by this routine reverts to what it was before the trigger was fired.)^ 2465** 2466** ^An [INSERT] that fails due to a constraint violation is not a 2467** successful [INSERT] and does not change the value returned by this 2468** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2469** and INSERT OR ABORT make no changes to the return value of this 2470** routine when their insertion fails. ^(When INSERT OR REPLACE 2471** encounters a constraint violation, it does not fail. The 2472** INSERT continues to completion after deleting rows that caused 2473** the constraint problem so INSERT OR REPLACE will always change 2474** the return value of this interface.)^ 2475** 2476** ^For the purposes of this routine, an [INSERT] is considered to 2477** be successful even if it is subsequently rolled back. 2478** 2479** This function is accessible to SQL statements via the 2480** [last_insert_rowid() SQL function]. 2481** 2482** If a separate thread performs a new [INSERT] on the same 2483** database connection while the [sqlite3_last_insert_rowid()] 2484** function is running and thus changes the last insert [rowid], 2485** then the value returned by [sqlite3_last_insert_rowid()] is 2486** unpredictable and might not equal either the old or the new 2487** last insert [rowid]. 2488*/ 2489sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2490 2491/* 2492** CAPI3REF: Set the Last Insert Rowid value. 2493** METHOD: sqlite3 2494** 2495** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2496** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2497** without inserting a row into the database. 2498*/ 2499void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2500 2501/* 2502** CAPI3REF: Count The Number Of Rows Modified 2503** METHOD: sqlite3 2504** 2505** ^These functions return the number of rows modified, inserted or 2506** deleted by the most recently completed INSERT, UPDATE or DELETE 2507** statement on the database connection specified by the only parameter. 2508** The two functions are identical except for the type of the return value 2509** and that if the number of rows modified by the most recent INSERT, UPDATE 2510** or DELETE is greater than the maximum value supported by type "int", then 2511** the return value of sqlite3_changes() is undefined. ^Executing any other 2512** type of SQL statement does not modify the value returned by these functions. 2513** 2514** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2515** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2516** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2517** 2518** Changes to a view that are intercepted by 2519** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2520** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2521** DELETE statement run on a view is always zero. Only changes made to real 2522** tables are counted. 2523** 2524** Things are more complicated if the sqlite3_changes() function is 2525** executed while a trigger program is running. This may happen if the 2526** program uses the [changes() SQL function], or if some other callback 2527** function invokes sqlite3_changes() directly. Essentially: 2528** 2529** <ul> 2530** <li> ^(Before entering a trigger program the value returned by 2531** sqlite3_changes() function is saved. After the trigger program 2532** has finished, the original value is restored.)^ 2533** 2534** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2535** statement sets the value returned by sqlite3_changes() 2536** upon completion as normal. Of course, this value will not include 2537** any changes performed by sub-triggers, as the sqlite3_changes() 2538** value will be saved and restored after each sub-trigger has run.)^ 2539** </ul> 2540** 2541** ^This means that if the changes() SQL function (or similar) is used 2542** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2543** returns the value as set when the calling statement began executing. 2544** ^If it is used by the second or subsequent such statement within a trigger 2545** program, the value returned reflects the number of rows modified by the 2546** previous INSERT, UPDATE or DELETE statement within the same trigger. 2547** 2548** If a separate thread makes changes on the same database connection 2549** while [sqlite3_changes()] is running then the value returned 2550** is unpredictable and not meaningful. 2551** 2552** See also: 2553** <ul> 2554** <li> the [sqlite3_total_changes()] interface 2555** <li> the [count_changes pragma] 2556** <li> the [changes() SQL function] 2557** <li> the [data_version pragma] 2558** </ul> 2559*/ 2560int sqlite3_changes(sqlite3*); 2561sqlite3_int64 sqlite3_changes64(sqlite3*); 2562 2563/* 2564** CAPI3REF: Total Number Of Rows Modified 2565** METHOD: sqlite3 2566** 2567** ^These functions return the total number of rows inserted, modified or 2568** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2569** since the database connection was opened, including those executed as 2570** part of trigger programs. The two functions are identical except for the 2571** type of the return value and that if the number of rows modified by the 2572** connection exceeds the maximum value supported by type "int", then 2573** the return value of sqlite3_total_changes() is undefined. ^Executing 2574** any other type of SQL statement does not affect the value returned by 2575** sqlite3_total_changes(). 2576** 2577** ^Changes made as part of [foreign key actions] are included in the 2578** count, but those made as part of REPLACE constraint resolution are 2579** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2580** are not counted. 2581** 2582** The [sqlite3_total_changes(D)] interface only reports the number 2583** of rows that changed due to SQL statement run against database 2584** connection D. Any changes by other database connections are ignored. 2585** To detect changes against a database file from other database 2586** connections use the [PRAGMA data_version] command or the 2587** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2588** 2589** If a separate thread makes changes on the same database connection 2590** while [sqlite3_total_changes()] is running then the value 2591** returned is unpredictable and not meaningful. 2592** 2593** See also: 2594** <ul> 2595** <li> the [sqlite3_changes()] interface 2596** <li> the [count_changes pragma] 2597** <li> the [changes() SQL function] 2598** <li> the [data_version pragma] 2599** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2600** </ul> 2601*/ 2602int sqlite3_total_changes(sqlite3*); 2603sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2604 2605/* 2606** CAPI3REF: Interrupt A Long-Running Query 2607** METHOD: sqlite3 2608** 2609** ^This function causes any pending database operation to abort and 2610** return at its earliest opportunity. This routine is typically 2611** called in response to a user action such as pressing "Cancel" 2612** or Ctrl-C where the user wants a long query operation to halt 2613** immediately. 2614** 2615** ^It is safe to call this routine from a thread different from the 2616** thread that is currently running the database operation. But it 2617** is not safe to call this routine with a [database connection] that 2618** is closed or might close before sqlite3_interrupt() returns. 2619** 2620** ^If an SQL operation is very nearly finished at the time when 2621** sqlite3_interrupt() is called, then it might not have an opportunity 2622** to be interrupted and might continue to completion. 2623** 2624** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2625** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2626** that is inside an explicit transaction, then the entire transaction 2627** will be rolled back automatically. 2628** 2629** ^The sqlite3_interrupt(D) call is in effect until all currently running 2630** SQL statements on [database connection] D complete. ^Any new SQL statements 2631** that are started after the sqlite3_interrupt() call and before the 2632** running statement count reaches zero are interrupted as if they had been 2633** running prior to the sqlite3_interrupt() call. ^New SQL statements 2634** that are started after the running statement count reaches zero are 2635** not effected by the sqlite3_interrupt(). 2636** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2637** SQL statements is a no-op and has no effect on SQL statements 2638** that are started after the sqlite3_interrupt() call returns. 2639*/ 2640void sqlite3_interrupt(sqlite3*); 2641 2642/* 2643** CAPI3REF: Determine If An SQL Statement Is Complete 2644** 2645** These routines are useful during command-line input to determine if the 2646** currently entered text seems to form a complete SQL statement or 2647** if additional input is needed before sending the text into 2648** SQLite for parsing. ^These routines return 1 if the input string 2649** appears to be a complete SQL statement. ^A statement is judged to be 2650** complete if it ends with a semicolon token and is not a prefix of a 2651** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2652** string literals or quoted identifier names or comments are not 2653** independent tokens (they are part of the token in which they are 2654** embedded) and thus do not count as a statement terminator. ^Whitespace 2655** and comments that follow the final semicolon are ignored. 2656** 2657** ^These routines return 0 if the statement is incomplete. ^If a 2658** memory allocation fails, then SQLITE_NOMEM is returned. 2659** 2660** ^These routines do not parse the SQL statements thus 2661** will not detect syntactically incorrect SQL. 2662** 2663** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2664** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2665** automatically by sqlite3_complete16(). If that initialization fails, 2666** then the return value from sqlite3_complete16() will be non-zero 2667** regardless of whether or not the input SQL is complete.)^ 2668** 2669** The input to [sqlite3_complete()] must be a zero-terminated 2670** UTF-8 string. 2671** 2672** The input to [sqlite3_complete16()] must be a zero-terminated 2673** UTF-16 string in native byte order. 2674*/ 2675int sqlite3_complete(const char *sql); 2676int sqlite3_complete16(const void *sql); 2677 2678/* 2679** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2680** KEYWORDS: {busy-handler callback} {busy handler} 2681** METHOD: sqlite3 2682** 2683** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2684** that might be invoked with argument P whenever 2685** an attempt is made to access a database table associated with 2686** [database connection] D when another thread 2687** or process has the table locked. 2688** The sqlite3_busy_handler() interface is used to implement 2689** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2690** 2691** ^If the busy callback is NULL, then [SQLITE_BUSY] 2692** is returned immediately upon encountering the lock. ^If the busy callback 2693** is not NULL, then the callback might be invoked with two arguments. 2694** 2695** ^The first argument to the busy handler is a copy of the void* pointer which 2696** is the third argument to sqlite3_busy_handler(). ^The second argument to 2697** the busy handler callback is the number of times that the busy handler has 2698** been invoked previously for the same locking event. ^If the 2699** busy callback returns 0, then no additional attempts are made to 2700** access the database and [SQLITE_BUSY] is returned 2701** to the application. 2702** ^If the callback returns non-zero, then another attempt 2703** is made to access the database and the cycle repeats. 2704** 2705** The presence of a busy handler does not guarantee that it will be invoked 2706** when there is lock contention. ^If SQLite determines that invoking the busy 2707** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2708** to the application instead of invoking the 2709** busy handler. 2710** Consider a scenario where one process is holding a read lock that 2711** it is trying to promote to a reserved lock and 2712** a second process is holding a reserved lock that it is trying 2713** to promote to an exclusive lock. The first process cannot proceed 2714** because it is blocked by the second and the second process cannot 2715** proceed because it is blocked by the first. If both processes 2716** invoke the busy handlers, neither will make any progress. Therefore, 2717** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2718** will induce the first process to release its read lock and allow 2719** the second process to proceed. 2720** 2721** ^The default busy callback is NULL. 2722** 2723** ^(There can only be a single busy handler defined for each 2724** [database connection]. Setting a new busy handler clears any 2725** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2726** or evaluating [PRAGMA busy_timeout=N] will change the 2727** busy handler and thus clear any previously set busy handler. 2728** 2729** The busy callback should not take any actions which modify the 2730** database connection that invoked the busy handler. In other words, 2731** the busy handler is not reentrant. Any such actions 2732** result in undefined behavior. 2733** 2734** A busy handler must not close the database connection 2735** or [prepared statement] that invoked the busy handler. 2736*/ 2737int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2738 2739/* 2740** CAPI3REF: Set A Busy Timeout 2741** METHOD: sqlite3 2742** 2743** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2744** for a specified amount of time when a table is locked. ^The handler 2745** will sleep multiple times until at least "ms" milliseconds of sleeping 2746** have accumulated. ^After at least "ms" milliseconds of sleeping, 2747** the handler returns 0 which causes [sqlite3_step()] to return 2748** [SQLITE_BUSY]. 2749** 2750** ^Calling this routine with an argument less than or equal to zero 2751** turns off all busy handlers. 2752** 2753** ^(There can only be a single busy handler for a particular 2754** [database connection] at any given moment. If another busy handler 2755** was defined (using [sqlite3_busy_handler()]) prior to calling 2756** this routine, that other busy handler is cleared.)^ 2757** 2758** See also: [PRAGMA busy_timeout] 2759*/ 2760int sqlite3_busy_timeout(sqlite3*, int ms); 2761 2762/* 2763** CAPI3REF: Convenience Routines For Running Queries 2764** METHOD: sqlite3 2765** 2766** This is a legacy interface that is preserved for backwards compatibility. 2767** Use of this interface is not recommended. 2768** 2769** Definition: A <b>result table</b> is memory data structure created by the 2770** [sqlite3_get_table()] interface. A result table records the 2771** complete query results from one or more queries. 2772** 2773** The table conceptually has a number of rows and columns. But 2774** these numbers are not part of the result table itself. These 2775** numbers are obtained separately. Let N be the number of rows 2776** and M be the number of columns. 2777** 2778** A result table is an array of pointers to zero-terminated UTF-8 strings. 2779** There are (N+1)*M elements in the array. The first M pointers point 2780** to zero-terminated strings that contain the names of the columns. 2781** The remaining entries all point to query results. NULL values result 2782** in NULL pointers. All other values are in their UTF-8 zero-terminated 2783** string representation as returned by [sqlite3_column_text()]. 2784** 2785** A result table might consist of one or more memory allocations. 2786** It is not safe to pass a result table directly to [sqlite3_free()]. 2787** A result table should be deallocated using [sqlite3_free_table()]. 2788** 2789** ^(As an example of the result table format, suppose a query result 2790** is as follows: 2791** 2792** <blockquote><pre> 2793** Name | Age 2794** ----------------------- 2795** Alice | 43 2796** Bob | 28 2797** Cindy | 21 2798** </pre></blockquote> 2799** 2800** There are two columns (M==2) and three rows (N==3). Thus the 2801** result table has 8 entries. Suppose the result table is stored 2802** in an array named azResult. Then azResult holds this content: 2803** 2804** <blockquote><pre> 2805** azResult[0] = "Name"; 2806** azResult[1] = "Age"; 2807** azResult[2] = "Alice"; 2808** azResult[3] = "43"; 2809** azResult[4] = "Bob"; 2810** azResult[5] = "28"; 2811** azResult[6] = "Cindy"; 2812** azResult[7] = "21"; 2813** </pre></blockquote>)^ 2814** 2815** ^The sqlite3_get_table() function evaluates one or more 2816** semicolon-separated SQL statements in the zero-terminated UTF-8 2817** string of its 2nd parameter and returns a result table to the 2818** pointer given in its 3rd parameter. 2819** 2820** After the application has finished with the result from sqlite3_get_table(), 2821** it must pass the result table pointer to sqlite3_free_table() in order to 2822** release the memory that was malloced. Because of the way the 2823** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2824** function must not try to call [sqlite3_free()] directly. Only 2825** [sqlite3_free_table()] is able to release the memory properly and safely. 2826** 2827** The sqlite3_get_table() interface is implemented as a wrapper around 2828** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2829** to any internal data structures of SQLite. It uses only the public 2830** interface defined here. As a consequence, errors that occur in the 2831** wrapper layer outside of the internal [sqlite3_exec()] call are not 2832** reflected in subsequent calls to [sqlite3_errcode()] or 2833** [sqlite3_errmsg()]. 2834*/ 2835int sqlite3_get_table( 2836 sqlite3 *db, /* An open database */ 2837 const char *zSql, /* SQL to be evaluated */ 2838 char ***pazResult, /* Results of the query */ 2839 int *pnRow, /* Number of result rows written here */ 2840 int *pnColumn, /* Number of result columns written here */ 2841 char **pzErrmsg /* Error msg written here */ 2842); 2843void sqlite3_free_table(char **result); 2844 2845/* 2846** CAPI3REF: Formatted String Printing Functions 2847** 2848** These routines are work-alikes of the "printf()" family of functions 2849** from the standard C library. 2850** These routines understand most of the common formatting options from 2851** the standard library printf() 2852** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2853** See the [built-in printf()] documentation for details. 2854** 2855** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2856** results into memory obtained from [sqlite3_malloc64()]. 2857** The strings returned by these two routines should be 2858** released by [sqlite3_free()]. ^Both routines return a 2859** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2860** memory to hold the resulting string. 2861** 2862** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2863** the standard C library. The result is written into the 2864** buffer supplied as the second parameter whose size is given by 2865** the first parameter. Note that the order of the 2866** first two parameters is reversed from snprintf().)^ This is an 2867** historical accident that cannot be fixed without breaking 2868** backwards compatibility. ^(Note also that sqlite3_snprintf() 2869** returns a pointer to its buffer instead of the number of 2870** characters actually written into the buffer.)^ We admit that 2871** the number of characters written would be a more useful return 2872** value but we cannot change the implementation of sqlite3_snprintf() 2873** now without breaking compatibility. 2874** 2875** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2876** guarantees that the buffer is always zero-terminated. ^The first 2877** parameter "n" is the total size of the buffer, including space for 2878** the zero terminator. So the longest string that can be completely 2879** written will be n-1 characters. 2880** 2881** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2882** 2883** See also: [built-in printf()], [printf() SQL function] 2884*/ 2885char *sqlite3_mprintf(const char*,...); 2886char *sqlite3_vmprintf(const char*, va_list); 2887char *sqlite3_snprintf(int,char*,const char*, ...); 2888char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2889 2890/* 2891** CAPI3REF: Memory Allocation Subsystem 2892** 2893** The SQLite core uses these three routines for all of its own 2894** internal memory allocation needs. "Core" in the previous sentence 2895** does not include operating-system specific [VFS] implementation. The 2896** Windows VFS uses native malloc() and free() for some operations. 2897** 2898** ^The sqlite3_malloc() routine returns a pointer to a block 2899** of memory at least N bytes in length, where N is the parameter. 2900** ^If sqlite3_malloc() is unable to obtain sufficient free 2901** memory, it returns a NULL pointer. ^If the parameter N to 2902** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2903** a NULL pointer. 2904** 2905** ^The sqlite3_malloc64(N) routine works just like 2906** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2907** of a signed 32-bit integer. 2908** 2909** ^Calling sqlite3_free() with a pointer previously returned 2910** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2911** that it might be reused. ^The sqlite3_free() routine is 2912** a no-op if is called with a NULL pointer. Passing a NULL pointer 2913** to sqlite3_free() is harmless. After being freed, memory 2914** should neither be read nor written. Even reading previously freed 2915** memory might result in a segmentation fault or other severe error. 2916** Memory corruption, a segmentation fault, or other severe error 2917** might result if sqlite3_free() is called with a non-NULL pointer that 2918** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2919** 2920** ^The sqlite3_realloc(X,N) interface attempts to resize a 2921** prior memory allocation X to be at least N bytes. 2922** ^If the X parameter to sqlite3_realloc(X,N) 2923** is a NULL pointer then its behavior is identical to calling 2924** sqlite3_malloc(N). 2925** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2926** negative then the behavior is exactly the same as calling 2927** sqlite3_free(X). 2928** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2929** of at least N bytes in size or NULL if insufficient memory is available. 2930** ^If M is the size of the prior allocation, then min(N,M) bytes 2931** of the prior allocation are copied into the beginning of buffer returned 2932** by sqlite3_realloc(X,N) and the prior allocation is freed. 2933** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2934** prior allocation is not freed. 2935** 2936** ^The sqlite3_realloc64(X,N) interfaces works the same as 2937** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2938** of a 32-bit signed integer. 2939** 2940** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2941** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2942** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2943** ^The value returned by sqlite3_msize(X) might be larger than the number 2944** of bytes requested when X was allocated. ^If X is a NULL pointer then 2945** sqlite3_msize(X) returns zero. If X points to something that is not 2946** the beginning of memory allocation, or if it points to a formerly 2947** valid memory allocation that has now been freed, then the behavior 2948** of sqlite3_msize(X) is undefined and possibly harmful. 2949** 2950** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2951** sqlite3_malloc64(), and sqlite3_realloc64() 2952** is always aligned to at least an 8 byte boundary, or to a 2953** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2954** option is used. 2955** 2956** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2957** must be either NULL or else pointers obtained from a prior 2958** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2959** not yet been released. 2960** 2961** The application must not read or write any part of 2962** a block of memory after it has been released using 2963** [sqlite3_free()] or [sqlite3_realloc()]. 2964*/ 2965void *sqlite3_malloc(int); 2966void *sqlite3_malloc64(sqlite3_uint64); 2967void *sqlite3_realloc(void*, int); 2968void *sqlite3_realloc64(void*, sqlite3_uint64); 2969void sqlite3_free(void*); 2970sqlite3_uint64 sqlite3_msize(void*); 2971 2972/* 2973** CAPI3REF: Memory Allocator Statistics 2974** 2975** SQLite provides these two interfaces for reporting on the status 2976** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2977** routines, which form the built-in memory allocation subsystem. 2978** 2979** ^The [sqlite3_memory_used()] routine returns the number of bytes 2980** of memory currently outstanding (malloced but not freed). 2981** ^The [sqlite3_memory_highwater()] routine returns the maximum 2982** value of [sqlite3_memory_used()] since the high-water mark 2983** was last reset. ^The values returned by [sqlite3_memory_used()] and 2984** [sqlite3_memory_highwater()] include any overhead 2985** added by SQLite in its implementation of [sqlite3_malloc()], 2986** but not overhead added by the any underlying system library 2987** routines that [sqlite3_malloc()] may call. 2988** 2989** ^The memory high-water mark is reset to the current value of 2990** [sqlite3_memory_used()] if and only if the parameter to 2991** [sqlite3_memory_highwater()] is true. ^The value returned 2992** by [sqlite3_memory_highwater(1)] is the high-water mark 2993** prior to the reset. 2994*/ 2995sqlite3_int64 sqlite3_memory_used(void); 2996sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2997 2998/* 2999** CAPI3REF: Pseudo-Random Number Generator 3000** 3001** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3002** select random [ROWID | ROWIDs] when inserting new records into a table that 3003** already uses the largest possible [ROWID]. The PRNG is also used for 3004** the built-in random() and randomblob() SQL functions. This interface allows 3005** applications to access the same PRNG for other purposes. 3006** 3007** ^A call to this routine stores N bytes of randomness into buffer P. 3008** ^The P parameter can be a NULL pointer. 3009** 3010** ^If this routine has not been previously called or if the previous 3011** call had N less than one or a NULL pointer for P, then the PRNG is 3012** seeded using randomness obtained from the xRandomness method of 3013** the default [sqlite3_vfs] object. 3014** ^If the previous call to this routine had an N of 1 or more and a 3015** non-NULL P then the pseudo-randomness is generated 3016** internally and without recourse to the [sqlite3_vfs] xRandomness 3017** method. 3018*/ 3019void sqlite3_randomness(int N, void *P); 3020 3021/* 3022** CAPI3REF: Compile-Time Authorization Callbacks 3023** METHOD: sqlite3 3024** KEYWORDS: {authorizer callback} 3025** 3026** ^This routine registers an authorizer callback with a particular 3027** [database connection], supplied in the first argument. 3028** ^The authorizer callback is invoked as SQL statements are being compiled 3029** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3030** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3031** and [sqlite3_prepare16_v3()]. ^At various 3032** points during the compilation process, as logic is being created 3033** to perform various actions, the authorizer callback is invoked to 3034** see if those actions are allowed. ^The authorizer callback should 3035** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3036** specific action but allow the SQL statement to continue to be 3037** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3038** rejected with an error. ^If the authorizer callback returns 3039** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3040** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3041** the authorizer will fail with an error message. 3042** 3043** When the callback returns [SQLITE_OK], that means the operation 3044** requested is ok. ^When the callback returns [SQLITE_DENY], the 3045** [sqlite3_prepare_v2()] or equivalent call that triggered the 3046** authorizer will fail with an error message explaining that 3047** access is denied. 3048** 3049** ^The first parameter to the authorizer callback is a copy of the third 3050** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3051** to the callback is an integer [SQLITE_COPY | action code] that specifies 3052** the particular action to be authorized. ^The third through sixth parameters 3053** to the callback are either NULL pointers or zero-terminated strings 3054** that contain additional details about the action to be authorized. 3055** Applications must always be prepared to encounter a NULL pointer in any 3056** of the third through the sixth parameters of the authorization callback. 3057** 3058** ^If the action code is [SQLITE_READ] 3059** and the callback returns [SQLITE_IGNORE] then the 3060** [prepared statement] statement is constructed to substitute 3061** a NULL value in place of the table column that would have 3062** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3063** return can be used to deny an untrusted user access to individual 3064** columns of a table. 3065** ^When a table is referenced by a [SELECT] but no column values are 3066** extracted from that table (for example in a query like 3067** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3068** is invoked once for that table with a column name that is an empty string. 3069** ^If the action code is [SQLITE_DELETE] and the callback returns 3070** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3071** [truncate optimization] is disabled and all rows are deleted individually. 3072** 3073** An authorizer is used when [sqlite3_prepare | preparing] 3074** SQL statements from an untrusted source, to ensure that the SQL statements 3075** do not try to access data they are not allowed to see, or that they do not 3076** try to execute malicious statements that damage the database. For 3077** example, an application may allow a user to enter arbitrary 3078** SQL queries for evaluation by a database. But the application does 3079** not want the user to be able to make arbitrary changes to the 3080** database. An authorizer could then be put in place while the 3081** user-entered SQL is being [sqlite3_prepare | prepared] that 3082** disallows everything except [SELECT] statements. 3083** 3084** Applications that need to process SQL from untrusted sources 3085** might also consider lowering resource limits using [sqlite3_limit()] 3086** and limiting database size using the [max_page_count] [PRAGMA] 3087** in addition to using an authorizer. 3088** 3089** ^(Only a single authorizer can be in place on a database connection 3090** at a time. Each call to sqlite3_set_authorizer overrides the 3091** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3092** The authorizer is disabled by default. 3093** 3094** The authorizer callback must not do anything that will modify 3095** the database connection that invoked the authorizer callback. 3096** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3097** database connections for the meaning of "modify" in this paragraph. 3098** 3099** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3100** statement might be re-prepared during [sqlite3_step()] due to a 3101** schema change. Hence, the application should ensure that the 3102** correct authorizer callback remains in place during the [sqlite3_step()]. 3103** 3104** ^Note that the authorizer callback is invoked only during 3105** [sqlite3_prepare()] or its variants. Authorization is not 3106** performed during statement evaluation in [sqlite3_step()], unless 3107** as stated in the previous paragraph, sqlite3_step() invokes 3108** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3109*/ 3110int sqlite3_set_authorizer( 3111 sqlite3*, 3112 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3113 void *pUserData 3114); 3115 3116/* 3117** CAPI3REF: Authorizer Return Codes 3118** 3119** The [sqlite3_set_authorizer | authorizer callback function] must 3120** return either [SQLITE_OK] or one of these two constants in order 3121** to signal SQLite whether or not the action is permitted. See the 3122** [sqlite3_set_authorizer | authorizer documentation] for additional 3123** information. 3124** 3125** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3126** returned from the [sqlite3_vtab_on_conflict()] interface. 3127*/ 3128#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3129#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3130 3131/* 3132** CAPI3REF: Authorizer Action Codes 3133** 3134** The [sqlite3_set_authorizer()] interface registers a callback function 3135** that is invoked to authorize certain SQL statement actions. The 3136** second parameter to the callback is an integer code that specifies 3137** what action is being authorized. These are the integer action codes that 3138** the authorizer callback may be passed. 3139** 3140** These action code values signify what kind of operation is to be 3141** authorized. The 3rd and 4th parameters to the authorization 3142** callback function will be parameters or NULL depending on which of these 3143** codes is used as the second parameter. ^(The 5th parameter to the 3144** authorizer callback is the name of the database ("main", "temp", 3145** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3146** is the name of the inner-most trigger or view that is responsible for 3147** the access attempt or NULL if this access attempt is directly from 3148** top-level SQL code. 3149*/ 3150/******************************************* 3rd ************ 4th ***********/ 3151#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3152#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3153#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3154#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3155#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3156#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3157#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3158#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3159#define SQLITE_DELETE 9 /* Table Name NULL */ 3160#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3161#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3162#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3163#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3164#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3165#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3166#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3167#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3168#define SQLITE_INSERT 18 /* Table Name NULL */ 3169#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3170#define SQLITE_READ 20 /* Table Name Column Name */ 3171#define SQLITE_SELECT 21 /* NULL NULL */ 3172#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3173#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3174#define SQLITE_ATTACH 24 /* Filename NULL */ 3175#define SQLITE_DETACH 25 /* Database Name NULL */ 3176#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3177#define SQLITE_REINDEX 27 /* Index Name NULL */ 3178#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3179#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3180#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3181#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3182#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3183#define SQLITE_COPY 0 /* No longer used */ 3184#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3185 3186/* 3187** CAPI3REF: Tracing And Profiling Functions 3188** METHOD: sqlite3 3189** 3190** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3191** instead of the routines described here. 3192** 3193** These routines register callback functions that can be used for 3194** tracing and profiling the execution of SQL statements. 3195** 3196** ^The callback function registered by sqlite3_trace() is invoked at 3197** various times when an SQL statement is being run by [sqlite3_step()]. 3198** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3199** SQL statement text as the statement first begins executing. 3200** ^(Additional sqlite3_trace() callbacks might occur 3201** as each triggered subprogram is entered. The callbacks for triggers 3202** contain a UTF-8 SQL comment that identifies the trigger.)^ 3203** 3204** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3205** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3206** 3207** ^The callback function registered by sqlite3_profile() is invoked 3208** as each SQL statement finishes. ^The profile callback contains 3209** the original statement text and an estimate of wall-clock time 3210** of how long that statement took to run. ^The profile callback 3211** time is in units of nanoseconds, however the current implementation 3212** is only capable of millisecond resolution so the six least significant 3213** digits in the time are meaningless. Future versions of SQLite 3214** might provide greater resolution on the profiler callback. Invoking 3215** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3216** profile callback. 3217*/ 3218SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3219 void(*xTrace)(void*,const char*), void*); 3220SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3221 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3222 3223/* 3224** CAPI3REF: SQL Trace Event Codes 3225** KEYWORDS: SQLITE_TRACE 3226** 3227** These constants identify classes of events that can be monitored 3228** using the [sqlite3_trace_v2()] tracing logic. The M argument 3229** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3230** the following constants. ^The first argument to the trace callback 3231** is one of the following constants. 3232** 3233** New tracing constants may be added in future releases. 3234** 3235** ^A trace callback has four arguments: xCallback(T,C,P,X). 3236** ^The T argument is one of the integer type codes above. 3237** ^The C argument is a copy of the context pointer passed in as the 3238** fourth argument to [sqlite3_trace_v2()]. 3239** The P and X arguments are pointers whose meanings depend on T. 3240** 3241** <dl> 3242** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3243** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3244** first begins running and possibly at other times during the 3245** execution of the prepared statement, such as at the start of each 3246** trigger subprogram. ^The P argument is a pointer to the 3247** [prepared statement]. ^The X argument is a pointer to a string which 3248** is the unexpanded SQL text of the prepared statement or an SQL comment 3249** that indicates the invocation of a trigger. ^The callback can compute 3250** the same text that would have been returned by the legacy [sqlite3_trace()] 3251** interface by using the X argument when X begins with "--" and invoking 3252** [sqlite3_expanded_sql(P)] otherwise. 3253** 3254** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3255** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3256** information as is provided by the [sqlite3_profile()] callback. 3257** ^The P argument is a pointer to the [prepared statement] and the 3258** X argument points to a 64-bit integer which is the estimated of 3259** the number of nanosecond that the prepared statement took to run. 3260** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3261** 3262** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3263** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3264** statement generates a single row of result. 3265** ^The P argument is a pointer to the [prepared statement] and the 3266** X argument is unused. 3267** 3268** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3269** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3270** connection closes. 3271** ^The P argument is a pointer to the [database connection] object 3272** and the X argument is unused. 3273** </dl> 3274*/ 3275#define SQLITE_TRACE_STMT 0x01 3276#define SQLITE_TRACE_PROFILE 0x02 3277#define SQLITE_TRACE_ROW 0x04 3278#define SQLITE_TRACE_CLOSE 0x08 3279 3280/* 3281** CAPI3REF: SQL Trace Hook 3282** METHOD: sqlite3 3283** 3284** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3285** function X against [database connection] D, using property mask M 3286** and context pointer P. ^If the X callback is 3287** NULL or if the M mask is zero, then tracing is disabled. The 3288** M argument should be the bitwise OR-ed combination of 3289** zero or more [SQLITE_TRACE] constants. 3290** 3291** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3292** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3293** 3294** ^The X callback is invoked whenever any of the events identified by 3295** mask M occur. ^The integer return value from the callback is currently 3296** ignored, though this may change in future releases. Callback 3297** implementations should return zero to ensure future compatibility. 3298** 3299** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3300** ^The T argument is one of the [SQLITE_TRACE] 3301** constants to indicate why the callback was invoked. 3302** ^The C argument is a copy of the context pointer. 3303** The P and X arguments are pointers whose meanings depend on T. 3304** 3305** The sqlite3_trace_v2() interface is intended to replace the legacy 3306** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3307** are deprecated. 3308*/ 3309int sqlite3_trace_v2( 3310 sqlite3*, 3311 unsigned uMask, 3312 int(*xCallback)(unsigned,void*,void*,void*), 3313 void *pCtx 3314); 3315 3316/* 3317** CAPI3REF: Query Progress Callbacks 3318** METHOD: sqlite3 3319** 3320** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3321** function X to be invoked periodically during long running calls to 3322** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3323** database connection D. An example use for this 3324** interface is to keep a GUI updated during a large query. 3325** 3326** ^The parameter P is passed through as the only parameter to the 3327** callback function X. ^The parameter N is the approximate number of 3328** [virtual machine instructions] that are evaluated between successive 3329** invocations of the callback X. ^If N is less than one then the progress 3330** handler is disabled. 3331** 3332** ^Only a single progress handler may be defined at one time per 3333** [database connection]; setting a new progress handler cancels the 3334** old one. ^Setting parameter X to NULL disables the progress handler. 3335** ^The progress handler is also disabled by setting N to a value less 3336** than 1. 3337** 3338** ^If the progress callback returns non-zero, the operation is 3339** interrupted. This feature can be used to implement a 3340** "Cancel" button on a GUI progress dialog box. 3341** 3342** The progress handler callback must not do anything that will modify 3343** the database connection that invoked the progress handler. 3344** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3345** database connections for the meaning of "modify" in this paragraph. 3346** 3347*/ 3348void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3349 3350/* 3351** CAPI3REF: Opening A New Database Connection 3352** CONSTRUCTOR: sqlite3 3353** 3354** ^These routines open an SQLite database file as specified by the 3355** filename argument. ^The filename argument is interpreted as UTF-8 for 3356** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3357** order for sqlite3_open16(). ^(A [database connection] handle is usually 3358** returned in *ppDb, even if an error occurs. The only exception is that 3359** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3360** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3361** object.)^ ^(If the database is opened (and/or created) successfully, then 3362** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3363** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3364** an English language description of the error following a failure of any 3365** of the sqlite3_open() routines. 3366** 3367** ^The default encoding will be UTF-8 for databases created using 3368** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3369** created using sqlite3_open16() will be UTF-16 in the native byte order. 3370** 3371** Whether or not an error occurs when it is opened, resources 3372** associated with the [database connection] handle should be released by 3373** passing it to [sqlite3_close()] when it is no longer required. 3374** 3375** The sqlite3_open_v2() interface works like sqlite3_open() 3376** except that it accepts two additional parameters for additional control 3377** over the new database connection. ^(The flags parameter to 3378** sqlite3_open_v2() must include, at a minimum, one of the following 3379** three flag combinations:)^ 3380** 3381** <dl> 3382** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3383** <dd>The database is opened in read-only mode. If the database does not 3384** already exist, an error is returned.</dd>)^ 3385** 3386** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3387** <dd>The database is opened for reading and writing if possible, or reading 3388** only if the file is write protected by the operating system. In either 3389** case the database must already exist, otherwise an error is returned.</dd>)^ 3390** 3391** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3392** <dd>The database is opened for reading and writing, and is created if 3393** it does not already exist. This is the behavior that is always used for 3394** sqlite3_open() and sqlite3_open16().</dd>)^ 3395** </dl> 3396** 3397** In addition to the required flags, the following optional flags are 3398** also supported: 3399** 3400** <dl> 3401** ^(<dt>[SQLITE_OPEN_URI]</dt> 3402** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3403** 3404** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3405** <dd>The database will be opened as an in-memory database. The database 3406** is named by the "filename" argument for the purposes of cache-sharing, 3407** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3408** </dd>)^ 3409** 3410** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3411** <dd>The new database connection will use the "multi-thread" 3412** [threading mode].)^ This means that separate threads are allowed 3413** to use SQLite at the same time, as long as each thread is using 3414** a different [database connection]. 3415** 3416** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3417** <dd>The new database connection will use the "serialized" 3418** [threading mode].)^ This means the multiple threads can safely 3419** attempt to use the same database connection at the same time. 3420** (Mutexes will block any actual concurrency, but in this mode 3421** there is no harm in trying.) 3422** 3423** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3424** <dd>The database is opened [shared cache] enabled, overriding 3425** the default shared cache setting provided by 3426** [sqlite3_enable_shared_cache()].)^ 3427** 3428** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3429** <dd>The database is opened [shared cache] disabled, overriding 3430** the default shared cache setting provided by 3431** [sqlite3_enable_shared_cache()].)^ 3432** 3433** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3434** <dd>The database connection comes up in "extended result code mode". 3435** In other words, the database behaves has if 3436** [sqlite3_extended_result_codes(db,1)] where called on the database 3437** connection as soon as the connection is created. In addition to setting 3438** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3439** to return an extended result code.</dd> 3440** 3441** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3442** <dd>The database filename is not allowed to be a symbolic link</dd> 3443** </dl>)^ 3444** 3445** If the 3rd parameter to sqlite3_open_v2() is not one of the 3446** required combinations shown above optionally combined with other 3447** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3448** then the behavior is undefined. Historic versions of SQLite 3449** have silently ignored surplus bits in the flags parameter to 3450** sqlite3_open_v2(), however that behavior might not be carried through 3451** into future versions of SQLite and so applications should not rely 3452** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3453** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3454** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3455** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3456** by sqlite3_open_v2(). 3457** 3458** ^The fourth parameter to sqlite3_open_v2() is the name of the 3459** [sqlite3_vfs] object that defines the operating system interface that 3460** the new database connection should use. ^If the fourth parameter is 3461** a NULL pointer then the default [sqlite3_vfs] object is used. 3462** 3463** ^If the filename is ":memory:", then a private, temporary in-memory database 3464** is created for the connection. ^This in-memory database will vanish when 3465** the database connection is closed. Future versions of SQLite might 3466** make use of additional special filenames that begin with the ":" character. 3467** It is recommended that when a database filename actually does begin with 3468** a ":" character you should prefix the filename with a pathname such as 3469** "./" to avoid ambiguity. 3470** 3471** ^If the filename is an empty string, then a private, temporary 3472** on-disk database will be created. ^This private database will be 3473** automatically deleted as soon as the database connection is closed. 3474** 3475** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3476** 3477** ^If [URI filename] interpretation is enabled, and the filename argument 3478** begins with "file:", then the filename is interpreted as a URI. ^URI 3479** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3480** set in the third argument to sqlite3_open_v2(), or if it has 3481** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3482** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3483** URI filename interpretation is turned off 3484** by default, but future releases of SQLite might enable URI filename 3485** interpretation by default. See "[URI filenames]" for additional 3486** information. 3487** 3488** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3489** authority, then it must be either an empty string or the string 3490** "localhost". ^If the authority is not an empty string or "localhost", an 3491** error is returned to the caller. ^The fragment component of a URI, if 3492** present, is ignored. 3493** 3494** ^SQLite uses the path component of the URI as the name of the disk file 3495** which contains the database. ^If the path begins with a '/' character, 3496** then it is interpreted as an absolute path. ^If the path does not begin 3497** with a '/' (meaning that the authority section is omitted from the URI) 3498** then the path is interpreted as a relative path. 3499** ^(On windows, the first component of an absolute path 3500** is a drive specification (e.g. "C:").)^ 3501** 3502** [[core URI query parameters]] 3503** The query component of a URI may contain parameters that are interpreted 3504** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3505** SQLite and its built-in [VFSes] interpret the 3506** following query parameters: 3507** 3508** <ul> 3509** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3510** a VFS object that provides the operating system interface that should 3511** be used to access the database file on disk. ^If this option is set to 3512** an empty string the default VFS object is used. ^Specifying an unknown 3513** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3514** present, then the VFS specified by the option takes precedence over 3515** the value passed as the fourth parameter to sqlite3_open_v2(). 3516** 3517** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3518** "rwc", or "memory". Attempting to set it to any other value is 3519** an error)^. 3520** ^If "ro" is specified, then the database is opened for read-only 3521** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3522** third argument to sqlite3_open_v2(). ^If the mode option is set to 3523** "rw", then the database is opened for read-write (but not create) 3524** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3525** been set. ^Value "rwc" is equivalent to setting both 3526** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3527** set to "memory" then a pure [in-memory database] that never reads 3528** or writes from disk is used. ^It is an error to specify a value for 3529** the mode parameter that is less restrictive than that specified by 3530** the flags passed in the third parameter to sqlite3_open_v2(). 3531** 3532** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3533** "private". ^Setting it to "shared" is equivalent to setting the 3534** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3535** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3536** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3537** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3538** a URI filename, its value overrides any behavior requested by setting 3539** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3540** 3541** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3542** [powersafe overwrite] property does or does not apply to the 3543** storage media on which the database file resides. 3544** 3545** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3546** which if set disables file locking in rollback journal modes. This 3547** is useful for accessing a database on a filesystem that does not 3548** support locking. Caution: Database corruption might result if two 3549** or more processes write to the same database and any one of those 3550** processes uses nolock=1. 3551** 3552** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3553** parameter that indicates that the database file is stored on 3554** read-only media. ^When immutable is set, SQLite assumes that the 3555** database file cannot be changed, even by a process with higher 3556** privilege, and so the database is opened read-only and all locking 3557** and change detection is disabled. Caution: Setting the immutable 3558** property on a database file that does in fact change can result 3559** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3560** See also: [SQLITE_IOCAP_IMMUTABLE]. 3561** 3562** </ul> 3563** 3564** ^Specifying an unknown parameter in the query component of a URI is not an 3565** error. Future versions of SQLite might understand additional query 3566** parameters. See "[query parameters with special meaning to SQLite]" for 3567** additional information. 3568** 3569** [[URI filename examples]] <h3>URI filename examples</h3> 3570** 3571** <table border="1" align=center cellpadding=5> 3572** <tr><th> URI filenames <th> Results 3573** <tr><td> file:data.db <td> 3574** Open the file "data.db" in the current directory. 3575** <tr><td> file:/home/fred/data.db<br> 3576** file:///home/fred/data.db <br> 3577** file://localhost/home/fred/data.db <br> <td> 3578** Open the database file "/home/fred/data.db". 3579** <tr><td> file://darkstar/home/fred/data.db <td> 3580** An error. "darkstar" is not a recognized authority. 3581** <tr><td style="white-space:nowrap"> 3582** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3583** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3584** C:. Note that the %20 escaping in this example is not strictly 3585** necessary - space characters can be used literally 3586** in URI filenames. 3587** <tr><td> file:data.db?mode=ro&cache=private <td> 3588** Open file "data.db" in the current directory for read-only access. 3589** Regardless of whether or not shared-cache mode is enabled by 3590** default, use a private cache. 3591** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3592** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3593** that uses dot-files in place of posix advisory locking. 3594** <tr><td> file:data.db?mode=readonly <td> 3595** An error. "readonly" is not a valid option for the "mode" parameter. 3596** Use "ro" instead: "file:data.db?mode=ro". 3597** </table> 3598** 3599** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3600** query components of a URI. A hexadecimal escape sequence consists of a 3601** percent sign - "%" - followed by exactly two hexadecimal digits 3602** specifying an octet value. ^Before the path or query components of a 3603** URI filename are interpreted, they are encoded using UTF-8 and all 3604** hexadecimal escape sequences replaced by a single byte containing the 3605** corresponding octet. If this process generates an invalid UTF-8 encoding, 3606** the results are undefined. 3607** 3608** <b>Note to Windows users:</b> The encoding used for the filename argument 3609** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3610** codepage is currently defined. Filenames containing international 3611** characters must be converted to UTF-8 prior to passing them into 3612** sqlite3_open() or sqlite3_open_v2(). 3613** 3614** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3615** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3616** features that require the use of temporary files may fail. 3617** 3618** See also: [sqlite3_temp_directory] 3619*/ 3620int sqlite3_open( 3621 const char *filename, /* Database filename (UTF-8) */ 3622 sqlite3 **ppDb /* OUT: SQLite db handle */ 3623); 3624int sqlite3_open16( 3625 const void *filename, /* Database filename (UTF-16) */ 3626 sqlite3 **ppDb /* OUT: SQLite db handle */ 3627); 3628int sqlite3_open_v2( 3629 const char *filename, /* Database filename (UTF-8) */ 3630 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3631 int flags, /* Flags */ 3632 const char *zVfs /* Name of VFS module to use */ 3633); 3634 3635/* 3636** CAPI3REF: Obtain Values For URI Parameters 3637** 3638** These are utility routines, useful to [VFS|custom VFS implementations], 3639** that check if a database file was a URI that contained a specific query 3640** parameter, and if so obtains the value of that query parameter. 3641** 3642** The first parameter to these interfaces (hereafter referred to 3643** as F) must be one of: 3644** <ul> 3645** <li> A database filename pointer created by the SQLite core and 3646** passed into the xOpen() method of a VFS implemention, or 3647** <li> A filename obtained from [sqlite3_db_filename()], or 3648** <li> A new filename constructed using [sqlite3_create_filename()]. 3649** </ul> 3650** If the F parameter is not one of the above, then the behavior is 3651** undefined and probably undesirable. Older versions of SQLite were 3652** more tolerant of invalid F parameters than newer versions. 3653** 3654** If F is a suitable filename (as described in the previous paragraph) 3655** and if P is the name of the query parameter, then 3656** sqlite3_uri_parameter(F,P) returns the value of the P 3657** parameter if it exists or a NULL pointer if P does not appear as a 3658** query parameter on F. If P is a query parameter of F and it 3659** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3660** a pointer to an empty string. 3661** 3662** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3663** parameter and returns true (1) or false (0) according to the value 3664** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3665** value of query parameter P is one of "yes", "true", or "on" in any 3666** case or if the value begins with a non-zero number. The 3667** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3668** query parameter P is one of "no", "false", or "off" in any case or 3669** if the value begins with a numeric zero. If P is not a query 3670** parameter on F or if the value of P does not match any of the 3671** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3672** 3673** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3674** 64-bit signed integer and returns that integer, or D if P does not 3675** exist. If the value of P is something other than an integer, then 3676** zero is returned. 3677** 3678** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3679** the value) of the N-th query parameter for filename F, or a NULL 3680** pointer if N is less than zero or greater than the number of query 3681** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3682** the name of the first query parameter, 1 for the second parameter, and 3683** so forth. 3684** 3685** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3686** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3687** is not a database file pathname pointer that the SQLite core passed 3688** into the xOpen VFS method, then the behavior of this routine is undefined 3689** and probably undesirable. 3690** 3691** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3692** parameter can also be the name of a rollback journal file or WAL file 3693** in addition to the main database file. Prior to version 3.31.0, these 3694** routines would only work if F was the name of the main database file. 3695** When the F parameter is the name of the rollback journal or WAL file, 3696** it has access to all the same query parameters as were found on the 3697** main database file. 3698** 3699** See the [URI filename] documentation for additional information. 3700*/ 3701const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3702int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3703sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3704const char *sqlite3_uri_key(const char *zFilename, int N); 3705 3706/* 3707** CAPI3REF: Translate filenames 3708** 3709** These routines are available to [VFS|custom VFS implementations] for 3710** translating filenames between the main database file, the journal file, 3711** and the WAL file. 3712** 3713** If F is the name of an sqlite database file, journal file, or WAL file 3714** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3715** returns the name of the corresponding database file. 3716** 3717** If F is the name of an sqlite database file, journal file, or WAL file 3718** passed by the SQLite core into the VFS, or if F is a database filename 3719** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3720** returns the name of the corresponding rollback journal file. 3721** 3722** If F is the name of an sqlite database file, journal file, or WAL file 3723** that was passed by the SQLite core into the VFS, or if F is a database 3724** filename obtained from [sqlite3_db_filename()], then 3725** sqlite3_filename_wal(F) returns the name of the corresponding 3726** WAL file. 3727** 3728** In all of the above, if F is not the name of a database, journal or WAL 3729** filename passed into the VFS from the SQLite core and F is not the 3730** return value from [sqlite3_db_filename()], then the result is 3731** undefined and is likely a memory access violation. 3732*/ 3733const char *sqlite3_filename_database(const char*); 3734const char *sqlite3_filename_journal(const char*); 3735const char *sqlite3_filename_wal(const char*); 3736 3737/* 3738** CAPI3REF: Database File Corresponding To A Journal 3739** 3740** ^If X is the name of a rollback or WAL-mode journal file that is 3741** passed into the xOpen method of [sqlite3_vfs], then 3742** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3743** object that represents the main database file. 3744** 3745** This routine is intended for use in custom [VFS] implementations 3746** only. It is not a general-purpose interface. 3747** The argument sqlite3_file_object(X) must be a filename pointer that 3748** has been passed into [sqlite3_vfs].xOpen method where the 3749** flags parameter to xOpen contains one of the bits 3750** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3751** of this routine results in undefined and probably undesirable 3752** behavior. 3753*/ 3754sqlite3_file *sqlite3_database_file_object(const char*); 3755 3756/* 3757** CAPI3REF: Create and Destroy VFS Filenames 3758** 3759** These interfces are provided for use by [VFS shim] implementations and 3760** are not useful outside of that context. 3761** 3762** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3763** database filename D with corresponding journal file J and WAL file W and 3764** with N URI parameters key/values pairs in the array P. The result from 3765** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3766** is safe to pass to routines like: 3767** <ul> 3768** <li> [sqlite3_uri_parameter()], 3769** <li> [sqlite3_uri_boolean()], 3770** <li> [sqlite3_uri_int64()], 3771** <li> [sqlite3_uri_key()], 3772** <li> [sqlite3_filename_database()], 3773** <li> [sqlite3_filename_journal()], or 3774** <li> [sqlite3_filename_wal()]. 3775** </ul> 3776** If a memory allocation error occurs, sqlite3_create_filename() might 3777** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3778** must be released by a corresponding call to sqlite3_free_filename(Y). 3779** 3780** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3781** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3782** to a key and value for a query parameter. The P parameter may be a NULL 3783** pointer if N is zero. None of the 2*N pointers in the P array may be 3784** NULL pointers and key pointers should not be empty strings. 3785** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3786** be NULL pointers, though they can be empty strings. 3787** 3788** The sqlite3_free_filename(Y) routine releases a memory allocation 3789** previously obtained from sqlite3_create_filename(). Invoking 3790** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3791** 3792** If the Y parameter to sqlite3_free_filename(Y) is anything other 3793** than a NULL pointer or a pointer previously acquired from 3794** sqlite3_create_filename(), then bad things such as heap 3795** corruption or segfaults may occur. The value Y should not be 3796** used again after sqlite3_free_filename(Y) has been called. This means 3797** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3798** then the corresponding [sqlite3_module.xClose() method should also be 3799** invoked prior to calling sqlite3_free_filename(Y). 3800*/ 3801char *sqlite3_create_filename( 3802 const char *zDatabase, 3803 const char *zJournal, 3804 const char *zWal, 3805 int nParam, 3806 const char **azParam 3807); 3808void sqlite3_free_filename(char*); 3809 3810/* 3811** CAPI3REF: Error Codes And Messages 3812** METHOD: sqlite3 3813** 3814** ^If the most recent sqlite3_* API call associated with 3815** [database connection] D failed, then the sqlite3_errcode(D) interface 3816** returns the numeric [result code] or [extended result code] for that 3817** API call. 3818** ^The sqlite3_extended_errcode() 3819** interface is the same except that it always returns the 3820** [extended result code] even when extended result codes are 3821** disabled. 3822** 3823** The values returned by sqlite3_errcode() and/or 3824** sqlite3_extended_errcode() might change with each API call. 3825** Except, there are some interfaces that are guaranteed to never 3826** change the value of the error code. The error-code preserving 3827** interfaces include the following: 3828** 3829** <ul> 3830** <li> sqlite3_errcode() 3831** <li> sqlite3_extended_errcode() 3832** <li> sqlite3_errmsg() 3833** <li> sqlite3_errmsg16() 3834** <li> sqlite3_error_offset() 3835** </ul> 3836** 3837** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3838** text that describes the error, as either UTF-8 or UTF-16 respectively. 3839** ^(Memory to hold the error message string is managed internally. 3840** The application does not need to worry about freeing the result. 3841** However, the error string might be overwritten or deallocated by 3842** subsequent calls to other SQLite interface functions.)^ 3843** 3844** ^The sqlite3_errstr() interface returns the English-language text 3845** that describes the [result code], as UTF-8. 3846** ^(Memory to hold the error message string is managed internally 3847** and must not be freed by the application)^. 3848** 3849** ^If the most recent error references a specific token in the input 3850** SQL, the sqlite3_error_offset() interface returns the byte offset 3851** of the start of that token. ^The byte offset returned by 3852** sqlite3_error_offset() assumes that the input SQL is UTF8. 3853** ^If the most recent error does not reference a specific token in the input 3854** SQL, then the sqlite3_error_offset() function returns -1. 3855** 3856** When the serialized [threading mode] is in use, it might be the 3857** case that a second error occurs on a separate thread in between 3858** the time of the first error and the call to these interfaces. 3859** When that happens, the second error will be reported since these 3860** interfaces always report the most recent result. To avoid 3861** this, each thread can obtain exclusive use of the [database connection] D 3862** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3863** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3864** all calls to the interfaces listed here are completed. 3865** 3866** If an interface fails with SQLITE_MISUSE, that means the interface 3867** was invoked incorrectly by the application. In that case, the 3868** error code and message may or may not be set. 3869*/ 3870int sqlite3_errcode(sqlite3 *db); 3871int sqlite3_extended_errcode(sqlite3 *db); 3872const char *sqlite3_errmsg(sqlite3*); 3873const void *sqlite3_errmsg16(sqlite3*); 3874const char *sqlite3_errstr(int); 3875int sqlite3_error_offset(sqlite3 *db); 3876 3877/* 3878** CAPI3REF: Prepared Statement Object 3879** KEYWORDS: {prepared statement} {prepared statements} 3880** 3881** An instance of this object represents a single SQL statement that 3882** has been compiled into binary form and is ready to be evaluated. 3883** 3884** Think of each SQL statement as a separate computer program. The 3885** original SQL text is source code. A prepared statement object 3886** is the compiled object code. All SQL must be converted into a 3887** prepared statement before it can be run. 3888** 3889** The life-cycle of a prepared statement object usually goes like this: 3890** 3891** <ol> 3892** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3893** <li> Bind values to [parameters] using the sqlite3_bind_*() 3894** interfaces. 3895** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3896** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3897** to step 2. Do this zero or more times. 3898** <li> Destroy the object using [sqlite3_finalize()]. 3899** </ol> 3900*/ 3901typedef struct sqlite3_stmt sqlite3_stmt; 3902 3903/* 3904** CAPI3REF: Run-time Limits 3905** METHOD: sqlite3 3906** 3907** ^(This interface allows the size of various constructs to be limited 3908** on a connection by connection basis. The first parameter is the 3909** [database connection] whose limit is to be set or queried. The 3910** second parameter is one of the [limit categories] that define a 3911** class of constructs to be size limited. The third parameter is the 3912** new limit for that construct.)^ 3913** 3914** ^If the new limit is a negative number, the limit is unchanged. 3915** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3916** [limits | hard upper bound] 3917** set at compile-time by a C preprocessor macro called 3918** [limits | SQLITE_MAX_<i>NAME</i>]. 3919** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3920** ^Attempts to increase a limit above its hard upper bound are 3921** silently truncated to the hard upper bound. 3922** 3923** ^Regardless of whether or not the limit was changed, the 3924** [sqlite3_limit()] interface returns the prior value of the limit. 3925** ^Hence, to find the current value of a limit without changing it, 3926** simply invoke this interface with the third parameter set to -1. 3927** 3928** Run-time limits are intended for use in applications that manage 3929** both their own internal database and also databases that are controlled 3930** by untrusted external sources. An example application might be a 3931** web browser that has its own databases for storing history and 3932** separate databases controlled by JavaScript applications downloaded 3933** off the Internet. The internal databases can be given the 3934** large, default limits. Databases managed by external sources can 3935** be given much smaller limits designed to prevent a denial of service 3936** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3937** interface to further control untrusted SQL. The size of the database 3938** created by an untrusted script can be contained using the 3939** [max_page_count] [PRAGMA]. 3940** 3941** New run-time limit categories may be added in future releases. 3942*/ 3943int sqlite3_limit(sqlite3*, int id, int newVal); 3944 3945/* 3946** CAPI3REF: Run-Time Limit Categories 3947** KEYWORDS: {limit category} {*limit categories} 3948** 3949** These constants define various performance limits 3950** that can be lowered at run-time using [sqlite3_limit()]. 3951** The synopsis of the meanings of the various limits is shown below. 3952** Additional information is available at [limits | Limits in SQLite]. 3953** 3954** <dl> 3955** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3956** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3957** 3958** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3959** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3960** 3961** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3962** <dd>The maximum number of columns in a table definition or in the 3963** result set of a [SELECT] or the maximum number of columns in an index 3964** or in an ORDER BY or GROUP BY clause.</dd>)^ 3965** 3966** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3967** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3968** 3969** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3970** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3971** 3972** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3973** <dd>The maximum number of instructions in a virtual machine program 3974** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3975** the equivalent tries to allocate space for more than this many opcodes 3976** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3977** 3978** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3979** <dd>The maximum number of arguments on a function.</dd>)^ 3980** 3981** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3982** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3983** 3984** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3985** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3986** <dd>The maximum length of the pattern argument to the [LIKE] or 3987** [GLOB] operators.</dd>)^ 3988** 3989** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3990** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3991** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3992** 3993** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3994** <dd>The maximum depth of recursion for triggers.</dd>)^ 3995** 3996** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3997** <dd>The maximum number of auxiliary worker threads that a single 3998** [prepared statement] may start.</dd>)^ 3999** </dl> 4000*/ 4001#define SQLITE_LIMIT_LENGTH 0 4002#define SQLITE_LIMIT_SQL_LENGTH 1 4003#define SQLITE_LIMIT_COLUMN 2 4004#define SQLITE_LIMIT_EXPR_DEPTH 3 4005#define SQLITE_LIMIT_COMPOUND_SELECT 4 4006#define SQLITE_LIMIT_VDBE_OP 5 4007#define SQLITE_LIMIT_FUNCTION_ARG 6 4008#define SQLITE_LIMIT_ATTACHED 7 4009#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4010#define SQLITE_LIMIT_VARIABLE_NUMBER 9 4011#define SQLITE_LIMIT_TRIGGER_DEPTH 10 4012#define SQLITE_LIMIT_WORKER_THREADS 11 4013 4014/* 4015** CAPI3REF: Prepare Flags 4016** 4017** These constants define various flags that can be passed into 4018** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4019** [sqlite3_prepare16_v3()] interfaces. 4020** 4021** New flags may be added in future releases of SQLite. 4022** 4023** <dl> 4024** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4025** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4026** that the prepared statement will be retained for a long time and 4027** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4028** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4029** be used just once or at most a few times and then destroyed using 4030** [sqlite3_finalize()] relatively soon. The current implementation acts 4031** on this hint by avoiding the use of [lookaside memory] so as not to 4032** deplete the limited store of lookaside memory. Future versions of 4033** SQLite may act on this hint differently. 4034** 4035** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4036** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4037** to be required for any prepared statement that wanted to use the 4038** [sqlite3_normalized_sql()] interface. However, the 4039** [sqlite3_normalized_sql()] interface is now available to all 4040** prepared statements, regardless of whether or not they use this 4041** flag. 4042** 4043** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4044** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4045** to return an error (error code SQLITE_ERROR) if the statement uses 4046** any virtual tables. 4047** </dl> 4048*/ 4049#define SQLITE_PREPARE_PERSISTENT 0x01 4050#define SQLITE_PREPARE_NORMALIZE 0x02 4051#define SQLITE_PREPARE_NO_VTAB 0x04 4052 4053/* 4054** CAPI3REF: Compiling An SQL Statement 4055** KEYWORDS: {SQL statement compiler} 4056** METHOD: sqlite3 4057** CONSTRUCTOR: sqlite3_stmt 4058** 4059** To execute an SQL statement, it must first be compiled into a byte-code 4060** program using one of these routines. Or, in other words, these routines 4061** are constructors for the [prepared statement] object. 4062** 4063** The preferred routine to use is [sqlite3_prepare_v2()]. The 4064** [sqlite3_prepare()] interface is legacy and should be avoided. 4065** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4066** for special purposes. 4067** 4068** The use of the UTF-8 interfaces is preferred, as SQLite currently 4069** does all parsing using UTF-8. The UTF-16 interfaces are provided 4070** as a convenience. The UTF-16 interfaces work by converting the 4071** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4072** 4073** The first argument, "db", is a [database connection] obtained from a 4074** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4075** [sqlite3_open16()]. The database connection must not have been closed. 4076** 4077** The second argument, "zSql", is the statement to be compiled, encoded 4078** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4079** and sqlite3_prepare_v3() 4080** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4081** and sqlite3_prepare16_v3() use UTF-16. 4082** 4083** ^If the nByte argument is negative, then zSql is read up to the 4084** first zero terminator. ^If nByte is positive, then it is the 4085** number of bytes read from zSql. ^If nByte is zero, then no prepared 4086** statement is generated. 4087** If the caller knows that the supplied string is nul-terminated, then 4088** there is a small performance advantage to passing an nByte parameter that 4089** is the number of bytes in the input string <i>including</i> 4090** the nul-terminator. 4091** 4092** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4093** past the end of the first SQL statement in zSql. These routines only 4094** compile the first statement in zSql, so *pzTail is left pointing to 4095** what remains uncompiled. 4096** 4097** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4098** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4099** to NULL. ^If the input text contains no SQL (if the input is an empty 4100** string or a comment) then *ppStmt is set to NULL. 4101** The calling procedure is responsible for deleting the compiled 4102** SQL statement using [sqlite3_finalize()] after it has finished with it. 4103** ppStmt may not be NULL. 4104** 4105** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4106** otherwise an [error code] is returned. 4107** 4108** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4109** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4110** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4111** are retained for backwards compatibility, but their use is discouraged. 4112** ^In the "vX" interfaces, the prepared statement 4113** that is returned (the [sqlite3_stmt] object) contains a copy of the 4114** original SQL text. This causes the [sqlite3_step()] interface to 4115** behave differently in three ways: 4116** 4117** <ol> 4118** <li> 4119** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4120** always used to do, [sqlite3_step()] will automatically recompile the SQL 4121** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4122** retries will occur before sqlite3_step() gives up and returns an error. 4123** </li> 4124** 4125** <li> 4126** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4127** [error codes] or [extended error codes]. ^The legacy behavior was that 4128** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4129** and the application would have to make a second call to [sqlite3_reset()] 4130** in order to find the underlying cause of the problem. With the "v2" prepare 4131** interfaces, the underlying reason for the error is returned immediately. 4132** </li> 4133** 4134** <li> 4135** ^If the specific value bound to a [parameter | host parameter] in the 4136** WHERE clause might influence the choice of query plan for a statement, 4137** then the statement will be automatically recompiled, as if there had been 4138** a schema change, on the first [sqlite3_step()] call following any change 4139** to the [sqlite3_bind_text | bindings] of that [parameter]. 4140** ^The specific value of a WHERE-clause [parameter] might influence the 4141** choice of query plan if the parameter is the left-hand side of a [LIKE] 4142** or [GLOB] operator or if the parameter is compared to an indexed column 4143** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4144** </li> 4145** </ol> 4146** 4147** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4148** the extra prepFlags parameter, which is a bit array consisting of zero or 4149** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4150** sqlite3_prepare_v2() interface works exactly the same as 4151** sqlite3_prepare_v3() with a zero prepFlags parameter. 4152*/ 4153int sqlite3_prepare( 4154 sqlite3 *db, /* Database handle */ 4155 const char *zSql, /* SQL statement, UTF-8 encoded */ 4156 int nByte, /* Maximum length of zSql in bytes. */ 4157 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4158 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4159); 4160int sqlite3_prepare_v2( 4161 sqlite3 *db, /* Database handle */ 4162 const char *zSql, /* SQL statement, UTF-8 encoded */ 4163 int nByte, /* Maximum length of zSql in bytes. */ 4164 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4165 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4166); 4167int sqlite3_prepare_v3( 4168 sqlite3 *db, /* Database handle */ 4169 const char *zSql, /* SQL statement, UTF-8 encoded */ 4170 int nByte, /* Maximum length of zSql in bytes. */ 4171 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4172 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4173 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4174); 4175int sqlite3_prepare16( 4176 sqlite3 *db, /* Database handle */ 4177 const void *zSql, /* SQL statement, UTF-16 encoded */ 4178 int nByte, /* Maximum length of zSql in bytes. */ 4179 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4180 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4181); 4182int sqlite3_prepare16_v2( 4183 sqlite3 *db, /* Database handle */ 4184 const void *zSql, /* SQL statement, UTF-16 encoded */ 4185 int nByte, /* Maximum length of zSql in bytes. */ 4186 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4187 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4188); 4189int sqlite3_prepare16_v3( 4190 sqlite3 *db, /* Database handle */ 4191 const void *zSql, /* SQL statement, UTF-16 encoded */ 4192 int nByte, /* Maximum length of zSql in bytes. */ 4193 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4194 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4195 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4196); 4197 4198/* 4199** CAPI3REF: Retrieving Statement SQL 4200** METHOD: sqlite3_stmt 4201** 4202** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4203** SQL text used to create [prepared statement] P if P was 4204** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4205** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4206** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4207** string containing the SQL text of prepared statement P with 4208** [bound parameters] expanded. 4209** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4210** string containing the normalized SQL text of prepared statement P. The 4211** semantics used to normalize a SQL statement are unspecified and subject 4212** to change. At a minimum, literal values will be replaced with suitable 4213** placeholders. 4214** 4215** ^(For example, if a prepared statement is created using the SQL 4216** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4217** and parameter :xyz is unbound, then sqlite3_sql() will return 4218** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4219** will return "SELECT 2345,NULL".)^ 4220** 4221** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4222** is available to hold the result, or if the result would exceed the 4223** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4224** 4225** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4226** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4227** option causes sqlite3_expanded_sql() to always return NULL. 4228** 4229** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4230** are managed by SQLite and are automatically freed when the prepared 4231** statement is finalized. 4232** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4233** is obtained from [sqlite3_malloc()] and must be freed by the application 4234** by passing it to [sqlite3_free()]. 4235** 4236** ^The sqlite3_normalized_sql() interface is only available if 4237** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4238*/ 4239const char *sqlite3_sql(sqlite3_stmt *pStmt); 4240char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4241#ifdef SQLITE_ENABLE_NORMALIZE 4242const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4243#endif 4244 4245/* 4246** CAPI3REF: Determine If An SQL Statement Writes The Database 4247** METHOD: sqlite3_stmt 4248** 4249** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4250** and only if the [prepared statement] X makes no direct changes to 4251** the content of the database file. 4252** 4253** Note that [application-defined SQL functions] or 4254** [virtual tables] might change the database indirectly as a side effect. 4255** ^(For example, if an application defines a function "eval()" that 4256** calls [sqlite3_exec()], then the following SQL statement would 4257** change the database file through side-effects: 4258** 4259** <blockquote><pre> 4260** SELECT eval('DELETE FROM t1') FROM t2; 4261** </pre></blockquote> 4262** 4263** But because the [SELECT] statement does not change the database file 4264** directly, sqlite3_stmt_readonly() would still return true.)^ 4265** 4266** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4267** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4268** since the statements themselves do not actually modify the database but 4269** rather they control the timing of when other statements modify the 4270** database. ^The [ATTACH] and [DETACH] statements also cause 4271** sqlite3_stmt_readonly() to return true since, while those statements 4272** change the configuration of a database connection, they do not make 4273** changes to the content of the database files on disk. 4274** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4275** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4276** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4277** sqlite3_stmt_readonly() returns false for those commands. 4278** 4279** ^This routine returns false if there is any possibility that the 4280** statement might change the database file. ^A false return does 4281** not guarantee that the statement will change the database file. 4282** ^For example, an UPDATE statement might have a WHERE clause that 4283** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4284** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4285** read-only no-op if the table already exists, but 4286** sqlite3_stmt_readonly() still returns false for such a statement. 4287** 4288** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4289** statement, then sqlite3_stmt_readonly(X) returns the same value as 4290** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4291*/ 4292int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4293 4294/* 4295** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4296** METHOD: sqlite3_stmt 4297** 4298** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4299** prepared statement S is an EXPLAIN statement, or 2 if the 4300** statement S is an EXPLAIN QUERY PLAN. 4301** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4302** an ordinary statement or a NULL pointer. 4303*/ 4304int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4305 4306/* 4307** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4308** METHOD: sqlite3_stmt 4309** 4310** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4311** [prepared statement] S has been stepped at least once using 4312** [sqlite3_step(S)] but has neither run to completion (returned 4313** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4314** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4315** interface returns false if S is a NULL pointer. If S is not a 4316** NULL pointer and is not a pointer to a valid [prepared statement] 4317** object, then the behavior is undefined and probably undesirable. 4318** 4319** This interface can be used in combination [sqlite3_next_stmt()] 4320** to locate all prepared statements associated with a database 4321** connection that are in need of being reset. This can be used, 4322** for example, in diagnostic routines to search for prepared 4323** statements that are holding a transaction open. 4324*/ 4325int sqlite3_stmt_busy(sqlite3_stmt*); 4326 4327/* 4328** CAPI3REF: Dynamically Typed Value Object 4329** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4330** 4331** SQLite uses the sqlite3_value object to represent all values 4332** that can be stored in a database table. SQLite uses dynamic typing 4333** for the values it stores. ^Values stored in sqlite3_value objects 4334** can be integers, floating point values, strings, BLOBs, or NULL. 4335** 4336** An sqlite3_value object may be either "protected" or "unprotected". 4337** Some interfaces require a protected sqlite3_value. Other interfaces 4338** will accept either a protected or an unprotected sqlite3_value. 4339** Every interface that accepts sqlite3_value arguments specifies 4340** whether or not it requires a protected sqlite3_value. The 4341** [sqlite3_value_dup()] interface can be used to construct a new 4342** protected sqlite3_value from an unprotected sqlite3_value. 4343** 4344** The terms "protected" and "unprotected" refer to whether or not 4345** a mutex is held. An internal mutex is held for a protected 4346** sqlite3_value object but no mutex is held for an unprotected 4347** sqlite3_value object. If SQLite is compiled to be single-threaded 4348** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4349** or if SQLite is run in one of reduced mutex modes 4350** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4351** then there is no distinction between protected and unprotected 4352** sqlite3_value objects and they can be used interchangeably. However, 4353** for maximum code portability it is recommended that applications 4354** still make the distinction between protected and unprotected 4355** sqlite3_value objects even when not strictly required. 4356** 4357** ^The sqlite3_value objects that are passed as parameters into the 4358** implementation of [application-defined SQL functions] are protected. 4359** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4360** are protected. 4361** ^The sqlite3_value object returned by 4362** [sqlite3_column_value()] is unprotected. 4363** Unprotected sqlite3_value objects may only be used as arguments 4364** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4365** [sqlite3_value_dup()]. 4366** The [sqlite3_value_blob | sqlite3_value_type()] family of 4367** interfaces require protected sqlite3_value objects. 4368*/ 4369typedef struct sqlite3_value sqlite3_value; 4370 4371/* 4372** CAPI3REF: SQL Function Context Object 4373** 4374** The context in which an SQL function executes is stored in an 4375** sqlite3_context object. ^A pointer to an sqlite3_context object 4376** is always first parameter to [application-defined SQL functions]. 4377** The application-defined SQL function implementation will pass this 4378** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4379** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4380** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4381** and/or [sqlite3_set_auxdata()]. 4382*/ 4383typedef struct sqlite3_context sqlite3_context; 4384 4385/* 4386** CAPI3REF: Binding Values To Prepared Statements 4387** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4388** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4389** METHOD: sqlite3_stmt 4390** 4391** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4392** literals may be replaced by a [parameter] that matches one of following 4393** templates: 4394** 4395** <ul> 4396** <li> ? 4397** <li> ?NNN 4398** <li> :VVV 4399** <li> @VVV 4400** <li> $VVV 4401** </ul> 4402** 4403** In the templates above, NNN represents an integer literal, 4404** and VVV represents an alphanumeric identifier.)^ ^The values of these 4405** parameters (also called "host parameter names" or "SQL parameters") 4406** can be set using the sqlite3_bind_*() routines defined here. 4407** 4408** ^The first argument to the sqlite3_bind_*() routines is always 4409** a pointer to the [sqlite3_stmt] object returned from 4410** [sqlite3_prepare_v2()] or its variants. 4411** 4412** ^The second argument is the index of the SQL parameter to be set. 4413** ^The leftmost SQL parameter has an index of 1. ^When the same named 4414** SQL parameter is used more than once, second and subsequent 4415** occurrences have the same index as the first occurrence. 4416** ^The index for named parameters can be looked up using the 4417** [sqlite3_bind_parameter_index()] API if desired. ^The index 4418** for "?NNN" parameters is the value of NNN. 4419** ^The NNN value must be between 1 and the [sqlite3_limit()] 4420** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4421** 4422** ^The third argument is the value to bind to the parameter. 4423** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4424** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4425** is ignored and the end result is the same as sqlite3_bind_null(). 4426** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4427** it should be a pointer to well-formed UTF8 text. 4428** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4429** it should be a pointer to well-formed UTF16 text. 4430** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4431** it should be a pointer to a well-formed unicode string that is 4432** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4433** otherwise. 4434** 4435** [[byte-order determination rules]] ^The byte-order of 4436** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4437** found in first character, which is removed, or in the absence of a BOM 4438** the byte order is the native byte order of the host 4439** machine for sqlite3_bind_text16() or the byte order specified in 4440** the 6th parameter for sqlite3_bind_text64().)^ 4441** ^If UTF16 input text contains invalid unicode 4442** characters, then SQLite might change those invalid characters 4443** into the unicode replacement character: U+FFFD. 4444** 4445** ^(In those routines that have a fourth argument, its value is the 4446** number of bytes in the parameter. To be clear: the value is the 4447** number of <u>bytes</u> in the value, not the number of characters.)^ 4448** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4449** is negative, then the length of the string is 4450** the number of bytes up to the first zero terminator. 4451** If the fourth parameter to sqlite3_bind_blob() is negative, then 4452** the behavior is undefined. 4453** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4454** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4455** that parameter must be the byte offset 4456** where the NUL terminator would occur assuming the string were NUL 4457** terminated. If any NUL characters occurs at byte offsets less than 4458** the value of the fourth parameter then the resulting string value will 4459** contain embedded NULs. The result of expressions involving strings 4460** with embedded NULs is undefined. 4461** 4462** ^The fifth argument to the BLOB and string binding interfaces controls 4463** or indicates the lifetime of the object referenced by the third parameter. 4464** These three options exist: 4465** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4466** with it may be passed. ^It is called to dispose of the BLOB or string even 4467** if the call to the bind API fails, except the destructor is not called if 4468** the third parameter is a NULL pointer or the fourth parameter is negative. 4469** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that 4470** the application remains responsible for disposing of the object. ^In this 4471** case, the object and the provided pointer to it must remain valid until 4472** either the prepared statement is finalized or the same SQL parameter is 4473** bound to something else, whichever occurs sooner. 4474** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4475** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4476** object and pointer to it must remain valid until then. ^SQLite will then 4477** manage the lifetime of its private copy. 4478** 4479** ^The sixth argument to sqlite3_bind_text64() must be one of 4480** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4481** to specify the encoding of the text in the third parameter. If 4482** the sixth argument to sqlite3_bind_text64() is not one of the 4483** allowed values shown above, or if the text encoding is different 4484** from the encoding specified by the sixth parameter, then the behavior 4485** is undefined. 4486** 4487** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4488** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4489** (just an integer to hold its size) while it is being processed. 4490** Zeroblobs are intended to serve as placeholders for BLOBs whose 4491** content is later written using 4492** [sqlite3_blob_open | incremental BLOB I/O] routines. 4493** ^A negative value for the zeroblob results in a zero-length BLOB. 4494** 4495** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4496** [prepared statement] S to have an SQL value of NULL, but to also be 4497** associated with the pointer P of type T. ^D is either a NULL pointer or 4498** a pointer to a destructor function for P. ^SQLite will invoke the 4499** destructor D with a single argument of P when it is finished using 4500** P. The T parameter should be a static string, preferably a string 4501** literal. The sqlite3_bind_pointer() routine is part of the 4502** [pointer passing interface] added for SQLite 3.20.0. 4503** 4504** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4505** for the [prepared statement] or with a prepared statement for which 4506** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4507** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4508** routine is passed a [prepared statement] that has been finalized, the 4509** result is undefined and probably harmful. 4510** 4511** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4512** ^Unbound parameters are interpreted as NULL. 4513** 4514** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4515** [error code] if anything goes wrong. 4516** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4517** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4518** [SQLITE_MAX_LENGTH]. 4519** ^[SQLITE_RANGE] is returned if the parameter 4520** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4521** 4522** See also: [sqlite3_bind_parameter_count()], 4523** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4524*/ 4525int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4526int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4527 void(*)(void*)); 4528int sqlite3_bind_double(sqlite3_stmt*, int, double); 4529int sqlite3_bind_int(sqlite3_stmt*, int, int); 4530int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4531int sqlite3_bind_null(sqlite3_stmt*, int); 4532int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4533int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4534int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4535 void(*)(void*), unsigned char encoding); 4536int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4537int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4538int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4539int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4540 4541/* 4542** CAPI3REF: Number Of SQL Parameters 4543** METHOD: sqlite3_stmt 4544** 4545** ^This routine can be used to find the number of [SQL parameters] 4546** in a [prepared statement]. SQL parameters are tokens of the 4547** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4548** placeholders for values that are [sqlite3_bind_blob | bound] 4549** to the parameters at a later time. 4550** 4551** ^(This routine actually returns the index of the largest (rightmost) 4552** parameter. For all forms except ?NNN, this will correspond to the 4553** number of unique parameters. If parameters of the ?NNN form are used, 4554** there may be gaps in the list.)^ 4555** 4556** See also: [sqlite3_bind_blob|sqlite3_bind()], 4557** [sqlite3_bind_parameter_name()], and 4558** [sqlite3_bind_parameter_index()]. 4559*/ 4560int sqlite3_bind_parameter_count(sqlite3_stmt*); 4561 4562/* 4563** CAPI3REF: Name Of A Host Parameter 4564** METHOD: sqlite3_stmt 4565** 4566** ^The sqlite3_bind_parameter_name(P,N) interface returns 4567** the name of the N-th [SQL parameter] in the [prepared statement] P. 4568** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4569** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4570** respectively. 4571** In other words, the initial ":" or "$" or "@" or "?" 4572** is included as part of the name.)^ 4573** ^Parameters of the form "?" without a following integer have no name 4574** and are referred to as "nameless" or "anonymous parameters". 4575** 4576** ^The first host parameter has an index of 1, not 0. 4577** 4578** ^If the value N is out of range or if the N-th parameter is 4579** nameless, then NULL is returned. ^The returned string is 4580** always in UTF-8 encoding even if the named parameter was 4581** originally specified as UTF-16 in [sqlite3_prepare16()], 4582** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4583** 4584** See also: [sqlite3_bind_blob|sqlite3_bind()], 4585** [sqlite3_bind_parameter_count()], and 4586** [sqlite3_bind_parameter_index()]. 4587*/ 4588const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4589 4590/* 4591** CAPI3REF: Index Of A Parameter With A Given Name 4592** METHOD: sqlite3_stmt 4593** 4594** ^Return the index of an SQL parameter given its name. ^The 4595** index value returned is suitable for use as the second 4596** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4597** is returned if no matching parameter is found. ^The parameter 4598** name must be given in UTF-8 even if the original statement 4599** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4600** [sqlite3_prepare16_v3()]. 4601** 4602** See also: [sqlite3_bind_blob|sqlite3_bind()], 4603** [sqlite3_bind_parameter_count()], and 4604** [sqlite3_bind_parameter_name()]. 4605*/ 4606int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4607 4608/* 4609** CAPI3REF: Reset All Bindings On A Prepared Statement 4610** METHOD: sqlite3_stmt 4611** 4612** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4613** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4614** ^Use this routine to reset all host parameters to NULL. 4615*/ 4616int sqlite3_clear_bindings(sqlite3_stmt*); 4617 4618/* 4619** CAPI3REF: Number Of Columns In A Result Set 4620** METHOD: sqlite3_stmt 4621** 4622** ^Return the number of columns in the result set returned by the 4623** [prepared statement]. ^If this routine returns 0, that means the 4624** [prepared statement] returns no data (for example an [UPDATE]). 4625** ^However, just because this routine returns a positive number does not 4626** mean that one or more rows of data will be returned. ^A SELECT statement 4627** will always have a positive sqlite3_column_count() but depending on the 4628** WHERE clause constraints and the table content, it might return no rows. 4629** 4630** See also: [sqlite3_data_count()] 4631*/ 4632int sqlite3_column_count(sqlite3_stmt *pStmt); 4633 4634/* 4635** CAPI3REF: Column Names In A Result Set 4636** METHOD: sqlite3_stmt 4637** 4638** ^These routines return the name assigned to a particular column 4639** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4640** interface returns a pointer to a zero-terminated UTF-8 string 4641** and sqlite3_column_name16() returns a pointer to a zero-terminated 4642** UTF-16 string. ^The first parameter is the [prepared statement] 4643** that implements the [SELECT] statement. ^The second parameter is the 4644** column number. ^The leftmost column is number 0. 4645** 4646** ^The returned string pointer is valid until either the [prepared statement] 4647** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4648** reprepared by the first call to [sqlite3_step()] for a particular run 4649** or until the next call to 4650** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4651** 4652** ^If sqlite3_malloc() fails during the processing of either routine 4653** (for example during a conversion from UTF-8 to UTF-16) then a 4654** NULL pointer is returned. 4655** 4656** ^The name of a result column is the value of the "AS" clause for 4657** that column, if there is an AS clause. If there is no AS clause 4658** then the name of the column is unspecified and may change from 4659** one release of SQLite to the next. 4660*/ 4661const char *sqlite3_column_name(sqlite3_stmt*, int N); 4662const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4663 4664/* 4665** CAPI3REF: Source Of Data In A Query Result 4666** METHOD: sqlite3_stmt 4667** 4668** ^These routines provide a means to determine the database, table, and 4669** table column that is the origin of a particular result column in 4670** [SELECT] statement. 4671** ^The name of the database or table or column can be returned as 4672** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4673** the database name, the _table_ routines return the table name, and 4674** the origin_ routines return the column name. 4675** ^The returned string is valid until the [prepared statement] is destroyed 4676** using [sqlite3_finalize()] or until the statement is automatically 4677** reprepared by the first call to [sqlite3_step()] for a particular run 4678** or until the same information is requested 4679** again in a different encoding. 4680** 4681** ^The names returned are the original un-aliased names of the 4682** database, table, and column. 4683** 4684** ^The first argument to these interfaces is a [prepared statement]. 4685** ^These functions return information about the Nth result column returned by 4686** the statement, where N is the second function argument. 4687** ^The left-most column is column 0 for these routines. 4688** 4689** ^If the Nth column returned by the statement is an expression or 4690** subquery and is not a column value, then all of these functions return 4691** NULL. ^These routines might also return NULL if a memory allocation error 4692** occurs. ^Otherwise, they return the name of the attached database, table, 4693** or column that query result column was extracted from. 4694** 4695** ^As with all other SQLite APIs, those whose names end with "16" return 4696** UTF-16 encoded strings and the other functions return UTF-8. 4697** 4698** ^These APIs are only available if the library was compiled with the 4699** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4700** 4701** If two or more threads call one or more 4702** [sqlite3_column_database_name | column metadata interfaces] 4703** for the same [prepared statement] and result column 4704** at the same time then the results are undefined. 4705*/ 4706const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4707const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4708const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4709const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4710const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4711const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4712 4713/* 4714** CAPI3REF: Declared Datatype Of A Query Result 4715** METHOD: sqlite3_stmt 4716** 4717** ^(The first parameter is a [prepared statement]. 4718** If this statement is a [SELECT] statement and the Nth column of the 4719** returned result set of that [SELECT] is a table column (not an 4720** expression or subquery) then the declared type of the table 4721** column is returned.)^ ^If the Nth column of the result set is an 4722** expression or subquery, then a NULL pointer is returned. 4723** ^The returned string is always UTF-8 encoded. 4724** 4725** ^(For example, given the database schema: 4726** 4727** CREATE TABLE t1(c1 VARIANT); 4728** 4729** and the following statement to be compiled: 4730** 4731** SELECT c1 + 1, c1 FROM t1; 4732** 4733** this routine would return the string "VARIANT" for the second result 4734** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4735** 4736** ^SQLite uses dynamic run-time typing. ^So just because a column 4737** is declared to contain a particular type does not mean that the 4738** data stored in that column is of the declared type. SQLite is 4739** strongly typed, but the typing is dynamic not static. ^Type 4740** is associated with individual values, not with the containers 4741** used to hold those values. 4742*/ 4743const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4744const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4745 4746/* 4747** CAPI3REF: Evaluate An SQL Statement 4748** METHOD: sqlite3_stmt 4749** 4750** After a [prepared statement] has been prepared using any of 4751** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4752** or [sqlite3_prepare16_v3()] or one of the legacy 4753** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4754** must be called one or more times to evaluate the statement. 4755** 4756** The details of the behavior of the sqlite3_step() interface depend 4757** on whether the statement was prepared using the newer "vX" interfaces 4758** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4759** [sqlite3_prepare16_v2()] or the older legacy 4760** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4761** new "vX" interface is recommended for new applications but the legacy 4762** interface will continue to be supported. 4763** 4764** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4765** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4766** ^With the "v2" interface, any of the other [result codes] or 4767** [extended result codes] might be returned as well. 4768** 4769** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4770** database locks it needs to do its job. ^If the statement is a [COMMIT] 4771** or occurs outside of an explicit transaction, then you can retry the 4772** statement. If the statement is not a [COMMIT] and occurs within an 4773** explicit transaction then you should rollback the transaction before 4774** continuing. 4775** 4776** ^[SQLITE_DONE] means that the statement has finished executing 4777** successfully. sqlite3_step() should not be called again on this virtual 4778** machine without first calling [sqlite3_reset()] to reset the virtual 4779** machine back to its initial state. 4780** 4781** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4782** is returned each time a new row of data is ready for processing by the 4783** caller. The values may be accessed using the [column access functions]. 4784** sqlite3_step() is called again to retrieve the next row of data. 4785** 4786** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4787** violation) has occurred. sqlite3_step() should not be called again on 4788** the VM. More information may be found by calling [sqlite3_errmsg()]. 4789** ^With the legacy interface, a more specific error code (for example, 4790** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4791** can be obtained by calling [sqlite3_reset()] on the 4792** [prepared statement]. ^In the "v2" interface, 4793** the more specific error code is returned directly by sqlite3_step(). 4794** 4795** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4796** Perhaps it was called on a [prepared statement] that has 4797** already been [sqlite3_finalize | finalized] or on one that had 4798** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4799** be the case that the same database connection is being used by two or 4800** more threads at the same moment in time. 4801** 4802** For all versions of SQLite up to and including 3.6.23.1, a call to 4803** [sqlite3_reset()] was required after sqlite3_step() returned anything 4804** other than [SQLITE_ROW] before any subsequent invocation of 4805** sqlite3_step(). Failure to reset the prepared statement using 4806** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4807** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4808** sqlite3_step() began 4809** calling [sqlite3_reset()] automatically in this circumstance rather 4810** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4811** break because any application that ever receives an SQLITE_MISUSE error 4812** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4813** can be used to restore the legacy behavior. 4814** 4815** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4816** API always returns a generic error code, [SQLITE_ERROR], following any 4817** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4818** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4819** specific [error codes] that better describes the error. 4820** We admit that this is a goofy design. The problem has been fixed 4821** with the "v2" interface. If you prepare all of your SQL statements 4822** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4823** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4824** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4825** then the more specific [error codes] are returned directly 4826** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4827*/ 4828int sqlite3_step(sqlite3_stmt*); 4829 4830/* 4831** CAPI3REF: Number of columns in a result set 4832** METHOD: sqlite3_stmt 4833** 4834** ^The sqlite3_data_count(P) interface returns the number of columns in the 4835** current row of the result set of [prepared statement] P. 4836** ^If prepared statement P does not have results ready to return 4837** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4838** interfaces) then sqlite3_data_count(P) returns 0. 4839** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4840** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4841** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4842** will return non-zero if previous call to [sqlite3_step](P) returned 4843** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4844** where it always returns zero since each step of that multi-step 4845** pragma returns 0 columns of data. 4846** 4847** See also: [sqlite3_column_count()] 4848*/ 4849int sqlite3_data_count(sqlite3_stmt *pStmt); 4850 4851/* 4852** CAPI3REF: Fundamental Datatypes 4853** KEYWORDS: SQLITE_TEXT 4854** 4855** ^(Every value in SQLite has one of five fundamental datatypes: 4856** 4857** <ul> 4858** <li> 64-bit signed integer 4859** <li> 64-bit IEEE floating point number 4860** <li> string 4861** <li> BLOB 4862** <li> NULL 4863** </ul>)^ 4864** 4865** These constants are codes for each of those types. 4866** 4867** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4868** for a completely different meaning. Software that links against both 4869** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4870** SQLITE_TEXT. 4871*/ 4872#define SQLITE_INTEGER 1 4873#define SQLITE_FLOAT 2 4874#define SQLITE_BLOB 4 4875#define SQLITE_NULL 5 4876#ifdef SQLITE_TEXT 4877# undef SQLITE_TEXT 4878#else 4879# define SQLITE_TEXT 3 4880#endif 4881#define SQLITE3_TEXT 3 4882 4883/* 4884** CAPI3REF: Result Values From A Query 4885** KEYWORDS: {column access functions} 4886** METHOD: sqlite3_stmt 4887** 4888** <b>Summary:</b> 4889** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4890** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4891** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4892** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4893** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4894** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4895** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4896** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4897** [sqlite3_value|unprotected sqlite3_value] object. 4898** <tr><td> <td> <td> 4899** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4900** or a UTF-8 TEXT result in bytes 4901** <tr><td><b>sqlite3_column_bytes16 </b> 4902** <td>→ <td>Size of UTF-16 4903** TEXT in bytes 4904** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4905** datatype of the result 4906** </table></blockquote> 4907** 4908** <b>Details:</b> 4909** 4910** ^These routines return information about a single column of the current 4911** result row of a query. ^In every case the first argument is a pointer 4912** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4913** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4914** and the second argument is the index of the column for which information 4915** should be returned. ^The leftmost column of the result set has the index 0. 4916** ^The number of columns in the result can be determined using 4917** [sqlite3_column_count()]. 4918** 4919** If the SQL statement does not currently point to a valid row, or if the 4920** column index is out of range, the result is undefined. 4921** These routines may only be called when the most recent call to 4922** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4923** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4924** If any of these routines are called after [sqlite3_reset()] or 4925** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4926** something other than [SQLITE_ROW], the results are undefined. 4927** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4928** are called from a different thread while any of these routines 4929** are pending, then the results are undefined. 4930** 4931** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4932** each return the value of a result column in a specific data format. If 4933** the result column is not initially in the requested format (for example, 4934** if the query returns an integer but the sqlite3_column_text() interface 4935** is used to extract the value) then an automatic type conversion is performed. 4936** 4937** ^The sqlite3_column_type() routine returns the 4938** [SQLITE_INTEGER | datatype code] for the initial data type 4939** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4940** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4941** The return value of sqlite3_column_type() can be used to decide which 4942** of the first six interface should be used to extract the column value. 4943** The value returned by sqlite3_column_type() is only meaningful if no 4944** automatic type conversions have occurred for the value in question. 4945** After a type conversion, the result of calling sqlite3_column_type() 4946** is undefined, though harmless. Future 4947** versions of SQLite may change the behavior of sqlite3_column_type() 4948** following a type conversion. 4949** 4950** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4951** or sqlite3_column_bytes16() interfaces can be used to determine the size 4952** of that BLOB or string. 4953** 4954** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4955** routine returns the number of bytes in that BLOB or string. 4956** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4957** the string to UTF-8 and then returns the number of bytes. 4958** ^If the result is a numeric value then sqlite3_column_bytes() uses 4959** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4960** the number of bytes in that string. 4961** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4962** 4963** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4964** routine returns the number of bytes in that BLOB or string. 4965** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4966** the string to UTF-16 and then returns the number of bytes. 4967** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4968** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4969** the number of bytes in that string. 4970** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4971** 4972** ^The values returned by [sqlite3_column_bytes()] and 4973** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4974** of the string. ^For clarity: the values returned by 4975** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4976** bytes in the string, not the number of characters. 4977** 4978** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4979** even empty strings, are always zero-terminated. ^The return 4980** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4981** 4982** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4983** [unprotected sqlite3_value] object. In a multithreaded environment, 4984** an unprotected sqlite3_value object may only be used safely with 4985** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4986** If the [unprotected sqlite3_value] object returned by 4987** [sqlite3_column_value()] is used in any other way, including calls 4988** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4989** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4990** Hence, the sqlite3_column_value() interface 4991** is normally only useful within the implementation of 4992** [application-defined SQL functions] or [virtual tables], not within 4993** top-level application code. 4994** 4995** The these routines may attempt to convert the datatype of the result. 4996** ^For example, if the internal representation is FLOAT and a text result 4997** is requested, [sqlite3_snprintf()] is used internally to perform the 4998** conversion automatically. ^(The following table details the conversions 4999** that are applied: 5000** 5001** <blockquote> 5002** <table border="1"> 5003** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5004** 5005** <tr><td> NULL <td> INTEGER <td> Result is 0 5006** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5007** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5008** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5009** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5010** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5011** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5012** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5013** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5014** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5015** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5016** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5017** <tr><td> TEXT <td> BLOB <td> No change 5018** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5019** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5020** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 5021** </table> 5022** </blockquote>)^ 5023** 5024** Note that when type conversions occur, pointers returned by prior 5025** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5026** sqlite3_column_text16() may be invalidated. 5027** Type conversions and pointer invalidations might occur 5028** in the following cases: 5029** 5030** <ul> 5031** <li> The initial content is a BLOB and sqlite3_column_text() or 5032** sqlite3_column_text16() is called. A zero-terminator might 5033** need to be added to the string.</li> 5034** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5035** sqlite3_column_text16() is called. The content must be converted 5036** to UTF-16.</li> 5037** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5038** sqlite3_column_text() is called. The content must be converted 5039** to UTF-8.</li> 5040** </ul> 5041** 5042** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5043** not invalidate a prior pointer, though of course the content of the buffer 5044** that the prior pointer references will have been modified. Other kinds 5045** of conversion are done in place when it is possible, but sometimes they 5046** are not possible and in those cases prior pointers are invalidated. 5047** 5048** The safest policy is to invoke these routines 5049** in one of the following ways: 5050** 5051** <ul> 5052** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5053** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5054** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5055** </ul> 5056** 5057** In other words, you should call sqlite3_column_text(), 5058** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5059** into the desired format, then invoke sqlite3_column_bytes() or 5060** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5061** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5062** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5063** with calls to sqlite3_column_bytes(). 5064** 5065** ^The pointers returned are valid until a type conversion occurs as 5066** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5067** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5068** and BLOBs is freed automatically. Do not pass the pointers returned 5069** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5070** [sqlite3_free()]. 5071** 5072** As long as the input parameters are correct, these routines will only 5073** fail if an out-of-memory error occurs during a format conversion. 5074** Only the following subset of interfaces are subject to out-of-memory 5075** errors: 5076** 5077** <ul> 5078** <li> sqlite3_column_blob() 5079** <li> sqlite3_column_text() 5080** <li> sqlite3_column_text16() 5081** <li> sqlite3_column_bytes() 5082** <li> sqlite3_column_bytes16() 5083** </ul> 5084** 5085** If an out-of-memory error occurs, then the return value from these 5086** routines is the same as if the column had contained an SQL NULL value. 5087** Valid SQL NULL returns can be distinguished from out-of-memory errors 5088** by invoking the [sqlite3_errcode()] immediately after the suspect 5089** return value is obtained and before any 5090** other SQLite interface is called on the same [database connection]. 5091*/ 5092const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5093double sqlite3_column_double(sqlite3_stmt*, int iCol); 5094int sqlite3_column_int(sqlite3_stmt*, int iCol); 5095sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5096const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5097const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5098sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5099int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5100int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5101int sqlite3_column_type(sqlite3_stmt*, int iCol); 5102 5103/* 5104** CAPI3REF: Destroy A Prepared Statement Object 5105** DESTRUCTOR: sqlite3_stmt 5106** 5107** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5108** ^If the most recent evaluation of the statement encountered no errors 5109** or if the statement is never been evaluated, then sqlite3_finalize() returns 5110** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5111** sqlite3_finalize(S) returns the appropriate [error code] or 5112** [extended error code]. 5113** 5114** ^The sqlite3_finalize(S) routine can be called at any point during 5115** the life cycle of [prepared statement] S: 5116** before statement S is ever evaluated, after 5117** one or more calls to [sqlite3_reset()], or after any call 5118** to [sqlite3_step()] regardless of whether or not the statement has 5119** completed execution. 5120** 5121** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5122** 5123** The application must finalize every [prepared statement] in order to avoid 5124** resource leaks. It is a grievous error for the application to try to use 5125** a prepared statement after it has been finalized. Any use of a prepared 5126** statement after it has been finalized can result in undefined and 5127** undesirable behavior such as segfaults and heap corruption. 5128*/ 5129int sqlite3_finalize(sqlite3_stmt *pStmt); 5130 5131/* 5132** CAPI3REF: Reset A Prepared Statement Object 5133** METHOD: sqlite3_stmt 5134** 5135** The sqlite3_reset() function is called to reset a [prepared statement] 5136** object back to its initial state, ready to be re-executed. 5137** ^Any SQL statement variables that had values bound to them using 5138** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5139** Use [sqlite3_clear_bindings()] to reset the bindings. 5140** 5141** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5142** back to the beginning of its program. 5143** 5144** ^If the most recent call to [sqlite3_step(S)] for the 5145** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5146** or if [sqlite3_step(S)] has never before been called on S, 5147** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5148** 5149** ^If the most recent call to [sqlite3_step(S)] for the 5150** [prepared statement] S indicated an error, then 5151** [sqlite3_reset(S)] returns an appropriate [error code]. 5152** 5153** ^The [sqlite3_reset(S)] interface does not change the values 5154** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5155*/ 5156int sqlite3_reset(sqlite3_stmt *pStmt); 5157 5158/* 5159** CAPI3REF: Create Or Redefine SQL Functions 5160** KEYWORDS: {function creation routines} 5161** METHOD: sqlite3 5162** 5163** ^These functions (collectively known as "function creation routines") 5164** are used to add SQL functions or aggregates or to redefine the behavior 5165** of existing SQL functions or aggregates. The only differences between 5166** the three "sqlite3_create_function*" routines are the text encoding 5167** expected for the second parameter (the name of the function being 5168** created) and the presence or absence of a destructor callback for 5169** the application data pointer. Function sqlite3_create_window_function() 5170** is similar, but allows the user to supply the extra callback functions 5171** needed by [aggregate window functions]. 5172** 5173** ^The first parameter is the [database connection] to which the SQL 5174** function is to be added. ^If an application uses more than one database 5175** connection then application-defined SQL functions must be added 5176** to each database connection separately. 5177** 5178** ^The second parameter is the name of the SQL function to be created or 5179** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5180** representation, exclusive of the zero-terminator. ^Note that the name 5181** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5182** ^Any attempt to create a function with a longer name 5183** will result in [SQLITE_MISUSE] being returned. 5184** 5185** ^The third parameter (nArg) 5186** is the number of arguments that the SQL function or 5187** aggregate takes. ^If this parameter is -1, then the SQL function or 5188** aggregate may take any number of arguments between 0 and the limit 5189** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5190** parameter is less than -1 or greater than 127 then the behavior is 5191** undefined. 5192** 5193** ^The fourth parameter, eTextRep, specifies what 5194** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5195** its parameters. The application should set this parameter to 5196** [SQLITE_UTF16LE] if the function implementation invokes 5197** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5198** implementation invokes [sqlite3_value_text16be()] on an input, or 5199** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5200** otherwise. ^The same SQL function may be registered multiple times using 5201** different preferred text encodings, with different implementations for 5202** each encoding. 5203** ^When multiple implementations of the same function are available, SQLite 5204** will pick the one that involves the least amount of data conversion. 5205** 5206** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5207** to signal that the function will always return the same result given 5208** the same inputs within a single SQL statement. Most SQL functions are 5209** deterministic. The built-in [random()] SQL function is an example of a 5210** function that is not deterministic. The SQLite query planner is able to 5211** perform additional optimizations on deterministic functions, so use 5212** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5213** 5214** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5215** flag, which if present prevents the function from being invoked from 5216** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5217** index expressions, or the WHERE clause of partial indexes. 5218** 5219** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5220** all application-defined SQL functions that do not need to be 5221** used inside of triggers, view, CHECK constraints, or other elements of 5222** the database schema. This flags is especially recommended for SQL 5223** functions that have side effects or reveal internal application state. 5224** Without this flag, an attacker might be able to modify the schema of 5225** a database file to include invocations of the function with parameters 5226** chosen by the attacker, which the application will then execute when 5227** the database file is opened and read. 5228** 5229** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5230** function can gain access to this pointer using [sqlite3_user_data()].)^ 5231** 5232** ^The sixth, seventh and eighth parameters passed to the three 5233** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5234** pointers to C-language functions that implement the SQL function or 5235** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5236** callback only; NULL pointers must be passed as the xStep and xFinal 5237** parameters. ^An aggregate SQL function requires an implementation of xStep 5238** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5239** SQL function or aggregate, pass NULL pointers for all three function 5240** callbacks. 5241** 5242** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5243** and xInverse) passed to sqlite3_create_window_function are pointers to 5244** C-language callbacks that implement the new function. xStep and xFinal 5245** must both be non-NULL. xValue and xInverse may either both be NULL, in 5246** which case a regular aggregate function is created, or must both be 5247** non-NULL, in which case the new function may be used as either an aggregate 5248** or aggregate window function. More details regarding the implementation 5249** of aggregate window functions are 5250** [user-defined window functions|available here]. 5251** 5252** ^(If the final parameter to sqlite3_create_function_v2() or 5253** sqlite3_create_window_function() is not NULL, then it is destructor for 5254** the application data pointer. The destructor is invoked when the function 5255** is deleted, either by being overloaded or when the database connection 5256** closes.)^ ^The destructor is also invoked if the call to 5257** sqlite3_create_function_v2() fails. ^When the destructor callback is 5258** invoked, it is passed a single argument which is a copy of the application 5259** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5260** 5261** ^It is permitted to register multiple implementations of the same 5262** functions with the same name but with either differing numbers of 5263** arguments or differing preferred text encodings. ^SQLite will use 5264** the implementation that most closely matches the way in which the 5265** SQL function is used. ^A function implementation with a non-negative 5266** nArg parameter is a better match than a function implementation with 5267** a negative nArg. ^A function where the preferred text encoding 5268** matches the database encoding is a better 5269** match than a function where the encoding is different. 5270** ^A function where the encoding difference is between UTF16le and UTF16be 5271** is a closer match than a function where the encoding difference is 5272** between UTF8 and UTF16. 5273** 5274** ^Built-in functions may be overloaded by new application-defined functions. 5275** 5276** ^An application-defined function is permitted to call other 5277** SQLite interfaces. However, such calls must not 5278** close the database connection nor finalize or reset the prepared 5279** statement in which the function is running. 5280*/ 5281int sqlite3_create_function( 5282 sqlite3 *db, 5283 const char *zFunctionName, 5284 int nArg, 5285 int eTextRep, 5286 void *pApp, 5287 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5288 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5289 void (*xFinal)(sqlite3_context*) 5290); 5291int sqlite3_create_function16( 5292 sqlite3 *db, 5293 const void *zFunctionName, 5294 int nArg, 5295 int eTextRep, 5296 void *pApp, 5297 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5298 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5299 void (*xFinal)(sqlite3_context*) 5300); 5301int sqlite3_create_function_v2( 5302 sqlite3 *db, 5303 const char *zFunctionName, 5304 int nArg, 5305 int eTextRep, 5306 void *pApp, 5307 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5308 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5309 void (*xFinal)(sqlite3_context*), 5310 void(*xDestroy)(void*) 5311); 5312int sqlite3_create_window_function( 5313 sqlite3 *db, 5314 const char *zFunctionName, 5315 int nArg, 5316 int eTextRep, 5317 void *pApp, 5318 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5319 void (*xFinal)(sqlite3_context*), 5320 void (*xValue)(sqlite3_context*), 5321 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5322 void(*xDestroy)(void*) 5323); 5324 5325/* 5326** CAPI3REF: Text Encodings 5327** 5328** These constant define integer codes that represent the various 5329** text encodings supported by SQLite. 5330*/ 5331#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5332#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5333#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5334#define SQLITE_UTF16 4 /* Use native byte order */ 5335#define SQLITE_ANY 5 /* Deprecated */ 5336#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5337 5338/* 5339** CAPI3REF: Function Flags 5340** 5341** These constants may be ORed together with the 5342** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5343** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5344** [sqlite3_create_function_v2()]. 5345** 5346** <dl> 5347** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5348** The SQLITE_DETERMINISTIC flag means that the new function always gives 5349** the same output when the input parameters are the same. 5350** The [abs|abs() function] is deterministic, for example, but 5351** [randomblob|randomblob()] is not. Functions must 5352** be deterministic in order to be used in certain contexts such as 5353** with the WHERE clause of [partial indexes] or in [generated columns]. 5354** SQLite might also optimize deterministic functions by factoring them 5355** out of inner loops. 5356** </dd> 5357** 5358** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5359** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5360** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5361** schema structures such as [CHECK constraints], [DEFAULT clauses], 5362** [expression indexes], [partial indexes], or [generated columns]. 5363** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5364** for all [application-defined SQL functions], and especially for functions 5365** that have side-effects or that could potentially leak sensitive 5366** information. 5367** </dd> 5368** 5369** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5370** The SQLITE_INNOCUOUS flag means that the function is unlikely 5371** to cause problems even if misused. An innocuous function should have 5372** no side effects and should not depend on any values other than its 5373** input parameters. The [abs|abs() function] is an example of an 5374** innocuous function. 5375** The [load_extension() SQL function] is not innocuous because of its 5376** side effects. 5377** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5378** exactly the same. The [random|random() function] is an example of a 5379** function that is innocuous but not deterministic. 5380** <p>Some heightened security settings 5381** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5382** disable the use of SQL functions inside views and triggers and in 5383** schema structures such as [CHECK constraints], [DEFAULT clauses], 5384** [expression indexes], [partial indexes], and [generated columns] unless 5385** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5386** are innocuous. Developers are advised to avoid using the 5387** SQLITE_INNOCUOUS flag for application-defined functions unless the 5388** function has been carefully audited and found to be free of potentially 5389** security-adverse side-effects and information-leaks. 5390** </dd> 5391** 5392** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5393** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5394** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5395** Specifying this flag makes no difference for scalar or aggregate user 5396** functions. However, if it is not specified for a user-defined window 5397** function, then any sub-types belonging to arguments passed to the window 5398** function may be discarded before the window function is called (i.e. 5399** sqlite3_value_subtype() will always return 0). 5400** </dd> 5401** </dl> 5402*/ 5403#define SQLITE_DETERMINISTIC 0x000000800 5404#define SQLITE_DIRECTONLY 0x000080000 5405#define SQLITE_SUBTYPE 0x000100000 5406#define SQLITE_INNOCUOUS 0x000200000 5407 5408/* 5409** CAPI3REF: Deprecated Functions 5410** DEPRECATED 5411** 5412** These functions are [deprecated]. In order to maintain 5413** backwards compatibility with older code, these functions continue 5414** to be supported. However, new applications should avoid 5415** the use of these functions. To encourage programmers to avoid 5416** these functions, we will not explain what they do. 5417*/ 5418#ifndef SQLITE_OMIT_DEPRECATED 5419SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5420SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5421SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5422SQLITE_DEPRECATED int sqlite3_global_recover(void); 5423SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5424SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5425 void*,sqlite3_int64); 5426#endif 5427 5428/* 5429** CAPI3REF: Obtaining SQL Values 5430** METHOD: sqlite3_value 5431** 5432** <b>Summary:</b> 5433** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5434** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5435** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5436** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5437** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5438** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5439** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5440** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5441** the native byteorder 5442** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5443** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5444** <tr><td> <td> <td> 5445** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5446** or a UTF-8 TEXT in bytes 5447** <tr><td><b>sqlite3_value_bytes16 </b> 5448** <td>→ <td>Size of UTF-16 5449** TEXT in bytes 5450** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5451** datatype of the value 5452** <tr><td><b>sqlite3_value_numeric_type </b> 5453** <td>→ <td>Best numeric datatype of the value 5454** <tr><td><b>sqlite3_value_nochange </b> 5455** <td>→ <td>True if the column is unchanged in an UPDATE 5456** against a virtual table. 5457** <tr><td><b>sqlite3_value_frombind </b> 5458** <td>→ <td>True if value originated from a [bound parameter] 5459** </table></blockquote> 5460** 5461** <b>Details:</b> 5462** 5463** These routines extract type, size, and content information from 5464** [protected sqlite3_value] objects. Protected sqlite3_value objects 5465** are used to pass parameter information into the functions that 5466** implement [application-defined SQL functions] and [virtual tables]. 5467** 5468** These routines work only with [protected sqlite3_value] objects. 5469** Any attempt to use these routines on an [unprotected sqlite3_value] 5470** is not threadsafe. 5471** 5472** ^These routines work just like the corresponding [column access functions] 5473** except that these routines take a single [protected sqlite3_value] object 5474** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5475** 5476** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5477** in the native byte-order of the host machine. ^The 5478** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5479** extract UTF-16 strings as big-endian and little-endian respectively. 5480** 5481** ^If [sqlite3_value] object V was initialized 5482** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5483** and if X and Y are strings that compare equal according to strcmp(X,Y), 5484** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5485** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5486** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5487** 5488** ^(The sqlite3_value_type(V) interface returns the 5489** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5490** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5491** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5492** Other interfaces might change the datatype for an sqlite3_value object. 5493** For example, if the datatype is initially SQLITE_INTEGER and 5494** sqlite3_value_text(V) is called to extract a text value for that 5495** integer, then subsequent calls to sqlite3_value_type(V) might return 5496** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5497** occurs is undefined and may change from one release of SQLite to the next. 5498** 5499** ^(The sqlite3_value_numeric_type() interface attempts to apply 5500** numeric affinity to the value. This means that an attempt is 5501** made to convert the value to an integer or floating point. If 5502** such a conversion is possible without loss of information (in other 5503** words, if the value is a string that looks like a number) 5504** then the conversion is performed. Otherwise no conversion occurs. 5505** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5506** 5507** ^Within the [xUpdate] method of a [virtual table], the 5508** sqlite3_value_nochange(X) interface returns true if and only if 5509** the column corresponding to X is unchanged by the UPDATE operation 5510** that the xUpdate method call was invoked to implement and if 5511** and the prior [xColumn] method call that was invoked to extracted 5512** the value for that column returned without setting a result (probably 5513** because it queried [sqlite3_vtab_nochange()] and found that the column 5514** was unchanging). ^Within an [xUpdate] method, any value for which 5515** sqlite3_value_nochange(X) is true will in all other respects appear 5516** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5517** than within an [xUpdate] method call for an UPDATE statement, then 5518** the return value is arbitrary and meaningless. 5519** 5520** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5521** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5522** interfaces. ^If X comes from an SQL literal value, or a table column, 5523** or an expression, then sqlite3_value_frombind(X) returns zero. 5524** 5525** Please pay particular attention to the fact that the pointer returned 5526** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5527** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5528** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5529** or [sqlite3_value_text16()]. 5530** 5531** These routines must be called from the same thread as 5532** the SQL function that supplied the [sqlite3_value*] parameters. 5533** 5534** As long as the input parameter is correct, these routines can only 5535** fail if an out-of-memory error occurs during a format conversion. 5536** Only the following subset of interfaces are subject to out-of-memory 5537** errors: 5538** 5539** <ul> 5540** <li> sqlite3_value_blob() 5541** <li> sqlite3_value_text() 5542** <li> sqlite3_value_text16() 5543** <li> sqlite3_value_text16le() 5544** <li> sqlite3_value_text16be() 5545** <li> sqlite3_value_bytes() 5546** <li> sqlite3_value_bytes16() 5547** </ul> 5548** 5549** If an out-of-memory error occurs, then the return value from these 5550** routines is the same as if the column had contained an SQL NULL value. 5551** Valid SQL NULL returns can be distinguished from out-of-memory errors 5552** by invoking the [sqlite3_errcode()] immediately after the suspect 5553** return value is obtained and before any 5554** other SQLite interface is called on the same [database connection]. 5555*/ 5556const void *sqlite3_value_blob(sqlite3_value*); 5557double sqlite3_value_double(sqlite3_value*); 5558int sqlite3_value_int(sqlite3_value*); 5559sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5560void *sqlite3_value_pointer(sqlite3_value*, const char*); 5561const unsigned char *sqlite3_value_text(sqlite3_value*); 5562const void *sqlite3_value_text16(sqlite3_value*); 5563const void *sqlite3_value_text16le(sqlite3_value*); 5564const void *sqlite3_value_text16be(sqlite3_value*); 5565int sqlite3_value_bytes(sqlite3_value*); 5566int sqlite3_value_bytes16(sqlite3_value*); 5567int sqlite3_value_type(sqlite3_value*); 5568int sqlite3_value_numeric_type(sqlite3_value*); 5569int sqlite3_value_nochange(sqlite3_value*); 5570int sqlite3_value_frombind(sqlite3_value*); 5571 5572/* 5573** CAPI3REF: Finding The Subtype Of SQL Values 5574** METHOD: sqlite3_value 5575** 5576** The sqlite3_value_subtype(V) function returns the subtype for 5577** an [application-defined SQL function] argument V. The subtype 5578** information can be used to pass a limited amount of context from 5579** one SQL function to another. Use the [sqlite3_result_subtype()] 5580** routine to set the subtype for the return value of an SQL function. 5581*/ 5582unsigned int sqlite3_value_subtype(sqlite3_value*); 5583 5584/* 5585** CAPI3REF: Copy And Free SQL Values 5586** METHOD: sqlite3_value 5587** 5588** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5589** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5590** is a [protected sqlite3_value] object even if the input is not. 5591** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5592** memory allocation fails. 5593** 5594** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5595** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5596** then sqlite3_value_free(V) is a harmless no-op. 5597*/ 5598sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5599void sqlite3_value_free(sqlite3_value*); 5600 5601/* 5602** CAPI3REF: Obtain Aggregate Function Context 5603** METHOD: sqlite3_context 5604** 5605** Implementations of aggregate SQL functions use this 5606** routine to allocate memory for storing their state. 5607** 5608** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5609** for a particular aggregate function, SQLite allocates 5610** N bytes of memory, zeroes out that memory, and returns a pointer 5611** to the new memory. ^On second and subsequent calls to 5612** sqlite3_aggregate_context() for the same aggregate function instance, 5613** the same buffer is returned. Sqlite3_aggregate_context() is normally 5614** called once for each invocation of the xStep callback and then one 5615** last time when the xFinal callback is invoked. ^(When no rows match 5616** an aggregate query, the xStep() callback of the aggregate function 5617** implementation is never called and xFinal() is called exactly once. 5618** In those cases, sqlite3_aggregate_context() might be called for the 5619** first time from within xFinal().)^ 5620** 5621** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5622** when first called if N is less than or equal to zero or if a memory 5623** allocate error occurs. 5624** 5625** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5626** determined by the N parameter on first successful call. Changing the 5627** value of N in any subsequent call to sqlite3_aggregate_context() within 5628** the same aggregate function instance will not resize the memory 5629** allocation.)^ Within the xFinal callback, it is customary to set 5630** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5631** pointless memory allocations occur. 5632** 5633** ^SQLite automatically frees the memory allocated by 5634** sqlite3_aggregate_context() when the aggregate query concludes. 5635** 5636** The first parameter must be a copy of the 5637** [sqlite3_context | SQL function context] that is the first parameter 5638** to the xStep or xFinal callback routine that implements the aggregate 5639** function. 5640** 5641** This routine must be called from the same thread in which 5642** the aggregate SQL function is running. 5643*/ 5644void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5645 5646/* 5647** CAPI3REF: User Data For Functions 5648** METHOD: sqlite3_context 5649** 5650** ^The sqlite3_user_data() interface returns a copy of 5651** the pointer that was the pUserData parameter (the 5th parameter) 5652** of the [sqlite3_create_function()] 5653** and [sqlite3_create_function16()] routines that originally 5654** registered the application defined function. 5655** 5656** This routine must be called from the same thread in which 5657** the application-defined function is running. 5658*/ 5659void *sqlite3_user_data(sqlite3_context*); 5660 5661/* 5662** CAPI3REF: Database Connection For Functions 5663** METHOD: sqlite3_context 5664** 5665** ^The sqlite3_context_db_handle() interface returns a copy of 5666** the pointer to the [database connection] (the 1st parameter) 5667** of the [sqlite3_create_function()] 5668** and [sqlite3_create_function16()] routines that originally 5669** registered the application defined function. 5670*/ 5671sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5672 5673/* 5674** CAPI3REF: Function Auxiliary Data 5675** METHOD: sqlite3_context 5676** 5677** These functions may be used by (non-aggregate) SQL functions to 5678** associate metadata with argument values. If the same value is passed to 5679** multiple invocations of the same SQL function during query execution, under 5680** some circumstances the associated metadata may be preserved. An example 5681** of where this might be useful is in a regular-expression matching 5682** function. The compiled version of the regular expression can be stored as 5683** metadata associated with the pattern string. 5684** Then as long as the pattern string remains the same, 5685** the compiled regular expression can be reused on multiple 5686** invocations of the same function. 5687** 5688** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5689** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5690** value to the application-defined function. ^N is zero for the left-most 5691** function argument. ^If there is no metadata 5692** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5693** returns a NULL pointer. 5694** 5695** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5696** argument of the application-defined function. ^Subsequent 5697** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5698** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5699** NULL if the metadata has been discarded. 5700** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5701** SQLite will invoke the destructor function X with parameter P exactly 5702** once, when the metadata is discarded. 5703** SQLite is free to discard the metadata at any time, including: <ul> 5704** <li> ^(when the corresponding function parameter changes)^, or 5705** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5706** SQL statement)^, or 5707** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5708** parameter)^, or 5709** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5710** allocation error occurs.)^ </ul> 5711** 5712** Note the last bullet in particular. The destructor X in 5713** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5714** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5715** should be called near the end of the function implementation and the 5716** function implementation should not make any use of P after 5717** sqlite3_set_auxdata() has been called. 5718** 5719** ^(In practice, metadata is preserved between function calls for 5720** function parameters that are compile-time constants, including literal 5721** values and [parameters] and expressions composed from the same.)^ 5722** 5723** The value of the N parameter to these interfaces should be non-negative. 5724** Future enhancements may make use of negative N values to define new 5725** kinds of function caching behavior. 5726** 5727** These routines must be called from the same thread in which 5728** the SQL function is running. 5729*/ 5730void *sqlite3_get_auxdata(sqlite3_context*, int N); 5731void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5732 5733 5734/* 5735** CAPI3REF: Constants Defining Special Destructor Behavior 5736** 5737** These are special values for the destructor that is passed in as the 5738** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5739** argument is SQLITE_STATIC, it means that the content pointer is constant 5740** and will never change. It does not need to be destroyed. ^The 5741** SQLITE_TRANSIENT value means that the content will likely change in 5742** the near future and that SQLite should make its own private copy of 5743** the content before returning. 5744** 5745** The typedef is necessary to work around problems in certain 5746** C++ compilers. 5747*/ 5748typedef void (*sqlite3_destructor_type)(void*); 5749#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5750#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5751 5752/* 5753** CAPI3REF: Setting The Result Of An SQL Function 5754** METHOD: sqlite3_context 5755** 5756** These routines are used by the xFunc or xFinal callbacks that 5757** implement SQL functions and aggregates. See 5758** [sqlite3_create_function()] and [sqlite3_create_function16()] 5759** for additional information. 5760** 5761** These functions work very much like the [parameter binding] family of 5762** functions used to bind values to host parameters in prepared statements. 5763** Refer to the [SQL parameter] documentation for additional information. 5764** 5765** ^The sqlite3_result_blob() interface sets the result from 5766** an application-defined function to be the BLOB whose content is pointed 5767** to by the second parameter and which is N bytes long where N is the 5768** third parameter. 5769** 5770** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5771** interfaces set the result of the application-defined function to be 5772** a BLOB containing all zero bytes and N bytes in size. 5773** 5774** ^The sqlite3_result_double() interface sets the result from 5775** an application-defined function to be a floating point value specified 5776** by its 2nd argument. 5777** 5778** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5779** cause the implemented SQL function to throw an exception. 5780** ^SQLite uses the string pointed to by the 5781** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5782** as the text of an error message. ^SQLite interprets the error 5783** message string from sqlite3_result_error() as UTF-8. ^SQLite 5784** interprets the string from sqlite3_result_error16() as UTF-16 using 5785** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5786** ^If the third parameter to sqlite3_result_error() 5787** or sqlite3_result_error16() is negative then SQLite takes as the error 5788** message all text up through the first zero character. 5789** ^If the third parameter to sqlite3_result_error() or 5790** sqlite3_result_error16() is non-negative then SQLite takes that many 5791** bytes (not characters) from the 2nd parameter as the error message. 5792** ^The sqlite3_result_error() and sqlite3_result_error16() 5793** routines make a private copy of the error message text before 5794** they return. Hence, the calling function can deallocate or 5795** modify the text after they return without harm. 5796** ^The sqlite3_result_error_code() function changes the error code 5797** returned by SQLite as a result of an error in a function. ^By default, 5798** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5799** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5800** 5801** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5802** error indicating that a string or BLOB is too long to represent. 5803** 5804** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5805** error indicating that a memory allocation failed. 5806** 5807** ^The sqlite3_result_int() interface sets the return value 5808** of the application-defined function to be the 32-bit signed integer 5809** value given in the 2nd argument. 5810** ^The sqlite3_result_int64() interface sets the return value 5811** of the application-defined function to be the 64-bit signed integer 5812** value given in the 2nd argument. 5813** 5814** ^The sqlite3_result_null() interface sets the return value 5815** of the application-defined function to be NULL. 5816** 5817** ^The sqlite3_result_text(), sqlite3_result_text16(), 5818** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5819** set the return value of the application-defined function to be 5820** a text string which is represented as UTF-8, UTF-16 native byte order, 5821** UTF-16 little endian, or UTF-16 big endian, respectively. 5822** ^The sqlite3_result_text64() interface sets the return value of an 5823** application-defined function to be a text string in an encoding 5824** specified by the fifth (and last) parameter, which must be one 5825** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5826** ^SQLite takes the text result from the application from 5827** the 2nd parameter of the sqlite3_result_text* interfaces. 5828** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5829** is negative, then SQLite takes result text from the 2nd parameter 5830** through the first zero character. 5831** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5832** is non-negative, then as many bytes (not characters) of the text 5833** pointed to by the 2nd parameter are taken as the application-defined 5834** function result. If the 3rd parameter is non-negative, then it 5835** must be the byte offset into the string where the NUL terminator would 5836** appear if the string where NUL terminated. If any NUL characters occur 5837** in the string at a byte offset that is less than the value of the 3rd 5838** parameter, then the resulting string will contain embedded NULs and the 5839** result of expressions operating on strings with embedded NULs is undefined. 5840** ^If the 4th parameter to the sqlite3_result_text* interfaces 5841** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5842** function as the destructor on the text or BLOB result when it has 5843** finished using that result. 5844** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5845** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5846** assumes that the text or BLOB result is in constant space and does not 5847** copy the content of the parameter nor call a destructor on the content 5848** when it has finished using that result. 5849** ^If the 4th parameter to the sqlite3_result_text* interfaces 5850** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5851** then SQLite makes a copy of the result into space obtained 5852** from [sqlite3_malloc()] before it returns. 5853** 5854** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5855** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5856** when the encoding is not UTF8, if the input UTF16 begins with a 5857** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5858** string and the rest of the string is interpreted according to the 5859** byte-order specified by the BOM. ^The byte-order specified by 5860** the BOM at the beginning of the text overrides the byte-order 5861** specified by the interface procedure. ^So, for example, if 5862** sqlite3_result_text16le() is invoked with text that begins 5863** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5864** first two bytes of input are skipped and the remaining input 5865** is interpreted as UTF16BE text. 5866** 5867** ^For UTF16 input text to the sqlite3_result_text16(), 5868** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5869** sqlite3_result_text64() routines, if the text contains invalid 5870** UTF16 characters, the invalid characters might be converted 5871** into the unicode replacement character, U+FFFD. 5872** 5873** ^The sqlite3_result_value() interface sets the result of 5874** the application-defined function to be a copy of the 5875** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5876** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5877** so that the [sqlite3_value] specified in the parameter may change or 5878** be deallocated after sqlite3_result_value() returns without harm. 5879** ^A [protected sqlite3_value] object may always be used where an 5880** [unprotected sqlite3_value] object is required, so either 5881** kind of [sqlite3_value] object can be used with this interface. 5882** 5883** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5884** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5885** also associates the host-language pointer P or type T with that 5886** NULL value such that the pointer can be retrieved within an 5887** [application-defined SQL function] using [sqlite3_value_pointer()]. 5888** ^If the D parameter is not NULL, then it is a pointer to a destructor 5889** for the P parameter. ^SQLite invokes D with P as its only argument 5890** when SQLite is finished with P. The T parameter should be a static 5891** string and preferably a string literal. The sqlite3_result_pointer() 5892** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5893** 5894** If these routines are called from within the different thread 5895** than the one containing the application-defined function that received 5896** the [sqlite3_context] pointer, the results are undefined. 5897*/ 5898void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5899void sqlite3_result_blob64(sqlite3_context*,const void*, 5900 sqlite3_uint64,void(*)(void*)); 5901void sqlite3_result_double(sqlite3_context*, double); 5902void sqlite3_result_error(sqlite3_context*, const char*, int); 5903void sqlite3_result_error16(sqlite3_context*, const void*, int); 5904void sqlite3_result_error_toobig(sqlite3_context*); 5905void sqlite3_result_error_nomem(sqlite3_context*); 5906void sqlite3_result_error_code(sqlite3_context*, int); 5907void sqlite3_result_int(sqlite3_context*, int); 5908void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5909void sqlite3_result_null(sqlite3_context*); 5910void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5911void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5912 void(*)(void*), unsigned char encoding); 5913void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5914void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5915void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5916void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5917void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5918void sqlite3_result_zeroblob(sqlite3_context*, int n); 5919int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5920 5921 5922/* 5923** CAPI3REF: Setting The Subtype Of An SQL Function 5924** METHOD: sqlite3_context 5925** 5926** The sqlite3_result_subtype(C,T) function causes the subtype of 5927** the result from the [application-defined SQL function] with 5928** [sqlite3_context] C to be the value T. Only the lower 8 bits 5929** of the subtype T are preserved in current versions of SQLite; 5930** higher order bits are discarded. 5931** The number of subtype bytes preserved by SQLite might increase 5932** in future releases of SQLite. 5933*/ 5934void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5935 5936/* 5937** CAPI3REF: Define New Collating Sequences 5938** METHOD: sqlite3 5939** 5940** ^These functions add, remove, or modify a [collation] associated 5941** with the [database connection] specified as the first argument. 5942** 5943** ^The name of the collation is a UTF-8 string 5944** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5945** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5946** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5947** considered to be the same name. 5948** 5949** ^(The third argument (eTextRep) must be one of the constants: 5950** <ul> 5951** <li> [SQLITE_UTF8], 5952** <li> [SQLITE_UTF16LE], 5953** <li> [SQLITE_UTF16BE], 5954** <li> [SQLITE_UTF16], or 5955** <li> [SQLITE_UTF16_ALIGNED]. 5956** </ul>)^ 5957** ^The eTextRep argument determines the encoding of strings passed 5958** to the collating function callback, xCompare. 5959** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5960** force strings to be UTF16 with native byte order. 5961** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5962** on an even byte address. 5963** 5964** ^The fourth argument, pArg, is an application data pointer that is passed 5965** through as the first argument to the collating function callback. 5966** 5967** ^The fifth argument, xCompare, is a pointer to the collating function. 5968** ^Multiple collating functions can be registered using the same name but 5969** with different eTextRep parameters and SQLite will use whichever 5970** function requires the least amount of data transformation. 5971** ^If the xCompare argument is NULL then the collating function is 5972** deleted. ^When all collating functions having the same name are deleted, 5973** that collation is no longer usable. 5974** 5975** ^The collating function callback is invoked with a copy of the pArg 5976** application data pointer and with two strings in the encoding specified 5977** by the eTextRep argument. The two integer parameters to the collating 5978** function callback are the length of the two strings, in bytes. The collating 5979** function must return an integer that is negative, zero, or positive 5980** if the first string is less than, equal to, or greater than the second, 5981** respectively. A collating function must always return the same answer 5982** given the same inputs. If two or more collating functions are registered 5983** to the same collation name (using different eTextRep values) then all 5984** must give an equivalent answer when invoked with equivalent strings. 5985** The collating function must obey the following properties for all 5986** strings A, B, and C: 5987** 5988** <ol> 5989** <li> If A==B then B==A. 5990** <li> If A==B and B==C then A==C. 5991** <li> If A<B THEN B>A. 5992** <li> If A<B and B<C then A<C. 5993** </ol> 5994** 5995** If a collating function fails any of the above constraints and that 5996** collating function is registered and used, then the behavior of SQLite 5997** is undefined. 5998** 5999** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6000** with the addition that the xDestroy callback is invoked on pArg when 6001** the collating function is deleted. 6002** ^Collating functions are deleted when they are overridden by later 6003** calls to the collation creation functions or when the 6004** [database connection] is closed using [sqlite3_close()]. 6005** 6006** ^The xDestroy callback is <u>not</u> called if the 6007** sqlite3_create_collation_v2() function fails. Applications that invoke 6008** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6009** check the return code and dispose of the application data pointer 6010** themselves rather than expecting SQLite to deal with it for them. 6011** This is different from every other SQLite interface. The inconsistency 6012** is unfortunate but cannot be changed without breaking backwards 6013** compatibility. 6014** 6015** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6016*/ 6017int sqlite3_create_collation( 6018 sqlite3*, 6019 const char *zName, 6020 int eTextRep, 6021 void *pArg, 6022 int(*xCompare)(void*,int,const void*,int,const void*) 6023); 6024int sqlite3_create_collation_v2( 6025 sqlite3*, 6026 const char *zName, 6027 int eTextRep, 6028 void *pArg, 6029 int(*xCompare)(void*,int,const void*,int,const void*), 6030 void(*xDestroy)(void*) 6031); 6032int sqlite3_create_collation16( 6033 sqlite3*, 6034 const void *zName, 6035 int eTextRep, 6036 void *pArg, 6037 int(*xCompare)(void*,int,const void*,int,const void*) 6038); 6039 6040/* 6041** CAPI3REF: Collation Needed Callbacks 6042** METHOD: sqlite3 6043** 6044** ^To avoid having to register all collation sequences before a database 6045** can be used, a single callback function may be registered with the 6046** [database connection] to be invoked whenever an undefined collation 6047** sequence is required. 6048** 6049** ^If the function is registered using the sqlite3_collation_needed() API, 6050** then it is passed the names of undefined collation sequences as strings 6051** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6052** the names are passed as UTF-16 in machine native byte order. 6053** ^A call to either function replaces the existing collation-needed callback. 6054** 6055** ^(When the callback is invoked, the first argument passed is a copy 6056** of the second argument to sqlite3_collation_needed() or 6057** sqlite3_collation_needed16(). The second argument is the database 6058** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6059** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6060** sequence function required. The fourth parameter is the name of the 6061** required collation sequence.)^ 6062** 6063** The callback function should register the desired collation using 6064** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6065** [sqlite3_create_collation_v2()]. 6066*/ 6067int sqlite3_collation_needed( 6068 sqlite3*, 6069 void*, 6070 void(*)(void*,sqlite3*,int eTextRep,const char*) 6071); 6072int sqlite3_collation_needed16( 6073 sqlite3*, 6074 void*, 6075 void(*)(void*,sqlite3*,int eTextRep,const void*) 6076); 6077 6078#ifdef SQLITE_ENABLE_CEROD 6079/* 6080** Specify the activation key for a CEROD database. Unless 6081** activated, none of the CEROD routines will work. 6082*/ 6083void sqlite3_activate_cerod( 6084 const char *zPassPhrase /* Activation phrase */ 6085); 6086#endif 6087 6088/* 6089** CAPI3REF: Suspend Execution For A Short Time 6090** 6091** The sqlite3_sleep() function causes the current thread to suspend execution 6092** for at least a number of milliseconds specified in its parameter. 6093** 6094** If the operating system does not support sleep requests with 6095** millisecond time resolution, then the time will be rounded up to 6096** the nearest second. The number of milliseconds of sleep actually 6097** requested from the operating system is returned. 6098** 6099** ^SQLite implements this interface by calling the xSleep() 6100** method of the default [sqlite3_vfs] object. If the xSleep() method 6101** of the default VFS is not implemented correctly, or not implemented at 6102** all, then the behavior of sqlite3_sleep() may deviate from the description 6103** in the previous paragraphs. 6104*/ 6105int sqlite3_sleep(int); 6106 6107/* 6108** CAPI3REF: Name Of The Folder Holding Temporary Files 6109** 6110** ^(If this global variable is made to point to a string which is 6111** the name of a folder (a.k.a. directory), then all temporary files 6112** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6113** will be placed in that directory.)^ ^If this variable 6114** is a NULL pointer, then SQLite performs a search for an appropriate 6115** temporary file directory. 6116** 6117** Applications are strongly discouraged from using this global variable. 6118** It is required to set a temporary folder on Windows Runtime (WinRT). 6119** But for all other platforms, it is highly recommended that applications 6120** neither read nor write this variable. This global variable is a relic 6121** that exists for backwards compatibility of legacy applications and should 6122** be avoided in new projects. 6123** 6124** It is not safe to read or modify this variable in more than one 6125** thread at a time. It is not safe to read or modify this variable 6126** if a [database connection] is being used at the same time in a separate 6127** thread. 6128** It is intended that this variable be set once 6129** as part of process initialization and before any SQLite interface 6130** routines have been called and that this variable remain unchanged 6131** thereafter. 6132** 6133** ^The [temp_store_directory pragma] may modify this variable and cause 6134** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6135** the [temp_store_directory pragma] always assumes that any string 6136** that this variable points to is held in memory obtained from 6137** [sqlite3_malloc] and the pragma may attempt to free that memory 6138** using [sqlite3_free]. 6139** Hence, if this variable is modified directly, either it should be 6140** made NULL or made to point to memory obtained from [sqlite3_malloc] 6141** or else the use of the [temp_store_directory pragma] should be avoided. 6142** Except when requested by the [temp_store_directory pragma], SQLite 6143** does not free the memory that sqlite3_temp_directory points to. If 6144** the application wants that memory to be freed, it must do 6145** so itself, taking care to only do so after all [database connection] 6146** objects have been destroyed. 6147** 6148** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6149** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6150** features that require the use of temporary files may fail. Here is an 6151** example of how to do this using C++ with the Windows Runtime: 6152** 6153** <blockquote><pre> 6154** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6155** TemporaryFolder->Path->Data(); 6156** char zPathBuf[MAX_PATH + 1]; 6157** memset(zPathBuf, 0, sizeof(zPathBuf)); 6158** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6159** NULL, NULL); 6160** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6161** </pre></blockquote> 6162*/ 6163SQLITE_EXTERN char *sqlite3_temp_directory; 6164 6165/* 6166** CAPI3REF: Name Of The Folder Holding Database Files 6167** 6168** ^(If this global variable is made to point to a string which is 6169** the name of a folder (a.k.a. directory), then all database files 6170** specified with a relative pathname and created or accessed by 6171** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6172** to be relative to that directory.)^ ^If this variable is a NULL 6173** pointer, then SQLite assumes that all database files specified 6174** with a relative pathname are relative to the current directory 6175** for the process. Only the windows VFS makes use of this global 6176** variable; it is ignored by the unix VFS. 6177** 6178** Changing the value of this variable while a database connection is 6179** open can result in a corrupt database. 6180** 6181** It is not safe to read or modify this variable in more than one 6182** thread at a time. It is not safe to read or modify this variable 6183** if a [database connection] is being used at the same time in a separate 6184** thread. 6185** It is intended that this variable be set once 6186** as part of process initialization and before any SQLite interface 6187** routines have been called and that this variable remain unchanged 6188** thereafter. 6189** 6190** ^The [data_store_directory pragma] may modify this variable and cause 6191** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6192** the [data_store_directory pragma] always assumes that any string 6193** that this variable points to is held in memory obtained from 6194** [sqlite3_malloc] and the pragma may attempt to free that memory 6195** using [sqlite3_free]. 6196** Hence, if this variable is modified directly, either it should be 6197** made NULL or made to point to memory obtained from [sqlite3_malloc] 6198** or else the use of the [data_store_directory pragma] should be avoided. 6199*/ 6200SQLITE_EXTERN char *sqlite3_data_directory; 6201 6202/* 6203** CAPI3REF: Win32 Specific Interface 6204** 6205** These interfaces are available only on Windows. The 6206** [sqlite3_win32_set_directory] interface is used to set the value associated 6207** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6208** zValue, depending on the value of the type parameter. The zValue parameter 6209** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6210** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6211** prior to being used. The [sqlite3_win32_set_directory] interface returns 6212** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6213** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6214** [sqlite3_data_directory] variable is intended to act as a replacement for 6215** the current directory on the sub-platforms of Win32 where that concept is 6216** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6217** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6218** sqlite3_win32_set_directory interface except the string parameter must be 6219** UTF-8 or UTF-16, respectively. 6220*/ 6221int sqlite3_win32_set_directory( 6222 unsigned long type, /* Identifier for directory being set or reset */ 6223 void *zValue /* New value for directory being set or reset */ 6224); 6225int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6226int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6227 6228/* 6229** CAPI3REF: Win32 Directory Types 6230** 6231** These macros are only available on Windows. They define the allowed values 6232** for the type argument to the [sqlite3_win32_set_directory] interface. 6233*/ 6234#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6235#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6236 6237/* 6238** CAPI3REF: Test For Auto-Commit Mode 6239** KEYWORDS: {autocommit mode} 6240** METHOD: sqlite3 6241** 6242** ^The sqlite3_get_autocommit() interface returns non-zero or 6243** zero if the given database connection is or is not in autocommit mode, 6244** respectively. ^Autocommit mode is on by default. 6245** ^Autocommit mode is disabled by a [BEGIN] statement. 6246** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6247** 6248** If certain kinds of errors occur on a statement within a multi-statement 6249** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6250** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6251** transaction might be rolled back automatically. The only way to 6252** find out whether SQLite automatically rolled back the transaction after 6253** an error is to use this function. 6254** 6255** If another thread changes the autocommit status of the database 6256** connection while this routine is running, then the return value 6257** is undefined. 6258*/ 6259int sqlite3_get_autocommit(sqlite3*); 6260 6261/* 6262** CAPI3REF: Find The Database Handle Of A Prepared Statement 6263** METHOD: sqlite3_stmt 6264** 6265** ^The sqlite3_db_handle interface returns the [database connection] handle 6266** to which a [prepared statement] belongs. ^The [database connection] 6267** returned by sqlite3_db_handle is the same [database connection] 6268** that was the first argument 6269** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6270** create the statement in the first place. 6271*/ 6272sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6273 6274/* 6275** CAPI3REF: Return The Filename For A Database Connection 6276** METHOD: sqlite3 6277** 6278** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6279** associated with database N of connection D. 6280** ^If there is no attached database N on the database 6281** connection D, or if database N is a temporary or in-memory database, then 6282** this function will return either a NULL pointer or an empty string. 6283** 6284** ^The string value returned by this routine is owned and managed by 6285** the database connection. ^The value will be valid until the database N 6286** is [DETACH]-ed or until the database connection closes. 6287** 6288** ^The filename returned by this function is the output of the 6289** xFullPathname method of the [VFS]. ^In other words, the filename 6290** will be an absolute pathname, even if the filename used 6291** to open the database originally was a URI or relative pathname. 6292** 6293** If the filename pointer returned by this routine is not NULL, then it 6294** can be used as the filename input parameter to these routines: 6295** <ul> 6296** <li> [sqlite3_uri_parameter()] 6297** <li> [sqlite3_uri_boolean()] 6298** <li> [sqlite3_uri_int64()] 6299** <li> [sqlite3_filename_database()] 6300** <li> [sqlite3_filename_journal()] 6301** <li> [sqlite3_filename_wal()] 6302** </ul> 6303*/ 6304const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6305 6306/* 6307** CAPI3REF: Determine if a database is read-only 6308** METHOD: sqlite3 6309** 6310** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6311** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6312** the name of a database on connection D. 6313*/ 6314int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6315 6316/* 6317** CAPI3REF: Determine the transaction state of a database 6318** METHOD: sqlite3 6319** 6320** ^The sqlite3_txn_state(D,S) interface returns the current 6321** [transaction state] of schema S in database connection D. ^If S is NULL, 6322** then the highest transaction state of any schema on database connection D 6323** is returned. Transaction states are (in order of lowest to highest): 6324** <ol> 6325** <li value="0"> SQLITE_TXN_NONE 6326** <li value="1"> SQLITE_TXN_READ 6327** <li value="2"> SQLITE_TXN_WRITE 6328** </ol> 6329** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6330** a valid schema, then -1 is returned. 6331*/ 6332int sqlite3_txn_state(sqlite3*,const char *zSchema); 6333 6334/* 6335** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6336** KEYWORDS: {transaction state} 6337** 6338** These constants define the current transaction state of a database file. 6339** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6340** constants in order to describe the transaction state of schema S 6341** in [database connection] D. 6342** 6343** <dl> 6344** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6345** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6346** pending.</dd> 6347** 6348** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6349** <dd>The SQLITE_TXN_READ state means that the database is currently 6350** in a read transaction. Content has been read from the database file 6351** but nothing in the database file has changed. The transaction state 6352** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6353** no other conflicting concurrent write transactions. The transaction 6354** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6355** [COMMIT].</dd> 6356** 6357** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6358** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6359** in a write transaction. Content has been written to the database file 6360** but has not yet committed. The transaction state will change to 6361** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6362*/ 6363#define SQLITE_TXN_NONE 0 6364#define SQLITE_TXN_READ 1 6365#define SQLITE_TXN_WRITE 2 6366 6367/* 6368** CAPI3REF: Find the next prepared statement 6369** METHOD: sqlite3 6370** 6371** ^This interface returns a pointer to the next [prepared statement] after 6372** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6373** then this interface returns a pointer to the first prepared statement 6374** associated with the database connection pDb. ^If no prepared statement 6375** satisfies the conditions of this routine, it returns NULL. 6376** 6377** The [database connection] pointer D in a call to 6378** [sqlite3_next_stmt(D,S)] must refer to an open database 6379** connection and in particular must not be a NULL pointer. 6380*/ 6381sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6382 6383/* 6384** CAPI3REF: Commit And Rollback Notification Callbacks 6385** METHOD: sqlite3 6386** 6387** ^The sqlite3_commit_hook() interface registers a callback 6388** function to be invoked whenever a transaction is [COMMIT | committed]. 6389** ^Any callback set by a previous call to sqlite3_commit_hook() 6390** for the same database connection is overridden. 6391** ^The sqlite3_rollback_hook() interface registers a callback 6392** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6393** ^Any callback set by a previous call to sqlite3_rollback_hook() 6394** for the same database connection is overridden. 6395** ^The pArg argument is passed through to the callback. 6396** ^If the callback on a commit hook function returns non-zero, 6397** then the commit is converted into a rollback. 6398** 6399** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6400** return the P argument from the previous call of the same function 6401** on the same [database connection] D, or NULL for 6402** the first call for each function on D. 6403** 6404** The commit and rollback hook callbacks are not reentrant. 6405** The callback implementation must not do anything that will modify 6406** the database connection that invoked the callback. Any actions 6407** to modify the database connection must be deferred until after the 6408** completion of the [sqlite3_step()] call that triggered the commit 6409** or rollback hook in the first place. 6410** Note that running any other SQL statements, including SELECT statements, 6411** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6412** the database connections for the meaning of "modify" in this paragraph. 6413** 6414** ^Registering a NULL function disables the callback. 6415** 6416** ^When the commit hook callback routine returns zero, the [COMMIT] 6417** operation is allowed to continue normally. ^If the commit hook 6418** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6419** ^The rollback hook is invoked on a rollback that results from a commit 6420** hook returning non-zero, just as it would be with any other rollback. 6421** 6422** ^For the purposes of this API, a transaction is said to have been 6423** rolled back if an explicit "ROLLBACK" statement is executed, or 6424** an error or constraint causes an implicit rollback to occur. 6425** ^The rollback callback is not invoked if a transaction is 6426** automatically rolled back because the database connection is closed. 6427** 6428** See also the [sqlite3_update_hook()] interface. 6429*/ 6430void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6431void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6432 6433/* 6434** CAPI3REF: Autovacuum Compaction Amount Callback 6435** METHOD: sqlite3 6436** 6437** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 6438** function C that is invoked prior to each autovacuum of the database 6439** file. ^The callback is passed a copy of the generic data pointer (P), 6440** the schema-name of the attached database that is being autovacuumed, 6441** the the size of the database file in pages, the number of free pages, 6442** and the number of bytes per page, respectively. The callback should 6443** return the number of free pages that should be removed by the 6444** autovacuum. ^If the callback returns zero, then no autovacuum happens. 6445** ^If the value returned is greater than or equal to the number of 6446** free pages, then a complete autovacuum happens. 6447** 6448** <p>^If there are multiple ATTACH-ed database files that are being 6449** modified as part of a transaction commit, then the autovacuum pages 6450** callback is invoked separately for each file. 6451** 6452** <p><b>The callback is not reentrant.</b> The callback function should 6453** not attempt to invoke any other SQLite interface. If it does, bad 6454** things may happen, including segmentation faults and corrupt database 6455** files. The callback function should be a simple function that 6456** does some arithmetic on its input parameters and returns a result. 6457** 6458** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 6459** destructor for the P parameter. ^If X is not NULL, then X(P) is 6460** invoked whenever the database connection closes or when the callback 6461** is overwritten by another invocation of sqlite3_autovacuum_pages(). 6462** 6463** <p>^There is only one autovacuum pages callback per database connection. 6464** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 6465** previous invocations for that database connection. ^If the callback 6466** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 6467** then the autovacuum steps callback is cancelled. The return value 6468** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 6469** be some other error code if something goes wrong. The current 6470** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 6471** return codes might be added in future releases. 6472** 6473** <p>If no autovacuum pages callback is specified (the usual case) or 6474** a NULL pointer is provided for the callback, 6475** then the default behavior is to vacuum all free pages. So, in other 6476** words, the default behavior is the same as if the callback function 6477** were something like this: 6478** 6479** <blockquote><pre> 6480** unsigned int demonstration_autovac_pages_callback( 6481** void *pClientData, 6482** const char *zSchema, 6483** unsigned int nDbPage, 6484** unsigned int nFreePage, 6485** unsigned int nBytePerPage 6486** ){ 6487** return nFreePage; 6488** } 6489** </pre></blockquote> 6490*/ 6491int sqlite3_autovacuum_pages( 6492 sqlite3 *db, 6493 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 6494 void*, 6495 void(*)(void*) 6496); 6497 6498 6499/* 6500** CAPI3REF: Data Change Notification Callbacks 6501** METHOD: sqlite3 6502** 6503** ^The sqlite3_update_hook() interface registers a callback function 6504** with the [database connection] identified by the first argument 6505** to be invoked whenever a row is updated, inserted or deleted in 6506** a [rowid table]. 6507** ^Any callback set by a previous call to this function 6508** for the same database connection is overridden. 6509** 6510** ^The second argument is a pointer to the function to invoke when a 6511** row is updated, inserted or deleted in a rowid table. 6512** ^The first argument to the callback is a copy of the third argument 6513** to sqlite3_update_hook(). 6514** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6515** or [SQLITE_UPDATE], depending on the operation that caused the callback 6516** to be invoked. 6517** ^The third and fourth arguments to the callback contain pointers to the 6518** database and table name containing the affected row. 6519** ^The final callback parameter is the [rowid] of the row. 6520** ^In the case of an update, this is the [rowid] after the update takes place. 6521** 6522** ^(The update hook is not invoked when internal system tables are 6523** modified (i.e. sqlite_sequence).)^ 6524** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6525** 6526** ^In the current implementation, the update hook 6527** is not invoked when conflicting rows are deleted because of an 6528** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6529** invoked when rows are deleted using the [truncate optimization]. 6530** The exceptions defined in this paragraph might change in a future 6531** release of SQLite. 6532** 6533** The update hook implementation must not do anything that will modify 6534** the database connection that invoked the update hook. Any actions 6535** to modify the database connection must be deferred until after the 6536** completion of the [sqlite3_step()] call that triggered the update hook. 6537** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6538** database connections for the meaning of "modify" in this paragraph. 6539** 6540** ^The sqlite3_update_hook(D,C,P) function 6541** returns the P argument from the previous call 6542** on the same [database connection] D, or NULL for 6543** the first call on D. 6544** 6545** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6546** and [sqlite3_preupdate_hook()] interfaces. 6547*/ 6548void *sqlite3_update_hook( 6549 sqlite3*, 6550 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6551 void* 6552); 6553 6554/* 6555** CAPI3REF: Enable Or Disable Shared Pager Cache 6556** 6557** ^(This routine enables or disables the sharing of the database cache 6558** and schema data structures between [database connection | connections] 6559** to the same database. Sharing is enabled if the argument is true 6560** and disabled if the argument is false.)^ 6561** 6562** ^Cache sharing is enabled and disabled for an entire process. 6563** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6564** In prior versions of SQLite, 6565** sharing was enabled or disabled for each thread separately. 6566** 6567** ^(The cache sharing mode set by this interface effects all subsequent 6568** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6569** Existing database connections continue to use the sharing mode 6570** that was in effect at the time they were opened.)^ 6571** 6572** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6573** successfully. An [error code] is returned otherwise.)^ 6574** 6575** ^Shared cache is disabled by default. It is recommended that it stay 6576** that way. In other words, do not use this routine. This interface 6577** continues to be provided for historical compatibility, but its use is 6578** discouraged. Any use of shared cache is discouraged. If shared cache 6579** must be used, it is recommended that shared cache only be enabled for 6580** individual database connections using the [sqlite3_open_v2()] interface 6581** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6582** 6583** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6584** and will always return SQLITE_MISUSE. On those systems, 6585** shared cache mode should be enabled per-database connection via 6586** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6587** 6588** This interface is threadsafe on processors where writing a 6589** 32-bit integer is atomic. 6590** 6591** See Also: [SQLite Shared-Cache Mode] 6592*/ 6593int sqlite3_enable_shared_cache(int); 6594 6595/* 6596** CAPI3REF: Attempt To Free Heap Memory 6597** 6598** ^The sqlite3_release_memory() interface attempts to free N bytes 6599** of heap memory by deallocating non-essential memory allocations 6600** held by the database library. Memory used to cache database 6601** pages to improve performance is an example of non-essential memory. 6602** ^sqlite3_release_memory() returns the number of bytes actually freed, 6603** which might be more or less than the amount requested. 6604** ^The sqlite3_release_memory() routine is a no-op returning zero 6605** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6606** 6607** See also: [sqlite3_db_release_memory()] 6608*/ 6609int sqlite3_release_memory(int); 6610 6611/* 6612** CAPI3REF: Free Memory Used By A Database Connection 6613** METHOD: sqlite3 6614** 6615** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6616** memory as possible from database connection D. Unlike the 6617** [sqlite3_release_memory()] interface, this interface is in effect even 6618** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6619** omitted. 6620** 6621** See also: [sqlite3_release_memory()] 6622*/ 6623int sqlite3_db_release_memory(sqlite3*); 6624 6625/* 6626** CAPI3REF: Impose A Limit On Heap Size 6627** 6628** These interfaces impose limits on the amount of heap memory that will be 6629** by all database connections within a single process. 6630** 6631** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6632** soft limit on the amount of heap memory that may be allocated by SQLite. 6633** ^SQLite strives to keep heap memory utilization below the soft heap 6634** limit by reducing the number of pages held in the page cache 6635** as heap memory usages approaches the limit. 6636** ^The soft heap limit is "soft" because even though SQLite strives to stay 6637** below the limit, it will exceed the limit rather than generate 6638** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6639** is advisory only. 6640** 6641** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6642** N bytes on the amount of memory that will be allocated. ^The 6643** sqlite3_hard_heap_limit64(N) interface is similar to 6644** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6645** when the hard heap limit is reached. 6646** 6647** ^The return value from both sqlite3_soft_heap_limit64() and 6648** sqlite3_hard_heap_limit64() is the size of 6649** the heap limit prior to the call, or negative in the case of an 6650** error. ^If the argument N is negative 6651** then no change is made to the heap limit. Hence, the current 6652** size of heap limits can be determined by invoking 6653** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6654** 6655** ^Setting the heap limits to zero disables the heap limiter mechanism. 6656** 6657** ^The soft heap limit may not be greater than the hard heap limit. 6658** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6659** is invoked with a value of N that is greater than the hard heap limit, 6660** the the soft heap limit is set to the value of the hard heap limit. 6661** ^The soft heap limit is automatically enabled whenever the hard heap 6662** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6663** the soft heap limit is outside the range of 1..N, then the soft heap 6664** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6665** hard heap limit is enabled makes the soft heap limit equal to the 6666** hard heap limit. 6667** 6668** The memory allocation limits can also be adjusted using 6669** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6670** 6671** ^(The heap limits are not enforced in the current implementation 6672** if one or more of following conditions are true: 6673** 6674** <ul> 6675** <li> The limit value is set to zero. 6676** <li> Memory accounting is disabled using a combination of the 6677** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6678** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6679** <li> An alternative page cache implementation is specified using 6680** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6681** <li> The page cache allocates from its own memory pool supplied 6682** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6683** from the heap. 6684** </ul>)^ 6685** 6686** The circumstances under which SQLite will enforce the heap limits may 6687** changes in future releases of SQLite. 6688*/ 6689sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6690sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6691 6692/* 6693** CAPI3REF: Deprecated Soft Heap Limit Interface 6694** DEPRECATED 6695** 6696** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6697** interface. This routine is provided for historical compatibility 6698** only. All new applications should use the 6699** [sqlite3_soft_heap_limit64()] interface rather than this one. 6700*/ 6701SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6702 6703 6704/* 6705** CAPI3REF: Extract Metadata About A Column Of A Table 6706** METHOD: sqlite3 6707** 6708** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6709** information about column C of table T in database D 6710** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6711** interface returns SQLITE_OK and fills in the non-NULL pointers in 6712** the final five arguments with appropriate values if the specified 6713** column exists. ^The sqlite3_table_column_metadata() interface returns 6714** SQLITE_ERROR if the specified column does not exist. 6715** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6716** NULL pointer, then this routine simply checks for the existence of the 6717** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6718** does not. If the table name parameter T in a call to 6719** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6720** undefined behavior. 6721** 6722** ^The column is identified by the second, third and fourth parameters to 6723** this function. ^(The second parameter is either the name of the database 6724** (i.e. "main", "temp", or an attached database) containing the specified 6725** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6726** for the table using the same algorithm used by the database engine to 6727** resolve unqualified table references. 6728** 6729** ^The third and fourth parameters to this function are the table and column 6730** name of the desired column, respectively. 6731** 6732** ^Metadata is returned by writing to the memory locations passed as the 5th 6733** and subsequent parameters to this function. ^Any of these arguments may be 6734** NULL, in which case the corresponding element of metadata is omitted. 6735** 6736** ^(<blockquote> 6737** <table border="1"> 6738** <tr><th> Parameter <th> Output<br>Type <th> Description 6739** 6740** <tr><td> 5th <td> const char* <td> Data type 6741** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6742** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6743** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6744** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6745** </table> 6746** </blockquote>)^ 6747** 6748** ^The memory pointed to by the character pointers returned for the 6749** declaration type and collation sequence is valid until the next 6750** call to any SQLite API function. 6751** 6752** ^If the specified table is actually a view, an [error code] is returned. 6753** 6754** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6755** is not a [WITHOUT ROWID] table and an 6756** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6757** parameters are set for the explicitly declared column. ^(If there is no 6758** [INTEGER PRIMARY KEY] column, then the outputs 6759** for the [rowid] are set as follows: 6760** 6761** <pre> 6762** data type: "INTEGER" 6763** collation sequence: "BINARY" 6764** not null: 0 6765** primary key: 1 6766** auto increment: 0 6767** </pre>)^ 6768** 6769** ^This function causes all database schemas to be read from disk and 6770** parsed, if that has not already been done, and returns an error if 6771** any errors are encountered while loading the schema. 6772*/ 6773int sqlite3_table_column_metadata( 6774 sqlite3 *db, /* Connection handle */ 6775 const char *zDbName, /* Database name or NULL */ 6776 const char *zTableName, /* Table name */ 6777 const char *zColumnName, /* Column name */ 6778 char const **pzDataType, /* OUTPUT: Declared data type */ 6779 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6780 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6781 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6782 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6783); 6784 6785/* 6786** CAPI3REF: Load An Extension 6787** METHOD: sqlite3 6788** 6789** ^This interface loads an SQLite extension library from the named file. 6790** 6791** ^The sqlite3_load_extension() interface attempts to load an 6792** [SQLite extension] library contained in the file zFile. If 6793** the file cannot be loaded directly, attempts are made to load 6794** with various operating-system specific extensions added. 6795** So for example, if "samplelib" cannot be loaded, then names like 6796** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6797** be tried also. 6798** 6799** ^The entry point is zProc. 6800** ^(zProc may be 0, in which case SQLite will try to come up with an 6801** entry point name on its own. It first tries "sqlite3_extension_init". 6802** If that does not work, it constructs a name "sqlite3_X_init" where the 6803** X is consists of the lower-case equivalent of all ASCII alphabetic 6804** characters in the filename from the last "/" to the first following 6805** "." and omitting any initial "lib".)^ 6806** ^The sqlite3_load_extension() interface returns 6807** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6808** ^If an error occurs and pzErrMsg is not 0, then the 6809** [sqlite3_load_extension()] interface shall attempt to 6810** fill *pzErrMsg with error message text stored in memory 6811** obtained from [sqlite3_malloc()]. The calling function 6812** should free this memory by calling [sqlite3_free()]. 6813** 6814** ^Extension loading must be enabled using 6815** [sqlite3_enable_load_extension()] or 6816** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6817** prior to calling this API, 6818** otherwise an error will be returned. 6819** 6820** <b>Security warning:</b> It is recommended that the 6821** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6822** interface. The use of the [sqlite3_enable_load_extension()] interface 6823** should be avoided. This will keep the SQL function [load_extension()] 6824** disabled and prevent SQL injections from giving attackers 6825** access to extension loading capabilities. 6826** 6827** See also the [load_extension() SQL function]. 6828*/ 6829int sqlite3_load_extension( 6830 sqlite3 *db, /* Load the extension into this database connection */ 6831 const char *zFile, /* Name of the shared library containing extension */ 6832 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6833 char **pzErrMsg /* Put error message here if not 0 */ 6834); 6835 6836/* 6837** CAPI3REF: Enable Or Disable Extension Loading 6838** METHOD: sqlite3 6839** 6840** ^So as not to open security holes in older applications that are 6841** unprepared to deal with [extension loading], and as a means of disabling 6842** [extension loading] while evaluating user-entered SQL, the following API 6843** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6844** 6845** ^Extension loading is off by default. 6846** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6847** to turn extension loading on and call it with onoff==0 to turn 6848** it back off again. 6849** 6850** ^This interface enables or disables both the C-API 6851** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6852** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6853** to enable or disable only the C-API.)^ 6854** 6855** <b>Security warning:</b> It is recommended that extension loading 6856** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6857** rather than this interface, so the [load_extension()] SQL function 6858** remains disabled. This will prevent SQL injections from giving attackers 6859** access to extension loading capabilities. 6860*/ 6861int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6862 6863/* 6864** CAPI3REF: Automatically Load Statically Linked Extensions 6865** 6866** ^This interface causes the xEntryPoint() function to be invoked for 6867** each new [database connection] that is created. The idea here is that 6868** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6869** that is to be automatically loaded into all new database connections. 6870** 6871** ^(Even though the function prototype shows that xEntryPoint() takes 6872** no arguments and returns void, SQLite invokes xEntryPoint() with three 6873** arguments and expects an integer result as if the signature of the 6874** entry point where as follows: 6875** 6876** <blockquote><pre> 6877** int xEntryPoint( 6878** sqlite3 *db, 6879** const char **pzErrMsg, 6880** const struct sqlite3_api_routines *pThunk 6881** ); 6882** </pre></blockquote>)^ 6883** 6884** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6885** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6886** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6887** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6888** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6889** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6890** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6891** 6892** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6893** on the list of automatic extensions is a harmless no-op. ^No entry point 6894** will be called more than once for each database connection that is opened. 6895** 6896** See also: [sqlite3_reset_auto_extension()] 6897** and [sqlite3_cancel_auto_extension()] 6898*/ 6899int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6900 6901/* 6902** CAPI3REF: Cancel Automatic Extension Loading 6903** 6904** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6905** initialization routine X that was registered using a prior call to 6906** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6907** routine returns 1 if initialization routine X was successfully 6908** unregistered and it returns 0 if X was not on the list of initialization 6909** routines. 6910*/ 6911int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6912 6913/* 6914** CAPI3REF: Reset Automatic Extension Loading 6915** 6916** ^This interface disables all automatic extensions previously 6917** registered using [sqlite3_auto_extension()]. 6918*/ 6919void sqlite3_reset_auto_extension(void); 6920 6921/* 6922** The interface to the virtual-table mechanism is currently considered 6923** to be experimental. The interface might change in incompatible ways. 6924** If this is a problem for you, do not use the interface at this time. 6925** 6926** When the virtual-table mechanism stabilizes, we will declare the 6927** interface fixed, support it indefinitely, and remove this comment. 6928*/ 6929 6930/* 6931** Structures used by the virtual table interface 6932*/ 6933typedef struct sqlite3_vtab sqlite3_vtab; 6934typedef struct sqlite3_index_info sqlite3_index_info; 6935typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6936typedef struct sqlite3_module sqlite3_module; 6937 6938/* 6939** CAPI3REF: Virtual Table Object 6940** KEYWORDS: sqlite3_module {virtual table module} 6941** 6942** This structure, sometimes called a "virtual table module", 6943** defines the implementation of a [virtual table]. 6944** This structure consists mostly of methods for the module. 6945** 6946** ^A virtual table module is created by filling in a persistent 6947** instance of this structure and passing a pointer to that instance 6948** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6949** ^The registration remains valid until it is replaced by a different 6950** module or until the [database connection] closes. The content 6951** of this structure must not change while it is registered with 6952** any database connection. 6953*/ 6954struct sqlite3_module { 6955 int iVersion; 6956 int (*xCreate)(sqlite3*, void *pAux, 6957 int argc, const char *const*argv, 6958 sqlite3_vtab **ppVTab, char**); 6959 int (*xConnect)(sqlite3*, void *pAux, 6960 int argc, const char *const*argv, 6961 sqlite3_vtab **ppVTab, char**); 6962 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6963 int (*xDisconnect)(sqlite3_vtab *pVTab); 6964 int (*xDestroy)(sqlite3_vtab *pVTab); 6965 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6966 int (*xClose)(sqlite3_vtab_cursor*); 6967 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6968 int argc, sqlite3_value **argv); 6969 int (*xNext)(sqlite3_vtab_cursor*); 6970 int (*xEof)(sqlite3_vtab_cursor*); 6971 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6972 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6973 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6974 int (*xBegin)(sqlite3_vtab *pVTab); 6975 int (*xSync)(sqlite3_vtab *pVTab); 6976 int (*xCommit)(sqlite3_vtab *pVTab); 6977 int (*xRollback)(sqlite3_vtab *pVTab); 6978 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6979 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6980 void **ppArg); 6981 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6982 /* The methods above are in version 1 of the sqlite_module object. Those 6983 ** below are for version 2 and greater. */ 6984 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6985 int (*xRelease)(sqlite3_vtab *pVTab, int); 6986 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6987 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6988 ** Those below are for version 3 and greater. */ 6989 int (*xShadowName)(const char*); 6990}; 6991 6992/* 6993** CAPI3REF: Virtual Table Indexing Information 6994** KEYWORDS: sqlite3_index_info 6995** 6996** The sqlite3_index_info structure and its substructures is used as part 6997** of the [virtual table] interface to 6998** pass information into and receive the reply from the [xBestIndex] 6999** method of a [virtual table module]. The fields under **Inputs** are the 7000** inputs to xBestIndex and are read-only. xBestIndex inserts its 7001** results into the **Outputs** fields. 7002** 7003** ^(The aConstraint[] array records WHERE clause constraints of the form: 7004** 7005** <blockquote>column OP expr</blockquote> 7006** 7007** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7008** stored in aConstraint[].op using one of the 7009** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7010** ^(The index of the column is stored in 7011** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7012** expr on the right-hand side can be evaluated (and thus the constraint 7013** is usable) and false if it cannot.)^ 7014** 7015** ^The optimizer automatically inverts terms of the form "expr OP column" 7016** and makes other simplifications to the WHERE clause in an attempt to 7017** get as many WHERE clause terms into the form shown above as possible. 7018** ^The aConstraint[] array only reports WHERE clause terms that are 7019** relevant to the particular virtual table being queried. 7020** 7021** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7022** ^Each term of aOrderBy records a column of the ORDER BY clause. 7023** 7024** The colUsed field indicates which columns of the virtual table may be 7025** required by the current scan. Virtual table columns are numbered from 7026** zero in the order in which they appear within the CREATE TABLE statement 7027** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7028** the corresponding bit is set within the colUsed mask if the column may be 7029** required by SQLite. If the table has at least 64 columns and any column 7030** to the right of the first 63 is required, then bit 63 of colUsed is also 7031** set. In other words, column iCol may be required if the expression 7032** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7033** non-zero. 7034** 7035** The [xBestIndex] method must fill aConstraintUsage[] with information 7036** about what parameters to pass to xFilter. ^If argvIndex>0 then 7037** the right-hand side of the corresponding aConstraint[] is evaluated 7038** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7039** is true, then the constraint is assumed to be fully handled by the 7040** virtual table and might not be checked again by the byte code.)^ ^(The 7041** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7042** is left in its default setting of false, the constraint will always be 7043** checked separately in byte code. If the omit flag is change to true, then 7044** the constraint may or may not be checked in byte code. In other words, 7045** when the omit flag is true there is no guarantee that the constraint will 7046** not be checked again using byte code.)^ 7047** 7048** ^The idxNum and idxPtr values are recorded and passed into the 7049** [xFilter] method. 7050** ^[sqlite3_free()] is used to free idxPtr if and only if 7051** needToFreeIdxPtr is true. 7052** 7053** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7054** the correct order to satisfy the ORDER BY clause so that no separate 7055** sorting step is required. 7056** 7057** ^The estimatedCost value is an estimate of the cost of a particular 7058** strategy. A cost of N indicates that the cost of the strategy is similar 7059** to a linear scan of an SQLite table with N rows. A cost of log(N) 7060** indicates that the expense of the operation is similar to that of a 7061** binary search on a unique indexed field of an SQLite table with N rows. 7062** 7063** ^The estimatedRows value is an estimate of the number of rows that 7064** will be returned by the strategy. 7065** 7066** The xBestIndex method may optionally populate the idxFlags field with a 7067** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 7068** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 7069** assumes that the strategy may visit at most one row. 7070** 7071** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7072** SQLite also assumes that if a call to the xUpdate() method is made as 7073** part of the same statement to delete or update a virtual table row and the 7074** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7075** any database changes. In other words, if the xUpdate() returns 7076** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7077** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7078** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7079** the xUpdate method are automatically rolled back by SQLite. 7080** 7081** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7082** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7083** If a virtual table extension is 7084** used with an SQLite version earlier than 3.8.2, the results of attempting 7085** to read or write the estimatedRows field are undefined (but are likely 7086** to include crashing the application). The estimatedRows field should 7087** therefore only be used if [sqlite3_libversion_number()] returns a 7088** value greater than or equal to 3008002. Similarly, the idxFlags field 7089** was added for [version 3.9.0] ([dateof:3.9.0]). 7090** It may therefore only be used if 7091** sqlite3_libversion_number() returns a value greater than or equal to 7092** 3009000. 7093*/ 7094struct sqlite3_index_info { 7095 /* Inputs */ 7096 int nConstraint; /* Number of entries in aConstraint */ 7097 struct sqlite3_index_constraint { 7098 int iColumn; /* Column constrained. -1 for ROWID */ 7099 unsigned char op; /* Constraint operator */ 7100 unsigned char usable; /* True if this constraint is usable */ 7101 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7102 } *aConstraint; /* Table of WHERE clause constraints */ 7103 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7104 struct sqlite3_index_orderby { 7105 int iColumn; /* Column number */ 7106 unsigned char desc; /* True for DESC. False for ASC. */ 7107 } *aOrderBy; /* The ORDER BY clause */ 7108 /* Outputs */ 7109 struct sqlite3_index_constraint_usage { 7110 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7111 unsigned char omit; /* Do not code a test for this constraint */ 7112 } *aConstraintUsage; 7113 int idxNum; /* Number used to identify the index */ 7114 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7115 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7116 int orderByConsumed; /* True if output is already ordered */ 7117 double estimatedCost; /* Estimated cost of using this index */ 7118 /* Fields below are only available in SQLite 3.8.2 and later */ 7119 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7120 /* Fields below are only available in SQLite 3.9.0 and later */ 7121 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7122 /* Fields below are only available in SQLite 3.10.0 and later */ 7123 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7124}; 7125 7126/* 7127** CAPI3REF: Virtual Table Scan Flags 7128** 7129** Virtual table implementations are allowed to set the 7130** [sqlite3_index_info].idxFlags field to some combination of 7131** these bits. 7132*/ 7133#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7134 7135/* 7136** CAPI3REF: Virtual Table Constraint Operator Codes 7137** 7138** These macros define the allowed values for the 7139** [sqlite3_index_info].aConstraint[].op field. Each value represents 7140** an operator that is part of a constraint term in the WHERE clause of 7141** a query that uses a [virtual table]. 7142** 7143** ^The left-hand operand of the operator is given by the corresponding 7144** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7145** operand is the rowid. 7146** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7147** operators have no left-hand operand, and so for those operators the 7148** corresponding aConstraint[].iColumn is meaningless and should not be 7149** used. 7150** 7151** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7152** value 255 are reserved to represent functions that are overloaded 7153** by the [xFindFunction|xFindFunction method] of the virtual table 7154** implementation. 7155** 7156** The right-hand operands for each constraint might be accessible using 7157** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7158** operand is only available if it appears as a single constant literal 7159** in the input SQL. If the right-hand operand is another column or an 7160** expression (even a constant expression) or a parameter, then the 7161** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7162** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7163** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7164** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7165** always return SQLITE_NOTFOUND. 7166** 7167** The collating sequence to be used for comparison can be found using 7168** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7169** tables, the collating sequence of constraints does not matter (for example 7170** because the constraints are numeric) and so the sqlite3_vtab_collation() 7171** interface is no commonly needed. 7172*/ 7173#define SQLITE_INDEX_CONSTRAINT_EQ 2 7174#define SQLITE_INDEX_CONSTRAINT_GT 4 7175#define SQLITE_INDEX_CONSTRAINT_LE 8 7176#define SQLITE_INDEX_CONSTRAINT_LT 16 7177#define SQLITE_INDEX_CONSTRAINT_GE 32 7178#define SQLITE_INDEX_CONSTRAINT_MATCH 64 7179#define SQLITE_INDEX_CONSTRAINT_LIKE 65 7180#define SQLITE_INDEX_CONSTRAINT_GLOB 66 7181#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7182#define SQLITE_INDEX_CONSTRAINT_NE 68 7183#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7184#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7185#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7186#define SQLITE_INDEX_CONSTRAINT_IS 72 7187#define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7188#define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7189#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7190 7191/* 7192** CAPI3REF: Register A Virtual Table Implementation 7193** METHOD: sqlite3 7194** 7195** ^These routines are used to register a new [virtual table module] name. 7196** ^Module names must be registered before 7197** creating a new [virtual table] using the module and before using a 7198** preexisting [virtual table] for the module. 7199** 7200** ^The module name is registered on the [database connection] specified 7201** by the first parameter. ^The name of the module is given by the 7202** second parameter. ^The third parameter is a pointer to 7203** the implementation of the [virtual table module]. ^The fourth 7204** parameter is an arbitrary client data pointer that is passed through 7205** into the [xCreate] and [xConnect] methods of the virtual table module 7206** when a new virtual table is be being created or reinitialized. 7207** 7208** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7209** is a pointer to a destructor for the pClientData. ^SQLite will 7210** invoke the destructor function (if it is not NULL) when SQLite 7211** no longer needs the pClientData pointer. ^The destructor will also 7212** be invoked if the call to sqlite3_create_module_v2() fails. 7213** ^The sqlite3_create_module() 7214** interface is equivalent to sqlite3_create_module_v2() with a NULL 7215** destructor. 7216** 7217** ^If the third parameter (the pointer to the sqlite3_module object) is 7218** NULL then no new module is created and any existing modules with the 7219** same name are dropped. 7220** 7221** See also: [sqlite3_drop_modules()] 7222*/ 7223int sqlite3_create_module( 7224 sqlite3 *db, /* SQLite connection to register module with */ 7225 const char *zName, /* Name of the module */ 7226 const sqlite3_module *p, /* Methods for the module */ 7227 void *pClientData /* Client data for xCreate/xConnect */ 7228); 7229int sqlite3_create_module_v2( 7230 sqlite3 *db, /* SQLite connection to register module with */ 7231 const char *zName, /* Name of the module */ 7232 const sqlite3_module *p, /* Methods for the module */ 7233 void *pClientData, /* Client data for xCreate/xConnect */ 7234 void(*xDestroy)(void*) /* Module destructor function */ 7235); 7236 7237/* 7238** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7239** METHOD: sqlite3 7240** 7241** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7242** table modules from database connection D except those named on list L. 7243** The L parameter must be either NULL or a pointer to an array of pointers 7244** to strings where the array is terminated by a single NULL pointer. 7245** ^If the L parameter is NULL, then all virtual table modules are removed. 7246** 7247** See also: [sqlite3_create_module()] 7248*/ 7249int sqlite3_drop_modules( 7250 sqlite3 *db, /* Remove modules from this connection */ 7251 const char **azKeep /* Except, do not remove the ones named here */ 7252); 7253 7254/* 7255** CAPI3REF: Virtual Table Instance Object 7256** KEYWORDS: sqlite3_vtab 7257** 7258** Every [virtual table module] implementation uses a subclass 7259** of this object to describe a particular instance 7260** of the [virtual table]. Each subclass will 7261** be tailored to the specific needs of the module implementation. 7262** The purpose of this superclass is to define certain fields that are 7263** common to all module implementations. 7264** 7265** ^Virtual tables methods can set an error message by assigning a 7266** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7267** take care that any prior string is freed by a call to [sqlite3_free()] 7268** prior to assigning a new string to zErrMsg. ^After the error message 7269** is delivered up to the client application, the string will be automatically 7270** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7271*/ 7272struct sqlite3_vtab { 7273 const sqlite3_module *pModule; /* The module for this virtual table */ 7274 int nRef; /* Number of open cursors */ 7275 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7276 /* Virtual table implementations will typically add additional fields */ 7277}; 7278 7279/* 7280** CAPI3REF: Virtual Table Cursor Object 7281** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7282** 7283** Every [virtual table module] implementation uses a subclass of the 7284** following structure to describe cursors that point into the 7285** [virtual table] and are used 7286** to loop through the virtual table. Cursors are created using the 7287** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7288** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7289** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7290** of the module. Each module implementation will define 7291** the content of a cursor structure to suit its own needs. 7292** 7293** This superclass exists in order to define fields of the cursor that 7294** are common to all implementations. 7295*/ 7296struct sqlite3_vtab_cursor { 7297 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7298 /* Virtual table implementations will typically add additional fields */ 7299}; 7300 7301/* 7302** CAPI3REF: Declare The Schema Of A Virtual Table 7303** 7304** ^The [xCreate] and [xConnect] methods of a 7305** [virtual table module] call this interface 7306** to declare the format (the names and datatypes of the columns) of 7307** the virtual tables they implement. 7308*/ 7309int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7310 7311/* 7312** CAPI3REF: Overload A Function For A Virtual Table 7313** METHOD: sqlite3 7314** 7315** ^(Virtual tables can provide alternative implementations of functions 7316** using the [xFindFunction] method of the [virtual table module]. 7317** But global versions of those functions 7318** must exist in order to be overloaded.)^ 7319** 7320** ^(This API makes sure a global version of a function with a particular 7321** name and number of parameters exists. If no such function exists 7322** before this API is called, a new function is created.)^ ^The implementation 7323** of the new function always causes an exception to be thrown. So 7324** the new function is not good for anything by itself. Its only 7325** purpose is to be a placeholder function that can be overloaded 7326** by a [virtual table]. 7327*/ 7328int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7329 7330/* 7331** The interface to the virtual-table mechanism defined above (back up 7332** to a comment remarkably similar to this one) is currently considered 7333** to be experimental. The interface might change in incompatible ways. 7334** If this is a problem for you, do not use the interface at this time. 7335** 7336** When the virtual-table mechanism stabilizes, we will declare the 7337** interface fixed, support it indefinitely, and remove this comment. 7338*/ 7339 7340/* 7341** CAPI3REF: A Handle To An Open BLOB 7342** KEYWORDS: {BLOB handle} {BLOB handles} 7343** 7344** An instance of this object represents an open BLOB on which 7345** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7346** ^Objects of this type are created by [sqlite3_blob_open()] 7347** and destroyed by [sqlite3_blob_close()]. 7348** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7349** can be used to read or write small subsections of the BLOB. 7350** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7351*/ 7352typedef struct sqlite3_blob sqlite3_blob; 7353 7354/* 7355** CAPI3REF: Open A BLOB For Incremental I/O 7356** METHOD: sqlite3 7357** CONSTRUCTOR: sqlite3_blob 7358** 7359** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7360** in row iRow, column zColumn, table zTable in database zDb; 7361** in other words, the same BLOB that would be selected by: 7362** 7363** <pre> 7364** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7365** </pre>)^ 7366** 7367** ^(Parameter zDb is not the filename that contains the database, but 7368** rather the symbolic name of the database. For attached databases, this is 7369** the name that appears after the AS keyword in the [ATTACH] statement. 7370** For the main database file, the database name is "main". For TEMP 7371** tables, the database name is "temp".)^ 7372** 7373** ^If the flags parameter is non-zero, then the BLOB is opened for read 7374** and write access. ^If the flags parameter is zero, the BLOB is opened for 7375** read-only access. 7376** 7377** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7378** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7379** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7380** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7381** on *ppBlob after this function it returns. 7382** 7383** This function fails with SQLITE_ERROR if any of the following are true: 7384** <ul> 7385** <li> ^(Database zDb does not exist)^, 7386** <li> ^(Table zTable does not exist within database zDb)^, 7387** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7388** <li> ^(Column zColumn does not exist)^, 7389** <li> ^(Row iRow is not present in the table)^, 7390** <li> ^(The specified column of row iRow contains a value that is not 7391** a TEXT or BLOB value)^, 7392** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7393** constraint and the blob is being opened for read/write access)^, 7394** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7395** column zColumn is part of a [child key] definition and the blob is 7396** being opened for read/write access)^. 7397** </ul> 7398** 7399** ^Unless it returns SQLITE_MISUSE, this function sets the 7400** [database connection] error code and message accessible via 7401** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7402** 7403** A BLOB referenced by sqlite3_blob_open() may be read using the 7404** [sqlite3_blob_read()] interface and modified by using 7405** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7406** different row of the same table using the [sqlite3_blob_reopen()] 7407** interface. However, the column, table, or database of a [BLOB handle] 7408** cannot be changed after the [BLOB handle] is opened. 7409** 7410** ^(If the row that a BLOB handle points to is modified by an 7411** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7412** then the BLOB handle is marked as "expired". 7413** This is true if any column of the row is changed, even a column 7414** other than the one the BLOB handle is open on.)^ 7415** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7416** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7417** ^(Changes written into a BLOB prior to the BLOB expiring are not 7418** rolled back by the expiration of the BLOB. Such changes will eventually 7419** commit if the transaction continues to completion.)^ 7420** 7421** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7422** the opened blob. ^The size of a blob may not be changed by this 7423** interface. Use the [UPDATE] SQL command to change the size of a 7424** blob. 7425** 7426** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7427** and the built-in [zeroblob] SQL function may be used to create a 7428** zero-filled blob to read or write using the incremental-blob interface. 7429** 7430** To avoid a resource leak, every open [BLOB handle] should eventually 7431** be released by a call to [sqlite3_blob_close()]. 7432** 7433** See also: [sqlite3_blob_close()], 7434** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7435** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7436*/ 7437int sqlite3_blob_open( 7438 sqlite3*, 7439 const char *zDb, 7440 const char *zTable, 7441 const char *zColumn, 7442 sqlite3_int64 iRow, 7443 int flags, 7444 sqlite3_blob **ppBlob 7445); 7446 7447/* 7448** CAPI3REF: Move a BLOB Handle to a New Row 7449** METHOD: sqlite3_blob 7450** 7451** ^This function is used to move an existing [BLOB handle] so that it points 7452** to a different row of the same database table. ^The new row is identified 7453** by the rowid value passed as the second argument. Only the row can be 7454** changed. ^The database, table and column on which the blob handle is open 7455** remain the same. Moving an existing [BLOB handle] to a new row is 7456** faster than closing the existing handle and opening a new one. 7457** 7458** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7459** it must exist and there must be either a blob or text value stored in 7460** the nominated column.)^ ^If the new row is not present in the table, or if 7461** it does not contain a blob or text value, or if another error occurs, an 7462** SQLite error code is returned and the blob handle is considered aborted. 7463** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7464** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7465** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7466** always returns zero. 7467** 7468** ^This function sets the database handle error code and message. 7469*/ 7470int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7471 7472/* 7473** CAPI3REF: Close A BLOB Handle 7474** DESTRUCTOR: sqlite3_blob 7475** 7476** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7477** unconditionally. Even if this routine returns an error code, the 7478** handle is still closed.)^ 7479** 7480** ^If the blob handle being closed was opened for read-write access, and if 7481** the database is in auto-commit mode and there are no other open read-write 7482** blob handles or active write statements, the current transaction is 7483** committed. ^If an error occurs while committing the transaction, an error 7484** code is returned and the transaction rolled back. 7485** 7486** Calling this function with an argument that is not a NULL pointer or an 7487** open blob handle results in undefined behaviour. ^Calling this routine 7488** with a null pointer (such as would be returned by a failed call to 7489** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7490** is passed a valid open blob handle, the values returned by the 7491** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7492*/ 7493int sqlite3_blob_close(sqlite3_blob *); 7494 7495/* 7496** CAPI3REF: Return The Size Of An Open BLOB 7497** METHOD: sqlite3_blob 7498** 7499** ^Returns the size in bytes of the BLOB accessible via the 7500** successfully opened [BLOB handle] in its only argument. ^The 7501** incremental blob I/O routines can only read or overwriting existing 7502** blob content; they cannot change the size of a blob. 7503** 7504** This routine only works on a [BLOB handle] which has been created 7505** by a prior successful call to [sqlite3_blob_open()] and which has not 7506** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7507** to this routine results in undefined and probably undesirable behavior. 7508*/ 7509int sqlite3_blob_bytes(sqlite3_blob *); 7510 7511/* 7512** CAPI3REF: Read Data From A BLOB Incrementally 7513** METHOD: sqlite3_blob 7514** 7515** ^(This function is used to read data from an open [BLOB handle] into a 7516** caller-supplied buffer. N bytes of data are copied into buffer Z 7517** from the open BLOB, starting at offset iOffset.)^ 7518** 7519** ^If offset iOffset is less than N bytes from the end of the BLOB, 7520** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7521** less than zero, [SQLITE_ERROR] is returned and no data is read. 7522** ^The size of the blob (and hence the maximum value of N+iOffset) 7523** can be determined using the [sqlite3_blob_bytes()] interface. 7524** 7525** ^An attempt to read from an expired [BLOB handle] fails with an 7526** error code of [SQLITE_ABORT]. 7527** 7528** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7529** Otherwise, an [error code] or an [extended error code] is returned.)^ 7530** 7531** This routine only works on a [BLOB handle] which has been created 7532** by a prior successful call to [sqlite3_blob_open()] and which has not 7533** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7534** to this routine results in undefined and probably undesirable behavior. 7535** 7536** See also: [sqlite3_blob_write()]. 7537*/ 7538int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7539 7540/* 7541** CAPI3REF: Write Data Into A BLOB Incrementally 7542** METHOD: sqlite3_blob 7543** 7544** ^(This function is used to write data into an open [BLOB handle] from a 7545** caller-supplied buffer. N bytes of data are copied from the buffer Z 7546** into the open BLOB, starting at offset iOffset.)^ 7547** 7548** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7549** Otherwise, an [error code] or an [extended error code] is returned.)^ 7550** ^Unless SQLITE_MISUSE is returned, this function sets the 7551** [database connection] error code and message accessible via 7552** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7553** 7554** ^If the [BLOB handle] passed as the first argument was not opened for 7555** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7556** this function returns [SQLITE_READONLY]. 7557** 7558** This function may only modify the contents of the BLOB; it is 7559** not possible to increase the size of a BLOB using this API. 7560** ^If offset iOffset is less than N bytes from the end of the BLOB, 7561** [SQLITE_ERROR] is returned and no data is written. The size of the 7562** BLOB (and hence the maximum value of N+iOffset) can be determined 7563** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7564** than zero [SQLITE_ERROR] is returned and no data is written. 7565** 7566** ^An attempt to write to an expired [BLOB handle] fails with an 7567** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7568** before the [BLOB handle] expired are not rolled back by the 7569** expiration of the handle, though of course those changes might 7570** have been overwritten by the statement that expired the BLOB handle 7571** or by other independent statements. 7572** 7573** This routine only works on a [BLOB handle] which has been created 7574** by a prior successful call to [sqlite3_blob_open()] and which has not 7575** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7576** to this routine results in undefined and probably undesirable behavior. 7577** 7578** See also: [sqlite3_blob_read()]. 7579*/ 7580int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7581 7582/* 7583** CAPI3REF: Virtual File System Objects 7584** 7585** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7586** that SQLite uses to interact 7587** with the underlying operating system. Most SQLite builds come with a 7588** single default VFS that is appropriate for the host computer. 7589** New VFSes can be registered and existing VFSes can be unregistered. 7590** The following interfaces are provided. 7591** 7592** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7593** ^Names are case sensitive. 7594** ^Names are zero-terminated UTF-8 strings. 7595** ^If there is no match, a NULL pointer is returned. 7596** ^If zVfsName is NULL then the default VFS is returned. 7597** 7598** ^New VFSes are registered with sqlite3_vfs_register(). 7599** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7600** ^The same VFS can be registered multiple times without injury. 7601** ^To make an existing VFS into the default VFS, register it again 7602** with the makeDflt flag set. If two different VFSes with the 7603** same name are registered, the behavior is undefined. If a 7604** VFS is registered with a name that is NULL or an empty string, 7605** then the behavior is undefined. 7606** 7607** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7608** ^(If the default VFS is unregistered, another VFS is chosen as 7609** the default. The choice for the new VFS is arbitrary.)^ 7610*/ 7611sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7612int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7613int sqlite3_vfs_unregister(sqlite3_vfs*); 7614 7615/* 7616** CAPI3REF: Mutexes 7617** 7618** The SQLite core uses these routines for thread 7619** synchronization. Though they are intended for internal 7620** use by SQLite, code that links against SQLite is 7621** permitted to use any of these routines. 7622** 7623** The SQLite source code contains multiple implementations 7624** of these mutex routines. An appropriate implementation 7625** is selected automatically at compile-time. The following 7626** implementations are available in the SQLite core: 7627** 7628** <ul> 7629** <li> SQLITE_MUTEX_PTHREADS 7630** <li> SQLITE_MUTEX_W32 7631** <li> SQLITE_MUTEX_NOOP 7632** </ul> 7633** 7634** The SQLITE_MUTEX_NOOP implementation is a set of routines 7635** that does no real locking and is appropriate for use in 7636** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7637** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7638** and Windows. 7639** 7640** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7641** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7642** implementation is included with the library. In this case the 7643** application must supply a custom mutex implementation using the 7644** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7645** before calling sqlite3_initialize() or any other public sqlite3_ 7646** function that calls sqlite3_initialize(). 7647** 7648** ^The sqlite3_mutex_alloc() routine allocates a new 7649** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7650** routine returns NULL if it is unable to allocate the requested 7651** mutex. The argument to sqlite3_mutex_alloc() must one of these 7652** integer constants: 7653** 7654** <ul> 7655** <li> SQLITE_MUTEX_FAST 7656** <li> SQLITE_MUTEX_RECURSIVE 7657** <li> SQLITE_MUTEX_STATIC_MAIN 7658** <li> SQLITE_MUTEX_STATIC_MEM 7659** <li> SQLITE_MUTEX_STATIC_OPEN 7660** <li> SQLITE_MUTEX_STATIC_PRNG 7661** <li> SQLITE_MUTEX_STATIC_LRU 7662** <li> SQLITE_MUTEX_STATIC_PMEM 7663** <li> SQLITE_MUTEX_STATIC_APP1 7664** <li> SQLITE_MUTEX_STATIC_APP2 7665** <li> SQLITE_MUTEX_STATIC_APP3 7666** <li> SQLITE_MUTEX_STATIC_VFS1 7667** <li> SQLITE_MUTEX_STATIC_VFS2 7668** <li> SQLITE_MUTEX_STATIC_VFS3 7669** </ul> 7670** 7671** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7672** cause sqlite3_mutex_alloc() to create 7673** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7674** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7675** The mutex implementation does not need to make a distinction 7676** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7677** not want to. SQLite will only request a recursive mutex in 7678** cases where it really needs one. If a faster non-recursive mutex 7679** implementation is available on the host platform, the mutex subsystem 7680** might return such a mutex in response to SQLITE_MUTEX_FAST. 7681** 7682** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7683** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7684** a pointer to a static preexisting mutex. ^Nine static mutexes are 7685** used by the current version of SQLite. Future versions of SQLite 7686** may add additional static mutexes. Static mutexes are for internal 7687** use by SQLite only. Applications that use SQLite mutexes should 7688** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7689** SQLITE_MUTEX_RECURSIVE. 7690** 7691** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7692** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7693** returns a different mutex on every call. ^For the static 7694** mutex types, the same mutex is returned on every call that has 7695** the same type number. 7696** 7697** ^The sqlite3_mutex_free() routine deallocates a previously 7698** allocated dynamic mutex. Attempting to deallocate a static 7699** mutex results in undefined behavior. 7700** 7701** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7702** to enter a mutex. ^If another thread is already within the mutex, 7703** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7704** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7705** upon successful entry. ^(Mutexes created using 7706** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7707** In such cases, the 7708** mutex must be exited an equal number of times before another thread 7709** can enter.)^ If the same thread tries to enter any mutex other 7710** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7711** 7712** ^(Some systems (for example, Windows 95) do not support the operation 7713** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7714** will always return SQLITE_BUSY. The SQLite core only ever uses 7715** sqlite3_mutex_try() as an optimization so this is acceptable 7716** behavior.)^ 7717** 7718** ^The sqlite3_mutex_leave() routine exits a mutex that was 7719** previously entered by the same thread. The behavior 7720** is undefined if the mutex is not currently entered by the 7721** calling thread or is not currently allocated. 7722** 7723** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7724** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7725** behave as no-ops. 7726** 7727** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7728*/ 7729sqlite3_mutex *sqlite3_mutex_alloc(int); 7730void sqlite3_mutex_free(sqlite3_mutex*); 7731void sqlite3_mutex_enter(sqlite3_mutex*); 7732int sqlite3_mutex_try(sqlite3_mutex*); 7733void sqlite3_mutex_leave(sqlite3_mutex*); 7734 7735/* 7736** CAPI3REF: Mutex Methods Object 7737** 7738** An instance of this structure defines the low-level routines 7739** used to allocate and use mutexes. 7740** 7741** Usually, the default mutex implementations provided by SQLite are 7742** sufficient, however the application has the option of substituting a custom 7743** implementation for specialized deployments or systems for which SQLite 7744** does not provide a suitable implementation. In this case, the application 7745** creates and populates an instance of this structure to pass 7746** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7747** Additionally, an instance of this structure can be used as an 7748** output variable when querying the system for the current mutex 7749** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7750** 7751** ^The xMutexInit method defined by this structure is invoked as 7752** part of system initialization by the sqlite3_initialize() function. 7753** ^The xMutexInit routine is called by SQLite exactly once for each 7754** effective call to [sqlite3_initialize()]. 7755** 7756** ^The xMutexEnd method defined by this structure is invoked as 7757** part of system shutdown by the sqlite3_shutdown() function. The 7758** implementation of this method is expected to release all outstanding 7759** resources obtained by the mutex methods implementation, especially 7760** those obtained by the xMutexInit method. ^The xMutexEnd() 7761** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7762** 7763** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7764** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7765** xMutexNotheld) implement the following interfaces (respectively): 7766** 7767** <ul> 7768** <li> [sqlite3_mutex_alloc()] </li> 7769** <li> [sqlite3_mutex_free()] </li> 7770** <li> [sqlite3_mutex_enter()] </li> 7771** <li> [sqlite3_mutex_try()] </li> 7772** <li> [sqlite3_mutex_leave()] </li> 7773** <li> [sqlite3_mutex_held()] </li> 7774** <li> [sqlite3_mutex_notheld()] </li> 7775** </ul>)^ 7776** 7777** The only difference is that the public sqlite3_XXX functions enumerated 7778** above silently ignore any invocations that pass a NULL pointer instead 7779** of a valid mutex handle. The implementations of the methods defined 7780** by this structure are not required to handle this case. The results 7781** of passing a NULL pointer instead of a valid mutex handle are undefined 7782** (i.e. it is acceptable to provide an implementation that segfaults if 7783** it is passed a NULL pointer). 7784** 7785** The xMutexInit() method must be threadsafe. It must be harmless to 7786** invoke xMutexInit() multiple times within the same process and without 7787** intervening calls to xMutexEnd(). Second and subsequent calls to 7788** xMutexInit() must be no-ops. 7789** 7790** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7791** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7792** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7793** memory allocation for a fast or recursive mutex. 7794** 7795** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7796** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7797** If xMutexInit fails in any way, it is expected to clean up after itself 7798** prior to returning. 7799*/ 7800typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7801struct sqlite3_mutex_methods { 7802 int (*xMutexInit)(void); 7803 int (*xMutexEnd)(void); 7804 sqlite3_mutex *(*xMutexAlloc)(int); 7805 void (*xMutexFree)(sqlite3_mutex *); 7806 void (*xMutexEnter)(sqlite3_mutex *); 7807 int (*xMutexTry)(sqlite3_mutex *); 7808 void (*xMutexLeave)(sqlite3_mutex *); 7809 int (*xMutexHeld)(sqlite3_mutex *); 7810 int (*xMutexNotheld)(sqlite3_mutex *); 7811}; 7812 7813/* 7814** CAPI3REF: Mutex Verification Routines 7815** 7816** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7817** are intended for use inside assert() statements. The SQLite core 7818** never uses these routines except inside an assert() and applications 7819** are advised to follow the lead of the core. The SQLite core only 7820** provides implementations for these routines when it is compiled 7821** with the SQLITE_DEBUG flag. External mutex implementations 7822** are only required to provide these routines if SQLITE_DEBUG is 7823** defined and if NDEBUG is not defined. 7824** 7825** These routines should return true if the mutex in their argument 7826** is held or not held, respectively, by the calling thread. 7827** 7828** The implementation is not required to provide versions of these 7829** routines that actually work. If the implementation does not provide working 7830** versions of these routines, it should at least provide stubs that always 7831** return true so that one does not get spurious assertion failures. 7832** 7833** If the argument to sqlite3_mutex_held() is a NULL pointer then 7834** the routine should return 1. This seems counter-intuitive since 7835** clearly the mutex cannot be held if it does not exist. But 7836** the reason the mutex does not exist is because the build is not 7837** using mutexes. And we do not want the assert() containing the 7838** call to sqlite3_mutex_held() to fail, so a non-zero return is 7839** the appropriate thing to do. The sqlite3_mutex_notheld() 7840** interface should also return 1 when given a NULL pointer. 7841*/ 7842#ifndef NDEBUG 7843int sqlite3_mutex_held(sqlite3_mutex*); 7844int sqlite3_mutex_notheld(sqlite3_mutex*); 7845#endif 7846 7847/* 7848** CAPI3REF: Mutex Types 7849** 7850** The [sqlite3_mutex_alloc()] interface takes a single argument 7851** which is one of these integer constants. 7852** 7853** The set of static mutexes may change from one SQLite release to the 7854** next. Applications that override the built-in mutex logic must be 7855** prepared to accommodate additional static mutexes. 7856*/ 7857#define SQLITE_MUTEX_FAST 0 7858#define SQLITE_MUTEX_RECURSIVE 1 7859#define SQLITE_MUTEX_STATIC_MAIN 2 7860#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7861#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7862#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7863#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7864#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7865#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7866#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7867#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7868#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7869#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7870#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7871#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7872#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7873 7874/* Legacy compatibility: */ 7875#define SQLITE_MUTEX_STATIC_MASTER 2 7876 7877 7878/* 7879** CAPI3REF: Retrieve the mutex for a database connection 7880** METHOD: sqlite3 7881** 7882** ^This interface returns a pointer the [sqlite3_mutex] object that 7883** serializes access to the [database connection] given in the argument 7884** when the [threading mode] is Serialized. 7885** ^If the [threading mode] is Single-thread or Multi-thread then this 7886** routine returns a NULL pointer. 7887*/ 7888sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7889 7890/* 7891** CAPI3REF: Low-Level Control Of Database Files 7892** METHOD: sqlite3 7893** KEYWORDS: {file control} 7894** 7895** ^The [sqlite3_file_control()] interface makes a direct call to the 7896** xFileControl method for the [sqlite3_io_methods] object associated 7897** with a particular database identified by the second argument. ^The 7898** name of the database is "main" for the main database or "temp" for the 7899** TEMP database, or the name that appears after the AS keyword for 7900** databases that are added using the [ATTACH] SQL command. 7901** ^A NULL pointer can be used in place of "main" to refer to the 7902** main database file. 7903** ^The third and fourth parameters to this routine 7904** are passed directly through to the second and third parameters of 7905** the xFileControl method. ^The return value of the xFileControl 7906** method becomes the return value of this routine. 7907** 7908** A few opcodes for [sqlite3_file_control()] are handled directly 7909** by the SQLite core and never invoke the 7910** sqlite3_io_methods.xFileControl method. 7911** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7912** a pointer to the underlying [sqlite3_file] object to be written into 7913** the space pointed to by the 4th parameter. The 7914** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7915** the [sqlite3_file] object associated with the journal file instead of 7916** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7917** a pointer to the underlying [sqlite3_vfs] object for the file. 7918** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7919** from the pager. 7920** 7921** ^If the second parameter (zDbName) does not match the name of any 7922** open database file, then SQLITE_ERROR is returned. ^This error 7923** code is not remembered and will not be recalled by [sqlite3_errcode()] 7924** or [sqlite3_errmsg()]. The underlying xFileControl method might 7925** also return SQLITE_ERROR. There is no way to distinguish between 7926** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7927** xFileControl method. 7928** 7929** See also: [file control opcodes] 7930*/ 7931int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7932 7933/* 7934** CAPI3REF: Testing Interface 7935** 7936** ^The sqlite3_test_control() interface is used to read out internal 7937** state of SQLite and to inject faults into SQLite for testing 7938** purposes. ^The first parameter is an operation code that determines 7939** the number, meaning, and operation of all subsequent parameters. 7940** 7941** This interface is not for use by applications. It exists solely 7942** for verifying the correct operation of the SQLite library. Depending 7943** on how the SQLite library is compiled, this interface might not exist. 7944** 7945** The details of the operation codes, their meanings, the parameters 7946** they take, and what they do are all subject to change without notice. 7947** Unlike most of the SQLite API, this function is not guaranteed to 7948** operate consistently from one release to the next. 7949*/ 7950int sqlite3_test_control(int op, ...); 7951 7952/* 7953** CAPI3REF: Testing Interface Operation Codes 7954** 7955** These constants are the valid operation code parameters used 7956** as the first argument to [sqlite3_test_control()]. 7957** 7958** These parameters and their meanings are subject to change 7959** without notice. These values are for testing purposes only. 7960** Applications should not use any of these parameters or the 7961** [sqlite3_test_control()] interface. 7962*/ 7963#define SQLITE_TESTCTRL_FIRST 5 7964#define SQLITE_TESTCTRL_PRNG_SAVE 5 7965#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7966#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7967#define SQLITE_TESTCTRL_BITVEC_TEST 8 7968#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7969#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7970#define SQLITE_TESTCTRL_PENDING_BYTE 11 7971#define SQLITE_TESTCTRL_ASSERT 12 7972#define SQLITE_TESTCTRL_ALWAYS 13 7973#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 7974#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7975#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7976#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7977#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7978#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7979#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7980#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7981#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7982#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7983#define SQLITE_TESTCTRL_BYTEORDER 22 7984#define SQLITE_TESTCTRL_ISINIT 23 7985#define SQLITE_TESTCTRL_SORTER_MMAP 24 7986#define SQLITE_TESTCTRL_IMPOSTER 25 7987#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7988#define SQLITE_TESTCTRL_RESULT_INTREAL 27 7989#define SQLITE_TESTCTRL_PRNG_SEED 28 7990#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7991#define SQLITE_TESTCTRL_SEEK_COUNT 30 7992#define SQLITE_TESTCTRL_TRACEFLAGS 31 7993#define SQLITE_TESTCTRL_TUNE 32 7994#define SQLITE_TESTCTRL_LOGEST 33 7995#define SQLITE_TESTCTRL_LAST 33 /* Largest TESTCTRL */ 7996 7997/* 7998** CAPI3REF: SQL Keyword Checking 7999** 8000** These routines provide access to the set of SQL language keywords 8001** recognized by SQLite. Applications can uses these routines to determine 8002** whether or not a specific identifier needs to be escaped (for example, 8003** by enclosing in double-quotes) so as not to confuse the parser. 8004** 8005** The sqlite3_keyword_count() interface returns the number of distinct 8006** keywords understood by SQLite. 8007** 8008** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 8009** makes *Z point to that keyword expressed as UTF8 and writes the number 8010** of bytes in the keyword into *L. The string that *Z points to is not 8011** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8012** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8013** or L are NULL or invalid pointers then calls to 8014** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8015** 8016** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8017** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8018** if it is and zero if not. 8019** 8020** The parser used by SQLite is forgiving. It is often possible to use 8021** a keyword as an identifier as long as such use does not result in a 8022** parsing ambiguity. For example, the statement 8023** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8024** creates a new table named "BEGIN" with three columns named 8025** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8026** using keywords as identifiers. Common techniques used to avoid keyword 8027** name collisions include: 8028** <ul> 8029** <li> Put all identifier names inside double-quotes. This is the official 8030** SQL way to escape identifier names. 8031** <li> Put identifier names inside [...]. This is not standard SQL, 8032** but it is what SQL Server does and so lots of programmers use this 8033** technique. 8034** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8035** with "Z". 8036** <li> Include a digit somewhere in every identifier name. 8037** </ul> 8038** 8039** Note that the number of keywords understood by SQLite can depend on 8040** compile-time options. For example, "VACUUM" is not a keyword if 8041** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8042** new keywords may be added to future releases of SQLite. 8043*/ 8044int sqlite3_keyword_count(void); 8045int sqlite3_keyword_name(int,const char**,int*); 8046int sqlite3_keyword_check(const char*,int); 8047 8048/* 8049** CAPI3REF: Dynamic String Object 8050** KEYWORDS: {dynamic string} 8051** 8052** An instance of the sqlite3_str object contains a dynamically-sized 8053** string under construction. 8054** 8055** The lifecycle of an sqlite3_str object is as follows: 8056** <ol> 8057** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8058** <li> ^Text is appended to the sqlite3_str object using various 8059** methods, such as [sqlite3_str_appendf()]. 8060** <li> ^The sqlite3_str object is destroyed and the string it created 8061** is returned using the [sqlite3_str_finish()] interface. 8062** </ol> 8063*/ 8064typedef struct sqlite3_str sqlite3_str; 8065 8066/* 8067** CAPI3REF: Create A New Dynamic String Object 8068** CONSTRUCTOR: sqlite3_str 8069** 8070** ^The [sqlite3_str_new(D)] interface allocates and initializes 8071** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8072** [sqlite3_str_new()] must be freed by a subsequent call to 8073** [sqlite3_str_finish(X)]. 8074** 8075** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8076** valid [sqlite3_str] object, though in the event of an out-of-memory 8077** error the returned object might be a special singleton that will 8078** silently reject new text, always return SQLITE_NOMEM from 8079** [sqlite3_str_errcode()], always return 0 for 8080** [sqlite3_str_length()], and always return NULL from 8081** [sqlite3_str_finish(X)]. It is always safe to use the value 8082** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8083** to any of the other [sqlite3_str] methods. 8084** 8085** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8086** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8087** length of the string contained in the [sqlite3_str] object will be 8088** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8089** of [SQLITE_MAX_LENGTH]. 8090*/ 8091sqlite3_str *sqlite3_str_new(sqlite3*); 8092 8093/* 8094** CAPI3REF: Finalize A Dynamic String 8095** DESTRUCTOR: sqlite3_str 8096** 8097** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8098** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8099** that contains the constructed string. The calling application should 8100** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8101** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8102** errors were encountered during construction of the string. ^The 8103** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8104** string in [sqlite3_str] object X is zero bytes long. 8105*/ 8106char *sqlite3_str_finish(sqlite3_str*); 8107 8108/* 8109** CAPI3REF: Add Content To A Dynamic String 8110** METHOD: sqlite3_str 8111** 8112** These interfaces add content to an sqlite3_str object previously obtained 8113** from [sqlite3_str_new()]. 8114** 8115** ^The [sqlite3_str_appendf(X,F,...)] and 8116** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8117** functionality of SQLite to append formatted text onto the end of 8118** [sqlite3_str] object X. 8119** 8120** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8121** onto the end of the [sqlite3_str] object X. N must be non-negative. 8122** S must contain at least N non-zero bytes of content. To append a 8123** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8124** method instead. 8125** 8126** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8127** zero-terminated string S onto the end of [sqlite3_str] object X. 8128** 8129** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8130** single-byte character C onto the end of [sqlite3_str] object X. 8131** ^This method can be used, for example, to add whitespace indentation. 8132** 8133** ^The [sqlite3_str_reset(X)] method resets the string under construction 8134** inside [sqlite3_str] object X back to zero bytes in length. 8135** 8136** These methods do not return a result code. ^If an error occurs, that fact 8137** is recorded in the [sqlite3_str] object and can be recovered by a 8138** subsequent call to [sqlite3_str_errcode(X)]. 8139*/ 8140void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8141void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8142void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8143void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8144void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8145void sqlite3_str_reset(sqlite3_str*); 8146 8147/* 8148** CAPI3REF: Status Of A Dynamic String 8149** METHOD: sqlite3_str 8150** 8151** These interfaces return the current status of an [sqlite3_str] object. 8152** 8153** ^If any prior errors have occurred while constructing the dynamic string 8154** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8155** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8156** [SQLITE_NOMEM] following any out-of-memory error, or 8157** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8158** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8159** 8160** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8161** of the dynamic string under construction in [sqlite3_str] object X. 8162** ^The length returned by [sqlite3_str_length(X)] does not include the 8163** zero-termination byte. 8164** 8165** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8166** content of the dynamic string under construction in X. The value 8167** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8168** and might be freed or altered by any subsequent method on the same 8169** [sqlite3_str] object. Applications must not used the pointer returned 8170** [sqlite3_str_value(X)] after any subsequent method call on the same 8171** object. ^Applications may change the content of the string returned 8172** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8173** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8174** write any byte after any subsequent sqlite3_str method call. 8175*/ 8176int sqlite3_str_errcode(sqlite3_str*); 8177int sqlite3_str_length(sqlite3_str*); 8178char *sqlite3_str_value(sqlite3_str*); 8179 8180/* 8181** CAPI3REF: SQLite Runtime Status 8182** 8183** ^These interfaces are used to retrieve runtime status information 8184** about the performance of SQLite, and optionally to reset various 8185** highwater marks. ^The first argument is an integer code for 8186** the specific parameter to measure. ^(Recognized integer codes 8187** are of the form [status parameters | SQLITE_STATUS_...].)^ 8188** ^The current value of the parameter is returned into *pCurrent. 8189** ^The highest recorded value is returned in *pHighwater. ^If the 8190** resetFlag is true, then the highest record value is reset after 8191** *pHighwater is written. ^(Some parameters do not record the highest 8192** value. For those parameters 8193** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8194** ^(Other parameters record only the highwater mark and not the current 8195** value. For these latter parameters nothing is written into *pCurrent.)^ 8196** 8197** ^The sqlite3_status() and sqlite3_status64() routines return 8198** SQLITE_OK on success and a non-zero [error code] on failure. 8199** 8200** If either the current value or the highwater mark is too large to 8201** be represented by a 32-bit integer, then the values returned by 8202** sqlite3_status() are undefined. 8203** 8204** See also: [sqlite3_db_status()] 8205*/ 8206int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8207int sqlite3_status64( 8208 int op, 8209 sqlite3_int64 *pCurrent, 8210 sqlite3_int64 *pHighwater, 8211 int resetFlag 8212); 8213 8214 8215/* 8216** CAPI3REF: Status Parameters 8217** KEYWORDS: {status parameters} 8218** 8219** These integer constants designate various run-time status parameters 8220** that can be returned by [sqlite3_status()]. 8221** 8222** <dl> 8223** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8224** <dd>This parameter is the current amount of memory checked out 8225** using [sqlite3_malloc()], either directly or indirectly. The 8226** figure includes calls made to [sqlite3_malloc()] by the application 8227** and internal memory usage by the SQLite library. Auxiliary page-cache 8228** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8229** this parameter. The amount returned is the sum of the allocation 8230** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8231** 8232** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8233** <dd>This parameter records the largest memory allocation request 8234** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8235** internal equivalents). Only the value returned in the 8236** *pHighwater parameter to [sqlite3_status()] is of interest. 8237** The value written into the *pCurrent parameter is undefined.</dd>)^ 8238** 8239** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8240** <dd>This parameter records the number of separate memory allocations 8241** currently checked out.</dd>)^ 8242** 8243** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8244** <dd>This parameter returns the number of pages used out of the 8245** [pagecache memory allocator] that was configured using 8246** [SQLITE_CONFIG_PAGECACHE]. The 8247** value returned is in pages, not in bytes.</dd>)^ 8248** 8249** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8250** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8251** <dd>This parameter returns the number of bytes of page cache 8252** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8253** buffer and where forced to overflow to [sqlite3_malloc()]. The 8254** returned value includes allocations that overflowed because they 8255** where too large (they were larger than the "sz" parameter to 8256** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8257** no space was left in the page cache.</dd>)^ 8258** 8259** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8260** <dd>This parameter records the largest memory allocation request 8261** handed to the [pagecache memory allocator]. Only the value returned in the 8262** *pHighwater parameter to [sqlite3_status()] is of interest. 8263** The value written into the *pCurrent parameter is undefined.</dd>)^ 8264** 8265** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8266** <dd>No longer used.</dd> 8267** 8268** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8269** <dd>No longer used.</dd> 8270** 8271** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8272** <dd>No longer used.</dd> 8273** 8274** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8275** <dd>The *pHighwater parameter records the deepest parser stack. 8276** The *pCurrent value is undefined. The *pHighwater value is only 8277** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8278** </dl> 8279** 8280** New status parameters may be added from time to time. 8281*/ 8282#define SQLITE_STATUS_MEMORY_USED 0 8283#define SQLITE_STATUS_PAGECACHE_USED 1 8284#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8285#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8286#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8287#define SQLITE_STATUS_MALLOC_SIZE 5 8288#define SQLITE_STATUS_PARSER_STACK 6 8289#define SQLITE_STATUS_PAGECACHE_SIZE 7 8290#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8291#define SQLITE_STATUS_MALLOC_COUNT 9 8292 8293/* 8294** CAPI3REF: Database Connection Status 8295** METHOD: sqlite3 8296** 8297** ^This interface is used to retrieve runtime status information 8298** about a single [database connection]. ^The first argument is the 8299** database connection object to be interrogated. ^The second argument 8300** is an integer constant, taken from the set of 8301** [SQLITE_DBSTATUS options], that 8302** determines the parameter to interrogate. The set of 8303** [SQLITE_DBSTATUS options] is likely 8304** to grow in future releases of SQLite. 8305** 8306** ^The current value of the requested parameter is written into *pCur 8307** and the highest instantaneous value is written into *pHiwtr. ^If 8308** the resetFlg is true, then the highest instantaneous value is 8309** reset back down to the current value. 8310** 8311** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8312** non-zero [error code] on failure. 8313** 8314** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8315*/ 8316int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8317 8318/* 8319** CAPI3REF: Status Parameters for database connections 8320** KEYWORDS: {SQLITE_DBSTATUS options} 8321** 8322** These constants are the available integer "verbs" that can be passed as 8323** the second argument to the [sqlite3_db_status()] interface. 8324** 8325** New verbs may be added in future releases of SQLite. Existing verbs 8326** might be discontinued. Applications should check the return code from 8327** [sqlite3_db_status()] to make sure that the call worked. 8328** The [sqlite3_db_status()] interface will return a non-zero error code 8329** if a discontinued or unsupported verb is invoked. 8330** 8331** <dl> 8332** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8333** <dd>This parameter returns the number of lookaside memory slots currently 8334** checked out.</dd>)^ 8335** 8336** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8337** <dd>This parameter returns the number of malloc attempts that were 8338** satisfied using lookaside memory. Only the high-water value is meaningful; 8339** the current value is always zero.)^ 8340** 8341** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8342** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8343** <dd>This parameter returns the number malloc attempts that might have 8344** been satisfied using lookaside memory but failed due to the amount of 8345** memory requested being larger than the lookaside slot size. 8346** Only the high-water value is meaningful; 8347** the current value is always zero.)^ 8348** 8349** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8350** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8351** <dd>This parameter returns the number malloc attempts that might have 8352** been satisfied using lookaside memory but failed due to all lookaside 8353** memory already being in use. 8354** Only the high-water value is meaningful; 8355** the current value is always zero.)^ 8356** 8357** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8358** <dd>This parameter returns the approximate number of bytes of heap 8359** memory used by all pager caches associated with the database connection.)^ 8360** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8361** 8362** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8363** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8364** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8365** pager cache is shared between two or more connections the bytes of heap 8366** memory used by that pager cache is divided evenly between the attached 8367** connections.)^ In other words, if none of the pager caches associated 8368** with the database connection are shared, this request returns the same 8369** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8370** shared, the value returned by this call will be smaller than that returned 8371** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8372** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8373** 8374** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8375** <dd>This parameter returns the approximate number of bytes of heap 8376** memory used to store the schema for all databases associated 8377** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8378** ^The full amount of memory used by the schemas is reported, even if the 8379** schema memory is shared with other database connections due to 8380** [shared cache mode] being enabled. 8381** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8382** 8383** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8384** <dd>This parameter returns the approximate number of bytes of heap 8385** and lookaside memory used by all prepared statements associated with 8386** the database connection.)^ 8387** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8388** </dd> 8389** 8390** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8391** <dd>This parameter returns the number of pager cache hits that have 8392** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8393** is always 0. 8394** </dd> 8395** 8396** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8397** <dd>This parameter returns the number of pager cache misses that have 8398** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8399** is always 0. 8400** </dd> 8401** 8402** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8403** <dd>This parameter returns the number of dirty cache entries that have 8404** been written to disk. Specifically, the number of pages written to the 8405** wal file in wal mode databases, or the number of pages written to the 8406** database file in rollback mode databases. Any pages written as part of 8407** transaction rollback or database recovery operations are not included. 8408** If an IO or other error occurs while writing a page to disk, the effect 8409** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8410** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8411** </dd> 8412** 8413** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8414** <dd>This parameter returns the number of dirty cache entries that have 8415** been written to disk in the middle of a transaction due to the page 8416** cache overflowing. Transactions are more efficient if they are written 8417** to disk all at once. When pages spill mid-transaction, that introduces 8418** additional overhead. This parameter can be used help identify 8419** inefficiencies that can be resolved by increasing the cache size. 8420** </dd> 8421** 8422** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8423** <dd>This parameter returns zero for the current value if and only if 8424** all foreign key constraints (deferred or immediate) have been 8425** resolved.)^ ^The highwater mark is always 0. 8426** </dd> 8427** </dl> 8428*/ 8429#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8430#define SQLITE_DBSTATUS_CACHE_USED 1 8431#define SQLITE_DBSTATUS_SCHEMA_USED 2 8432#define SQLITE_DBSTATUS_STMT_USED 3 8433#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8434#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8435#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8436#define SQLITE_DBSTATUS_CACHE_HIT 7 8437#define SQLITE_DBSTATUS_CACHE_MISS 8 8438#define SQLITE_DBSTATUS_CACHE_WRITE 9 8439#define SQLITE_DBSTATUS_DEFERRED_FKS 10 8440#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8441#define SQLITE_DBSTATUS_CACHE_SPILL 12 8442#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8443 8444 8445/* 8446** CAPI3REF: Prepared Statement Status 8447** METHOD: sqlite3_stmt 8448** 8449** ^(Each prepared statement maintains various 8450** [SQLITE_STMTSTATUS counters] that measure the number 8451** of times it has performed specific operations.)^ These counters can 8452** be used to monitor the performance characteristics of the prepared 8453** statements. For example, if the number of table steps greatly exceeds 8454** the number of table searches or result rows, that would tend to indicate 8455** that the prepared statement is using a full table scan rather than 8456** an index. 8457** 8458** ^(This interface is used to retrieve and reset counter values from 8459** a [prepared statement]. The first argument is the prepared statement 8460** object to be interrogated. The second argument 8461** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8462** to be interrogated.)^ 8463** ^The current value of the requested counter is returned. 8464** ^If the resetFlg is true, then the counter is reset to zero after this 8465** interface call returns. 8466** 8467** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8468*/ 8469int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8470 8471/* 8472** CAPI3REF: Status Parameters for prepared statements 8473** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8474** 8475** These preprocessor macros define integer codes that name counter 8476** values associated with the [sqlite3_stmt_status()] interface. 8477** The meanings of the various counters are as follows: 8478** 8479** <dl> 8480** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8481** <dd>^This is the number of times that SQLite has stepped forward in 8482** a table as part of a full table scan. Large numbers for this counter 8483** may indicate opportunities for performance improvement through 8484** careful use of indices.</dd> 8485** 8486** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8487** <dd>^This is the number of sort operations that have occurred. 8488** A non-zero value in this counter may indicate an opportunity to 8489** improvement performance through careful use of indices.</dd> 8490** 8491** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8492** <dd>^This is the number of rows inserted into transient indices that 8493** were created automatically in order to help joins run faster. 8494** A non-zero value in this counter may indicate an opportunity to 8495** improvement performance by adding permanent indices that do not 8496** need to be reinitialized each time the statement is run.</dd> 8497** 8498** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8499** <dd>^This is the number of virtual machine operations executed 8500** by the prepared statement if that number is less than or equal 8501** to 2147483647. The number of virtual machine operations can be 8502** used as a proxy for the total work done by the prepared statement. 8503** If the number of virtual machine operations exceeds 2147483647 8504** then the value returned by this statement status code is undefined. 8505** 8506** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8507** <dd>^This is the number of times that the prepare statement has been 8508** automatically regenerated due to schema changes or changes to 8509** [bound parameters] that might affect the query plan. 8510** 8511** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8512** <dd>^This is the number of times that the prepared statement has 8513** been run. A single "run" for the purposes of this counter is one 8514** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8515** The counter is incremented on the first [sqlite3_step()] call of each 8516** cycle. 8517** 8518** [[SQLITE_STMTSTATUS_FILTER_MISS]] 8519** [[SQLITE_STMTSTATUS_FILTER HIT]] 8520** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 8521** SQLITE_STMTSTATUS_FILTER_MISS</dt> 8522** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 8523** step was bypassed because a Bloom filter returned not-found. The 8524** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 8525** times that the Bloom filter returned a find, and thus the join step 8526** had to be processed as normal. 8527** 8528** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8529** <dd>^This is the approximate number of bytes of heap memory 8530** used to store the prepared statement. ^This value is not actually 8531** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8532** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8533** </dd> 8534** </dl> 8535*/ 8536#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8537#define SQLITE_STMTSTATUS_SORT 2 8538#define SQLITE_STMTSTATUS_AUTOINDEX 3 8539#define SQLITE_STMTSTATUS_VM_STEP 4 8540#define SQLITE_STMTSTATUS_REPREPARE 5 8541#define SQLITE_STMTSTATUS_RUN 6 8542#define SQLITE_STMTSTATUS_FILTER_MISS 7 8543#define SQLITE_STMTSTATUS_FILTER_HIT 8 8544#define SQLITE_STMTSTATUS_MEMUSED 99 8545 8546/* 8547** CAPI3REF: Custom Page Cache Object 8548** 8549** The sqlite3_pcache type is opaque. It is implemented by 8550** the pluggable module. The SQLite core has no knowledge of 8551** its size or internal structure and never deals with the 8552** sqlite3_pcache object except by holding and passing pointers 8553** to the object. 8554** 8555** See [sqlite3_pcache_methods2] for additional information. 8556*/ 8557typedef struct sqlite3_pcache sqlite3_pcache; 8558 8559/* 8560** CAPI3REF: Custom Page Cache Object 8561** 8562** The sqlite3_pcache_page object represents a single page in the 8563** page cache. The page cache will allocate instances of this 8564** object. Various methods of the page cache use pointers to instances 8565** of this object as parameters or as their return value. 8566** 8567** See [sqlite3_pcache_methods2] for additional information. 8568*/ 8569typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8570struct sqlite3_pcache_page { 8571 void *pBuf; /* The content of the page */ 8572 void *pExtra; /* Extra information associated with the page */ 8573}; 8574 8575/* 8576** CAPI3REF: Application Defined Page Cache. 8577** KEYWORDS: {page cache} 8578** 8579** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8580** register an alternative page cache implementation by passing in an 8581** instance of the sqlite3_pcache_methods2 structure.)^ 8582** In many applications, most of the heap memory allocated by 8583** SQLite is used for the page cache. 8584** By implementing a 8585** custom page cache using this API, an application can better control 8586** the amount of memory consumed by SQLite, the way in which 8587** that memory is allocated and released, and the policies used to 8588** determine exactly which parts of a database file are cached and for 8589** how long. 8590** 8591** The alternative page cache mechanism is an 8592** extreme measure that is only needed by the most demanding applications. 8593** The built-in page cache is recommended for most uses. 8594** 8595** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8596** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8597** the application may discard the parameter after the call to 8598** [sqlite3_config()] returns.)^ 8599** 8600** [[the xInit() page cache method]] 8601** ^(The xInit() method is called once for each effective 8602** call to [sqlite3_initialize()])^ 8603** (usually only once during the lifetime of the process). ^(The xInit() 8604** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8605** The intent of the xInit() method is to set up global data structures 8606** required by the custom page cache implementation. 8607** ^(If the xInit() method is NULL, then the 8608** built-in default page cache is used instead of the application defined 8609** page cache.)^ 8610** 8611** [[the xShutdown() page cache method]] 8612** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8613** It can be used to clean up 8614** any outstanding resources before process shutdown, if required. 8615** ^The xShutdown() method may be NULL. 8616** 8617** ^SQLite automatically serializes calls to the xInit method, 8618** so the xInit method need not be threadsafe. ^The 8619** xShutdown method is only called from [sqlite3_shutdown()] so it does 8620** not need to be threadsafe either. All other methods must be threadsafe 8621** in multithreaded applications. 8622** 8623** ^SQLite will never invoke xInit() more than once without an intervening 8624** call to xShutdown(). 8625** 8626** [[the xCreate() page cache methods]] 8627** ^SQLite invokes the xCreate() method to construct a new cache instance. 8628** SQLite will typically create one cache instance for each open database file, 8629** though this is not guaranteed. ^The 8630** first parameter, szPage, is the size in bytes of the pages that must 8631** be allocated by the cache. ^szPage will always a power of two. ^The 8632** second parameter szExtra is a number of bytes of extra storage 8633** associated with each page cache entry. ^The szExtra parameter will 8634** a number less than 250. SQLite will use the 8635** extra szExtra bytes on each page to store metadata about the underlying 8636** database page on disk. The value passed into szExtra depends 8637** on the SQLite version, the target platform, and how SQLite was compiled. 8638** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8639** created will be used to cache database pages of a file stored on disk, or 8640** false if it is used for an in-memory database. The cache implementation 8641** does not have to do anything special based with the value of bPurgeable; 8642** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8643** never invoke xUnpin() except to deliberately delete a page. 8644** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8645** false will always have the "discard" flag set to true. 8646** ^Hence, a cache created with bPurgeable false will 8647** never contain any unpinned pages. 8648** 8649** [[the xCachesize() page cache method]] 8650** ^(The xCachesize() method may be called at any time by SQLite to set the 8651** suggested maximum cache-size (number of pages stored by) the cache 8652** instance passed as the first argument. This is the value configured using 8653** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8654** parameter, the implementation is not required to do anything with this 8655** value; it is advisory only. 8656** 8657** [[the xPagecount() page cache methods]] 8658** The xPagecount() method must return the number of pages currently 8659** stored in the cache, both pinned and unpinned. 8660** 8661** [[the xFetch() page cache methods]] 8662** The xFetch() method locates a page in the cache and returns a pointer to 8663** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8664** The pBuf element of the returned sqlite3_pcache_page object will be a 8665** pointer to a buffer of szPage bytes used to store the content of a 8666** single database page. The pExtra element of sqlite3_pcache_page will be 8667** a pointer to the szExtra bytes of extra storage that SQLite has requested 8668** for each entry in the page cache. 8669** 8670** The page to be fetched is determined by the key. ^The minimum key value 8671** is 1. After it has been retrieved using xFetch, the page is considered 8672** to be "pinned". 8673** 8674** If the requested page is already in the page cache, then the page cache 8675** implementation must return a pointer to the page buffer with its content 8676** intact. If the requested page is not already in the cache, then the 8677** cache implementation should use the value of the createFlag 8678** parameter to help it determined what action to take: 8679** 8680** <table border=1 width=85% align=center> 8681** <tr><th> createFlag <th> Behavior when page is not already in cache 8682** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8683** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8684** Otherwise return NULL. 8685** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8686** NULL if allocating a new page is effectively impossible. 8687** </table> 8688** 8689** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8690** will only use a createFlag of 2 after a prior call with a createFlag of 1 8691** failed.)^ In between the xFetch() calls, SQLite may 8692** attempt to unpin one or more cache pages by spilling the content of 8693** pinned pages to disk and synching the operating system disk cache. 8694** 8695** [[the xUnpin() page cache method]] 8696** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8697** as its second argument. If the third parameter, discard, is non-zero, 8698** then the page must be evicted from the cache. 8699** ^If the discard parameter is 8700** zero, then the page may be discarded or retained at the discretion of 8701** page cache implementation. ^The page cache implementation 8702** may choose to evict unpinned pages at any time. 8703** 8704** The cache must not perform any reference counting. A single 8705** call to xUnpin() unpins the page regardless of the number of prior calls 8706** to xFetch(). 8707** 8708** [[the xRekey() page cache methods]] 8709** The xRekey() method is used to change the key value associated with the 8710** page passed as the second argument. If the cache 8711** previously contains an entry associated with newKey, it must be 8712** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8713** to be pinned. 8714** 8715** When SQLite calls the xTruncate() method, the cache must discard all 8716** existing cache entries with page numbers (keys) greater than or equal 8717** to the value of the iLimit parameter passed to xTruncate(). If any 8718** of these pages are pinned, they are implicitly unpinned, meaning that 8719** they can be safely discarded. 8720** 8721** [[the xDestroy() page cache method]] 8722** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8723** All resources associated with the specified cache should be freed. ^After 8724** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8725** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8726** functions. 8727** 8728** [[the xShrink() page cache method]] 8729** ^SQLite invokes the xShrink() method when it wants the page cache to 8730** free up as much of heap memory as possible. The page cache implementation 8731** is not obligated to free any memory, but well-behaved implementations should 8732** do their best. 8733*/ 8734typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8735struct sqlite3_pcache_methods2 { 8736 int iVersion; 8737 void *pArg; 8738 int (*xInit)(void*); 8739 void (*xShutdown)(void*); 8740 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8741 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8742 int (*xPagecount)(sqlite3_pcache*); 8743 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8744 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8745 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8746 unsigned oldKey, unsigned newKey); 8747 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8748 void (*xDestroy)(sqlite3_pcache*); 8749 void (*xShrink)(sqlite3_pcache*); 8750}; 8751 8752/* 8753** This is the obsolete pcache_methods object that has now been replaced 8754** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8755** retained in the header file for backwards compatibility only. 8756*/ 8757typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8758struct sqlite3_pcache_methods { 8759 void *pArg; 8760 int (*xInit)(void*); 8761 void (*xShutdown)(void*); 8762 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8763 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8764 int (*xPagecount)(sqlite3_pcache*); 8765 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8766 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8767 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8768 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8769 void (*xDestroy)(sqlite3_pcache*); 8770}; 8771 8772 8773/* 8774** CAPI3REF: Online Backup Object 8775** 8776** The sqlite3_backup object records state information about an ongoing 8777** online backup operation. ^The sqlite3_backup object is created by 8778** a call to [sqlite3_backup_init()] and is destroyed by a call to 8779** [sqlite3_backup_finish()]. 8780** 8781** See Also: [Using the SQLite Online Backup API] 8782*/ 8783typedef struct sqlite3_backup sqlite3_backup; 8784 8785/* 8786** CAPI3REF: Online Backup API. 8787** 8788** The backup API copies the content of one database into another. 8789** It is useful either for creating backups of databases or 8790** for copying in-memory databases to or from persistent files. 8791** 8792** See Also: [Using the SQLite Online Backup API] 8793** 8794** ^SQLite holds a write transaction open on the destination database file 8795** for the duration of the backup operation. 8796** ^The source database is read-locked only while it is being read; 8797** it is not locked continuously for the entire backup operation. 8798** ^Thus, the backup may be performed on a live source database without 8799** preventing other database connections from 8800** reading or writing to the source database while the backup is underway. 8801** 8802** ^(To perform a backup operation: 8803** <ol> 8804** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8805** backup, 8806** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8807** the data between the two databases, and finally 8808** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8809** associated with the backup operation. 8810** </ol>)^ 8811** There should be exactly one call to sqlite3_backup_finish() for each 8812** successful call to sqlite3_backup_init(). 8813** 8814** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8815** 8816** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8817** [database connection] associated with the destination database 8818** and the database name, respectively. 8819** ^The database name is "main" for the main database, "temp" for the 8820** temporary database, or the name specified after the AS keyword in 8821** an [ATTACH] statement for an attached database. 8822** ^The S and M arguments passed to 8823** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8824** and database name of the source database, respectively. 8825** ^The source and destination [database connections] (parameters S and D) 8826** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8827** an error. 8828** 8829** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8830** there is already a read or read-write transaction open on the 8831** destination database. 8832** 8833** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8834** returned and an error code and error message are stored in the 8835** destination [database connection] D. 8836** ^The error code and message for the failed call to sqlite3_backup_init() 8837** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8838** [sqlite3_errmsg16()] functions. 8839** ^A successful call to sqlite3_backup_init() returns a pointer to an 8840** [sqlite3_backup] object. 8841** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8842** sqlite3_backup_finish() functions to perform the specified backup 8843** operation. 8844** 8845** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8846** 8847** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8848** the source and destination databases specified by [sqlite3_backup] object B. 8849** ^If N is negative, all remaining source pages are copied. 8850** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8851** are still more pages to be copied, then the function returns [SQLITE_OK]. 8852** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8853** from source to destination, then it returns [SQLITE_DONE]. 8854** ^If an error occurs while running sqlite3_backup_step(B,N), 8855** then an [error code] is returned. ^As well as [SQLITE_OK] and 8856** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8857** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8858** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8859** 8860** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8861** <ol> 8862** <li> the destination database was opened read-only, or 8863** <li> the destination database is using write-ahead-log journaling 8864** and the destination and source page sizes differ, or 8865** <li> the destination database is an in-memory database and the 8866** destination and source page sizes differ. 8867** </ol>)^ 8868** 8869** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8870** the [sqlite3_busy_handler | busy-handler function] 8871** is invoked (if one is specified). ^If the 8872** busy-handler returns non-zero before the lock is available, then 8873** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8874** sqlite3_backup_step() can be retried later. ^If the source 8875** [database connection] 8876** is being used to write to the source database when sqlite3_backup_step() 8877** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8878** case the call to sqlite3_backup_step() can be retried later on. ^(If 8879** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8880** [SQLITE_READONLY] is returned, then 8881** there is no point in retrying the call to sqlite3_backup_step(). These 8882** errors are considered fatal.)^ The application must accept 8883** that the backup operation has failed and pass the backup operation handle 8884** to the sqlite3_backup_finish() to release associated resources. 8885** 8886** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8887** on the destination file. ^The exclusive lock is not released until either 8888** sqlite3_backup_finish() is called or the backup operation is complete 8889** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8890** sqlite3_backup_step() obtains a [shared lock] on the source database that 8891** lasts for the duration of the sqlite3_backup_step() call. 8892** ^Because the source database is not locked between calls to 8893** sqlite3_backup_step(), the source database may be modified mid-way 8894** through the backup process. ^If the source database is modified by an 8895** external process or via a database connection other than the one being 8896** used by the backup operation, then the backup will be automatically 8897** restarted by the next call to sqlite3_backup_step(). ^If the source 8898** database is modified by the using the same database connection as is used 8899** by the backup operation, then the backup database is automatically 8900** updated at the same time. 8901** 8902** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8903** 8904** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8905** application wishes to abandon the backup operation, the application 8906** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8907** ^The sqlite3_backup_finish() interfaces releases all 8908** resources associated with the [sqlite3_backup] object. 8909** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8910** active write-transaction on the destination database is rolled back. 8911** The [sqlite3_backup] object is invalid 8912** and may not be used following a call to sqlite3_backup_finish(). 8913** 8914** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8915** sqlite3_backup_step() errors occurred, regardless or whether or not 8916** sqlite3_backup_step() completed. 8917** ^If an out-of-memory condition or IO error occurred during any prior 8918** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8919** sqlite3_backup_finish() returns the corresponding [error code]. 8920** 8921** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8922** is not a permanent error and does not affect the return value of 8923** sqlite3_backup_finish(). 8924** 8925** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8926** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8927** 8928** ^The sqlite3_backup_remaining() routine returns the number of pages still 8929** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8930** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8931** in the source database at the conclusion of the most recent 8932** sqlite3_backup_step(). 8933** ^(The values returned by these functions are only updated by 8934** sqlite3_backup_step(). If the source database is modified in a way that 8935** changes the size of the source database or the number of pages remaining, 8936** those changes are not reflected in the output of sqlite3_backup_pagecount() 8937** and sqlite3_backup_remaining() until after the next 8938** sqlite3_backup_step().)^ 8939** 8940** <b>Concurrent Usage of Database Handles</b> 8941** 8942** ^The source [database connection] may be used by the application for other 8943** purposes while a backup operation is underway or being initialized. 8944** ^If SQLite is compiled and configured to support threadsafe database 8945** connections, then the source database connection may be used concurrently 8946** from within other threads. 8947** 8948** However, the application must guarantee that the destination 8949** [database connection] is not passed to any other API (by any thread) after 8950** sqlite3_backup_init() is called and before the corresponding call to 8951** sqlite3_backup_finish(). SQLite does not currently check to see 8952** if the application incorrectly accesses the destination [database connection] 8953** and so no error code is reported, but the operations may malfunction 8954** nevertheless. Use of the destination database connection while a 8955** backup is in progress might also also cause a mutex deadlock. 8956** 8957** If running in [shared cache mode], the application must 8958** guarantee that the shared cache used by the destination database 8959** is not accessed while the backup is running. In practice this means 8960** that the application must guarantee that the disk file being 8961** backed up to is not accessed by any connection within the process, 8962** not just the specific connection that was passed to sqlite3_backup_init(). 8963** 8964** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8965** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8966** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8967** APIs are not strictly speaking threadsafe. If they are invoked at the 8968** same time as another thread is invoking sqlite3_backup_step() it is 8969** possible that they return invalid values. 8970*/ 8971sqlite3_backup *sqlite3_backup_init( 8972 sqlite3 *pDest, /* Destination database handle */ 8973 const char *zDestName, /* Destination database name */ 8974 sqlite3 *pSource, /* Source database handle */ 8975 const char *zSourceName /* Source database name */ 8976); 8977int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8978int sqlite3_backup_finish(sqlite3_backup *p); 8979int sqlite3_backup_remaining(sqlite3_backup *p); 8980int sqlite3_backup_pagecount(sqlite3_backup *p); 8981 8982/* 8983** CAPI3REF: Unlock Notification 8984** METHOD: sqlite3 8985** 8986** ^When running in shared-cache mode, a database operation may fail with 8987** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8988** individual tables within the shared-cache cannot be obtained. See 8989** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8990** ^This API may be used to register a callback that SQLite will invoke 8991** when the connection currently holding the required lock relinquishes it. 8992** ^This API is only available if the library was compiled with the 8993** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8994** 8995** See Also: [Using the SQLite Unlock Notification Feature]. 8996** 8997** ^Shared-cache locks are released when a database connection concludes 8998** its current transaction, either by committing it or rolling it back. 8999** 9000** ^When a connection (known as the blocked connection) fails to obtain a 9001** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9002** identity of the database connection (the blocking connection) that 9003** has locked the required resource is stored internally. ^After an 9004** application receives an SQLITE_LOCKED error, it may call the 9005** sqlite3_unlock_notify() method with the blocked connection handle as 9006** the first argument to register for a callback that will be invoked 9007** when the blocking connections current transaction is concluded. ^The 9008** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9009** call that concludes the blocking connection's transaction. 9010** 9011** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9012** there is a chance that the blocking connection will have already 9013** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9014** If this happens, then the specified callback is invoked immediately, 9015** from within the call to sqlite3_unlock_notify().)^ 9016** 9017** ^If the blocked connection is attempting to obtain a write-lock on a 9018** shared-cache table, and more than one other connection currently holds 9019** a read-lock on the same table, then SQLite arbitrarily selects one of 9020** the other connections to use as the blocking connection. 9021** 9022** ^(There may be at most one unlock-notify callback registered by a 9023** blocked connection. If sqlite3_unlock_notify() is called when the 9024** blocked connection already has a registered unlock-notify callback, 9025** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9026** called with a NULL pointer as its second argument, then any existing 9027** unlock-notify callback is canceled. ^The blocked connections 9028** unlock-notify callback may also be canceled by closing the blocked 9029** connection using [sqlite3_close()]. 9030** 9031** The unlock-notify callback is not reentrant. If an application invokes 9032** any sqlite3_xxx API functions from within an unlock-notify callback, a 9033** crash or deadlock may be the result. 9034** 9035** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9036** returns SQLITE_OK. 9037** 9038** <b>Callback Invocation Details</b> 9039** 9040** When an unlock-notify callback is registered, the application provides a 9041** single void* pointer that is passed to the callback when it is invoked. 9042** However, the signature of the callback function allows SQLite to pass 9043** it an array of void* context pointers. The first argument passed to 9044** an unlock-notify callback is a pointer to an array of void* pointers, 9045** and the second is the number of entries in the array. 9046** 9047** When a blocking connection's transaction is concluded, there may be 9048** more than one blocked connection that has registered for an unlock-notify 9049** callback. ^If two or more such blocked connections have specified the 9050** same callback function, then instead of invoking the callback function 9051** multiple times, it is invoked once with the set of void* context pointers 9052** specified by the blocked connections bundled together into an array. 9053** This gives the application an opportunity to prioritize any actions 9054** related to the set of unblocked database connections. 9055** 9056** <b>Deadlock Detection</b> 9057** 9058** Assuming that after registering for an unlock-notify callback a 9059** database waits for the callback to be issued before taking any further 9060** action (a reasonable assumption), then using this API may cause the 9061** application to deadlock. For example, if connection X is waiting for 9062** connection Y's transaction to be concluded, and similarly connection 9063** Y is waiting on connection X's transaction, then neither connection 9064** will proceed and the system may remain deadlocked indefinitely. 9065** 9066** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9067** detection. ^If a given call to sqlite3_unlock_notify() would put the 9068** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9069** unlock-notify callback is registered. The system is said to be in 9070** a deadlocked state if connection A has registered for an unlock-notify 9071** callback on the conclusion of connection B's transaction, and connection 9072** B has itself registered for an unlock-notify callback when connection 9073** A's transaction is concluded. ^Indirect deadlock is also detected, so 9074** the system is also considered to be deadlocked if connection B has 9075** registered for an unlock-notify callback on the conclusion of connection 9076** C's transaction, where connection C is waiting on connection A. ^Any 9077** number of levels of indirection are allowed. 9078** 9079** <b>The "DROP TABLE" Exception</b> 9080** 9081** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9082** always appropriate to call sqlite3_unlock_notify(). There is however, 9083** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9084** SQLite checks if there are any currently executing SELECT statements 9085** that belong to the same connection. If there are, SQLITE_LOCKED is 9086** returned. In this case there is no "blocking connection", so invoking 9087** sqlite3_unlock_notify() results in the unlock-notify callback being 9088** invoked immediately. If the application then re-attempts the "DROP TABLE" 9089** or "DROP INDEX" query, an infinite loop might be the result. 9090** 9091** One way around this problem is to check the extended error code returned 9092** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9093** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9094** the special "DROP TABLE/INDEX" case, the extended error code is just 9095** SQLITE_LOCKED.)^ 9096*/ 9097int sqlite3_unlock_notify( 9098 sqlite3 *pBlocked, /* Waiting connection */ 9099 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9100 void *pNotifyArg /* Argument to pass to xNotify */ 9101); 9102 9103 9104/* 9105** CAPI3REF: String Comparison 9106** 9107** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9108** and extensions to compare the contents of two buffers containing UTF-8 9109** strings in a case-independent fashion, using the same definition of "case 9110** independence" that SQLite uses internally when comparing identifiers. 9111*/ 9112int sqlite3_stricmp(const char *, const char *); 9113int sqlite3_strnicmp(const char *, const char *, int); 9114 9115/* 9116** CAPI3REF: String Globbing 9117* 9118** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9119** string X matches the [GLOB] pattern P. 9120** ^The definition of [GLOB] pattern matching used in 9121** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9122** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9123** is case sensitive. 9124** 9125** Note that this routine returns zero on a match and non-zero if the strings 9126** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9127** 9128** See also: [sqlite3_strlike()]. 9129*/ 9130int sqlite3_strglob(const char *zGlob, const char *zStr); 9131 9132/* 9133** CAPI3REF: String LIKE Matching 9134* 9135** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9136** string X matches the [LIKE] pattern P with escape character E. 9137** ^The definition of [LIKE] pattern matching used in 9138** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9139** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9140** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9141** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9142** insensitive - equivalent upper and lower case ASCII characters match 9143** one another. 9144** 9145** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9146** only ASCII characters are case folded. 9147** 9148** Note that this routine returns zero on a match and non-zero if the strings 9149** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9150** 9151** See also: [sqlite3_strglob()]. 9152*/ 9153int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9154 9155/* 9156** CAPI3REF: Error Logging Interface 9157** 9158** ^The [sqlite3_log()] interface writes a message into the [error log] 9159** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9160** ^If logging is enabled, the zFormat string and subsequent arguments are 9161** used with [sqlite3_snprintf()] to generate the final output string. 9162** 9163** The sqlite3_log() interface is intended for use by extensions such as 9164** virtual tables, collating functions, and SQL functions. While there is 9165** nothing to prevent an application from calling sqlite3_log(), doing so 9166** is considered bad form. 9167** 9168** The zFormat string must not be NULL. 9169** 9170** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9171** will not use dynamically allocated memory. The log message is stored in 9172** a fixed-length buffer on the stack. If the log message is longer than 9173** a few hundred characters, it will be truncated to the length of the 9174** buffer. 9175*/ 9176void sqlite3_log(int iErrCode, const char *zFormat, ...); 9177 9178/* 9179** CAPI3REF: Write-Ahead Log Commit Hook 9180** METHOD: sqlite3 9181** 9182** ^The [sqlite3_wal_hook()] function is used to register a callback that 9183** is invoked each time data is committed to a database in wal mode. 9184** 9185** ^(The callback is invoked by SQLite after the commit has taken place and 9186** the associated write-lock on the database released)^, so the implementation 9187** may read, write or [checkpoint] the database as required. 9188** 9189** ^The first parameter passed to the callback function when it is invoked 9190** is a copy of the third parameter passed to sqlite3_wal_hook() when 9191** registering the callback. ^The second is a copy of the database handle. 9192** ^The third parameter is the name of the database that was written to - 9193** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9194** is the number of pages currently in the write-ahead log file, 9195** including those that were just committed. 9196** 9197** The callback function should normally return [SQLITE_OK]. ^If an error 9198** code is returned, that error will propagate back up through the 9199** SQLite code base to cause the statement that provoked the callback 9200** to report an error, though the commit will have still occurred. If the 9201** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9202** that does not correspond to any valid SQLite error code, the results 9203** are undefined. 9204** 9205** A single database handle may have at most a single write-ahead log callback 9206** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9207** previously registered write-ahead log callback. ^The return value is 9208** a copy of the third parameter from the previous call, if any, or 0. 9209** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9210** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9211** overwrite any prior [sqlite3_wal_hook()] settings. 9212*/ 9213void *sqlite3_wal_hook( 9214 sqlite3*, 9215 int(*)(void *,sqlite3*,const char*,int), 9216 void* 9217); 9218 9219/* 9220** CAPI3REF: Configure an auto-checkpoint 9221** METHOD: sqlite3 9222** 9223** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9224** [sqlite3_wal_hook()] that causes any database on [database connection] D 9225** to automatically [checkpoint] 9226** after committing a transaction if there are N or 9227** more frames in the [write-ahead log] file. ^Passing zero or 9228** a negative value as the nFrame parameter disables automatic 9229** checkpoints entirely. 9230** 9231** ^The callback registered by this function replaces any existing callback 9232** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9233** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9234** configured by this function. 9235** 9236** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9237** from SQL. 9238** 9239** ^Checkpoints initiated by this mechanism are 9240** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9241** 9242** ^Every new [database connection] defaults to having the auto-checkpoint 9243** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9244** pages. The use of this interface 9245** is only necessary if the default setting is found to be suboptimal 9246** for a particular application. 9247*/ 9248int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9249 9250/* 9251** CAPI3REF: Checkpoint a database 9252** METHOD: sqlite3 9253** 9254** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9255** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9256** 9257** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9258** [write-ahead log] for database X on [database connection] D to be 9259** transferred into the database file and for the write-ahead log to 9260** be reset. See the [checkpointing] documentation for addition 9261** information. 9262** 9263** This interface used to be the only way to cause a checkpoint to 9264** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9265** interface was added. This interface is retained for backwards 9266** compatibility and as a convenience for applications that need to manually 9267** start a callback but which do not need the full power (and corresponding 9268** complication) of [sqlite3_wal_checkpoint_v2()]. 9269*/ 9270int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9271 9272/* 9273** CAPI3REF: Checkpoint a database 9274** METHOD: sqlite3 9275** 9276** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9277** operation on database X of [database connection] D in mode M. Status 9278** information is written back into integers pointed to by L and C.)^ 9279** ^(The M parameter must be a valid [checkpoint mode]:)^ 9280** 9281** <dl> 9282** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9283** ^Checkpoint as many frames as possible without waiting for any database 9284** readers or writers to finish, then sync the database file if all frames 9285** in the log were checkpointed. ^The [busy-handler callback] 9286** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9287** ^On the other hand, passive mode might leave the checkpoint unfinished 9288** if there are concurrent readers or writers. 9289** 9290** <dt>SQLITE_CHECKPOINT_FULL<dd> 9291** ^This mode blocks (it invokes the 9292** [sqlite3_busy_handler|busy-handler callback]) until there is no 9293** database writer and all readers are reading from the most recent database 9294** snapshot. ^It then checkpoints all frames in the log file and syncs the 9295** database file. ^This mode blocks new database writers while it is pending, 9296** but new database readers are allowed to continue unimpeded. 9297** 9298** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9299** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9300** that after checkpointing the log file it blocks (calls the 9301** [busy-handler callback]) 9302** until all readers are reading from the database file only. ^This ensures 9303** that the next writer will restart the log file from the beginning. 9304** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9305** database writer attempts while it is pending, but does not impede readers. 9306** 9307** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9308** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9309** addition that it also truncates the log file to zero bytes just prior 9310** to a successful return. 9311** </dl> 9312** 9313** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9314** the log file or to -1 if the checkpoint could not run because 9315** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9316** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9317** log file (including any that were already checkpointed before the function 9318** was called) or to -1 if the checkpoint could not run due to an error or 9319** because the database is not in WAL mode. ^Note that upon successful 9320** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9321** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9322** 9323** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9324** any other process is running a checkpoint operation at the same time, the 9325** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9326** busy-handler configured, it will not be invoked in this case. 9327** 9328** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9329** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9330** obtained immediately, and a busy-handler is configured, it is invoked and 9331** the writer lock retried until either the busy-handler returns 0 or the lock 9332** is successfully obtained. ^The busy-handler is also invoked while waiting for 9333** database readers as described above. ^If the busy-handler returns 0 before 9334** the writer lock is obtained or while waiting for database readers, the 9335** checkpoint operation proceeds from that point in the same way as 9336** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9337** without blocking any further. ^SQLITE_BUSY is returned in this case. 9338** 9339** ^If parameter zDb is NULL or points to a zero length string, then the 9340** specified operation is attempted on all WAL databases [attached] to 9341** [database connection] db. In this case the 9342** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9343** an SQLITE_BUSY error is encountered when processing one or more of the 9344** attached WAL databases, the operation is still attempted on any remaining 9345** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9346** error occurs while processing an attached database, processing is abandoned 9347** and the error code is returned to the caller immediately. ^If no error 9348** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9349** databases, SQLITE_OK is returned. 9350** 9351** ^If database zDb is the name of an attached database that is not in WAL 9352** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9353** zDb is not NULL (or a zero length string) and is not the name of any 9354** attached database, SQLITE_ERROR is returned to the caller. 9355** 9356** ^Unless it returns SQLITE_MISUSE, 9357** the sqlite3_wal_checkpoint_v2() interface 9358** sets the error information that is queried by 9359** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9360** 9361** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9362** from SQL. 9363*/ 9364int sqlite3_wal_checkpoint_v2( 9365 sqlite3 *db, /* Database handle */ 9366 const char *zDb, /* Name of attached database (or NULL) */ 9367 int eMode, /* SQLITE_CHECKPOINT_* value */ 9368 int *pnLog, /* OUT: Size of WAL log in frames */ 9369 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9370); 9371 9372/* 9373** CAPI3REF: Checkpoint Mode Values 9374** KEYWORDS: {checkpoint mode} 9375** 9376** These constants define all valid values for the "checkpoint mode" passed 9377** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9378** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9379** meaning of each of these checkpoint modes. 9380*/ 9381#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9382#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9383#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9384#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9385 9386/* 9387** CAPI3REF: Virtual Table Interface Configuration 9388** 9389** This function may be called by either the [xConnect] or [xCreate] method 9390** of a [virtual table] implementation to configure 9391** various facets of the virtual table interface. 9392** 9393** If this interface is invoked outside the context of an xConnect or 9394** xCreate virtual table method then the behavior is undefined. 9395** 9396** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9397** [database connection] in which the virtual table is being created and 9398** which is passed in as the first argument to the [xConnect] or [xCreate] 9399** method that is invoking sqlite3_vtab_config(). The C parameter is one 9400** of the [virtual table configuration options]. The presence and meaning 9401** of parameters after C depend on which [virtual table configuration option] 9402** is used. 9403*/ 9404int sqlite3_vtab_config(sqlite3*, int op, ...); 9405 9406/* 9407** CAPI3REF: Virtual Table Configuration Options 9408** KEYWORDS: {virtual table configuration options} 9409** KEYWORDS: {virtual table configuration option} 9410** 9411** These macros define the various options to the 9412** [sqlite3_vtab_config()] interface that [virtual table] implementations 9413** can use to customize and optimize their behavior. 9414** 9415** <dl> 9416** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9417** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9418** <dd>Calls of the form 9419** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9420** where X is an integer. If X is zero, then the [virtual table] whose 9421** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9422** support constraints. In this configuration (which is the default) if 9423** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9424** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9425** specified as part of the users SQL statement, regardless of the actual 9426** ON CONFLICT mode specified. 9427** 9428** If X is non-zero, then the virtual table implementation guarantees 9429** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9430** any modifications to internal or persistent data structures have been made. 9431** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9432** is able to roll back a statement or database transaction, and abandon 9433** or continue processing the current SQL statement as appropriate. 9434** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9435** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9436** had been ABORT. 9437** 9438** Virtual table implementations that are required to handle OR REPLACE 9439** must do so within the [xUpdate] method. If a call to the 9440** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9441** CONFLICT policy is REPLACE, the virtual table implementation should 9442** silently replace the appropriate rows within the xUpdate callback and 9443** return SQLITE_OK. Or, if this is not possible, it may return 9444** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9445** constraint handling. 9446** </dd> 9447** 9448** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9449** <dd>Calls of the form 9450** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9451** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9452** prohibits that virtual table from being used from within triggers and 9453** views. 9454** </dd> 9455** 9456** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9457** <dd>Calls of the form 9458** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9459** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9460** identify that virtual table as being safe to use from within triggers 9461** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9462** virtual table can do no serious harm even if it is controlled by a 9463** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9464** flag unless absolutely necessary. 9465** </dd> 9466** </dl> 9467*/ 9468#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9469#define SQLITE_VTAB_INNOCUOUS 2 9470#define SQLITE_VTAB_DIRECTONLY 3 9471 9472/* 9473** CAPI3REF: Determine The Virtual Table Conflict Policy 9474** 9475** This function may only be called from within a call to the [xUpdate] method 9476** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9477** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9478** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9479** of the SQL statement that triggered the call to the [xUpdate] method of the 9480** [virtual table]. 9481*/ 9482int sqlite3_vtab_on_conflict(sqlite3 *); 9483 9484/* 9485** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9486** 9487** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9488** method of a [virtual table], then it might return true if the 9489** column is being fetched as part of an UPDATE operation during which the 9490** column value will not change. The virtual table implementation can use 9491** this hint as permission to substitute a return value that is less 9492** expensive to compute and that the corresponding 9493** [xUpdate] method understands as a "no-change" value. 9494** 9495** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9496** the column is not changed by the UPDATE statement, then the xColumn 9497** method can optionally return without setting a result, without calling 9498** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9499** In that case, [sqlite3_value_nochange(X)] will return true for the 9500** same column in the [xUpdate] method. 9501** 9502** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9503** implementations should continue to give a correct answer even if the 9504** sqlite3_vtab_nochange() interface were to always return false. In the 9505** current implementation, the sqlite3_vtab_nochange() interface does always 9506** returns false for the enhanced [UPDATE FROM] statement. 9507*/ 9508int sqlite3_vtab_nochange(sqlite3_context*); 9509 9510/* 9511** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9512** METHOD: sqlite3_index_info 9513** 9514** This function may only be called from within a call to the [xBestIndex] 9515** method of a [virtual table]. This function returns a pointer to a string 9516** that is the name of the appropriate collation sequence to use for text 9517** comparisons on the constraint identified by its arguments. 9518** 9519** The first argument must be the pointer to the [sqlite3_index_info] object 9520** that is the first parameter to the xBestIndex() method. The second argument 9521** must be an index into the aConstraint[] array belonging to the 9522** sqlite3_index_info structure passed to xBestIndex. 9523** 9524** Important: 9525** The first parameter must be the same pointer that is passed into the 9526** xBestMethod() method. The first parameter may not be a pointer to a 9527** different [sqlite3_index_info] object, even an exact copy. 9528** 9529** The return value is computed as follows: 9530** 9531** <ol> 9532** <li><p> If the constraint comes from a WHERE clause expression that contains 9533** a [COLLATE operator], then the name of the collation specified by 9534** that COLLATE operator is returned. 9535** <li><p> If there is no COLLATE operator, but the column that is the subject 9536** of the constraint specifies an alternative collating sequence via 9537** a [COLLATE clause] on the column definition within the CREATE TABLE 9538** statement that was passed into [sqlite3_declare_vtab()], then the 9539** name of that alternative collating sequence is returned. 9540** <li><p> Otherwise, "BINARY" is returned. 9541** </ol> 9542*/ 9543SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9544 9545/* 9546** CAPI3REF: Determine if a virtual table query is DISTINCT 9547** METHOD: sqlite3_index_info 9548** 9549** This API may only be used from within an [xBestIndex|xBestIndex method] 9550** of a [virtual table] implementation. The result of calling this 9551** interface from outside of xBestIndex() is undefined and probably harmful. 9552** 9553** ^The sqlite3_vtab_distinct() interface returns an integer that is 9554** either 0, 1, or 2. The integer returned by sqlite3_vtab_distinct() 9555** gives the virtual table additional information about how the query 9556** planner wants the output to be ordered. As long as the virtual table 9557** can meet the ordering requirements of the query planner, it may set 9558** the "orderByConsumed" flag. 9559** 9560** <ol><li value="0"><p> 9561** ^If the sqlite3_vtab_distinct() interface returns 0, that means 9562** that the query planner needs the virtual table to return all rows in the 9563** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 9564** [sqlite3_index_info] object. This is the default expectation. If the 9565** virtual table outputs all rows in sorted order, then it is always safe for 9566** the xBestIndex method to set the "orderByConsumed" flag, regardless of 9567** the return value from sqlite3_vtab_distinct(). 9568** <li value="1"><p> 9569** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 9570** that the query planner does not need the rows to be returned in sorted order 9571** as long as all rows with the same values in all columns identified by the 9572** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 9573** is doing a GROUP BY. 9574** <li value="2"><p> 9575** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 9576** that the query planner does not need the rows returned in any particular 9577** order, as long as rows with the same values in all "aOrderBy" columns 9578** are adjacent.)^ ^(Furthermore, only a single row for each particular 9579** combination of values in the columns identified by the "aOrderBy" field 9580** needs to be returned.)^ ^It is always ok for two or more rows with the same 9581** values in all "aOrderBy" columns to be returned, as long as all such rows 9582** are adjacent. ^The virtual table may, if it chooses, omit extra rows 9583** that have the same value for all columns identified by "aOrderBy". 9584** ^However omitting the extra rows is optional. 9585** This mode is used for a DISTINCT query. 9586** </ol> 9587** 9588** ^For the purposes of comparing virtual table output values to see if the 9589** values are same value for sorting purposes, two NULL values are considered 9590** to be the same. In other words, the comparison operator is "IS" 9591** (or "IS NOT DISTINCT FROM") and not "==". 9592** 9593** If a virtual table implementation is unable to meet the requirements 9594** specified above, then it must not set the "orderByConsumed" flag in the 9595** [sqlite3_index_info] object or an incorrect answer may result. 9596** 9597** ^A virtual table implementation is always free to return rows in any order 9598** it wants, as long as the "orderByConsumed" flag is not set. ^When the 9599** the "orderByConsumed" flag is unset, the query planner will add extra 9600** [bytecode] to ensure that the final results returned by the SQL query are 9601** ordered correctly. The use of the "orderByConsumed" flag and the 9602** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 9603** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 9604** flag might help queries against a virtual table to run faster. Being 9605** overly aggressive and setting the "orderByConsumed" flag when it is not 9606** valid to do so, on the other hand, might cause SQLite to return incorrect 9607** results. 9608*/ 9609int sqlite3_vtab_distinct(sqlite3_index_info*); 9610 9611/* 9612** CAPI3REF: Identify and handle IN constraints in xBestIndex 9613** 9614** This interface may only be used from within an 9615** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 9616** The result of invoking this interface from any other context is 9617** undefined and probably harmful. 9618** 9619** ^(A constraint on a virtual table of the form 9620** "[IN operator|column IN (...)]" is 9621** communicated to the xBestIndex method as a 9622** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 9623** this constraint, it must set the corresponding 9624** aConstraintUsage[].argvIndex to a postive integer. ^(Then, under 9625** the usual mode of handling IN operators, SQLite generates [bytecode] 9626** that invokes the [xFilter|xFilter() method] once for each value 9627** on the right-hand side of the IN operator.)^ Thus the virtual table 9628** only sees a single value from the right-hand side of the IN operator 9629** at a time. 9630** 9631** In some cases, however, it would be advantageous for the virtual 9632** table to see all values on the right-hand of the IN operator all at 9633** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 9634** 9635** <ol> 9636** <li><p> 9637** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 9638** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 9639** is an [IN operator] that can be processed all at once. ^In other words, 9640** sqlite3_vtab_in() with -1 in the third argument is a mechanism 9641** by which the virtual table can ask SQLite if all-at-once processing 9642** of the IN operator is even possible. 9643** 9644** <li><p> 9645** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 9646** to SQLite that the virtual table does or does not want to process 9647** the IN operator all-at-once, respectively. ^Thus when the third 9648** parameter (F) is non-negative, this interface is the mechanism by 9649** which the virtual table tells SQLite how it wants to process the 9650** IN operator. 9651** </ol> 9652** 9653** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 9654** within the same xBestIndex method call. ^For any given P,N pair, 9655** the return value from sqlite3_vtab_in(P,N,F) will always be the same 9656** within the same xBestIndex call. ^If the interface returns true 9657** (non-zero), that means that the constraint is an IN operator 9658** that can be processed all-at-once. ^If the constraint is not an IN 9659** operator or cannot be processed all-at-once, then the interface returns 9660** false. 9661** 9662** ^(All-at-once processing of the IN operator is selected if both of the 9663** following conditions are met: 9664** 9665** <ol> 9666** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 9667** integer. This is how the virtual table tells SQLite that it wants to 9668** use the N-th constraint. 9669** 9670** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 9671** non-negative had F>=1. 9672** </ol>)^ 9673** 9674** ^If either or both of the conditions above are false, then SQLite uses 9675** the traditional one-at-a-time processing strategy for the IN constraint. 9676** ^If both conditions are true, then the argvIndex-th parameter to the 9677** xFilter method will be an [sqlite3_value] that appears to be NULL, 9678** but which can be passed to [sqlite3_vtab_in_first()] and 9679** [sqlite3_vtab_in_next()] to find all values on the right-hand side 9680** of the IN constraint. 9681*/ 9682int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 9683 9684/* 9685** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 9686** 9687** These interfaces are only useful from within the 9688** [xFilter|xFilter() method] of a [virtual table] implementation. 9689** The result of invoking these interfaces from any other context 9690** is undefined and probably harmful. 9691** 9692** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 9693** sqlite3_vtab_in_next(X,P) must be one of the parameters to the 9694** xFilter method which invokes these routines, and specifically 9695** a parameter that was previously selected for all-at-once IN constraint 9696** processing use the [sqlite3_vtab_in()] interface in the 9697** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 9698** an xFilter argument that was selected for all-at-once IN constraint 9699** processing, then these routines return [SQLITE_MISUSE])^ or perhaps 9700** exhibit some other undefined or harmful behavior. 9701** 9702** ^(Use these routines to access all values on the right-hand side 9703** of the IN constraint using code like the following: 9704** 9705** <blockquote><pre> 9706** for(rc=sqlite3_vtab_in_first(pList, &pVal); 9707** rc==SQLITE_OK && pVal 9708** rc=sqlite3_vtab_in_next(pList, &pVal) 9709** ){ 9710** // do something with pVal 9711** } 9712** if( rc!=SQLITE_OK ){ 9713** // an error has occurred 9714** } 9715** </pre></blockquote>)^ 9716** 9717** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 9718** routines return SQLITE_OK and set *P to point to the first or next value 9719** on the RHS of the IN constraint. ^If there are no more values on the 9720** right hand side of the IN constraint, then *P is set to NULL and these 9721** routines return [SQLITE_DONE]. ^The return value might be 9722** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 9723** 9724** The *ppOut values returned by these routines are only valid until the 9725** next call to either of these routines or until the end of the xFilter 9726** method from which these routines were called. If the virtual table 9727** implementation needs to retain the *ppOut values for longer, it must make 9728** copies. The *ppOut values are [protected sqlite3_value|protected]. 9729*/ 9730int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 9731int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 9732 9733/* 9734** CAPI3REF: Constraint values in xBestIndex() 9735** METHOD: sqlite3_index_info 9736** 9737** This API may only be used from within the [xBestIndex|xBestIndex method] 9738** of a [virtual table] implementation. The result of calling this interface 9739** from outside of an xBestIndex method are undefined and probably harmful. 9740** 9741** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 9742** the [xBestIndex] method of a [virtual table] implementation, with P being 9743** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 9744** J being a 0-based index into P->aConstraint[], then this routine 9745** attempts to set *V to the value of the right-hand operand of 9746** that constraint if the right-hand operand is known. ^If the 9747** right-hand operand is not known, then *V is set to a NULL pointer. 9748** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 9749** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 9750** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 9751** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 9752** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 9753** something goes wrong. 9754** 9755** The sqlite3_vtab_rhs_value() interface is usually only successful if 9756** the right-hand operand of a constraint is a literal value in the original 9757** SQL statement. If the right-hand operand is an expression or a reference 9758** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 9759** will probably return [SQLITE_NOTFOUND]. 9760** 9761** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 9762** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 9763** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 9764** 9765** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 9766** and remains valid for the duration of the xBestIndex method call. 9767** ^When xBestIndex returns, the sqlite3_value object returned by 9768** sqlite3_vtab_rhs_value() is automatically deallocated. 9769** 9770** The "_rhs_" in the name of this routine is an abbreviation for 9771** "Right-Hand Side". 9772*/ 9773int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 9774 9775/* 9776** CAPI3REF: Conflict resolution modes 9777** KEYWORDS: {conflict resolution mode} 9778** 9779** These constants are returned by [sqlite3_vtab_on_conflict()] to 9780** inform a [virtual table] implementation what the [ON CONFLICT] mode 9781** is for the SQL statement being evaluated. 9782** 9783** Note that the [SQLITE_IGNORE] constant is also used as a potential 9784** return value from the [sqlite3_set_authorizer()] callback and that 9785** [SQLITE_ABORT] is also a [result code]. 9786*/ 9787#define SQLITE_ROLLBACK 1 9788/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9789#define SQLITE_FAIL 3 9790/* #define SQLITE_ABORT 4 // Also an error code */ 9791#define SQLITE_REPLACE 5 9792 9793/* 9794** CAPI3REF: Prepared Statement Scan Status Opcodes 9795** KEYWORDS: {scanstatus options} 9796** 9797** The following constants can be used for the T parameter to the 9798** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9799** different metric for sqlite3_stmt_scanstatus() to return. 9800** 9801** When the value returned to V is a string, space to hold that string is 9802** managed by the prepared statement S and will be automatically freed when 9803** S is finalized. 9804** 9805** <dl> 9806** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9807** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9808** set to the total number of times that the X-th loop has run.</dd> 9809** 9810** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9811** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9812** to the total number of rows examined by all iterations of the X-th loop.</dd> 9813** 9814** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9815** <dd>^The "double" variable pointed to by the V parameter will be set to the 9816** query planner's estimate for the average number of rows output from each 9817** iteration of the X-th loop. If the query planner's estimates was accurate, 9818** then this value will approximate the quotient NVISIT/NLOOP and the 9819** product of this value for all prior loops with the same SELECTID will 9820** be the NLOOP value for the current loop. 9821** 9822** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9823** <dd>^The "const char *" variable pointed to by the V parameter will be set 9824** to a zero-terminated UTF-8 string containing the name of the index or table 9825** used for the X-th loop. 9826** 9827** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9828** <dd>^The "const char *" variable pointed to by the V parameter will be set 9829** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9830** description for the X-th loop. 9831** 9832** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9833** <dd>^The "int" variable pointed to by the V parameter will be set to the 9834** "select-id" for the X-th loop. The select-id identifies which query or 9835** subquery the loop is part of. The main query has a select-id of zero. 9836** The select-id is the same value as is output in the first column 9837** of an [EXPLAIN QUERY PLAN] query. 9838** </dl> 9839*/ 9840#define SQLITE_SCANSTAT_NLOOP 0 9841#define SQLITE_SCANSTAT_NVISIT 1 9842#define SQLITE_SCANSTAT_EST 2 9843#define SQLITE_SCANSTAT_NAME 3 9844#define SQLITE_SCANSTAT_EXPLAIN 4 9845#define SQLITE_SCANSTAT_SELECTID 5 9846 9847/* 9848** CAPI3REF: Prepared Statement Scan Status 9849** METHOD: sqlite3_stmt 9850** 9851** This interface returns information about the predicted and measured 9852** performance for pStmt. Advanced applications can use this 9853** interface to compare the predicted and the measured performance and 9854** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9855** 9856** Since this interface is expected to be rarely used, it is only 9857** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9858** compile-time option. 9859** 9860** The "iScanStatusOp" parameter determines which status information to return. 9861** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9862** of this interface is undefined. 9863** ^The requested measurement is written into a variable pointed to by 9864** the "pOut" parameter. 9865** Parameter "idx" identifies the specific loop to retrieve statistics for. 9866** Loops are numbered starting from zero. ^If idx is out of range - less than 9867** zero or greater than or equal to the total number of loops used to implement 9868** the statement - a non-zero value is returned and the variable that pOut 9869** points to is unchanged. 9870** 9871** ^Statistics might not be available for all loops in all statements. ^In cases 9872** where there exist loops with no available statistics, this function behaves 9873** as if the loop did not exist - it returns non-zero and leave the variable 9874** that pOut points to unchanged. 9875** 9876** See also: [sqlite3_stmt_scanstatus_reset()] 9877*/ 9878int sqlite3_stmt_scanstatus( 9879 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9880 int idx, /* Index of loop to report on */ 9881 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9882 void *pOut /* Result written here */ 9883); 9884 9885/* 9886** CAPI3REF: Zero Scan-Status Counters 9887** METHOD: sqlite3_stmt 9888** 9889** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9890** 9891** This API is only available if the library is built with pre-processor 9892** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9893*/ 9894void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9895 9896/* 9897** CAPI3REF: Flush caches to disk mid-transaction 9898** METHOD: sqlite3 9899** 9900** ^If a write-transaction is open on [database connection] D when the 9901** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9902** pages in the pager-cache that are not currently in use are written out 9903** to disk. A dirty page may be in use if a database cursor created by an 9904** active SQL statement is reading from it, or if it is page 1 of a database 9905** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9906** interface flushes caches for all schemas - "main", "temp", and 9907** any [attached] databases. 9908** 9909** ^If this function needs to obtain extra database locks before dirty pages 9910** can be flushed to disk, it does so. ^If those locks cannot be obtained 9911** immediately and there is a busy-handler callback configured, it is invoked 9912** in the usual manner. ^If the required lock still cannot be obtained, then 9913** the database is skipped and an attempt made to flush any dirty pages 9914** belonging to the next (if any) database. ^If any databases are skipped 9915** because locks cannot be obtained, but no other error occurs, this 9916** function returns SQLITE_BUSY. 9917** 9918** ^If any other error occurs while flushing dirty pages to disk (for 9919** example an IO error or out-of-memory condition), then processing is 9920** abandoned and an SQLite [error code] is returned to the caller immediately. 9921** 9922** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9923** 9924** ^This function does not set the database handle error code or message 9925** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9926*/ 9927int sqlite3_db_cacheflush(sqlite3*); 9928 9929/* 9930** CAPI3REF: The pre-update hook. 9931** METHOD: sqlite3 9932** 9933** ^These interfaces are only available if SQLite is compiled using the 9934** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9935** 9936** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9937** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9938** on a database table. 9939** ^At most one preupdate hook may be registered at a time on a single 9940** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9941** the previous setting. 9942** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9943** with a NULL pointer as the second parameter. 9944** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9945** the first parameter to callbacks. 9946** 9947** ^The preupdate hook only fires for changes to real database tables; the 9948** preupdate hook is not invoked for changes to [virtual tables] or to 9949** system tables like sqlite_sequence or sqlite_stat1. 9950** 9951** ^The second parameter to the preupdate callback is a pointer to 9952** the [database connection] that registered the preupdate hook. 9953** ^The third parameter to the preupdate callback is one of the constants 9954** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9955** kind of update operation that is about to occur. 9956** ^(The fourth parameter to the preupdate callback is the name of the 9957** database within the database connection that is being modified. This 9958** will be "main" for the main database or "temp" for TEMP tables or 9959** the name given after the AS keyword in the [ATTACH] statement for attached 9960** databases.)^ 9961** ^The fifth parameter to the preupdate callback is the name of the 9962** table that is being modified. 9963** 9964** For an UPDATE or DELETE operation on a [rowid table], the sixth 9965** parameter passed to the preupdate callback is the initial [rowid] of the 9966** row being modified or deleted. For an INSERT operation on a rowid table, 9967** or any operation on a WITHOUT ROWID table, the value of the sixth 9968** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9969** seventh parameter is the final rowid value of the row being inserted 9970** or updated. The value of the seventh parameter passed to the callback 9971** function is not defined for operations on WITHOUT ROWID tables, or for 9972** DELETE operations on rowid tables. 9973** 9974** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9975** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9976** provide additional information about a preupdate event. These routines 9977** may only be called from within a preupdate callback. Invoking any of 9978** these routines from outside of a preupdate callback or with a 9979** [database connection] pointer that is different from the one supplied 9980** to the preupdate callback results in undefined and probably undesirable 9981** behavior. 9982** 9983** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9984** in the row that is being inserted, updated, or deleted. 9985** 9986** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9987** a [protected sqlite3_value] that contains the value of the Nth column of 9988** the table row before it is updated. The N parameter must be between 0 9989** and one less than the number of columns or the behavior will be 9990** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9991** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9992** behavior is undefined. The [sqlite3_value] that P points to 9993** will be destroyed when the preupdate callback returns. 9994** 9995** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9996** a [protected sqlite3_value] that contains the value of the Nth column of 9997** the table row after it is updated. The N parameter must be between 0 9998** and one less than the number of columns or the behavior will be 9999** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10000** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10001** behavior is undefined. The [sqlite3_value] that P points to 10002** will be destroyed when the preupdate callback returns. 10003** 10004** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10005** callback was invoked as a result of a direct insert, update, or delete 10006** operation; or 1 for inserts, updates, or deletes invoked by top-level 10007** triggers; or 2 for changes resulting from triggers called by top-level 10008** triggers; and so forth. 10009** 10010** When the [sqlite3_blob_write()] API is used to update a blob column, 10011** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10012** in this case the new values are not available. In this case, when a 10013** callback made with op==SQLITE_DELETE is actuall a write using the 10014** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10015** the index of the column being written. In other cases, where the 10016** pre-update hook is being invoked for some other reason, including a 10017** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10018** 10019** See also: [sqlite3_update_hook()] 10020*/ 10021#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10022void *sqlite3_preupdate_hook( 10023 sqlite3 *db, 10024 void(*xPreUpdate)( 10025 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10026 sqlite3 *db, /* Database handle */ 10027 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10028 char const *zDb, /* Database name */ 10029 char const *zName, /* Table name */ 10030 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10031 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10032 ), 10033 void* 10034); 10035int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10036int sqlite3_preupdate_count(sqlite3 *); 10037int sqlite3_preupdate_depth(sqlite3 *); 10038int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10039int sqlite3_preupdate_blobwrite(sqlite3 *); 10040#endif 10041 10042/* 10043** CAPI3REF: Low-level system error code 10044** METHOD: sqlite3 10045** 10046** ^Attempt to return the underlying operating system error code or error 10047** number that caused the most recent I/O error or failure to open a file. 10048** The return value is OS-dependent. For example, on unix systems, after 10049** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10050** called to get back the underlying "errno" that caused the problem, such 10051** as ENOSPC, EAUTH, EISDIR, and so forth. 10052*/ 10053int sqlite3_system_errno(sqlite3*); 10054 10055/* 10056** CAPI3REF: Database Snapshot 10057** KEYWORDS: {snapshot} {sqlite3_snapshot} 10058** 10059** An instance of the snapshot object records the state of a [WAL mode] 10060** database for some specific point in history. 10061** 10062** In [WAL mode], multiple [database connections] that are open on the 10063** same database file can each be reading a different historical version 10064** of the database file. When a [database connection] begins a read 10065** transaction, that connection sees an unchanging copy of the database 10066** as it existed for the point in time when the transaction first started. 10067** Subsequent changes to the database from other connections are not seen 10068** by the reader until a new read transaction is started. 10069** 10070** The sqlite3_snapshot object records state information about an historical 10071** version of the database file so that it is possible to later open a new read 10072** transaction that sees that historical version of the database rather than 10073** the most recent version. 10074*/ 10075typedef struct sqlite3_snapshot { 10076 unsigned char hidden[48]; 10077} sqlite3_snapshot; 10078 10079/* 10080** CAPI3REF: Record A Database Snapshot 10081** CONSTRUCTOR: sqlite3_snapshot 10082** 10083** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10084** new [sqlite3_snapshot] object that records the current state of 10085** schema S in database connection D. ^On success, the 10086** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10087** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10088** If there is not already a read-transaction open on schema S when 10089** this function is called, one is opened automatically. 10090** 10091** The following must be true for this function to succeed. If any of 10092** the following statements are false when sqlite3_snapshot_get() is 10093** called, SQLITE_ERROR is returned. The final value of *P is undefined 10094** in this case. 10095** 10096** <ul> 10097** <li> The database handle must not be in [autocommit mode]. 10098** 10099** <li> Schema S of [database connection] D must be a [WAL mode] database. 10100** 10101** <li> There must not be a write transaction open on schema S of database 10102** connection D. 10103** 10104** <li> One or more transactions must have been written to the current wal 10105** file since it was created on disk (by any connection). This means 10106** that a snapshot cannot be taken on a wal mode database with no wal 10107** file immediately after it is first opened. At least one transaction 10108** must be written to it first. 10109** </ul> 10110** 10111** This function may also return SQLITE_NOMEM. If it is called with the 10112** database handle in autocommit mode but fails for some other reason, 10113** whether or not a read transaction is opened on schema S is undefined. 10114** 10115** The [sqlite3_snapshot] object returned from a successful call to 10116** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10117** to avoid a memory leak. 10118** 10119** The [sqlite3_snapshot_get()] interface is only available when the 10120** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10121*/ 10122SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10123 sqlite3 *db, 10124 const char *zSchema, 10125 sqlite3_snapshot **ppSnapshot 10126); 10127 10128/* 10129** CAPI3REF: Start a read transaction on an historical snapshot 10130** METHOD: sqlite3_snapshot 10131** 10132** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10133** transaction or upgrades an existing one for schema S of 10134** [database connection] D such that the read transaction refers to 10135** historical [snapshot] P, rather than the most recent change to the 10136** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10137** on success or an appropriate [error code] if it fails. 10138** 10139** ^In order to succeed, the database connection must not be in 10140** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10141** is already a read transaction open on schema S, then the database handle 10142** must have no active statements (SELECT statements that have been passed 10143** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10144** SQLITE_ERROR is returned if either of these conditions is violated, or 10145** if schema S does not exist, or if the snapshot object is invalid. 10146** 10147** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10148** snapshot has been overwritten by a [checkpoint]. In this case 10149** SQLITE_ERROR_SNAPSHOT is returned. 10150** 10151** If there is already a read transaction open when this function is 10152** invoked, then the same read transaction remains open (on the same 10153** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10154** is returned. If another error code - for example SQLITE_PROTOCOL or an 10155** SQLITE_IOERR error code - is returned, then the final state of the 10156** read transaction is undefined. If SQLITE_OK is returned, then the 10157** read transaction is now open on database snapshot P. 10158** 10159** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10160** database connection D does not know that the database file for 10161** schema S is in [WAL mode]. A database connection might not know 10162** that the database file is in [WAL mode] if there has been no prior 10163** I/O on that database connection, or if the database entered [WAL mode] 10164** after the most recent I/O on the database connection.)^ 10165** (Hint: Run "[PRAGMA application_id]" against a newly opened 10166** database connection in order to make it ready to use snapshots.) 10167** 10168** The [sqlite3_snapshot_open()] interface is only available when the 10169** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10170*/ 10171SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10172 sqlite3 *db, 10173 const char *zSchema, 10174 sqlite3_snapshot *pSnapshot 10175); 10176 10177/* 10178** CAPI3REF: Destroy a snapshot 10179** DESTRUCTOR: sqlite3_snapshot 10180** 10181** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10182** The application must eventually free every [sqlite3_snapshot] object 10183** using this routine to avoid a memory leak. 10184** 10185** The [sqlite3_snapshot_free()] interface is only available when the 10186** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10187*/ 10188SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10189 10190/* 10191** CAPI3REF: Compare the ages of two snapshot handles. 10192** METHOD: sqlite3_snapshot 10193** 10194** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10195** of two valid snapshot handles. 10196** 10197** If the two snapshot handles are not associated with the same database 10198** file, the result of the comparison is undefined. 10199** 10200** Additionally, the result of the comparison is only valid if both of the 10201** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10202** last time the wal file was deleted. The wal file is deleted when the 10203** database is changed back to rollback mode or when the number of database 10204** clients drops to zero. If either snapshot handle was obtained before the 10205** wal file was last deleted, the value returned by this function 10206** is undefined. 10207** 10208** Otherwise, this API returns a negative value if P1 refers to an older 10209** snapshot than P2, zero if the two handles refer to the same database 10210** snapshot, and a positive value if P1 is a newer snapshot than P2. 10211** 10212** This interface is only available if SQLite is compiled with the 10213** [SQLITE_ENABLE_SNAPSHOT] option. 10214*/ 10215SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10216 sqlite3_snapshot *p1, 10217 sqlite3_snapshot *p2 10218); 10219 10220/* 10221** CAPI3REF: Recover snapshots from a wal file 10222** METHOD: sqlite3_snapshot 10223** 10224** If a [WAL file] remains on disk after all database connections close 10225** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10226** or because the last process to have the database opened exited without 10227** calling [sqlite3_close()]) and a new connection is subsequently opened 10228** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10229** will only be able to open the last transaction added to the WAL file 10230** even though the WAL file contains other valid transactions. 10231** 10232** This function attempts to scan the WAL file associated with database zDb 10233** of database handle db and make all valid snapshots available to 10234** sqlite3_snapshot_open(). It is an error if there is already a read 10235** transaction open on the database, or if the database is not a WAL mode 10236** database. 10237** 10238** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10239** 10240** This interface is only available if SQLite is compiled with the 10241** [SQLITE_ENABLE_SNAPSHOT] option. 10242*/ 10243SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10244 10245/* 10246** CAPI3REF: Serialize a database 10247** 10248** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 10249** that is a serialization of the S database on [database connection] D. 10250** If P is not a NULL pointer, then the size of the database in bytes 10251** is written into *P. 10252** 10253** For an ordinary on-disk database file, the serialization is just a 10254** copy of the disk file. For an in-memory database or a "TEMP" database, 10255** the serialization is the same sequence of bytes which would be written 10256** to disk if that database where backed up to disk. 10257** 10258** The usual case is that sqlite3_serialize() copies the serialization of 10259** the database into memory obtained from [sqlite3_malloc64()] and returns 10260** a pointer to that memory. The caller is responsible for freeing the 10261** returned value to avoid a memory leak. However, if the F argument 10262** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10263** are made, and the sqlite3_serialize() function will return a pointer 10264** to the contiguous memory representation of the database that SQLite 10265** is currently using for that database, or NULL if the no such contiguous 10266** memory representation of the database exists. A contiguous memory 10267** representation of the database will usually only exist if there has 10268** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10269** values of D and S. 10270** The size of the database is written into *P even if the 10271** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10272** of the database exists. 10273** 10274** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10275** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10276** allocation error occurs. 10277** 10278** This interface is omitted if SQLite is compiled with the 10279** [SQLITE_OMIT_DESERIALIZE] option. 10280*/ 10281unsigned char *sqlite3_serialize( 10282 sqlite3 *db, /* The database connection */ 10283 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10284 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10285 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10286); 10287 10288/* 10289** CAPI3REF: Flags for sqlite3_serialize 10290** 10291** Zero or more of the following constants can be OR-ed together for 10292** the F argument to [sqlite3_serialize(D,S,P,F)]. 10293** 10294** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10295** a pointer to contiguous in-memory database that it is currently using, 10296** without making a copy of the database. If SQLite is not currently using 10297** a contiguous in-memory database, then this option causes 10298** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10299** using a contiguous in-memory database if it has been initialized by a 10300** prior call to [sqlite3_deserialize()]. 10301*/ 10302#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10303 10304/* 10305** CAPI3REF: Deserialize a database 10306** 10307** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10308** [database connection] D to disconnect from database S and then 10309** reopen S as an in-memory database based on the serialization contained 10310** in P. The serialized database P is N bytes in size. M is the size of 10311** the buffer P, which might be larger than N. If M is larger than N, and 10312** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10313** permitted to add content to the in-memory database as long as the total 10314** size does not exceed M bytes. 10315** 10316** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10317** invoke sqlite3_free() on the serialization buffer when the database 10318** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10319** SQLite will try to increase the buffer size using sqlite3_realloc64() 10320** if writes on the database cause it to grow larger than M bytes. 10321** 10322** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 10323** database is currently in a read transaction or is involved in a backup 10324** operation. 10325** 10326** It is not possible to deserialized into the TEMP database. If the 10327** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 10328** function returns SQLITE_ERROR. 10329** 10330** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 10331** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 10332** [sqlite3_free()] is invoked on argument P prior to returning. 10333** 10334** This interface is omitted if SQLite is compiled with the 10335** [SQLITE_OMIT_DESERIALIZE] option. 10336*/ 10337int sqlite3_deserialize( 10338 sqlite3 *db, /* The database connection */ 10339 const char *zSchema, /* Which DB to reopen with the deserialization */ 10340 unsigned char *pData, /* The serialized database content */ 10341 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 10342 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 10343 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 10344); 10345 10346/* 10347** CAPI3REF: Flags for sqlite3_deserialize() 10348** 10349** The following are allowed values for 6th argument (the F argument) to 10350** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 10351** 10352** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 10353** in the P argument is held in memory obtained from [sqlite3_malloc64()] 10354** and that SQLite should take ownership of this memory and automatically 10355** free it when it has finished using it. Without this flag, the caller 10356** is responsible for freeing any dynamically allocated memory. 10357** 10358** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 10359** grow the size of the database using calls to [sqlite3_realloc64()]. This 10360** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 10361** Without this flag, the deserialized database cannot increase in size beyond 10362** the number of bytes specified by the M parameter. 10363** 10364** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 10365** should be treated as read-only. 10366*/ 10367#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 10368#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 10369#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 10370 10371/* 10372** Undo the hack that converts floating point types to integer for 10373** builds on processors without floating point support. 10374*/ 10375#ifdef SQLITE_OMIT_FLOATING_POINT 10376# undef double 10377#endif 10378 10379#ifdef __cplusplus 10380} /* End of the 'extern "C"' block */ 10381#endif 10382#endif /* SQLITE3_H */ 10383