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)) 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() */ 612 613/* Reserved: 0x00F00000 */ 614/* Legacy compatibility: */ 615#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 616 617 618/* 619** CAPI3REF: Device Characteristics 620** 621** The xDeviceCharacteristics method of the [sqlite3_io_methods] 622** object returns an integer which is a vector of these 623** bit values expressing I/O characteristics of the mass storage 624** device that holds the file that the [sqlite3_io_methods] 625** refers to. 626** 627** The SQLITE_IOCAP_ATOMIC property means that all writes of 628** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 629** mean that writes of blocks that are nnn bytes in size and 630** are aligned to an address which is an integer multiple of 631** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 632** that when data is appended to a file, the data is appended 633** first then the size of the file is extended, never the other 634** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 635** information is written to disk in the same order as calls 636** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 637** after reboot following a crash or power loss, the only bytes in a 638** file that were written at the application level might have changed 639** and that adjacent bytes, even bytes within the same sector are 640** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 641** flag indicates that a file cannot be deleted when open. The 642** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 643** read-only media and cannot be changed even by processes with 644** elevated privileges. 645** 646** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 647** filesystem supports doing multiple write operations atomically when those 648** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 649** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 650*/ 651#define SQLITE_IOCAP_ATOMIC 0x00000001 652#define SQLITE_IOCAP_ATOMIC512 0x00000002 653#define SQLITE_IOCAP_ATOMIC1K 0x00000004 654#define SQLITE_IOCAP_ATOMIC2K 0x00000008 655#define SQLITE_IOCAP_ATOMIC4K 0x00000010 656#define SQLITE_IOCAP_ATOMIC8K 0x00000020 657#define SQLITE_IOCAP_ATOMIC16K 0x00000040 658#define SQLITE_IOCAP_ATOMIC32K 0x00000080 659#define SQLITE_IOCAP_ATOMIC64K 0x00000100 660#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 661#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 662#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 663#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 664#define SQLITE_IOCAP_IMMUTABLE 0x00002000 665#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 666 667/* 668** CAPI3REF: File Locking Levels 669** 670** SQLite uses one of these integer values as the second 671** argument to calls it makes to the xLock() and xUnlock() methods 672** of an [sqlite3_io_methods] object. 673*/ 674#define SQLITE_LOCK_NONE 0 675#define SQLITE_LOCK_SHARED 1 676#define SQLITE_LOCK_RESERVED 2 677#define SQLITE_LOCK_PENDING 3 678#define SQLITE_LOCK_EXCLUSIVE 4 679 680/* 681** CAPI3REF: Synchronization Type Flags 682** 683** When SQLite invokes the xSync() method of an 684** [sqlite3_io_methods] object it uses a combination of 685** these integer values as the second argument. 686** 687** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 688** sync operation only needs to flush data to mass storage. Inode 689** information need not be flushed. If the lower four bits of the flag 690** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 691** If the lower four bits equal SQLITE_SYNC_FULL, that means 692** to use Mac OS X style fullsync instead of fsync(). 693** 694** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 695** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 696** settings. The [synchronous pragma] determines when calls to the 697** xSync VFS method occur and applies uniformly across all platforms. 698** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 699** energetic or rigorous or forceful the sync operations are and 700** only make a difference on Mac OSX for the default SQLite code. 701** (Third-party VFS implementations might also make the distinction 702** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 703** operating systems natively supported by SQLite, only Mac OSX 704** cares about the difference.) 705*/ 706#define SQLITE_SYNC_NORMAL 0x00002 707#define SQLITE_SYNC_FULL 0x00003 708#define SQLITE_SYNC_DATAONLY 0x00010 709 710/* 711** CAPI3REF: OS Interface Open File Handle 712** 713** An [sqlite3_file] object represents an open file in the 714** [sqlite3_vfs | OS interface layer]. Individual OS interface 715** implementations will 716** want to subclass this object by appending additional fields 717** for their own use. The pMethods entry is a pointer to an 718** [sqlite3_io_methods] object that defines methods for performing 719** I/O operations on the open file. 720*/ 721typedef struct sqlite3_file sqlite3_file; 722struct sqlite3_file { 723 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 724}; 725 726/* 727** CAPI3REF: OS Interface File Virtual Methods Object 728** 729** Every file opened by the [sqlite3_vfs.xOpen] method populates an 730** [sqlite3_file] object (or, more commonly, a subclass of the 731** [sqlite3_file] object) with a pointer to an instance of this object. 732** This object defines the methods used to perform various operations 733** against the open file represented by the [sqlite3_file] object. 734** 735** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 736** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 737** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 738** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 739** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 740** to NULL. 741** 742** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 743** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 744** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 745** flag may be ORed in to indicate that only the data of the file 746** and not its inode needs to be synced. 747** 748** The integer values to xLock() and xUnlock() are one of 749** <ul> 750** <li> [SQLITE_LOCK_NONE], 751** <li> [SQLITE_LOCK_SHARED], 752** <li> [SQLITE_LOCK_RESERVED], 753** <li> [SQLITE_LOCK_PENDING], or 754** <li> [SQLITE_LOCK_EXCLUSIVE]. 755** </ul> 756** xLock() increases the lock. xUnlock() decreases the lock. 757** The xCheckReservedLock() method checks whether any database connection, 758** either in this process or in some other process, is holding a RESERVED, 759** PENDING, or EXCLUSIVE lock on the file. It returns true 760** if such a lock exists and false otherwise. 761** 762** The xFileControl() method is a generic interface that allows custom 763** VFS implementations to directly control an open file using the 764** [sqlite3_file_control()] interface. The second "op" argument is an 765** integer opcode. The third argument is a generic pointer intended to 766** point to a structure that may contain arguments or space in which to 767** write return values. Potential uses for xFileControl() might be 768** functions to enable blocking locks with timeouts, to change the 769** locking strategy (for example to use dot-file locks), to inquire 770** about the status of a lock, or to break stale locks. The SQLite 771** core reserves all opcodes less than 100 for its own use. 772** A [file control opcodes | list of opcodes] less than 100 is available. 773** Applications that define a custom xFileControl method should use opcodes 774** greater than 100 to avoid conflicts. VFS implementations should 775** return [SQLITE_NOTFOUND] for file control opcodes that they do not 776** recognize. 777** 778** The xSectorSize() method returns the sector size of the 779** device that underlies the file. The sector size is the 780** minimum write that can be performed without disturbing 781** other bytes in the file. The xDeviceCharacteristics() 782** method returns a bit vector describing behaviors of the 783** underlying device: 784** 785** <ul> 786** <li> [SQLITE_IOCAP_ATOMIC] 787** <li> [SQLITE_IOCAP_ATOMIC512] 788** <li> [SQLITE_IOCAP_ATOMIC1K] 789** <li> [SQLITE_IOCAP_ATOMIC2K] 790** <li> [SQLITE_IOCAP_ATOMIC4K] 791** <li> [SQLITE_IOCAP_ATOMIC8K] 792** <li> [SQLITE_IOCAP_ATOMIC16K] 793** <li> [SQLITE_IOCAP_ATOMIC32K] 794** <li> [SQLITE_IOCAP_ATOMIC64K] 795** <li> [SQLITE_IOCAP_SAFE_APPEND] 796** <li> [SQLITE_IOCAP_SEQUENTIAL] 797** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 798** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 799** <li> [SQLITE_IOCAP_IMMUTABLE] 800** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 801** </ul> 802** 803** The SQLITE_IOCAP_ATOMIC property means that all writes of 804** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 805** mean that writes of blocks that are nnn bytes in size and 806** are aligned to an address which is an integer multiple of 807** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 808** that when data is appended to a file, the data is appended 809** first then the size of the file is extended, never the other 810** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 811** information is written to disk in the same order as calls 812** to xWrite(). 813** 814** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 815** in the unread portions of the buffer with zeros. A VFS that 816** fails to zero-fill short reads might seem to work. However, 817** failure to zero-fill short reads will eventually lead to 818** database corruption. 819*/ 820typedef struct sqlite3_io_methods sqlite3_io_methods; 821struct sqlite3_io_methods { 822 int iVersion; 823 int (*xClose)(sqlite3_file*); 824 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 825 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 826 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 827 int (*xSync)(sqlite3_file*, int flags); 828 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 829 int (*xLock)(sqlite3_file*, int); 830 int (*xUnlock)(sqlite3_file*, int); 831 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 832 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 833 int (*xSectorSize)(sqlite3_file*); 834 int (*xDeviceCharacteristics)(sqlite3_file*); 835 /* Methods above are valid for version 1 */ 836 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 837 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 838 void (*xShmBarrier)(sqlite3_file*); 839 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 840 /* Methods above are valid for version 2 */ 841 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 842 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 843 /* Methods above are valid for version 3 */ 844 /* Additional methods may be added in future releases */ 845}; 846 847/* 848** CAPI3REF: Standard File Control Opcodes 849** KEYWORDS: {file control opcodes} {file control opcode} 850** 851** These integer constants are opcodes for the xFileControl method 852** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 853** interface. 854** 855** <ul> 856** <li>[[SQLITE_FCNTL_LOCKSTATE]] 857** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 858** opcode causes the xFileControl method to write the current state of 859** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 860** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 861** into an integer that the pArg argument points to. This capability 862** is used during testing and is only available when the SQLITE_TEST 863** compile-time option is used. 864** 865** <li>[[SQLITE_FCNTL_SIZE_HINT]] 866** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 867** layer a hint of how large the database file will grow to be during the 868** current transaction. This hint is not guaranteed to be accurate but it 869** is often close. The underlying VFS might choose to preallocate database 870** file space based on this hint in order to help writes to the database 871** file run faster. 872** 873** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 874** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 875** implements [sqlite3_deserialize()] to set an upper bound on the size 876** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 877** If the integer pointed to is negative, then it is filled in with the 878** current limit. Otherwise the limit is set to the larger of the value 879** of the integer pointed to and the current database size. The integer 880** pointed to is set to the new limit. 881** 882** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 883** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 884** extends and truncates the database file in chunks of a size specified 885** by the user. The fourth argument to [sqlite3_file_control()] should 886** point to an integer (type int) containing the new chunk-size to use 887** for the nominated database. Allocating database file space in large 888** chunks (say 1MB at a time), may reduce file-system fragmentation and 889** improve performance on some systems. 890** 891** <li>[[SQLITE_FCNTL_FILE_POINTER]] 892** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 893** to the [sqlite3_file] object associated with a particular database 894** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 895** 896** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 897** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 898** to the [sqlite3_file] object associated with the journal file (either 899** the [rollback journal] or the [write-ahead log]) for a particular database 900** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 901** 902** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 903** No longer in use. 904** 905** <li>[[SQLITE_FCNTL_SYNC]] 906** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 907** sent to the VFS immediately before the xSync method is invoked on a 908** database file descriptor. Or, if the xSync method is not invoked 909** because the user has configured SQLite with 910** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 911** of the xSync method. In most cases, the pointer argument passed with 912** this file-control is NULL. However, if the database file is being synced 913** as part of a multi-database commit, the argument points to a nul-terminated 914** string containing the transactions super-journal file name. VFSes that 915** do not need this signal should silently ignore this opcode. Applications 916** should not call [sqlite3_file_control()] with this opcode as doing so may 917** disrupt the operation of the specialized VFSes that do require it. 918** 919** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 920** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 921** and sent to the VFS after a transaction has been committed immediately 922** but before the database is unlocked. VFSes that do not need this signal 923** should silently ignore this opcode. Applications should not call 924** [sqlite3_file_control()] with this opcode as doing so may disrupt the 925** operation of the specialized VFSes that do require it. 926** 927** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 928** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 929** retry counts and intervals for certain disk I/O operations for the 930** windows [VFS] in order to provide robustness in the presence of 931** anti-virus programs. By default, the windows VFS will retry file read, 932** file write, and file delete operations up to 10 times, with a delay 933** of 25 milliseconds before the first retry and with the delay increasing 934** by an additional 25 milliseconds with each subsequent retry. This 935** opcode allows these two values (10 retries and 25 milliseconds of delay) 936** to be adjusted. The values are changed for all database connections 937** within the same process. The argument is a pointer to an array of two 938** integers where the first integer is the new retry count and the second 939** integer is the delay. If either integer is negative, then the setting 940** is not changed but instead the prior value of that setting is written 941** into the array entry, allowing the current retry settings to be 942** interrogated. The zDbName parameter is ignored. 943** 944** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 945** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 946** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 947** write ahead log ([WAL file]) and shared memory 948** files used for transaction control 949** are automatically deleted when the latest connection to the database 950** closes. Setting persistent WAL mode causes those files to persist after 951** close. Persisting the files is useful when other processes that do not 952** have write permission on the directory containing the database file want 953** to read the database file, as the WAL and shared memory files must exist 954** in order for the database to be readable. The fourth parameter to 955** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 956** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 957** WAL mode. If the integer is -1, then it is overwritten with the current 958** WAL persistence setting. 959** 960** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 961** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 962** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 963** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 964** xDeviceCharacteristics methods. The fourth parameter to 965** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 966** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 967** mode. If the integer is -1, then it is overwritten with the current 968** zero-damage mode setting. 969** 970** <li>[[SQLITE_FCNTL_OVERWRITE]] 971** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 972** a write transaction to indicate that, unless it is rolled back for some 973** reason, the entire database file will be overwritten by the current 974** transaction. This is used by VACUUM operations. 975** 976** <li>[[SQLITE_FCNTL_VFSNAME]] 977** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 978** all [VFSes] in the VFS stack. The names are of all VFS shims and the 979** final bottom-level VFS are written into memory obtained from 980** [sqlite3_malloc()] and the result is stored in the char* variable 981** that the fourth parameter of [sqlite3_file_control()] points to. 982** The caller is responsible for freeing the memory when done. As with 983** all file-control actions, there is no guarantee that this will actually 984** do anything. Callers should initialize the char* variable to a NULL 985** pointer in case this file-control is not implemented. This file-control 986** is intended for diagnostic use only. 987** 988** <li>[[SQLITE_FCNTL_VFS_POINTER]] 989** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 990** [VFSes] currently in use. ^(The argument X in 991** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 992** of type "[sqlite3_vfs] **". This opcodes will set *X 993** to a pointer to the top-level VFS.)^ 994** ^When there are multiple VFS shims in the stack, this opcode finds the 995** upper-most shim only. 996** 997** <li>[[SQLITE_FCNTL_PRAGMA]] 998** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 999** file control is sent to the open [sqlite3_file] object corresponding 1000** to the database file to which the pragma statement refers. ^The argument 1001** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1002** pointers to strings (char**) in which the second element of the array 1003** is the name of the pragma and the third element is the argument to the 1004** pragma or NULL if the pragma has no argument. ^The handler for an 1005** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1006** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1007** or the equivalent and that string will become the result of the pragma or 1008** the error message if the pragma fails. ^If the 1009** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1010** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1011** file control returns [SQLITE_OK], then the parser assumes that the 1012** VFS has handled the PRAGMA itself and the parser generates a no-op 1013** prepared statement if result string is NULL, or that returns a copy 1014** of the result string if the string is non-NULL. 1015** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1016** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1017** that the VFS encountered an error while handling the [PRAGMA] and the 1018** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1019** file control occurs at the beginning of pragma statement analysis and so 1020** it is able to override built-in [PRAGMA] statements. 1021** 1022** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1023** ^The [SQLITE_FCNTL_BUSYHANDLER] 1024** file-control may be invoked by SQLite on the database file handle 1025** shortly after it is opened in order to provide a custom VFS with access 1026** to the connection's busy-handler callback. The argument is of type (void**) 1027** - an array of two (void *) values. The first (void *) actually points 1028** to a function of type (int (*)(void *)). In order to invoke the connection's 1029** busy-handler, this function should be invoked with the second (void *) in 1030** the array as the only argument. If it returns non-zero, then the operation 1031** should be retried. If it returns zero, the custom VFS should abandon the 1032** current operation. 1033** 1034** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1035** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1036** to have SQLite generate a 1037** temporary filename using the same algorithm that is followed to generate 1038** temporary filenames for TEMP tables and other internal uses. The 1039** argument should be a char** which will be filled with the filename 1040** written into memory obtained from [sqlite3_malloc()]. The caller should 1041** invoke [sqlite3_free()] on the result to avoid a memory leak. 1042** 1043** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1044** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1045** maximum number of bytes that will be used for memory-mapped I/O. 1046** The argument is a pointer to a value of type sqlite3_int64 that 1047** is an advisory maximum number of bytes in the file to memory map. The 1048** pointer is overwritten with the old value. The limit is not changed if 1049** the value originally pointed to is negative, and so the current limit 1050** can be queried by passing in a pointer to a negative number. This 1051** file-control is used internally to implement [PRAGMA mmap_size]. 1052** 1053** <li>[[SQLITE_FCNTL_TRACE]] 1054** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1055** to the VFS about what the higher layers of the SQLite stack are doing. 1056** This file control is used by some VFS activity tracing [shims]. 1057** The argument is a zero-terminated string. Higher layers in the 1058** SQLite stack may generate instances of this file control if 1059** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1060** 1061** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1062** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1063** pointer to an integer and it writes a boolean into that integer depending 1064** on whether or not the file has been renamed, moved, or deleted since it 1065** was first opened. 1066** 1067** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1068** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1069** underlying native file handle associated with a file handle. This file 1070** control interprets its argument as a pointer to a native file handle and 1071** writes the resulting value there. 1072** 1073** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1074** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1075** opcode causes the xFileControl method to swap the file handle with the one 1076** pointed to by the pArg argument. This capability is used during testing 1077** and only needs to be supported when SQLITE_TEST is defined. 1078** 1079** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1080** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1081** be advantageous to block on the next WAL lock if the lock is not immediately 1082** available. The WAL subsystem issues this signal during rare 1083** circumstances in order to fix a problem with priority inversion. 1084** Applications should <em>not</em> use this file-control. 1085** 1086** <li>[[SQLITE_FCNTL_ZIPVFS]] 1087** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1088** VFS should return SQLITE_NOTFOUND for this opcode. 1089** 1090** <li>[[SQLITE_FCNTL_RBU]] 1091** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1092** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1093** this opcode. 1094** 1095** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1096** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1097** the file descriptor is placed in "batch write mode", which 1098** means all subsequent write operations will be deferred and done 1099** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1100** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1101** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1102** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1103** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1104** no VFS interface calls on the same [sqlite3_file] file descriptor 1105** except for calls to the xWrite method and the xFileControl method 1106** with [SQLITE_FCNTL_SIZE_HINT]. 1107** 1108** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1109** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1110** operations since the previous successful call to 1111** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1112** This file control returns [SQLITE_OK] if and only if the writes were 1113** all performed successfully and have been committed to persistent storage. 1114** ^Regardless of whether or not it is successful, this file control takes 1115** the file descriptor out of batch write mode so that all subsequent 1116** write operations are independent. 1117** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1118** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1119** 1120** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1121** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1122** operations since the previous successful call to 1123** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1124** ^This file control takes the file descriptor out of batch write mode 1125** so that all subsequent write operations are independent. 1126** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1127** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1128** 1129** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1130** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1131** to block for up to M milliseconds before failing when attempting to 1132** obtain a file lock using the xLock or xShmLock methods of the VFS. 1133** The parameter is a pointer to a 32-bit signed integer that contains 1134** the value that M is to be set to. Before returning, the 32-bit signed 1135** integer is overwritten with the previous value of M. 1136** 1137** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1138** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1139** a database file. The argument is a pointer to a 32-bit unsigned integer. 1140** The "data version" for the pager is written into the pointer. The 1141** "data version" changes whenever any change occurs to the corresponding 1142** database file, either through SQL statements on the same database 1143** connection or through transactions committed by separate database 1144** connections possibly in other processes. The [sqlite3_total_changes()] 1145** interface can be used to find if any database on the connection has changed, 1146** but that interface responds to changes on TEMP as well as MAIN and does 1147** not provide a mechanism to detect changes to MAIN only. Also, the 1148** [sqlite3_total_changes()] interface responds to internal changes only and 1149** omits changes made by other database connections. The 1150** [PRAGMA data_version] command provides a mechanism to detect changes to 1151** a single attached database that occur due to other database connections, 1152** but omits changes implemented by the database connection on which it is 1153** called. This file control is the only mechanism to detect changes that 1154** happen either internally or externally and that are associated with 1155** a particular attached database. 1156** 1157** <li>[[SQLITE_FCNTL_CKPT_START]] 1158** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1159** in wal mode before the client starts to copy pages from the wal 1160** file to the database file. 1161** 1162** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1163** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1164** in wal mode after the client has finished copying pages from the wal 1165** file to the database file, but before the *-shm file is updated to 1166** record the fact that the pages have been checkpointed. 1167** </ul> 1168** 1169** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1170** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1171** whether or not there is a database client in another process with a wal-mode 1172** transaction open on the database or not. It is only available on unix.The 1173** (void*) argument passed with this file-control should be a pointer to a 1174** value of type (int). The integer value is set to 1 if the database is a wal 1175** mode database and there exists at least one client in another process that 1176** currently has an SQL transaction open on the database. It is set to 0 if 1177** the database is not a wal-mode db, or if there is no such connection in any 1178** other process. This opcode cannot be used to detect transactions opened 1179** by clients within the current process, only within other processes. 1180** </ul> 1181** 1182** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1183** Used by the cksmvfs VFS module only. 1184** </ul> 1185*/ 1186#define SQLITE_FCNTL_LOCKSTATE 1 1187#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1188#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1189#define SQLITE_FCNTL_LAST_ERRNO 4 1190#define SQLITE_FCNTL_SIZE_HINT 5 1191#define SQLITE_FCNTL_CHUNK_SIZE 6 1192#define SQLITE_FCNTL_FILE_POINTER 7 1193#define SQLITE_FCNTL_SYNC_OMITTED 8 1194#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1195#define SQLITE_FCNTL_PERSIST_WAL 10 1196#define SQLITE_FCNTL_OVERWRITE 11 1197#define SQLITE_FCNTL_VFSNAME 12 1198#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1199#define SQLITE_FCNTL_PRAGMA 14 1200#define SQLITE_FCNTL_BUSYHANDLER 15 1201#define SQLITE_FCNTL_TEMPFILENAME 16 1202#define SQLITE_FCNTL_MMAP_SIZE 18 1203#define SQLITE_FCNTL_TRACE 19 1204#define SQLITE_FCNTL_HAS_MOVED 20 1205#define SQLITE_FCNTL_SYNC 21 1206#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1207#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1208#define SQLITE_FCNTL_WAL_BLOCK 24 1209#define SQLITE_FCNTL_ZIPVFS 25 1210#define SQLITE_FCNTL_RBU 26 1211#define SQLITE_FCNTL_VFS_POINTER 27 1212#define SQLITE_FCNTL_JOURNAL_POINTER 28 1213#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1214#define SQLITE_FCNTL_PDB 30 1215#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1216#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1217#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1218#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1219#define SQLITE_FCNTL_DATA_VERSION 35 1220#define SQLITE_FCNTL_SIZE_LIMIT 36 1221#define SQLITE_FCNTL_CKPT_DONE 37 1222#define SQLITE_FCNTL_RESERVE_BYTES 38 1223#define SQLITE_FCNTL_CKPT_START 39 1224#define SQLITE_FCNTL_EXTERNAL_READER 40 1225#define SQLITE_FCNTL_CKSM_FILE 41 1226 1227/* deprecated names */ 1228#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1229#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1230#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1231 1232 1233/* 1234** CAPI3REF: Mutex Handle 1235** 1236** The mutex module within SQLite defines [sqlite3_mutex] to be an 1237** abstract type for a mutex object. The SQLite core never looks 1238** at the internal representation of an [sqlite3_mutex]. It only 1239** deals with pointers to the [sqlite3_mutex] object. 1240** 1241** Mutexes are created using [sqlite3_mutex_alloc()]. 1242*/ 1243typedef struct sqlite3_mutex sqlite3_mutex; 1244 1245/* 1246** CAPI3REF: Loadable Extension Thunk 1247** 1248** A pointer to the opaque sqlite3_api_routines structure is passed as 1249** the third parameter to entry points of [loadable extensions]. This 1250** structure must be typedefed in order to work around compiler warnings 1251** on some platforms. 1252*/ 1253typedef struct sqlite3_api_routines sqlite3_api_routines; 1254 1255/* 1256** CAPI3REF: OS Interface Object 1257** 1258** An instance of the sqlite3_vfs object defines the interface between 1259** the SQLite core and the underlying operating system. The "vfs" 1260** in the name of the object stands for "virtual file system". See 1261** the [VFS | VFS documentation] for further information. 1262** 1263** The VFS interface is sometimes extended by adding new methods onto 1264** the end. Each time such an extension occurs, the iVersion field 1265** is incremented. The iVersion value started out as 1 in 1266** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1267** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1268** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1269** may be appended to the sqlite3_vfs object and the iVersion value 1270** may increase again in future versions of SQLite. 1271** Note that due to an oversight, the structure 1272** of the sqlite3_vfs object changed in the transition from 1273** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1274** and yet the iVersion field was not increased. 1275** 1276** The szOsFile field is the size of the subclassed [sqlite3_file] 1277** structure used by this VFS. mxPathname is the maximum length of 1278** a pathname in this VFS. 1279** 1280** Registered sqlite3_vfs objects are kept on a linked list formed by 1281** the pNext pointer. The [sqlite3_vfs_register()] 1282** and [sqlite3_vfs_unregister()] interfaces manage this list 1283** in a thread-safe way. The [sqlite3_vfs_find()] interface 1284** searches the list. Neither the application code nor the VFS 1285** implementation should use the pNext pointer. 1286** 1287** The pNext field is the only field in the sqlite3_vfs 1288** structure that SQLite will ever modify. SQLite will only access 1289** or modify this field while holding a particular static mutex. 1290** The application should never modify anything within the sqlite3_vfs 1291** object once the object has been registered. 1292** 1293** The zName field holds the name of the VFS module. The name must 1294** be unique across all VFS modules. 1295** 1296** [[sqlite3_vfs.xOpen]] 1297** ^SQLite guarantees that the zFilename parameter to xOpen 1298** is either a NULL pointer or string obtained 1299** from xFullPathname() with an optional suffix added. 1300** ^If a suffix is added to the zFilename parameter, it will 1301** consist of a single "-" character followed by no more than 1302** 11 alphanumeric and/or "-" characters. 1303** ^SQLite further guarantees that 1304** the string will be valid and unchanged until xClose() is 1305** called. Because of the previous sentence, 1306** the [sqlite3_file] can safely store a pointer to the 1307** filename if it needs to remember the filename for some reason. 1308** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1309** must invent its own temporary name for the file. ^Whenever the 1310** xFilename parameter is NULL it will also be the case that the 1311** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1312** 1313** The flags argument to xOpen() includes all bits set in 1314** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1315** or [sqlite3_open16()] is used, then flags includes at least 1316** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1317** If xOpen() opens a file read-only then it sets *pOutFlags to 1318** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1319** 1320** ^(SQLite will also add one of the following flags to the xOpen() 1321** call, depending on the object being opened: 1322** 1323** <ul> 1324** <li> [SQLITE_OPEN_MAIN_DB] 1325** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1326** <li> [SQLITE_OPEN_TEMP_DB] 1327** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1328** <li> [SQLITE_OPEN_TRANSIENT_DB] 1329** <li> [SQLITE_OPEN_SUBJOURNAL] 1330** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1331** <li> [SQLITE_OPEN_WAL] 1332** </ul>)^ 1333** 1334** The file I/O implementation can use the object type flags to 1335** change the way it deals with files. For example, an application 1336** that does not care about crash recovery or rollback might make 1337** the open of a journal file a no-op. Writes to this journal would 1338** also be no-ops, and any attempt to read the journal would return 1339** SQLITE_IOERR. Or the implementation might recognize that a database 1340** file will be doing page-aligned sector reads and writes in a random 1341** order and set up its I/O subsystem accordingly. 1342** 1343** SQLite might also add one of the following flags to the xOpen method: 1344** 1345** <ul> 1346** <li> [SQLITE_OPEN_DELETEONCLOSE] 1347** <li> [SQLITE_OPEN_EXCLUSIVE] 1348** </ul> 1349** 1350** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1351** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1352** will be set for TEMP databases and their journals, transient 1353** databases, and subjournals. 1354** 1355** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1356** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1357** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1358** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1359** SQLITE_OPEN_CREATE, is used to indicate that file should always 1360** be created, and that it is an error if it already exists. 1361** It is <i>not</i> used to indicate the file should be opened 1362** for exclusive access. 1363** 1364** ^At least szOsFile bytes of memory are allocated by SQLite 1365** to hold the [sqlite3_file] structure passed as the third 1366** argument to xOpen. The xOpen method does not have to 1367** allocate the structure; it should just fill it in. Note that 1368** the xOpen method must set the sqlite3_file.pMethods to either 1369** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1370** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1371** element will be valid after xOpen returns regardless of the success 1372** or failure of the xOpen call. 1373** 1374** [[sqlite3_vfs.xAccess]] 1375** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1376** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1377** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1378** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1379** flag is never actually used and is not implemented in the built-in 1380** VFSes of SQLite. The file is named by the second argument and can be a 1381** directory. The xAccess method returns [SQLITE_OK] on success or some 1382** non-zero error code if there is an I/O error or if the name of 1383** the file given in the second argument is illegal. If SQLITE_OK 1384** is returned, then non-zero or zero is written into *pResOut to indicate 1385** whether or not the file is accessible. 1386** 1387** ^SQLite will always allocate at least mxPathname+1 bytes for the 1388** output buffer xFullPathname. The exact size of the output buffer 1389** is also passed as a parameter to both methods. If the output buffer 1390** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1391** handled as a fatal error by SQLite, vfs implementations should endeavor 1392** to prevent this by setting mxPathname to a sufficiently large value. 1393** 1394** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1395** interfaces are not strictly a part of the filesystem, but they are 1396** included in the VFS structure for completeness. 1397** The xRandomness() function attempts to return nBytes bytes 1398** of good-quality randomness into zOut. The return value is 1399** the actual number of bytes of randomness obtained. 1400** The xSleep() method causes the calling thread to sleep for at 1401** least the number of microseconds given. ^The xCurrentTime() 1402** method returns a Julian Day Number for the current date and time as 1403** a floating point value. 1404** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1405** Day Number multiplied by 86400000 (the number of milliseconds in 1406** a 24-hour day). 1407** ^SQLite will use the xCurrentTimeInt64() method to get the current 1408** date and time if that method is available (if iVersion is 2 or 1409** greater and the function pointer is not NULL) and will fall back 1410** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1411** 1412** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1413** are not used by the SQLite core. These optional interfaces are provided 1414** by some VFSes to facilitate testing of the VFS code. By overriding 1415** system calls with functions under its control, a test program can 1416** simulate faults and error conditions that would otherwise be difficult 1417** or impossible to induce. The set of system calls that can be overridden 1418** varies from one VFS to another, and from one version of the same VFS to the 1419** next. Applications that use these interfaces must be prepared for any 1420** or all of these interfaces to be NULL or for their behavior to change 1421** from one release to the next. Applications must not attempt to access 1422** any of these methods if the iVersion of the VFS is less than 3. 1423*/ 1424typedef struct sqlite3_vfs sqlite3_vfs; 1425typedef void (*sqlite3_syscall_ptr)(void); 1426struct sqlite3_vfs { 1427 int iVersion; /* Structure version number (currently 3) */ 1428 int szOsFile; /* Size of subclassed sqlite3_file */ 1429 int mxPathname; /* Maximum file pathname length */ 1430 sqlite3_vfs *pNext; /* Next registered VFS */ 1431 const char *zName; /* Name of this virtual file system */ 1432 void *pAppData; /* Pointer to application-specific data */ 1433 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1434 int flags, int *pOutFlags); 1435 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1436 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1437 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1438 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1439 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1440 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1441 void (*xDlClose)(sqlite3_vfs*, void*); 1442 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1443 int (*xSleep)(sqlite3_vfs*, int microseconds); 1444 int (*xCurrentTime)(sqlite3_vfs*, double*); 1445 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1446 /* 1447 ** The methods above are in version 1 of the sqlite_vfs object 1448 ** definition. Those that follow are added in version 2 or later 1449 */ 1450 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1451 /* 1452 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1453 ** Those below are for version 3 and greater. 1454 */ 1455 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1456 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1457 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1458 /* 1459 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1460 ** New fields may be appended in future versions. The iVersion 1461 ** value will increment whenever this happens. 1462 */ 1463}; 1464 1465/* 1466** CAPI3REF: Flags for the xAccess VFS method 1467** 1468** These integer constants can be used as the third parameter to 1469** the xAccess method of an [sqlite3_vfs] object. They determine 1470** what kind of permissions the xAccess method is looking for. 1471** With SQLITE_ACCESS_EXISTS, the xAccess method 1472** simply checks whether the file exists. 1473** With SQLITE_ACCESS_READWRITE, the xAccess method 1474** checks whether the named directory is both readable and writable 1475** (in other words, if files can be added, removed, and renamed within 1476** the directory). 1477** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1478** [temp_store_directory pragma], though this could change in a future 1479** release of SQLite. 1480** With SQLITE_ACCESS_READ, the xAccess method 1481** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1482** currently unused, though it might be used in a future release of 1483** SQLite. 1484*/ 1485#define SQLITE_ACCESS_EXISTS 0 1486#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1487#define SQLITE_ACCESS_READ 2 /* Unused */ 1488 1489/* 1490** CAPI3REF: Flags for the xShmLock VFS method 1491** 1492** These integer constants define the various locking operations 1493** allowed by the xShmLock method of [sqlite3_io_methods]. The 1494** following are the only legal combinations of flags to the 1495** xShmLock method: 1496** 1497** <ul> 1498** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1499** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1500** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1501** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1502** </ul> 1503** 1504** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1505** was given on the corresponding lock. 1506** 1507** The xShmLock method can transition between unlocked and SHARED or 1508** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1509** and EXCLUSIVE. 1510*/ 1511#define SQLITE_SHM_UNLOCK 1 1512#define SQLITE_SHM_LOCK 2 1513#define SQLITE_SHM_SHARED 4 1514#define SQLITE_SHM_EXCLUSIVE 8 1515 1516/* 1517** CAPI3REF: Maximum xShmLock index 1518** 1519** The xShmLock method on [sqlite3_io_methods] may use values 1520** between 0 and this upper bound as its "offset" argument. 1521** The SQLite core will never attempt to acquire or release a 1522** lock outside of this range 1523*/ 1524#define SQLITE_SHM_NLOCK 8 1525 1526 1527/* 1528** CAPI3REF: Initialize The SQLite Library 1529** 1530** ^The sqlite3_initialize() routine initializes the 1531** SQLite library. ^The sqlite3_shutdown() routine 1532** deallocates any resources that were allocated by sqlite3_initialize(). 1533** These routines are designed to aid in process initialization and 1534** shutdown on embedded systems. Workstation applications using 1535** SQLite normally do not need to invoke either of these routines. 1536** 1537** A call to sqlite3_initialize() is an "effective" call if it is 1538** the first time sqlite3_initialize() is invoked during the lifetime of 1539** the process, or if it is the first time sqlite3_initialize() is invoked 1540** following a call to sqlite3_shutdown(). ^(Only an effective call 1541** of sqlite3_initialize() does any initialization. All other calls 1542** are harmless no-ops.)^ 1543** 1544** A call to sqlite3_shutdown() is an "effective" call if it is the first 1545** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1546** an effective call to sqlite3_shutdown() does any deinitialization. 1547** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1548** 1549** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1550** is not. The sqlite3_shutdown() interface must only be called from a 1551** single thread. All open [database connections] must be closed and all 1552** other SQLite resources must be deallocated prior to invoking 1553** sqlite3_shutdown(). 1554** 1555** Among other things, ^sqlite3_initialize() will invoke 1556** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1557** will invoke sqlite3_os_end(). 1558** 1559** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1560** ^If for some reason, sqlite3_initialize() is unable to initialize 1561** the library (perhaps it is unable to allocate a needed resource such 1562** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1563** 1564** ^The sqlite3_initialize() routine is called internally by many other 1565** SQLite interfaces so that an application usually does not need to 1566** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1567** calls sqlite3_initialize() so the SQLite library will be automatically 1568** initialized when [sqlite3_open()] is called if it has not be initialized 1569** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1570** compile-time option, then the automatic calls to sqlite3_initialize() 1571** are omitted and the application must call sqlite3_initialize() directly 1572** prior to using any other SQLite interface. For maximum portability, 1573** it is recommended that applications always invoke sqlite3_initialize() 1574** directly prior to using any other SQLite interface. Future releases 1575** of SQLite may require this. In other words, the behavior exhibited 1576** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1577** default behavior in some future release of SQLite. 1578** 1579** The sqlite3_os_init() routine does operating-system specific 1580** initialization of the SQLite library. The sqlite3_os_end() 1581** routine undoes the effect of sqlite3_os_init(). Typical tasks 1582** performed by these routines include allocation or deallocation 1583** of static resources, initialization of global variables, 1584** setting up a default [sqlite3_vfs] module, or setting up 1585** a default configuration using [sqlite3_config()]. 1586** 1587** The application should never invoke either sqlite3_os_init() 1588** or sqlite3_os_end() directly. The application should only invoke 1589** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1590** interface is called automatically by sqlite3_initialize() and 1591** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1592** implementations for sqlite3_os_init() and sqlite3_os_end() 1593** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1594** When [custom builds | built for other platforms] 1595** (using the [SQLITE_OS_OTHER=1] compile-time 1596** option) the application must supply a suitable implementation for 1597** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1598** implementation of sqlite3_os_init() or sqlite3_os_end() 1599** must return [SQLITE_OK] on success and some other [error code] upon 1600** failure. 1601*/ 1602int sqlite3_initialize(void); 1603int sqlite3_shutdown(void); 1604int sqlite3_os_init(void); 1605int sqlite3_os_end(void); 1606 1607/* 1608** CAPI3REF: Configuring The SQLite Library 1609** 1610** The sqlite3_config() interface is used to make global configuration 1611** changes to SQLite in order to tune SQLite to the specific needs of 1612** the application. The default configuration is recommended for most 1613** applications and so this routine is usually not necessary. It is 1614** provided to support rare applications with unusual needs. 1615** 1616** <b>The sqlite3_config() interface is not threadsafe. The application 1617** must ensure that no other SQLite interfaces are invoked by other 1618** threads while sqlite3_config() is running.</b> 1619** 1620** The sqlite3_config() interface 1621** may only be invoked prior to library initialization using 1622** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1623** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1624** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1625** Note, however, that ^sqlite3_config() can be called as part of the 1626** implementation of an application-defined [sqlite3_os_init()]. 1627** 1628** The first argument to sqlite3_config() is an integer 1629** [configuration option] that determines 1630** what property of SQLite is to be configured. Subsequent arguments 1631** vary depending on the [configuration option] 1632** in the first argument. 1633** 1634** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1635** ^If the option is unknown or SQLite is unable to set the option 1636** then this routine returns a non-zero [error code]. 1637*/ 1638int sqlite3_config(int, ...); 1639 1640/* 1641** CAPI3REF: Configure database connections 1642** METHOD: sqlite3 1643** 1644** The sqlite3_db_config() interface is used to make configuration 1645** changes to a [database connection]. The interface is similar to 1646** [sqlite3_config()] except that the changes apply to a single 1647** [database connection] (specified in the first argument). 1648** 1649** The second argument to sqlite3_db_config(D,V,...) is the 1650** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1651** that indicates what aspect of the [database connection] is being configured. 1652** Subsequent arguments vary depending on the configuration verb. 1653** 1654** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1655** the call is considered successful. 1656*/ 1657int sqlite3_db_config(sqlite3*, int op, ...); 1658 1659/* 1660** CAPI3REF: Memory Allocation Routines 1661** 1662** An instance of this object defines the interface between SQLite 1663** and low-level memory allocation routines. 1664** 1665** This object is used in only one place in the SQLite interface. 1666** A pointer to an instance of this object is the argument to 1667** [sqlite3_config()] when the configuration option is 1668** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1669** By creating an instance of this object 1670** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1671** during configuration, an application can specify an alternative 1672** memory allocation subsystem for SQLite to use for all of its 1673** dynamic memory needs. 1674** 1675** Note that SQLite comes with several [built-in memory allocators] 1676** that are perfectly adequate for the overwhelming majority of applications 1677** and that this object is only useful to a tiny minority of applications 1678** with specialized memory allocation requirements. This object is 1679** also used during testing of SQLite in order to specify an alternative 1680** memory allocator that simulates memory out-of-memory conditions in 1681** order to verify that SQLite recovers gracefully from such 1682** conditions. 1683** 1684** The xMalloc, xRealloc, and xFree methods must work like the 1685** malloc(), realloc() and free() functions from the standard C library. 1686** ^SQLite guarantees that the second argument to 1687** xRealloc is always a value returned by a prior call to xRoundup. 1688** 1689** xSize should return the allocated size of a memory allocation 1690** previously obtained from xMalloc or xRealloc. The allocated size 1691** is always at least as big as the requested size but may be larger. 1692** 1693** The xRoundup method returns what would be the allocated size of 1694** a memory allocation given a particular requested size. Most memory 1695** allocators round up memory allocations at least to the next multiple 1696** of 8. Some allocators round up to a larger multiple or to a power of 2. 1697** Every memory allocation request coming in through [sqlite3_malloc()] 1698** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1699** that causes the corresponding memory allocation to fail. 1700** 1701** The xInit method initializes the memory allocator. For example, 1702** it might allocate any required mutexes or initialize internal data 1703** structures. The xShutdown method is invoked (indirectly) by 1704** [sqlite3_shutdown()] and should deallocate any resources acquired 1705** by xInit. The pAppData pointer is used as the only parameter to 1706** xInit and xShutdown. 1707** 1708** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1709** the xInit method, so the xInit method need not be threadsafe. The 1710** xShutdown method is only called from [sqlite3_shutdown()] so it does 1711** not need to be threadsafe either. For all other methods, SQLite 1712** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1713** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1714** it is by default) and so the methods are automatically serialized. 1715** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1716** methods must be threadsafe or else make their own arrangements for 1717** serialization. 1718** 1719** SQLite will never invoke xInit() more than once without an intervening 1720** call to xShutdown(). 1721*/ 1722typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1723struct sqlite3_mem_methods { 1724 void *(*xMalloc)(int); /* Memory allocation function */ 1725 void (*xFree)(void*); /* Free a prior allocation */ 1726 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1727 int (*xSize)(void*); /* Return the size of an allocation */ 1728 int (*xRoundup)(int); /* Round up request size to allocation size */ 1729 int (*xInit)(void*); /* Initialize the memory allocator */ 1730 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1731 void *pAppData; /* Argument to xInit() and xShutdown() */ 1732}; 1733 1734/* 1735** CAPI3REF: Configuration Options 1736** KEYWORDS: {configuration option} 1737** 1738** These constants are the available integer configuration options that 1739** can be passed as the first argument to the [sqlite3_config()] interface. 1740** 1741** New configuration options may be added in future releases of SQLite. 1742** Existing configuration options might be discontinued. Applications 1743** should check the return code from [sqlite3_config()] to make sure that 1744** the call worked. The [sqlite3_config()] interface will return a 1745** non-zero [error code] if a discontinued or unsupported configuration option 1746** is invoked. 1747** 1748** <dl> 1749** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1750** <dd>There are no arguments to this option. ^This option sets the 1751** [threading mode] to Single-thread. In other words, it disables 1752** all mutexing and puts SQLite into a mode where it can only be used 1753** by a single thread. ^If SQLite is compiled with 1754** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1755** it is not possible to change the [threading mode] from its default 1756** value of Single-thread and so [sqlite3_config()] will return 1757** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1758** configuration option.</dd> 1759** 1760** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1761** <dd>There are no arguments to this option. ^This option sets the 1762** [threading mode] to Multi-thread. In other words, it disables 1763** mutexing on [database connection] and [prepared statement] objects. 1764** The application is responsible for serializing access to 1765** [database connections] and [prepared statements]. But other mutexes 1766** are enabled so that SQLite will be safe to use in a multi-threaded 1767** environment as long as no two threads attempt to use the same 1768** [database connection] at the same time. ^If SQLite is compiled with 1769** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1770** it is not possible to set the Multi-thread [threading mode] and 1771** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1772** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1773** 1774** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1775** <dd>There are no arguments to this option. ^This option sets the 1776** [threading mode] to Serialized. In other words, this option enables 1777** all mutexes including the recursive 1778** mutexes on [database connection] and [prepared statement] objects. 1779** In this mode (which is the default when SQLite is compiled with 1780** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1781** to [database connections] and [prepared statements] so that the 1782** application is free to use the same [database connection] or the 1783** same [prepared statement] in different threads at the same time. 1784** ^If SQLite is compiled with 1785** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1786** it is not possible to set the Serialized [threading mode] and 1787** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1788** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1789** 1790** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1791** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1792** a pointer to an instance of the [sqlite3_mem_methods] structure. 1793** The argument specifies 1794** alternative low-level memory allocation routines to be used in place of 1795** the memory allocation routines built into SQLite.)^ ^SQLite makes 1796** its own private copy of the content of the [sqlite3_mem_methods] structure 1797** before the [sqlite3_config()] call returns.</dd> 1798** 1799** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1800** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1801** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1802** The [sqlite3_mem_methods] 1803** structure is filled with the currently defined memory allocation routines.)^ 1804** This option can be used to overload the default memory allocation 1805** routines with a wrapper that simulations memory allocation failure or 1806** tracks memory usage, for example. </dd> 1807** 1808** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1809** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1810** type int, interpreted as a boolean, which if true provides a hint to 1811** SQLite that it should avoid large memory allocations if possible. 1812** SQLite will run faster if it is free to make large memory allocations, 1813** but some application might prefer to run slower in exchange for 1814** guarantees about memory fragmentation that are possible if large 1815** allocations are avoided. This hint is normally off. 1816** </dd> 1817** 1818** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1819** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1820** interpreted as a boolean, which enables or disables the collection of 1821** memory allocation statistics. ^(When memory allocation statistics are 1822** disabled, the following SQLite interfaces become non-operational: 1823** <ul> 1824** <li> [sqlite3_hard_heap_limit64()] 1825** <li> [sqlite3_memory_used()] 1826** <li> [sqlite3_memory_highwater()] 1827** <li> [sqlite3_soft_heap_limit64()] 1828** <li> [sqlite3_status64()] 1829** </ul>)^ 1830** ^Memory allocation statistics are enabled by default unless SQLite is 1831** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1832** allocation statistics are disabled by default. 1833** </dd> 1834** 1835** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1836** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1837** </dd> 1838** 1839** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1840** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1841** that SQLite can use for the database page cache with the default page 1842** cache implementation. 1843** This configuration option is a no-op if an application-defined page 1844** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1845** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1846** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1847** and the number of cache lines (N). 1848** The sz argument should be the size of the largest database page 1849** (a power of two between 512 and 65536) plus some extra bytes for each 1850** page header. ^The number of extra bytes needed by the page header 1851** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1852** ^It is harmless, apart from the wasted memory, 1853** for the sz parameter to be larger than necessary. The pMem 1854** argument must be either a NULL pointer or a pointer to an 8-byte 1855** aligned block of memory of at least sz*N bytes, otherwise 1856** subsequent behavior is undefined. 1857** ^When pMem is not NULL, SQLite will strive to use the memory provided 1858** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1859** a page cache line is larger than sz bytes or if all of the pMem buffer 1860** is exhausted. 1861** ^If pMem is NULL and N is non-zero, then each database connection 1862** does an initial bulk allocation for page cache memory 1863** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1864** of -1024*N bytes if N is negative, . ^If additional 1865** page cache memory is needed beyond what is provided by the initial 1866** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1867** additional cache line. </dd> 1868** 1869** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1870** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1871** that SQLite will use for all of its dynamic memory allocation needs 1872** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1873** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1874** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1875** [SQLITE_ERROR] if invoked otherwise. 1876** ^There are three arguments to SQLITE_CONFIG_HEAP: 1877** An 8-byte aligned pointer to the memory, 1878** the number of bytes in the memory buffer, and the minimum allocation size. 1879** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1880** to using its default memory allocator (the system malloc() implementation), 1881** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1882** memory pointer is not NULL then the alternative memory 1883** allocator is engaged to handle all of SQLites memory allocation needs. 1884** The first pointer (the memory pointer) must be aligned to an 8-byte 1885** boundary or subsequent behavior of SQLite will be undefined. 1886** The minimum allocation size is capped at 2**12. Reasonable values 1887** for the minimum allocation size are 2**5 through 2**8.</dd> 1888** 1889** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1890** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1891** pointer to an instance of the [sqlite3_mutex_methods] structure. 1892** The argument specifies alternative low-level mutex routines to be used 1893** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1894** the content of the [sqlite3_mutex_methods] structure before the call to 1895** [sqlite3_config()] returns. ^If SQLite is compiled with 1896** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1897** the entire mutexing subsystem is omitted from the build and hence calls to 1898** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1899** return [SQLITE_ERROR].</dd> 1900** 1901** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1902** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1903** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1904** [sqlite3_mutex_methods] 1905** structure is filled with the currently defined mutex routines.)^ 1906** This option can be used to overload the default mutex allocation 1907** routines with a wrapper used to track mutex usage for performance 1908** profiling or testing, for example. ^If SQLite is compiled with 1909** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1910** the entire mutexing subsystem is omitted from the build and hence calls to 1911** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1912** return [SQLITE_ERROR].</dd> 1913** 1914** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1915** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1916** the default size of lookaside memory on each [database connection]. 1917** The first argument is the 1918** size of each lookaside buffer slot and the second is the number of 1919** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1920** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1921** option to [sqlite3_db_config()] can be used to change the lookaside 1922** configuration on individual connections.)^ </dd> 1923** 1924** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1925** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1926** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1927** the interface to a custom page cache implementation.)^ 1928** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1929** 1930** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1931** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1932** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1933** the current page cache implementation into that object.)^ </dd> 1934** 1935** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1936** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1937** global [error log]. 1938** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1939** function with a call signature of void(*)(void*,int,const char*), 1940** and a pointer to void. ^If the function pointer is not NULL, it is 1941** invoked by [sqlite3_log()] to process each logging event. ^If the 1942** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1943** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1944** passed through as the first parameter to the application-defined logger 1945** function whenever that function is invoked. ^The second parameter to 1946** the logger function is a copy of the first parameter to the corresponding 1947** [sqlite3_log()] call and is intended to be a [result code] or an 1948** [extended result code]. ^The third parameter passed to the logger is 1949** log message after formatting via [sqlite3_snprintf()]. 1950** The SQLite logging interface is not reentrant; the logger function 1951** supplied by the application must not invoke any SQLite interface. 1952** In a multi-threaded application, the application-defined logger 1953** function must be threadsafe. </dd> 1954** 1955** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1956** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1957** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1958** then URI handling is globally disabled.)^ ^If URI handling is globally 1959** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1960** [sqlite3_open16()] or 1961** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1962** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1963** connection is opened. ^If it is globally disabled, filenames are 1964** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1965** database connection is opened. ^(By default, URI handling is globally 1966** disabled. The default value may be changed by compiling with the 1967** [SQLITE_USE_URI] symbol defined.)^ 1968** 1969** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1970** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1971** argument which is interpreted as a boolean in order to enable or disable 1972** the use of covering indices for full table scans in the query optimizer. 1973** ^The default setting is determined 1974** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1975** if that compile-time option is omitted. 1976** The ability to disable the use of covering indices for full table scans 1977** is because some incorrectly coded legacy applications might malfunction 1978** when the optimization is enabled. Providing the ability to 1979** disable the optimization allows the older, buggy application code to work 1980** without change even with newer versions of SQLite. 1981** 1982** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1983** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1984** <dd> These options are obsolete and should not be used by new code. 1985** They are retained for backwards compatibility but are now no-ops. 1986** </dd> 1987** 1988** [[SQLITE_CONFIG_SQLLOG]] 1989** <dt>SQLITE_CONFIG_SQLLOG 1990** <dd>This option is only available if sqlite is compiled with the 1991** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1992** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1993** The second should be of type (void*). The callback is invoked by the library 1994** in three separate circumstances, identified by the value passed as the 1995** fourth parameter. If the fourth parameter is 0, then the database connection 1996** passed as the second argument has just been opened. The third argument 1997** points to a buffer containing the name of the main database file. If the 1998** fourth parameter is 1, then the SQL statement that the third parameter 1999** points to has just been executed. Or, if the fourth parameter is 2, then 2000** the connection being passed as the second parameter is being closed. The 2001** third parameter is passed NULL In this case. An example of using this 2002** configuration option can be seen in the "test_sqllog.c" source file in 2003** the canonical SQLite source tree.</dd> 2004** 2005** [[SQLITE_CONFIG_MMAP_SIZE]] 2006** <dt>SQLITE_CONFIG_MMAP_SIZE 2007** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2008** that are the default mmap size limit (the default setting for 2009** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2010** ^The default setting can be overridden by each database connection using 2011** either the [PRAGMA mmap_size] command, or by using the 2012** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2013** will be silently truncated if necessary so that it does not exceed the 2014** compile-time maximum mmap size set by the 2015** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2016** ^If either argument to this option is negative, then that argument is 2017** changed to its compile-time default. 2018** 2019** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2020** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2021** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2022** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2023** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2024** that specifies the maximum size of the created heap. 2025** 2026** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2027** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2028** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2029** is a pointer to an integer and writes into that integer the number of extra 2030** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2031** The amount of extra space required can change depending on the compiler, 2032** target platform, and SQLite version. 2033** 2034** [[SQLITE_CONFIG_PMASZ]] 2035** <dt>SQLITE_CONFIG_PMASZ 2036** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2037** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2038** sorter to that integer. The default minimum PMA Size is set by the 2039** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2040** to help with sort operations when multithreaded sorting 2041** is enabled (using the [PRAGMA threads] command) and the amount of content 2042** to be sorted exceeds the page size times the minimum of the 2043** [PRAGMA cache_size] setting and this value. 2044** 2045** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2046** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2047** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2048** becomes the [statement journal] spill-to-disk threshold. 2049** [Statement journals] are held in memory until their size (in bytes) 2050** exceeds this threshold, at which point they are written to disk. 2051** Or if the threshold is -1, statement journals are always held 2052** exclusively in memory. 2053** Since many statement journals never become large, setting the spill 2054** threshold to a value such as 64KiB can greatly reduce the amount of 2055** I/O required to support statement rollback. 2056** The default value for this setting is controlled by the 2057** [SQLITE_STMTJRNL_SPILL] compile-time option. 2058** 2059** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2060** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2061** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2062** of type (int) - the new value of the sorter-reference size threshold. 2063** Usually, when SQLite uses an external sort to order records according 2064** to an ORDER BY clause, all fields required by the caller are present in the 2065** sorted records. However, if SQLite determines based on the declared type 2066** of a table column that its values are likely to be very large - larger 2067** than the configured sorter-reference size threshold - then a reference 2068** is stored in each sorted record and the required column values loaded 2069** from the database as records are returned in sorted order. The default 2070** value for this option is to never use this optimization. Specifying a 2071** negative value for this option restores the default behaviour. 2072** This option is only available if SQLite is compiled with the 2073** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2074** 2075** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2076** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2077** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2078** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2079** database created using [sqlite3_deserialize()]. This default maximum 2080** size can be adjusted up or down for individual databases using the 2081** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2082** configuration setting is never used, then the default maximum is determined 2083** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2084** compile-time option is not set, then the default maximum is 1073741824. 2085** </dl> 2086*/ 2087#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2088#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2089#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2090#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2091#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2092#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2093#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2094#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2095#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2096#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2097#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2098/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2099#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2100#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2101#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2102#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2103#define SQLITE_CONFIG_URI 17 /* int */ 2104#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2105#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2106#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2107#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2108#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2109#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2110#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2111#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2112#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2113#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2114#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2115#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2116 2117/* 2118** CAPI3REF: Database Connection Configuration Options 2119** 2120** These constants are the available integer configuration options that 2121** can be passed as the second argument to the [sqlite3_db_config()] interface. 2122** 2123** New configuration options may be added in future releases of SQLite. 2124** Existing configuration options might be discontinued. Applications 2125** should check the return code from [sqlite3_db_config()] to make sure that 2126** the call worked. ^The [sqlite3_db_config()] interface will return a 2127** non-zero [error code] if a discontinued or unsupported configuration option 2128** is invoked. 2129** 2130** <dl> 2131** [[SQLITE_DBCONFIG_LOOKASIDE]] 2132** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2133** <dd> ^This option takes three additional arguments that determine the 2134** [lookaside memory allocator] configuration for the [database connection]. 2135** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2136** pointer to a memory buffer to use for lookaside memory. 2137** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2138** may be NULL in which case SQLite will allocate the 2139** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2140** size of each lookaside buffer slot. ^The third argument is the number of 2141** slots. The size of the buffer in the first argument must be greater than 2142** or equal to the product of the second and third arguments. The buffer 2143** must be aligned to an 8-byte boundary. ^If the second argument to 2144** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2145** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2146** configuration for a database connection can only be changed when that 2147** connection is not currently using lookaside memory, or in other words 2148** when the "current value" returned by 2149** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2150** Any attempt to change the lookaside memory configuration when lookaside 2151** memory is in use leaves the configuration unchanged and returns 2152** [SQLITE_BUSY].)^</dd> 2153** 2154** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2155** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2156** <dd> ^This option is used to enable or disable the enforcement of 2157** [foreign key constraints]. There should be two additional arguments. 2158** The first argument is an integer which is 0 to disable FK enforcement, 2159** positive to enable FK enforcement or negative to leave FK enforcement 2160** unchanged. The second parameter is a pointer to an integer into which 2161** is written 0 or 1 to indicate whether FK enforcement is off or on 2162** following this call. The second parameter may be a NULL pointer, in 2163** which case the FK enforcement setting is not reported back. </dd> 2164** 2165** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2166** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2167** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2168** There should be two additional arguments. 2169** The first argument is an integer which is 0 to disable triggers, 2170** positive to enable triggers or negative to leave the setting unchanged. 2171** The second parameter is a pointer to an integer into which 2172** is written 0 or 1 to indicate whether triggers are disabled or enabled 2173** following this call. The second parameter may be a NULL pointer, in 2174** which case the trigger setting is not reported back. 2175** 2176** <p>Originally this option disabled all triggers. ^(However, since 2177** SQLite version 3.35.0, TEMP triggers are still allowed even if 2178** this option is off. So, in other words, this option now only disables 2179** triggers in the main database schema or in the schemas of ATTACH-ed 2180** databases.)^ </dd> 2181** 2182** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2183** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2184** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2185** There should be two additional arguments. 2186** The first argument is an integer which is 0 to disable views, 2187** positive to enable views or negative to leave the setting unchanged. 2188** The second parameter is a pointer to an integer into which 2189** is written 0 or 1 to indicate whether views are disabled or enabled 2190** following this call. The second parameter may be a NULL pointer, in 2191** which case the view setting is not reported back. 2192** 2193** <p>Originally this option disabled all views. ^(However, since 2194** SQLite version 3.35.0, TEMP views are still allowed even if 2195** this option is off. So, in other words, this option now only disables 2196** views in the main database schema or in the schemas of ATTACH-ed 2197** databases.)^ </dd> 2198** 2199** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2200** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2201** <dd> ^This option is used to enable or disable the 2202** [fts3_tokenizer()] function which is part of the 2203** [FTS3] full-text search engine extension. 2204** There should be two additional arguments. 2205** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2206** positive to enable fts3_tokenizer() or negative to leave the setting 2207** unchanged. 2208** The second parameter is a pointer to an integer into which 2209** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2210** following this call. The second parameter may be a NULL pointer, in 2211** which case the new setting is not reported back. </dd> 2212** 2213** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2214** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2215** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2216** interface independently of the [load_extension()] SQL function. 2217** The [sqlite3_enable_load_extension()] API enables or disables both the 2218** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2219** There should be two additional arguments. 2220** When the first argument to this interface is 1, then only the C-API is 2221** enabled and the SQL function remains disabled. If the first argument to 2222** this interface is 0, then both the C-API and the SQL function are disabled. 2223** If the first argument is -1, then no changes are made to state of either the 2224** C-API or the SQL function. 2225** The second parameter is a pointer to an integer into which 2226** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2227** is disabled or enabled following this call. The second parameter may 2228** be a NULL pointer, in which case the new setting is not reported back. 2229** </dd> 2230** 2231** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2232** <dd> ^This option is used to change the name of the "main" database 2233** schema. ^The sole argument is a pointer to a constant UTF8 string 2234** which will become the new schema name in place of "main". ^SQLite 2235** does not make a copy of the new main schema name string, so the application 2236** must ensure that the argument passed into this DBCONFIG option is unchanged 2237** until after the database connection closes. 2238** </dd> 2239** 2240** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2241** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2242** <dd> Usually, when a database in wal mode is closed or detached from a 2243** database handle, SQLite checks if this will mean that there are now no 2244** connections at all to the database. If so, it performs a checkpoint 2245** operation before closing the connection. This option may be used to 2246** override this behaviour. The first parameter passed to this operation 2247** is an integer - positive to disable checkpoints-on-close, or zero (the 2248** default) to enable them, and negative to leave the setting unchanged. 2249** The second parameter is a pointer to an integer 2250** into which is written 0 or 1 to indicate whether checkpoints-on-close 2251** have been disabled - 0 if they are not disabled, 1 if they are. 2252** </dd> 2253** 2254** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2255** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2256** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2257** a single SQL query statement will always use the same algorithm regardless 2258** of values of [bound parameters].)^ The QPSG disables some query optimizations 2259** that look at the values of bound parameters, which can make some queries 2260** slower. But the QPSG has the advantage of more predictable behavior. With 2261** the QPSG active, SQLite will always use the same query plan in the field as 2262** was used during testing in the lab. 2263** The first argument to this setting is an integer which is 0 to disable 2264** the QPSG, positive to enable QPSG, or negative to leave the setting 2265** unchanged. The second parameter is a pointer to an integer into which 2266** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2267** following this call. 2268** </dd> 2269** 2270** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2271** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2272** include output for any operations performed by trigger programs. This 2273** option is used to set or clear (the default) a flag that governs this 2274** behavior. The first parameter passed to this operation is an integer - 2275** positive to enable output for trigger programs, or zero to disable it, 2276** or negative to leave the setting unchanged. 2277** The second parameter is a pointer to an integer into which is written 2278** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2279** it is not disabled, 1 if it is. 2280** </dd> 2281** 2282** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2283** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2284** [VACUUM] in order to reset a database back to an empty database 2285** with no schema and no content. The following process works even for 2286** a badly corrupted database file: 2287** <ol> 2288** <li> If the database connection is newly opened, make sure it has read the 2289** database schema by preparing then discarding some query against the 2290** database, or calling sqlite3_table_column_metadata(), ignoring any 2291** errors. This step is only necessary if the application desires to keep 2292** the database in WAL mode after the reset if it was in WAL mode before 2293** the reset. 2294** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2295** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2296** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2297** </ol> 2298** Because resetting a database is destructive and irreversible, the 2299** process requires the use of this obscure API and multiple steps to help 2300** ensure that it does not happen by accident. 2301** 2302** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2303** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2304** "defensive" flag for a database connection. When the defensive 2305** flag is enabled, language features that allow ordinary SQL to 2306** deliberately corrupt the database file are disabled. The disabled 2307** features include but are not limited to the following: 2308** <ul> 2309** <li> The [PRAGMA writable_schema=ON] statement. 2310** <li> The [PRAGMA journal_mode=OFF] statement. 2311** <li> Writes to the [sqlite_dbpage] virtual table. 2312** <li> Direct writes to [shadow tables]. 2313** </ul> 2314** </dd> 2315** 2316** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2317** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2318** "writable_schema" flag. This has the same effect and is logically equivalent 2319** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2320** The first argument to this setting is an integer which is 0 to disable 2321** the writable_schema, positive to enable writable_schema, or negative to 2322** leave the setting unchanged. The second parameter is a pointer to an 2323** integer into which is written 0 or 1 to indicate whether the writable_schema 2324** is enabled or disabled following this call. 2325** </dd> 2326** 2327** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2328** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2329** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2330** the legacy behavior of the [ALTER TABLE RENAME] command such it 2331** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2332** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2333** additional information. This feature can also be turned on and off 2334** using the [PRAGMA legacy_alter_table] statement. 2335** </dd> 2336** 2337** [[SQLITE_DBCONFIG_DQS_DML]] 2338** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2339** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2340** the legacy [double-quoted string literal] misfeature for DML statements 2341** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2342** default value of this setting is determined by the [-DSQLITE_DQS] 2343** compile-time option. 2344** </dd> 2345** 2346** [[SQLITE_DBCONFIG_DQS_DDL]] 2347** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2348** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2349** the legacy [double-quoted string literal] misfeature for DDL statements, 2350** such as CREATE TABLE and CREATE INDEX. The 2351** default value of this setting is determined by the [-DSQLITE_DQS] 2352** compile-time option. 2353** </dd> 2354** 2355** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2356** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2357** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2358** assume that database schemas are untainted by malicious content. 2359** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2360** takes additional defensive steps to protect the application from harm 2361** including: 2362** <ul> 2363** <li> Prohibit the use of SQL functions inside triggers, views, 2364** CHECK constraints, DEFAULT clauses, expression indexes, 2365** partial indexes, or generated columns 2366** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2367** <li> Prohibit the use of virtual tables inside of triggers or views 2368** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2369** </ul> 2370** This setting defaults to "on" for legacy compatibility, however 2371** all applications are advised to turn it off if possible. This setting 2372** can also be controlled using the [PRAGMA trusted_schema] statement. 2373** </dd> 2374** 2375** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2376** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2377** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2378** the legacy file format flag. When activated, this flag causes all newly 2379** created database file to have a schema format version number (the 4-byte 2380** integer found at offset 44 into the database header) of 1. This in turn 2381** means that the resulting database file will be readable and writable by 2382** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2383** newly created databases are generally not understandable by SQLite versions 2384** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2385** is now scarcely any need to generated database files that are compatible 2386** all the way back to version 3.0.0, and so this setting is of little 2387** practical use, but is provided so that SQLite can continue to claim the 2388** ability to generate new database files that are compatible with version 2389** 3.0.0. 2390** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2391** the [VACUUM] command will fail with an obscure error when attempting to 2392** process a table with generated columns and a descending index. This is 2393** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2394** either generated columns or decending indexes. 2395** </dd> 2396** </dl> 2397*/ 2398#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2399#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2400#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2401#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2402#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2403#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2404#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2405#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2406#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2407#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2408#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2409#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2410#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2411#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2412#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2413#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2414#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2415#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2416#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2417 2418/* 2419** CAPI3REF: Enable Or Disable Extended Result Codes 2420** METHOD: sqlite3 2421** 2422** ^The sqlite3_extended_result_codes() routine enables or disables the 2423** [extended result codes] feature of SQLite. ^The extended result 2424** codes are disabled by default for historical compatibility. 2425*/ 2426int sqlite3_extended_result_codes(sqlite3*, int onoff); 2427 2428/* 2429** CAPI3REF: Last Insert Rowid 2430** METHOD: sqlite3 2431** 2432** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2433** has a unique 64-bit signed 2434** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2435** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2436** names are not also used by explicitly declared columns. ^If 2437** the table has a column of type [INTEGER PRIMARY KEY] then that column 2438** is another alias for the rowid. 2439** 2440** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2441** the most recent successful [INSERT] into a rowid table or [virtual table] 2442** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2443** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2444** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2445** zero. 2446** 2447** As well as being set automatically as rows are inserted into database 2448** tables, the value returned by this function may be set explicitly by 2449** [sqlite3_set_last_insert_rowid()] 2450** 2451** Some virtual table implementations may INSERT rows into rowid tables as 2452** part of committing a transaction (e.g. to flush data accumulated in memory 2453** to disk). In this case subsequent calls to this function return the rowid 2454** associated with these internal INSERT operations, which leads to 2455** unintuitive results. Virtual table implementations that do write to rowid 2456** tables in this way can avoid this problem by restoring the original 2457** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2458** control to the user. 2459** 2460** ^(If an [INSERT] occurs within a trigger then this routine will 2461** return the [rowid] of the inserted row as long as the trigger is 2462** running. Once the trigger program ends, the value returned 2463** by this routine reverts to what it was before the trigger was fired.)^ 2464** 2465** ^An [INSERT] that fails due to a constraint violation is not a 2466** successful [INSERT] and does not change the value returned by this 2467** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2468** and INSERT OR ABORT make no changes to the return value of this 2469** routine when their insertion fails. ^(When INSERT OR REPLACE 2470** encounters a constraint violation, it does not fail. The 2471** INSERT continues to completion after deleting rows that caused 2472** the constraint problem so INSERT OR REPLACE will always change 2473** the return value of this interface.)^ 2474** 2475** ^For the purposes of this routine, an [INSERT] is considered to 2476** be successful even if it is subsequently rolled back. 2477** 2478** This function is accessible to SQL statements via the 2479** [last_insert_rowid() SQL function]. 2480** 2481** If a separate thread performs a new [INSERT] on the same 2482** database connection while the [sqlite3_last_insert_rowid()] 2483** function is running and thus changes the last insert [rowid], 2484** then the value returned by [sqlite3_last_insert_rowid()] is 2485** unpredictable and might not equal either the old or the new 2486** last insert [rowid]. 2487*/ 2488sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2489 2490/* 2491** CAPI3REF: Set the Last Insert Rowid value. 2492** METHOD: sqlite3 2493** 2494** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2495** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2496** without inserting a row into the database. 2497*/ 2498void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2499 2500/* 2501** CAPI3REF: Count The Number Of Rows Modified 2502** METHOD: sqlite3 2503** 2504** ^These functions return the number of rows modified, inserted or 2505** deleted by the most recently completed INSERT, UPDATE or DELETE 2506** statement on the database connection specified by the only parameter. 2507** The two functions are identical except for the type of the return value 2508** and that if the number of rows modified by the most recent INSERT, UPDATE 2509** or DELETE is greater than the maximum value supported by type "int", then 2510** the return value of sqlite3_changes() is undefined. ^Executing any other 2511** type of SQL statement does not modify the value returned by these functions. 2512** 2513** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2514** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2515** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2516** 2517** Changes to a view that are intercepted by 2518** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2519** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2520** DELETE statement run on a view is always zero. Only changes made to real 2521** tables are counted. 2522** 2523** Things are more complicated if the sqlite3_changes() function is 2524** executed while a trigger program is running. This may happen if the 2525** program uses the [changes() SQL function], or if some other callback 2526** function invokes sqlite3_changes() directly. Essentially: 2527** 2528** <ul> 2529** <li> ^(Before entering a trigger program the value returned by 2530** sqlite3_changes() function is saved. After the trigger program 2531** has finished, the original value is restored.)^ 2532** 2533** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2534** statement sets the value returned by sqlite3_changes() 2535** upon completion as normal. Of course, this value will not include 2536** any changes performed by sub-triggers, as the sqlite3_changes() 2537** value will be saved and restored after each sub-trigger has run.)^ 2538** </ul> 2539** 2540** ^This means that if the changes() SQL function (or similar) is used 2541** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2542** returns the value as set when the calling statement began executing. 2543** ^If it is used by the second or subsequent such statement within a trigger 2544** program, the value returned reflects the number of rows modified by the 2545** previous INSERT, UPDATE or DELETE statement within the same trigger. 2546** 2547** If a separate thread makes changes on the same database connection 2548** while [sqlite3_changes()] is running then the value returned 2549** is unpredictable and not meaningful. 2550** 2551** See also: 2552** <ul> 2553** <li> the [sqlite3_total_changes()] interface 2554** <li> the [count_changes pragma] 2555** <li> the [changes() SQL function] 2556** <li> the [data_version pragma] 2557** </ul> 2558*/ 2559int sqlite3_changes(sqlite3*); 2560sqlite3_int64 sqlite3_changes64(sqlite3*); 2561 2562/* 2563** CAPI3REF: Total Number Of Rows Modified 2564** METHOD: sqlite3 2565** 2566** ^These functions return the total number of rows inserted, modified or 2567** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2568** since the database connection was opened, including those executed as 2569** part of trigger programs. The two functions are identical except for the 2570** type of the return value and that if the number of rows modified by the 2571** connection exceeds the maximum value supported by type "int", then 2572** the return value of sqlite3_total_changes() is undefined. ^Executing 2573** any other type of SQL statement does not affect the value returned by 2574** sqlite3_total_changes(). 2575** 2576** ^Changes made as part of [foreign key actions] are included in the 2577** count, but those made as part of REPLACE constraint resolution are 2578** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2579** are not counted. 2580** 2581** The [sqlite3_total_changes(D)] interface only reports the number 2582** of rows that changed due to SQL statement run against database 2583** connection D. Any changes by other database connections are ignored. 2584** To detect changes against a database file from other database 2585** connections use the [PRAGMA data_version] command or the 2586** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2587** 2588** If a separate thread makes changes on the same database connection 2589** while [sqlite3_total_changes()] is running then the value 2590** returned is unpredictable and not meaningful. 2591** 2592** See also: 2593** <ul> 2594** <li> the [sqlite3_changes()] interface 2595** <li> the [count_changes pragma] 2596** <li> the [changes() SQL function] 2597** <li> the [data_version pragma] 2598** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2599** </ul> 2600*/ 2601int sqlite3_total_changes(sqlite3*); 2602sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2603 2604/* 2605** CAPI3REF: Interrupt A Long-Running Query 2606** METHOD: sqlite3 2607** 2608** ^This function causes any pending database operation to abort and 2609** return at its earliest opportunity. This routine is typically 2610** called in response to a user action such as pressing "Cancel" 2611** or Ctrl-C where the user wants a long query operation to halt 2612** immediately. 2613** 2614** ^It is safe to call this routine from a thread different from the 2615** thread that is currently running the database operation. But it 2616** is not safe to call this routine with a [database connection] that 2617** is closed or might close before sqlite3_interrupt() returns. 2618** 2619** ^If an SQL operation is very nearly finished at the time when 2620** sqlite3_interrupt() is called, then it might not have an opportunity 2621** to be interrupted and might continue to completion. 2622** 2623** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2624** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2625** that is inside an explicit transaction, then the entire transaction 2626** will be rolled back automatically. 2627** 2628** ^The sqlite3_interrupt(D) call is in effect until all currently running 2629** SQL statements on [database connection] D complete. ^Any new SQL statements 2630** that are started after the sqlite3_interrupt() call and before the 2631** running statement count reaches zero are interrupted as if they had been 2632** running prior to the sqlite3_interrupt() call. ^New SQL statements 2633** that are started after the running statement count reaches zero are 2634** not effected by the sqlite3_interrupt(). 2635** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2636** SQL statements is a no-op and has no effect on SQL statements 2637** that are started after the sqlite3_interrupt() call returns. 2638*/ 2639void sqlite3_interrupt(sqlite3*); 2640 2641/* 2642** CAPI3REF: Determine If An SQL Statement Is Complete 2643** 2644** These routines are useful during command-line input to determine if the 2645** currently entered text seems to form a complete SQL statement or 2646** if additional input is needed before sending the text into 2647** SQLite for parsing. ^These routines return 1 if the input string 2648** appears to be a complete SQL statement. ^A statement is judged to be 2649** complete if it ends with a semicolon token and is not a prefix of a 2650** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2651** string literals or quoted identifier names or comments are not 2652** independent tokens (they are part of the token in which they are 2653** embedded) and thus do not count as a statement terminator. ^Whitespace 2654** and comments that follow the final semicolon are ignored. 2655** 2656** ^These routines return 0 if the statement is incomplete. ^If a 2657** memory allocation fails, then SQLITE_NOMEM is returned. 2658** 2659** ^These routines do not parse the SQL statements thus 2660** will not detect syntactically incorrect SQL. 2661** 2662** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2663** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2664** automatically by sqlite3_complete16(). If that initialization fails, 2665** then the return value from sqlite3_complete16() will be non-zero 2666** regardless of whether or not the input SQL is complete.)^ 2667** 2668** The input to [sqlite3_complete()] must be a zero-terminated 2669** UTF-8 string. 2670** 2671** The input to [sqlite3_complete16()] must be a zero-terminated 2672** UTF-16 string in native byte order. 2673*/ 2674int sqlite3_complete(const char *sql); 2675int sqlite3_complete16(const void *sql); 2676 2677/* 2678** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2679** KEYWORDS: {busy-handler callback} {busy handler} 2680** METHOD: sqlite3 2681** 2682** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2683** that might be invoked with argument P whenever 2684** an attempt is made to access a database table associated with 2685** [database connection] D when another thread 2686** or process has the table locked. 2687** The sqlite3_busy_handler() interface is used to implement 2688** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2689** 2690** ^If the busy callback is NULL, then [SQLITE_BUSY] 2691** is returned immediately upon encountering the lock. ^If the busy callback 2692** is not NULL, then the callback might be invoked with two arguments. 2693** 2694** ^The first argument to the busy handler is a copy of the void* pointer which 2695** is the third argument to sqlite3_busy_handler(). ^The second argument to 2696** the busy handler callback is the number of times that the busy handler has 2697** been invoked previously for the same locking event. ^If the 2698** busy callback returns 0, then no additional attempts are made to 2699** access the database and [SQLITE_BUSY] is returned 2700** to the application. 2701** ^If the callback returns non-zero, then another attempt 2702** is made to access the database and the cycle repeats. 2703** 2704** The presence of a busy handler does not guarantee that it will be invoked 2705** when there is lock contention. ^If SQLite determines that invoking the busy 2706** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2707** to the application instead of invoking the 2708** busy handler. 2709** Consider a scenario where one process is holding a read lock that 2710** it is trying to promote to a reserved lock and 2711** a second process is holding a reserved lock that it is trying 2712** to promote to an exclusive lock. The first process cannot proceed 2713** because it is blocked by the second and the second process cannot 2714** proceed because it is blocked by the first. If both processes 2715** invoke the busy handlers, neither will make any progress. Therefore, 2716** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2717** will induce the first process to release its read lock and allow 2718** the second process to proceed. 2719** 2720** ^The default busy callback is NULL. 2721** 2722** ^(There can only be a single busy handler defined for each 2723** [database connection]. Setting a new busy handler clears any 2724** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2725** or evaluating [PRAGMA busy_timeout=N] will change the 2726** busy handler and thus clear any previously set busy handler. 2727** 2728** The busy callback should not take any actions which modify the 2729** database connection that invoked the busy handler. In other words, 2730** the busy handler is not reentrant. Any such actions 2731** result in undefined behavior. 2732** 2733** A busy handler must not close the database connection 2734** or [prepared statement] that invoked the busy handler. 2735*/ 2736int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2737 2738/* 2739** CAPI3REF: Set A Busy Timeout 2740** METHOD: sqlite3 2741** 2742** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2743** for a specified amount of time when a table is locked. ^The handler 2744** will sleep multiple times until at least "ms" milliseconds of sleeping 2745** have accumulated. ^After at least "ms" milliseconds of sleeping, 2746** the handler returns 0 which causes [sqlite3_step()] to return 2747** [SQLITE_BUSY]. 2748** 2749** ^Calling this routine with an argument less than or equal to zero 2750** turns off all busy handlers. 2751** 2752** ^(There can only be a single busy handler for a particular 2753** [database connection] at any given moment. If another busy handler 2754** was defined (using [sqlite3_busy_handler()]) prior to calling 2755** this routine, that other busy handler is cleared.)^ 2756** 2757** See also: [PRAGMA busy_timeout] 2758*/ 2759int sqlite3_busy_timeout(sqlite3*, int ms); 2760 2761/* 2762** CAPI3REF: Convenience Routines For Running Queries 2763** METHOD: sqlite3 2764** 2765** This is a legacy interface that is preserved for backwards compatibility. 2766** Use of this interface is not recommended. 2767** 2768** Definition: A <b>result table</b> is memory data structure created by the 2769** [sqlite3_get_table()] interface. A result table records the 2770** complete query results from one or more queries. 2771** 2772** The table conceptually has a number of rows and columns. But 2773** these numbers are not part of the result table itself. These 2774** numbers are obtained separately. Let N be the number of rows 2775** and M be the number of columns. 2776** 2777** A result table is an array of pointers to zero-terminated UTF-8 strings. 2778** There are (N+1)*M elements in the array. The first M pointers point 2779** to zero-terminated strings that contain the names of the columns. 2780** The remaining entries all point to query results. NULL values result 2781** in NULL pointers. All other values are in their UTF-8 zero-terminated 2782** string representation as returned by [sqlite3_column_text()]. 2783** 2784** A result table might consist of one or more memory allocations. 2785** It is not safe to pass a result table directly to [sqlite3_free()]. 2786** A result table should be deallocated using [sqlite3_free_table()]. 2787** 2788** ^(As an example of the result table format, suppose a query result 2789** is as follows: 2790** 2791** <blockquote><pre> 2792** Name | Age 2793** ----------------------- 2794** Alice | 43 2795** Bob | 28 2796** Cindy | 21 2797** </pre></blockquote> 2798** 2799** There are two columns (M==2) and three rows (N==3). Thus the 2800** result table has 8 entries. Suppose the result table is stored 2801** in an array named azResult. Then azResult holds this content: 2802** 2803** <blockquote><pre> 2804** azResult[0] = "Name"; 2805** azResult[1] = "Age"; 2806** azResult[2] = "Alice"; 2807** azResult[3] = "43"; 2808** azResult[4] = "Bob"; 2809** azResult[5] = "28"; 2810** azResult[6] = "Cindy"; 2811** azResult[7] = "21"; 2812** </pre></blockquote>)^ 2813** 2814** ^The sqlite3_get_table() function evaluates one or more 2815** semicolon-separated SQL statements in the zero-terminated UTF-8 2816** string of its 2nd parameter and returns a result table to the 2817** pointer given in its 3rd parameter. 2818** 2819** After the application has finished with the result from sqlite3_get_table(), 2820** it must pass the result table pointer to sqlite3_free_table() in order to 2821** release the memory that was malloced. Because of the way the 2822** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2823** function must not try to call [sqlite3_free()] directly. Only 2824** [sqlite3_free_table()] is able to release the memory properly and safely. 2825** 2826** The sqlite3_get_table() interface is implemented as a wrapper around 2827** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2828** to any internal data structures of SQLite. It uses only the public 2829** interface defined here. As a consequence, errors that occur in the 2830** wrapper layer outside of the internal [sqlite3_exec()] call are not 2831** reflected in subsequent calls to [sqlite3_errcode()] or 2832** [sqlite3_errmsg()]. 2833*/ 2834int sqlite3_get_table( 2835 sqlite3 *db, /* An open database */ 2836 const char *zSql, /* SQL to be evaluated */ 2837 char ***pazResult, /* Results of the query */ 2838 int *pnRow, /* Number of result rows written here */ 2839 int *pnColumn, /* Number of result columns written here */ 2840 char **pzErrmsg /* Error msg written here */ 2841); 2842void sqlite3_free_table(char **result); 2843 2844/* 2845** CAPI3REF: Formatted String Printing Functions 2846** 2847** These routines are work-alikes of the "printf()" family of functions 2848** from the standard C library. 2849** These routines understand most of the common formatting options from 2850** the standard library printf() 2851** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2852** See the [built-in printf()] documentation for details. 2853** 2854** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2855** results into memory obtained from [sqlite3_malloc64()]. 2856** The strings returned by these two routines should be 2857** released by [sqlite3_free()]. ^Both routines return a 2858** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2859** memory to hold the resulting string. 2860** 2861** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2862** the standard C library. The result is written into the 2863** buffer supplied as the second parameter whose size is given by 2864** the first parameter. Note that the order of the 2865** first two parameters is reversed from snprintf().)^ This is an 2866** historical accident that cannot be fixed without breaking 2867** backwards compatibility. ^(Note also that sqlite3_snprintf() 2868** returns a pointer to its buffer instead of the number of 2869** characters actually written into the buffer.)^ We admit that 2870** the number of characters written would be a more useful return 2871** value but we cannot change the implementation of sqlite3_snprintf() 2872** now without breaking compatibility. 2873** 2874** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2875** guarantees that the buffer is always zero-terminated. ^The first 2876** parameter "n" is the total size of the buffer, including space for 2877** the zero terminator. So the longest string that can be completely 2878** written will be n-1 characters. 2879** 2880** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2881** 2882** See also: [built-in printf()], [printf() SQL function] 2883*/ 2884char *sqlite3_mprintf(const char*,...); 2885char *sqlite3_vmprintf(const char*, va_list); 2886char *sqlite3_snprintf(int,char*,const char*, ...); 2887char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2888 2889/* 2890** CAPI3REF: Memory Allocation Subsystem 2891** 2892** The SQLite core uses these three routines for all of its own 2893** internal memory allocation needs. "Core" in the previous sentence 2894** does not include operating-system specific [VFS] implementation. The 2895** Windows VFS uses native malloc() and free() for some operations. 2896** 2897** ^The sqlite3_malloc() routine returns a pointer to a block 2898** of memory at least N bytes in length, where N is the parameter. 2899** ^If sqlite3_malloc() is unable to obtain sufficient free 2900** memory, it returns a NULL pointer. ^If the parameter N to 2901** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2902** a NULL pointer. 2903** 2904** ^The sqlite3_malloc64(N) routine works just like 2905** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2906** of a signed 32-bit integer. 2907** 2908** ^Calling sqlite3_free() with a pointer previously returned 2909** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2910** that it might be reused. ^The sqlite3_free() routine is 2911** a no-op if is called with a NULL pointer. Passing a NULL pointer 2912** to sqlite3_free() is harmless. After being freed, memory 2913** should neither be read nor written. Even reading previously freed 2914** memory might result in a segmentation fault or other severe error. 2915** Memory corruption, a segmentation fault, or other severe error 2916** might result if sqlite3_free() is called with a non-NULL pointer that 2917** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2918** 2919** ^The sqlite3_realloc(X,N) interface attempts to resize a 2920** prior memory allocation X to be at least N bytes. 2921** ^If the X parameter to sqlite3_realloc(X,N) 2922** is a NULL pointer then its behavior is identical to calling 2923** sqlite3_malloc(N). 2924** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2925** negative then the behavior is exactly the same as calling 2926** sqlite3_free(X). 2927** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2928** of at least N bytes in size or NULL if insufficient memory is available. 2929** ^If M is the size of the prior allocation, then min(N,M) bytes 2930** of the prior allocation are copied into the beginning of buffer returned 2931** by sqlite3_realloc(X,N) and the prior allocation is freed. 2932** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2933** prior allocation is not freed. 2934** 2935** ^The sqlite3_realloc64(X,N) interfaces works the same as 2936** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2937** of a 32-bit signed integer. 2938** 2939** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2940** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2941** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2942** ^The value returned by sqlite3_msize(X) might be larger than the number 2943** of bytes requested when X was allocated. ^If X is a NULL pointer then 2944** sqlite3_msize(X) returns zero. If X points to something that is not 2945** the beginning of memory allocation, or if it points to a formerly 2946** valid memory allocation that has now been freed, then the behavior 2947** of sqlite3_msize(X) is undefined and possibly harmful. 2948** 2949** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2950** sqlite3_malloc64(), and sqlite3_realloc64() 2951** is always aligned to at least an 8 byte boundary, or to a 2952** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2953** option is used. 2954** 2955** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2956** must be either NULL or else pointers obtained from a prior 2957** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2958** not yet been released. 2959** 2960** The application must not read or write any part of 2961** a block of memory after it has been released using 2962** [sqlite3_free()] or [sqlite3_realloc()]. 2963*/ 2964void *sqlite3_malloc(int); 2965void *sqlite3_malloc64(sqlite3_uint64); 2966void *sqlite3_realloc(void*, int); 2967void *sqlite3_realloc64(void*, sqlite3_uint64); 2968void sqlite3_free(void*); 2969sqlite3_uint64 sqlite3_msize(void*); 2970 2971/* 2972** CAPI3REF: Memory Allocator Statistics 2973** 2974** SQLite provides these two interfaces for reporting on the status 2975** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2976** routines, which form the built-in memory allocation subsystem. 2977** 2978** ^The [sqlite3_memory_used()] routine returns the number of bytes 2979** of memory currently outstanding (malloced but not freed). 2980** ^The [sqlite3_memory_highwater()] routine returns the maximum 2981** value of [sqlite3_memory_used()] since the high-water mark 2982** was last reset. ^The values returned by [sqlite3_memory_used()] and 2983** [sqlite3_memory_highwater()] include any overhead 2984** added by SQLite in its implementation of [sqlite3_malloc()], 2985** but not overhead added by the any underlying system library 2986** routines that [sqlite3_malloc()] may call. 2987** 2988** ^The memory high-water mark is reset to the current value of 2989** [sqlite3_memory_used()] if and only if the parameter to 2990** [sqlite3_memory_highwater()] is true. ^The value returned 2991** by [sqlite3_memory_highwater(1)] is the high-water mark 2992** prior to the reset. 2993*/ 2994sqlite3_int64 sqlite3_memory_used(void); 2995sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2996 2997/* 2998** CAPI3REF: Pseudo-Random Number Generator 2999** 3000** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3001** select random [ROWID | ROWIDs] when inserting new records into a table that 3002** already uses the largest possible [ROWID]. The PRNG is also used for 3003** the built-in random() and randomblob() SQL functions. This interface allows 3004** applications to access the same PRNG for other purposes. 3005** 3006** ^A call to this routine stores N bytes of randomness into buffer P. 3007** ^The P parameter can be a NULL pointer. 3008** 3009** ^If this routine has not been previously called or if the previous 3010** call had N less than one or a NULL pointer for P, then the PRNG is 3011** seeded using randomness obtained from the xRandomness method of 3012** the default [sqlite3_vfs] object. 3013** ^If the previous call to this routine had an N of 1 or more and a 3014** non-NULL P then the pseudo-randomness is generated 3015** internally and without recourse to the [sqlite3_vfs] xRandomness 3016** method. 3017*/ 3018void sqlite3_randomness(int N, void *P); 3019 3020/* 3021** CAPI3REF: Compile-Time Authorization Callbacks 3022** METHOD: sqlite3 3023** KEYWORDS: {authorizer callback} 3024** 3025** ^This routine registers an authorizer callback with a particular 3026** [database connection], supplied in the first argument. 3027** ^The authorizer callback is invoked as SQL statements are being compiled 3028** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3029** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3030** and [sqlite3_prepare16_v3()]. ^At various 3031** points during the compilation process, as logic is being created 3032** to perform various actions, the authorizer callback is invoked to 3033** see if those actions are allowed. ^The authorizer callback should 3034** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3035** specific action but allow the SQL statement to continue to be 3036** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3037** rejected with an error. ^If the authorizer callback returns 3038** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3039** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3040** the authorizer will fail with an error message. 3041** 3042** When the callback returns [SQLITE_OK], that means the operation 3043** requested is ok. ^When the callback returns [SQLITE_DENY], the 3044** [sqlite3_prepare_v2()] or equivalent call that triggered the 3045** authorizer will fail with an error message explaining that 3046** access is denied. 3047** 3048** ^The first parameter to the authorizer callback is a copy of the third 3049** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3050** to the callback is an integer [SQLITE_COPY | action code] that specifies 3051** the particular action to be authorized. ^The third through sixth parameters 3052** to the callback are either NULL pointers or zero-terminated strings 3053** that contain additional details about the action to be authorized. 3054** Applications must always be prepared to encounter a NULL pointer in any 3055** of the third through the sixth parameters of the authorization callback. 3056** 3057** ^If the action code is [SQLITE_READ] 3058** and the callback returns [SQLITE_IGNORE] then the 3059** [prepared statement] statement is constructed to substitute 3060** a NULL value in place of the table column that would have 3061** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3062** return can be used to deny an untrusted user access to individual 3063** columns of a table. 3064** ^When a table is referenced by a [SELECT] but no column values are 3065** extracted from that table (for example in a query like 3066** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3067** is invoked once for that table with a column name that is an empty string. 3068** ^If the action code is [SQLITE_DELETE] and the callback returns 3069** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3070** [truncate optimization] is disabled and all rows are deleted individually. 3071** 3072** An authorizer is used when [sqlite3_prepare | preparing] 3073** SQL statements from an untrusted source, to ensure that the SQL statements 3074** do not try to access data they are not allowed to see, or that they do not 3075** try to execute malicious statements that damage the database. For 3076** example, an application may allow a user to enter arbitrary 3077** SQL queries for evaluation by a database. But the application does 3078** not want the user to be able to make arbitrary changes to the 3079** database. An authorizer could then be put in place while the 3080** user-entered SQL is being [sqlite3_prepare | prepared] that 3081** disallows everything except [SELECT] statements. 3082** 3083** Applications that need to process SQL from untrusted sources 3084** might also consider lowering resource limits using [sqlite3_limit()] 3085** and limiting database size using the [max_page_count] [PRAGMA] 3086** in addition to using an authorizer. 3087** 3088** ^(Only a single authorizer can be in place on a database connection 3089** at a time. Each call to sqlite3_set_authorizer overrides the 3090** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3091** The authorizer is disabled by default. 3092** 3093** The authorizer callback must not do anything that will modify 3094** the database connection that invoked the authorizer callback. 3095** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3096** database connections for the meaning of "modify" in this paragraph. 3097** 3098** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3099** statement might be re-prepared during [sqlite3_step()] due to a 3100** schema change. Hence, the application should ensure that the 3101** correct authorizer callback remains in place during the [sqlite3_step()]. 3102** 3103** ^Note that the authorizer callback is invoked only during 3104** [sqlite3_prepare()] or its variants. Authorization is not 3105** performed during statement evaluation in [sqlite3_step()], unless 3106** as stated in the previous paragraph, sqlite3_step() invokes 3107** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3108*/ 3109int sqlite3_set_authorizer( 3110 sqlite3*, 3111 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3112 void *pUserData 3113); 3114 3115/* 3116** CAPI3REF: Authorizer Return Codes 3117** 3118** The [sqlite3_set_authorizer | authorizer callback function] must 3119** return either [SQLITE_OK] or one of these two constants in order 3120** to signal SQLite whether or not the action is permitted. See the 3121** [sqlite3_set_authorizer | authorizer documentation] for additional 3122** information. 3123** 3124** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3125** returned from the [sqlite3_vtab_on_conflict()] interface. 3126*/ 3127#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3128#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3129 3130/* 3131** CAPI3REF: Authorizer Action Codes 3132** 3133** The [sqlite3_set_authorizer()] interface registers a callback function 3134** that is invoked to authorize certain SQL statement actions. The 3135** second parameter to the callback is an integer code that specifies 3136** what action is being authorized. These are the integer action codes that 3137** the authorizer callback may be passed. 3138** 3139** These action code values signify what kind of operation is to be 3140** authorized. The 3rd and 4th parameters to the authorization 3141** callback function will be parameters or NULL depending on which of these 3142** codes is used as the second parameter. ^(The 5th parameter to the 3143** authorizer callback is the name of the database ("main", "temp", 3144** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3145** is the name of the inner-most trigger or view that is responsible for 3146** the access attempt or NULL if this access attempt is directly from 3147** top-level SQL code. 3148*/ 3149/******************************************* 3rd ************ 4th ***********/ 3150#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3151#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3152#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3153#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3154#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3155#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3156#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3157#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3158#define SQLITE_DELETE 9 /* Table Name NULL */ 3159#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3160#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3161#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3162#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3163#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3164#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3165#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3166#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3167#define SQLITE_INSERT 18 /* Table Name NULL */ 3168#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3169#define SQLITE_READ 20 /* Table Name Column Name */ 3170#define SQLITE_SELECT 21 /* NULL NULL */ 3171#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3172#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3173#define SQLITE_ATTACH 24 /* Filename NULL */ 3174#define SQLITE_DETACH 25 /* Database Name NULL */ 3175#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3176#define SQLITE_REINDEX 27 /* Index Name NULL */ 3177#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3178#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3179#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3180#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3181#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3182#define SQLITE_COPY 0 /* No longer used */ 3183#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3184 3185/* 3186** CAPI3REF: Tracing And Profiling Functions 3187** METHOD: sqlite3 3188** 3189** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3190** instead of the routines described here. 3191** 3192** These routines register callback functions that can be used for 3193** tracing and profiling the execution of SQL statements. 3194** 3195** ^The callback function registered by sqlite3_trace() is invoked at 3196** various times when an SQL statement is being run by [sqlite3_step()]. 3197** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3198** SQL statement text as the statement first begins executing. 3199** ^(Additional sqlite3_trace() callbacks might occur 3200** as each triggered subprogram is entered. The callbacks for triggers 3201** contain a UTF-8 SQL comment that identifies the trigger.)^ 3202** 3203** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3204** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3205** 3206** ^The callback function registered by sqlite3_profile() is invoked 3207** as each SQL statement finishes. ^The profile callback contains 3208** the original statement text and an estimate of wall-clock time 3209** of how long that statement took to run. ^The profile callback 3210** time is in units of nanoseconds, however the current implementation 3211** is only capable of millisecond resolution so the six least significant 3212** digits in the time are meaningless. Future versions of SQLite 3213** might provide greater resolution on the profiler callback. Invoking 3214** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3215** profile callback. 3216*/ 3217SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3218 void(*xTrace)(void*,const char*), void*); 3219SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3220 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3221 3222/* 3223** CAPI3REF: SQL Trace Event Codes 3224** KEYWORDS: SQLITE_TRACE 3225** 3226** These constants identify classes of events that can be monitored 3227** using the [sqlite3_trace_v2()] tracing logic. The M argument 3228** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3229** the following constants. ^The first argument to the trace callback 3230** is one of the following constants. 3231** 3232** New tracing constants may be added in future releases. 3233** 3234** ^A trace callback has four arguments: xCallback(T,C,P,X). 3235** ^The T argument is one of the integer type codes above. 3236** ^The C argument is a copy of the context pointer passed in as the 3237** fourth argument to [sqlite3_trace_v2()]. 3238** The P and X arguments are pointers whose meanings depend on T. 3239** 3240** <dl> 3241** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3242** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3243** first begins running and possibly at other times during the 3244** execution of the prepared statement, such as at the start of each 3245** trigger subprogram. ^The P argument is a pointer to the 3246** [prepared statement]. ^The X argument is a pointer to a string which 3247** is the unexpanded SQL text of the prepared statement or an SQL comment 3248** that indicates the invocation of a trigger. ^The callback can compute 3249** the same text that would have been returned by the legacy [sqlite3_trace()] 3250** interface by using the X argument when X begins with "--" and invoking 3251** [sqlite3_expanded_sql(P)] otherwise. 3252** 3253** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3254** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3255** information as is provided by the [sqlite3_profile()] callback. 3256** ^The P argument is a pointer to the [prepared statement] and the 3257** X argument points to a 64-bit integer which is the estimated of 3258** the number of nanosecond that the prepared statement took to run. 3259** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3260** 3261** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3262** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3263** statement generates a single row of result. 3264** ^The P argument is a pointer to the [prepared statement] and the 3265** X argument is unused. 3266** 3267** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3268** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3269** connection closes. 3270** ^The P argument is a pointer to the [database connection] object 3271** and the X argument is unused. 3272** </dl> 3273*/ 3274#define SQLITE_TRACE_STMT 0x01 3275#define SQLITE_TRACE_PROFILE 0x02 3276#define SQLITE_TRACE_ROW 0x04 3277#define SQLITE_TRACE_CLOSE 0x08 3278 3279/* 3280** CAPI3REF: SQL Trace Hook 3281** METHOD: sqlite3 3282** 3283** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3284** function X against [database connection] D, using property mask M 3285** and context pointer P. ^If the X callback is 3286** NULL or if the M mask is zero, then tracing is disabled. The 3287** M argument should be the bitwise OR-ed combination of 3288** zero or more [SQLITE_TRACE] constants. 3289** 3290** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3291** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3292** 3293** ^The X callback is invoked whenever any of the events identified by 3294** mask M occur. ^The integer return value from the callback is currently 3295** ignored, though this may change in future releases. Callback 3296** implementations should return zero to ensure future compatibility. 3297** 3298** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3299** ^The T argument is one of the [SQLITE_TRACE] 3300** constants to indicate why the callback was invoked. 3301** ^The C argument is a copy of the context pointer. 3302** The P and X arguments are pointers whose meanings depend on T. 3303** 3304** The sqlite3_trace_v2() interface is intended to replace the legacy 3305** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3306** are deprecated. 3307*/ 3308int sqlite3_trace_v2( 3309 sqlite3*, 3310 unsigned uMask, 3311 int(*xCallback)(unsigned,void*,void*,void*), 3312 void *pCtx 3313); 3314 3315/* 3316** CAPI3REF: Query Progress Callbacks 3317** METHOD: sqlite3 3318** 3319** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3320** function X to be invoked periodically during long running calls to 3321** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3322** database connection D. An example use for this 3323** interface is to keep a GUI updated during a large query. 3324** 3325** ^The parameter P is passed through as the only parameter to the 3326** callback function X. ^The parameter N is the approximate number of 3327** [virtual machine instructions] that are evaluated between successive 3328** invocations of the callback X. ^If N is less than one then the progress 3329** handler is disabled. 3330** 3331** ^Only a single progress handler may be defined at one time per 3332** [database connection]; setting a new progress handler cancels the 3333** old one. ^Setting parameter X to NULL disables the progress handler. 3334** ^The progress handler is also disabled by setting N to a value less 3335** than 1. 3336** 3337** ^If the progress callback returns non-zero, the operation is 3338** interrupted. This feature can be used to implement a 3339** "Cancel" button on a GUI progress dialog box. 3340** 3341** The progress handler callback must not do anything that will modify 3342** the database connection that invoked the progress handler. 3343** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3344** database connections for the meaning of "modify" in this paragraph. 3345** 3346*/ 3347void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3348 3349/* 3350** CAPI3REF: Opening A New Database Connection 3351** CONSTRUCTOR: sqlite3 3352** 3353** ^These routines open an SQLite database file as specified by the 3354** filename argument. ^The filename argument is interpreted as UTF-8 for 3355** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3356** order for sqlite3_open16(). ^(A [database connection] handle is usually 3357** returned in *ppDb, even if an error occurs. The only exception is that 3358** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3359** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3360** object.)^ ^(If the database is opened (and/or created) successfully, then 3361** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3362** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3363** an English language description of the error following a failure of any 3364** of the sqlite3_open() routines. 3365** 3366** ^The default encoding will be UTF-8 for databases created using 3367** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3368** created using sqlite3_open16() will be UTF-16 in the native byte order. 3369** 3370** Whether or not an error occurs when it is opened, resources 3371** associated with the [database connection] handle should be released by 3372** passing it to [sqlite3_close()] when it is no longer required. 3373** 3374** The sqlite3_open_v2() interface works like sqlite3_open() 3375** except that it accepts two additional parameters for additional control 3376** over the new database connection. ^(The flags parameter to 3377** sqlite3_open_v2() must include, at a minimum, one of the following 3378** three flag combinations:)^ 3379** 3380** <dl> 3381** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3382** <dd>The database is opened in read-only mode. If the database does not 3383** already exist, an error is returned.</dd>)^ 3384** 3385** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3386** <dd>The database is opened for reading and writing if possible, or reading 3387** only if the file is write protected by the operating system. In either 3388** case the database must already exist, otherwise an error is returned.</dd>)^ 3389** 3390** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3391** <dd>The database is opened for reading and writing, and is created if 3392** it does not already exist. This is the behavior that is always used for 3393** sqlite3_open() and sqlite3_open16().</dd>)^ 3394** </dl> 3395** 3396** In addition to the required flags, the following optional flags are 3397** also supported: 3398** 3399** <dl> 3400** ^(<dt>[SQLITE_OPEN_URI]</dt> 3401** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3402** 3403** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3404** <dd>The database will be opened as an in-memory database. The database 3405** is named by the "filename" argument for the purposes of cache-sharing, 3406** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3407** </dd>)^ 3408** 3409** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3410** <dd>The new database connection will use the "multi-thread" 3411** [threading mode].)^ This means that separate threads are allowed 3412** to use SQLite at the same time, as long as each thread is using 3413** a different [database connection]. 3414** 3415** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3416** <dd>The new database connection will use the "serialized" 3417** [threading mode].)^ This means the multiple threads can safely 3418** attempt to use the same database connection at the same time. 3419** (Mutexes will block any actual concurrency, but in this mode 3420** there is no harm in trying.) 3421** 3422** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3423** <dd>The database is opened [shared cache] enabled, overriding 3424** the default shared cache setting provided by 3425** [sqlite3_enable_shared_cache()].)^ 3426** 3427** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3428** <dd>The database is opened [shared cache] disabled, overriding 3429** the default shared cache setting provided by 3430** [sqlite3_enable_shared_cache()].)^ 3431** 3432** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3433** <dd>The database filename is not allowed to be a symbolic link</dd> 3434** </dl>)^ 3435** 3436** If the 3rd parameter to sqlite3_open_v2() is not one of the 3437** required combinations shown above optionally combined with other 3438** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3439** then the behavior is undefined. Historic versions of SQLite 3440** have silently ignored surplus bits in the flags parameter to 3441** sqlite3_open_v2(), however that behavior might not be carried through 3442** into future versions of SQLite and so applications should not rely 3443** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3444** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3445** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3446** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3447** by sqlite3_open_v2(). 3448** 3449** ^The fourth parameter to sqlite3_open_v2() is the name of the 3450** [sqlite3_vfs] object that defines the operating system interface that 3451** the new database connection should use. ^If the fourth parameter is 3452** a NULL pointer then the default [sqlite3_vfs] object is used. 3453** 3454** ^If the filename is ":memory:", then a private, temporary in-memory database 3455** is created for the connection. ^This in-memory database will vanish when 3456** the database connection is closed. Future versions of SQLite might 3457** make use of additional special filenames that begin with the ":" character. 3458** It is recommended that when a database filename actually does begin with 3459** a ":" character you should prefix the filename with a pathname such as 3460** "./" to avoid ambiguity. 3461** 3462** ^If the filename is an empty string, then a private, temporary 3463** on-disk database will be created. ^This private database will be 3464** automatically deleted as soon as the database connection is closed. 3465** 3466** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3467** 3468** ^If [URI filename] interpretation is enabled, and the filename argument 3469** begins with "file:", then the filename is interpreted as a URI. ^URI 3470** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3471** set in the third argument to sqlite3_open_v2(), or if it has 3472** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3473** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3474** URI filename interpretation is turned off 3475** by default, but future releases of SQLite might enable URI filename 3476** interpretation by default. See "[URI filenames]" for additional 3477** information. 3478** 3479** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3480** authority, then it must be either an empty string or the string 3481** "localhost". ^If the authority is not an empty string or "localhost", an 3482** error is returned to the caller. ^The fragment component of a URI, if 3483** present, is ignored. 3484** 3485** ^SQLite uses the path component of the URI as the name of the disk file 3486** which contains the database. ^If the path begins with a '/' character, 3487** then it is interpreted as an absolute path. ^If the path does not begin 3488** with a '/' (meaning that the authority section is omitted from the URI) 3489** then the path is interpreted as a relative path. 3490** ^(On windows, the first component of an absolute path 3491** is a drive specification (e.g. "C:").)^ 3492** 3493** [[core URI query parameters]] 3494** The query component of a URI may contain parameters that are interpreted 3495** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3496** SQLite and its built-in [VFSes] interpret the 3497** following query parameters: 3498** 3499** <ul> 3500** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3501** a VFS object that provides the operating system interface that should 3502** be used to access the database file on disk. ^If this option is set to 3503** an empty string the default VFS object is used. ^Specifying an unknown 3504** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3505** present, then the VFS specified by the option takes precedence over 3506** the value passed as the fourth parameter to sqlite3_open_v2(). 3507** 3508** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3509** "rwc", or "memory". Attempting to set it to any other value is 3510** an error)^. 3511** ^If "ro" is specified, then the database is opened for read-only 3512** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3513** third argument to sqlite3_open_v2(). ^If the mode option is set to 3514** "rw", then the database is opened for read-write (but not create) 3515** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3516** been set. ^Value "rwc" is equivalent to setting both 3517** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3518** set to "memory" then a pure [in-memory database] that never reads 3519** or writes from disk is used. ^It is an error to specify a value for 3520** the mode parameter that is less restrictive than that specified by 3521** the flags passed in the third parameter to sqlite3_open_v2(). 3522** 3523** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3524** "private". ^Setting it to "shared" is equivalent to setting the 3525** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3526** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3527** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3528** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3529** a URI filename, its value overrides any behavior requested by setting 3530** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3531** 3532** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3533** [powersafe overwrite] property does or does not apply to the 3534** storage media on which the database file resides. 3535** 3536** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3537** which if set disables file locking in rollback journal modes. This 3538** is useful for accessing a database on a filesystem that does not 3539** support locking. Caution: Database corruption might result if two 3540** or more processes write to the same database and any one of those 3541** processes uses nolock=1. 3542** 3543** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3544** parameter that indicates that the database file is stored on 3545** read-only media. ^When immutable is set, SQLite assumes that the 3546** database file cannot be changed, even by a process with higher 3547** privilege, and so the database is opened read-only and all locking 3548** and change detection is disabled. Caution: Setting the immutable 3549** property on a database file that does in fact change can result 3550** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3551** See also: [SQLITE_IOCAP_IMMUTABLE]. 3552** 3553** </ul> 3554** 3555** ^Specifying an unknown parameter in the query component of a URI is not an 3556** error. Future versions of SQLite might understand additional query 3557** parameters. See "[query parameters with special meaning to SQLite]" for 3558** additional information. 3559** 3560** [[URI filename examples]] <h3>URI filename examples</h3> 3561** 3562** <table border="1" align=center cellpadding=5> 3563** <tr><th> URI filenames <th> Results 3564** <tr><td> file:data.db <td> 3565** Open the file "data.db" in the current directory. 3566** <tr><td> file:/home/fred/data.db<br> 3567** file:///home/fred/data.db <br> 3568** file://localhost/home/fred/data.db <br> <td> 3569** Open the database file "/home/fred/data.db". 3570** <tr><td> file://darkstar/home/fred/data.db <td> 3571** An error. "darkstar" is not a recognized authority. 3572** <tr><td style="white-space:nowrap"> 3573** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3574** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3575** C:. Note that the %20 escaping in this example is not strictly 3576** necessary - space characters can be used literally 3577** in URI filenames. 3578** <tr><td> file:data.db?mode=ro&cache=private <td> 3579** Open file "data.db" in the current directory for read-only access. 3580** Regardless of whether or not shared-cache mode is enabled by 3581** default, use a private cache. 3582** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3583** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3584** that uses dot-files in place of posix advisory locking. 3585** <tr><td> file:data.db?mode=readonly <td> 3586** An error. "readonly" is not a valid option for the "mode" parameter. 3587** Use "ro" instead: "file:data.db?mode=ro". 3588** </table> 3589** 3590** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3591** query components of a URI. A hexadecimal escape sequence consists of a 3592** percent sign - "%" - followed by exactly two hexadecimal digits 3593** specifying an octet value. ^Before the path or query components of a 3594** URI filename are interpreted, they are encoded using UTF-8 and all 3595** hexadecimal escape sequences replaced by a single byte containing the 3596** corresponding octet. If this process generates an invalid UTF-8 encoding, 3597** the results are undefined. 3598** 3599** <b>Note to Windows users:</b> The encoding used for the filename argument 3600** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3601** codepage is currently defined. Filenames containing international 3602** characters must be converted to UTF-8 prior to passing them into 3603** sqlite3_open() or sqlite3_open_v2(). 3604** 3605** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3606** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3607** features that require the use of temporary files may fail. 3608** 3609** See also: [sqlite3_temp_directory] 3610*/ 3611int sqlite3_open( 3612 const char *filename, /* Database filename (UTF-8) */ 3613 sqlite3 **ppDb /* OUT: SQLite db handle */ 3614); 3615int sqlite3_open16( 3616 const void *filename, /* Database filename (UTF-16) */ 3617 sqlite3 **ppDb /* OUT: SQLite db handle */ 3618); 3619int sqlite3_open_v2( 3620 const char *filename, /* Database filename (UTF-8) */ 3621 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3622 int flags, /* Flags */ 3623 const char *zVfs /* Name of VFS module to use */ 3624); 3625 3626/* 3627** CAPI3REF: Obtain Values For URI Parameters 3628** 3629** These are utility routines, useful to [VFS|custom VFS implementations], 3630** that check if a database file was a URI that contained a specific query 3631** parameter, and if so obtains the value of that query parameter. 3632** 3633** The first parameter to these interfaces (hereafter referred to 3634** as F) must be one of: 3635** <ul> 3636** <li> A database filename pointer created by the SQLite core and 3637** passed into the xOpen() method of a VFS implemention, or 3638** <li> A filename obtained from [sqlite3_db_filename()], or 3639** <li> A new filename constructed using [sqlite3_create_filename()]. 3640** </ul> 3641** If the F parameter is not one of the above, then the behavior is 3642** undefined and probably undesirable. Older versions of SQLite were 3643** more tolerant of invalid F parameters than newer versions. 3644** 3645** If F is a suitable filename (as described in the previous paragraph) 3646** and if P is the name of the query parameter, then 3647** sqlite3_uri_parameter(F,P) returns the value of the P 3648** parameter if it exists or a NULL pointer if P does not appear as a 3649** query parameter on F. If P is a query parameter of F and it 3650** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3651** a pointer to an empty string. 3652** 3653** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3654** parameter and returns true (1) or false (0) according to the value 3655** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3656** value of query parameter P is one of "yes", "true", or "on" in any 3657** case or if the value begins with a non-zero number. The 3658** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3659** query parameter P is one of "no", "false", or "off" in any case or 3660** if the value begins with a numeric zero. If P is not a query 3661** parameter on F or if the value of P does not match any of the 3662** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3663** 3664** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3665** 64-bit signed integer and returns that integer, or D if P does not 3666** exist. If the value of P is something other than an integer, then 3667** zero is returned. 3668** 3669** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3670** the value) of the N-th query parameter for filename F, or a NULL 3671** pointer if N is less than zero or greater than the number of query 3672** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3673** the name of the first query parameter, 1 for the second parameter, and 3674** so forth. 3675** 3676** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3677** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3678** is not a database file pathname pointer that the SQLite core passed 3679** into the xOpen VFS method, then the behavior of this routine is undefined 3680** and probably undesirable. 3681** 3682** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3683** parameter can also be the name of a rollback journal file or WAL file 3684** in addition to the main database file. Prior to version 3.31.0, these 3685** routines would only work if F was the name of the main database file. 3686** When the F parameter is the name of the rollback journal or WAL file, 3687** it has access to all the same query parameters as were found on the 3688** main database file. 3689** 3690** See the [URI filename] documentation for additional information. 3691*/ 3692const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3693int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3694sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3695const char *sqlite3_uri_key(const char *zFilename, int N); 3696 3697/* 3698** CAPI3REF: Translate filenames 3699** 3700** These routines are available to [VFS|custom VFS implementations] for 3701** translating filenames between the main database file, the journal file, 3702** and the WAL file. 3703** 3704** If F is the name of an sqlite database file, journal file, or WAL file 3705** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3706** returns the name of the corresponding database file. 3707** 3708** If F is the name of an sqlite database file, journal file, or WAL file 3709** passed by the SQLite core into the VFS, or if F is a database filename 3710** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3711** returns the name of the corresponding rollback journal file. 3712** 3713** If F is the name of an sqlite database file, journal file, or WAL file 3714** that was passed by the SQLite core into the VFS, or if F is a database 3715** filename obtained from [sqlite3_db_filename()], then 3716** sqlite3_filename_wal(F) returns the name of the corresponding 3717** WAL file. 3718** 3719** In all of the above, if F is not the name of a database, journal or WAL 3720** filename passed into the VFS from the SQLite core and F is not the 3721** return value from [sqlite3_db_filename()], then the result is 3722** undefined and is likely a memory access violation. 3723*/ 3724const char *sqlite3_filename_database(const char*); 3725const char *sqlite3_filename_journal(const char*); 3726const char *sqlite3_filename_wal(const char*); 3727 3728/* 3729** CAPI3REF: Database File Corresponding To A Journal 3730** 3731** ^If X is the name of a rollback or WAL-mode journal file that is 3732** passed into the xOpen method of [sqlite3_vfs], then 3733** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3734** object that represents the main database file. 3735** 3736** This routine is intended for use in custom [VFS] implementations 3737** only. It is not a general-purpose interface. 3738** The argument sqlite3_file_object(X) must be a filename pointer that 3739** has been passed into [sqlite3_vfs].xOpen method where the 3740** flags parameter to xOpen contains one of the bits 3741** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3742** of this routine results in undefined and probably undesirable 3743** behavior. 3744*/ 3745sqlite3_file *sqlite3_database_file_object(const char*); 3746 3747/* 3748** CAPI3REF: Create and Destroy VFS Filenames 3749** 3750** These interfces are provided for use by [VFS shim] implementations and 3751** are not useful outside of that context. 3752** 3753** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3754** database filename D with corresponding journal file J and WAL file W and 3755** with N URI parameters key/values pairs in the array P. The result from 3756** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3757** is safe to pass to routines like: 3758** <ul> 3759** <li> [sqlite3_uri_parameter()], 3760** <li> [sqlite3_uri_boolean()], 3761** <li> [sqlite3_uri_int64()], 3762** <li> [sqlite3_uri_key()], 3763** <li> [sqlite3_filename_database()], 3764** <li> [sqlite3_filename_journal()], or 3765** <li> [sqlite3_filename_wal()]. 3766** </ul> 3767** If a memory allocation error occurs, sqlite3_create_filename() might 3768** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3769** must be released by a corresponding call to sqlite3_free_filename(Y). 3770** 3771** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3772** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3773** to a key and value for a query parameter. The P parameter may be a NULL 3774** pointer if N is zero. None of the 2*N pointers in the P array may be 3775** NULL pointers and key pointers should not be empty strings. 3776** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3777** be NULL pointers, though they can be empty strings. 3778** 3779** The sqlite3_free_filename(Y) routine releases a memory allocation 3780** previously obtained from sqlite3_create_filename(). Invoking 3781** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3782** 3783** If the Y parameter to sqlite3_free_filename(Y) is anything other 3784** than a NULL pointer or a pointer previously acquired from 3785** sqlite3_create_filename(), then bad things such as heap 3786** corruption or segfaults may occur. The value Y should not be 3787** used again after sqlite3_free_filename(Y) has been called. This means 3788** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3789** then the corresponding [sqlite3_module.xClose() method should also be 3790** invoked prior to calling sqlite3_free_filename(Y). 3791*/ 3792char *sqlite3_create_filename( 3793 const char *zDatabase, 3794 const char *zJournal, 3795 const char *zWal, 3796 int nParam, 3797 const char **azParam 3798); 3799void sqlite3_free_filename(char*); 3800 3801/* 3802** CAPI3REF: Error Codes And Messages 3803** METHOD: sqlite3 3804** 3805** ^If the most recent sqlite3_* API call associated with 3806** [database connection] D failed, then the sqlite3_errcode(D) interface 3807** returns the numeric [result code] or [extended result code] for that 3808** API call. 3809** ^The sqlite3_extended_errcode() 3810** interface is the same except that it always returns the 3811** [extended result code] even when extended result codes are 3812** disabled. 3813** 3814** The values returned by sqlite3_errcode() and/or 3815** sqlite3_extended_errcode() might change with each API call. 3816** Except, there are some interfaces that are guaranteed to never 3817** change the value of the error code. The error-code preserving 3818** interfaces are: 3819** 3820** <ul> 3821** <li> sqlite3_errcode() 3822** <li> sqlite3_extended_errcode() 3823** <li> sqlite3_errmsg() 3824** <li> sqlite3_errmsg16() 3825** </ul> 3826** 3827** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3828** text that describes the error, as either UTF-8 or UTF-16 respectively. 3829** ^(Memory to hold the error message string is managed internally. 3830** The application does not need to worry about freeing the result. 3831** However, the error string might be overwritten or deallocated by 3832** subsequent calls to other SQLite interface functions.)^ 3833** 3834** ^The sqlite3_errstr() interface returns the English-language text 3835** that describes the [result code], as UTF-8. 3836** ^(Memory to hold the error message string is managed internally 3837** and must not be freed by the application)^. 3838** 3839** When the serialized [threading mode] is in use, it might be the 3840** case that a second error occurs on a separate thread in between 3841** the time of the first error and the call to these interfaces. 3842** When that happens, the second error will be reported since these 3843** interfaces always report the most recent result. To avoid 3844** this, each thread can obtain exclusive use of the [database connection] D 3845** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3846** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3847** all calls to the interfaces listed here are completed. 3848** 3849** If an interface fails with SQLITE_MISUSE, that means the interface 3850** was invoked incorrectly by the application. In that case, the 3851** error code and message may or may not be set. 3852*/ 3853int sqlite3_errcode(sqlite3 *db); 3854int sqlite3_extended_errcode(sqlite3 *db); 3855const char *sqlite3_errmsg(sqlite3*); 3856const void *sqlite3_errmsg16(sqlite3*); 3857const char *sqlite3_errstr(int); 3858 3859/* 3860** CAPI3REF: Prepared Statement Object 3861** KEYWORDS: {prepared statement} {prepared statements} 3862** 3863** An instance of this object represents a single SQL statement that 3864** has been compiled into binary form and is ready to be evaluated. 3865** 3866** Think of each SQL statement as a separate computer program. The 3867** original SQL text is source code. A prepared statement object 3868** is the compiled object code. All SQL must be converted into a 3869** prepared statement before it can be run. 3870** 3871** The life-cycle of a prepared statement object usually goes like this: 3872** 3873** <ol> 3874** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3875** <li> Bind values to [parameters] using the sqlite3_bind_*() 3876** interfaces. 3877** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3878** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3879** to step 2. Do this zero or more times. 3880** <li> Destroy the object using [sqlite3_finalize()]. 3881** </ol> 3882*/ 3883typedef struct sqlite3_stmt sqlite3_stmt; 3884 3885/* 3886** CAPI3REF: Run-time Limits 3887** METHOD: sqlite3 3888** 3889** ^(This interface allows the size of various constructs to be limited 3890** on a connection by connection basis. The first parameter is the 3891** [database connection] whose limit is to be set or queried. The 3892** second parameter is one of the [limit categories] that define a 3893** class of constructs to be size limited. The third parameter is the 3894** new limit for that construct.)^ 3895** 3896** ^If the new limit is a negative number, the limit is unchanged. 3897** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3898** [limits | hard upper bound] 3899** set at compile-time by a C preprocessor macro called 3900** [limits | SQLITE_MAX_<i>NAME</i>]. 3901** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3902** ^Attempts to increase a limit above its hard upper bound are 3903** silently truncated to the hard upper bound. 3904** 3905** ^Regardless of whether or not the limit was changed, the 3906** [sqlite3_limit()] interface returns the prior value of the limit. 3907** ^Hence, to find the current value of a limit without changing it, 3908** simply invoke this interface with the third parameter set to -1. 3909** 3910** Run-time limits are intended for use in applications that manage 3911** both their own internal database and also databases that are controlled 3912** by untrusted external sources. An example application might be a 3913** web browser that has its own databases for storing history and 3914** separate databases controlled by JavaScript applications downloaded 3915** off the Internet. The internal databases can be given the 3916** large, default limits. Databases managed by external sources can 3917** be given much smaller limits designed to prevent a denial of service 3918** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3919** interface to further control untrusted SQL. The size of the database 3920** created by an untrusted script can be contained using the 3921** [max_page_count] [PRAGMA]. 3922** 3923** New run-time limit categories may be added in future releases. 3924*/ 3925int sqlite3_limit(sqlite3*, int id, int newVal); 3926 3927/* 3928** CAPI3REF: Run-Time Limit Categories 3929** KEYWORDS: {limit category} {*limit categories} 3930** 3931** These constants define various performance limits 3932** that can be lowered at run-time using [sqlite3_limit()]. 3933** The synopsis of the meanings of the various limits is shown below. 3934** Additional information is available at [limits | Limits in SQLite]. 3935** 3936** <dl> 3937** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3938** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3939** 3940** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3941** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3942** 3943** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3944** <dd>The maximum number of columns in a table definition or in the 3945** result set of a [SELECT] or the maximum number of columns in an index 3946** or in an ORDER BY or GROUP BY clause.</dd>)^ 3947** 3948** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3949** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3950** 3951** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3952** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3953** 3954** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3955** <dd>The maximum number of instructions in a virtual machine program 3956** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3957** the equivalent tries to allocate space for more than this many opcodes 3958** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3959** 3960** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3961** <dd>The maximum number of arguments on a function.</dd>)^ 3962** 3963** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3964** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3965** 3966** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3967** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3968** <dd>The maximum length of the pattern argument to the [LIKE] or 3969** [GLOB] operators.</dd>)^ 3970** 3971** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3972** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3973** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3974** 3975** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3976** <dd>The maximum depth of recursion for triggers.</dd>)^ 3977** 3978** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3979** <dd>The maximum number of auxiliary worker threads that a single 3980** [prepared statement] may start.</dd>)^ 3981** </dl> 3982*/ 3983#define SQLITE_LIMIT_LENGTH 0 3984#define SQLITE_LIMIT_SQL_LENGTH 1 3985#define SQLITE_LIMIT_COLUMN 2 3986#define SQLITE_LIMIT_EXPR_DEPTH 3 3987#define SQLITE_LIMIT_COMPOUND_SELECT 4 3988#define SQLITE_LIMIT_VDBE_OP 5 3989#define SQLITE_LIMIT_FUNCTION_ARG 6 3990#define SQLITE_LIMIT_ATTACHED 7 3991#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3992#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3993#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3994#define SQLITE_LIMIT_WORKER_THREADS 11 3995 3996/* 3997** CAPI3REF: Prepare Flags 3998** 3999** These constants define various flags that can be passed into 4000** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4001** [sqlite3_prepare16_v3()] interfaces. 4002** 4003** New flags may be added in future releases of SQLite. 4004** 4005** <dl> 4006** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4007** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4008** that the prepared statement will be retained for a long time and 4009** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4010** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4011** be used just once or at most a few times and then destroyed using 4012** [sqlite3_finalize()] relatively soon. The current implementation acts 4013** on this hint by avoiding the use of [lookaside memory] so as not to 4014** deplete the limited store of lookaside memory. Future versions of 4015** SQLite may act on this hint differently. 4016** 4017** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4018** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4019** to be required for any prepared statement that wanted to use the 4020** [sqlite3_normalized_sql()] interface. However, the 4021** [sqlite3_normalized_sql()] interface is now available to all 4022** prepared statements, regardless of whether or not they use this 4023** flag. 4024** 4025** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4026** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4027** to return an error (error code SQLITE_ERROR) if the statement uses 4028** any virtual tables. 4029** </dl> 4030*/ 4031#define SQLITE_PREPARE_PERSISTENT 0x01 4032#define SQLITE_PREPARE_NORMALIZE 0x02 4033#define SQLITE_PREPARE_NO_VTAB 0x04 4034 4035/* 4036** CAPI3REF: Compiling An SQL Statement 4037** KEYWORDS: {SQL statement compiler} 4038** METHOD: sqlite3 4039** CONSTRUCTOR: sqlite3_stmt 4040** 4041** To execute an SQL statement, it must first be compiled into a byte-code 4042** program using one of these routines. Or, in other words, these routines 4043** are constructors for the [prepared statement] object. 4044** 4045** The preferred routine to use is [sqlite3_prepare_v2()]. The 4046** [sqlite3_prepare()] interface is legacy and should be avoided. 4047** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4048** for special purposes. 4049** 4050** The use of the UTF-8 interfaces is preferred, as SQLite currently 4051** does all parsing using UTF-8. The UTF-16 interfaces are provided 4052** as a convenience. The UTF-16 interfaces work by converting the 4053** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4054** 4055** The first argument, "db", is a [database connection] obtained from a 4056** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4057** [sqlite3_open16()]. The database connection must not have been closed. 4058** 4059** The second argument, "zSql", is the statement to be compiled, encoded 4060** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4061** and sqlite3_prepare_v3() 4062** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4063** and sqlite3_prepare16_v3() use UTF-16. 4064** 4065** ^If the nByte argument is negative, then zSql is read up to the 4066** first zero terminator. ^If nByte is positive, then it is the 4067** number of bytes read from zSql. ^If nByte is zero, then no prepared 4068** statement is generated. 4069** If the caller knows that the supplied string is nul-terminated, then 4070** there is a small performance advantage to passing an nByte parameter that 4071** is the number of bytes in the input string <i>including</i> 4072** the nul-terminator. 4073** 4074** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4075** past the end of the first SQL statement in zSql. These routines only 4076** compile the first statement in zSql, so *pzTail is left pointing to 4077** what remains uncompiled. 4078** 4079** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4080** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4081** to NULL. ^If the input text contains no SQL (if the input is an empty 4082** string or a comment) then *ppStmt is set to NULL. 4083** The calling procedure is responsible for deleting the compiled 4084** SQL statement using [sqlite3_finalize()] after it has finished with it. 4085** ppStmt may not be NULL. 4086** 4087** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4088** otherwise an [error code] is returned. 4089** 4090** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4091** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4092** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4093** are retained for backwards compatibility, but their use is discouraged. 4094** ^In the "vX" interfaces, the prepared statement 4095** that is returned (the [sqlite3_stmt] object) contains a copy of the 4096** original SQL text. This causes the [sqlite3_step()] interface to 4097** behave differently in three ways: 4098** 4099** <ol> 4100** <li> 4101** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4102** always used to do, [sqlite3_step()] will automatically recompile the SQL 4103** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4104** retries will occur before sqlite3_step() gives up and returns an error. 4105** </li> 4106** 4107** <li> 4108** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4109** [error codes] or [extended error codes]. ^The legacy behavior was that 4110** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4111** and the application would have to make a second call to [sqlite3_reset()] 4112** in order to find the underlying cause of the problem. With the "v2" prepare 4113** interfaces, the underlying reason for the error is returned immediately. 4114** </li> 4115** 4116** <li> 4117** ^If the specific value bound to a [parameter | host parameter] in the 4118** WHERE clause might influence the choice of query plan for a statement, 4119** then the statement will be automatically recompiled, as if there had been 4120** a schema change, on the first [sqlite3_step()] call following any change 4121** to the [sqlite3_bind_text | bindings] of that [parameter]. 4122** ^The specific value of a WHERE-clause [parameter] might influence the 4123** choice of query plan if the parameter is the left-hand side of a [LIKE] 4124** or [GLOB] operator or if the parameter is compared to an indexed column 4125** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4126** </li> 4127** </ol> 4128** 4129** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4130** the extra prepFlags parameter, which is a bit array consisting of zero or 4131** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4132** sqlite3_prepare_v2() interface works exactly the same as 4133** sqlite3_prepare_v3() with a zero prepFlags parameter. 4134*/ 4135int sqlite3_prepare( 4136 sqlite3 *db, /* Database handle */ 4137 const char *zSql, /* SQL statement, UTF-8 encoded */ 4138 int nByte, /* Maximum length of zSql in bytes. */ 4139 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4140 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4141); 4142int sqlite3_prepare_v2( 4143 sqlite3 *db, /* Database handle */ 4144 const char *zSql, /* SQL statement, UTF-8 encoded */ 4145 int nByte, /* Maximum length of zSql in bytes. */ 4146 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4147 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4148); 4149int sqlite3_prepare_v3( 4150 sqlite3 *db, /* Database handle */ 4151 const char *zSql, /* SQL statement, UTF-8 encoded */ 4152 int nByte, /* Maximum length of zSql in bytes. */ 4153 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4154 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4155 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4156); 4157int sqlite3_prepare16( 4158 sqlite3 *db, /* Database handle */ 4159 const void *zSql, /* SQL statement, UTF-16 encoded */ 4160 int nByte, /* Maximum length of zSql in bytes. */ 4161 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4162 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4163); 4164int sqlite3_prepare16_v2( 4165 sqlite3 *db, /* Database handle */ 4166 const void *zSql, /* SQL statement, UTF-16 encoded */ 4167 int nByte, /* Maximum length of zSql in bytes. */ 4168 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4169 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4170); 4171int sqlite3_prepare16_v3( 4172 sqlite3 *db, /* Database handle */ 4173 const void *zSql, /* SQL statement, UTF-16 encoded */ 4174 int nByte, /* Maximum length of zSql in bytes. */ 4175 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4176 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4177 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4178); 4179 4180/* 4181** CAPI3REF: Retrieving Statement SQL 4182** METHOD: sqlite3_stmt 4183** 4184** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4185** SQL text used to create [prepared statement] P if P was 4186** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4187** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4188** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4189** string containing the SQL text of prepared statement P with 4190** [bound parameters] expanded. 4191** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4192** string containing the normalized SQL text of prepared statement P. The 4193** semantics used to normalize a SQL statement are unspecified and subject 4194** to change. At a minimum, literal values will be replaced with suitable 4195** placeholders. 4196** 4197** ^(For example, if a prepared statement is created using the SQL 4198** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4199** and parameter :xyz is unbound, then sqlite3_sql() will return 4200** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4201** will return "SELECT 2345,NULL".)^ 4202** 4203** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4204** is available to hold the result, or if the result would exceed the 4205** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4206** 4207** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4208** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4209** option causes sqlite3_expanded_sql() to always return NULL. 4210** 4211** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4212** are managed by SQLite and are automatically freed when the prepared 4213** statement is finalized. 4214** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4215** is obtained from [sqlite3_malloc()] and must be freed by the application 4216** by passing it to [sqlite3_free()]. 4217** 4218** ^The sqlite3_normalized_sql() interface is only available if 4219** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4220*/ 4221const char *sqlite3_sql(sqlite3_stmt *pStmt); 4222char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4223#ifdef SQLITE_ENABLE_NORMALIZE 4224const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4225#endif 4226 4227/* 4228** CAPI3REF: Determine If An SQL Statement Writes The Database 4229** METHOD: sqlite3_stmt 4230** 4231** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4232** and only if the [prepared statement] X makes no direct changes to 4233** the content of the database file. 4234** 4235** Note that [application-defined SQL functions] or 4236** [virtual tables] might change the database indirectly as a side effect. 4237** ^(For example, if an application defines a function "eval()" that 4238** calls [sqlite3_exec()], then the following SQL statement would 4239** change the database file through side-effects: 4240** 4241** <blockquote><pre> 4242** SELECT eval('DELETE FROM t1') FROM t2; 4243** </pre></blockquote> 4244** 4245** But because the [SELECT] statement does not change the database file 4246** directly, sqlite3_stmt_readonly() would still return true.)^ 4247** 4248** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4249** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4250** since the statements themselves do not actually modify the database but 4251** rather they control the timing of when other statements modify the 4252** database. ^The [ATTACH] and [DETACH] statements also cause 4253** sqlite3_stmt_readonly() to return true since, while those statements 4254** change the configuration of a database connection, they do not make 4255** changes to the content of the database files on disk. 4256** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4257** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4258** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4259** sqlite3_stmt_readonly() returns false for those commands. 4260** 4261** ^This routine returns false if there is any possibility that the 4262** statement might change the database file. ^A false return does 4263** not guarantee that the statement will change the database file. 4264** ^For example, an UPDATE statement might have a WHERE clause that 4265** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4266** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4267** read-only no-op if the table already exists, but 4268** sqlite3_stmt_readonly() still returns false for such a statement. 4269*/ 4270int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4271 4272/* 4273** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4274** METHOD: sqlite3_stmt 4275** 4276** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4277** prepared statement S is an EXPLAIN statement, or 2 if the 4278** statement S is an EXPLAIN QUERY PLAN. 4279** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4280** an ordinary statement or a NULL pointer. 4281*/ 4282int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4283 4284/* 4285** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4286** METHOD: sqlite3_stmt 4287** 4288** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4289** [prepared statement] S has been stepped at least once using 4290** [sqlite3_step(S)] but has neither run to completion (returned 4291** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4292** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4293** interface returns false if S is a NULL pointer. If S is not a 4294** NULL pointer and is not a pointer to a valid [prepared statement] 4295** object, then the behavior is undefined and probably undesirable. 4296** 4297** This interface can be used in combination [sqlite3_next_stmt()] 4298** to locate all prepared statements associated with a database 4299** connection that are in need of being reset. This can be used, 4300** for example, in diagnostic routines to search for prepared 4301** statements that are holding a transaction open. 4302*/ 4303int sqlite3_stmt_busy(sqlite3_stmt*); 4304 4305/* 4306** CAPI3REF: Dynamically Typed Value Object 4307** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4308** 4309** SQLite uses the sqlite3_value object to represent all values 4310** that can be stored in a database table. SQLite uses dynamic typing 4311** for the values it stores. ^Values stored in sqlite3_value objects 4312** can be integers, floating point values, strings, BLOBs, or NULL. 4313** 4314** An sqlite3_value object may be either "protected" or "unprotected". 4315** Some interfaces require a protected sqlite3_value. Other interfaces 4316** will accept either a protected or an unprotected sqlite3_value. 4317** Every interface that accepts sqlite3_value arguments specifies 4318** whether or not it requires a protected sqlite3_value. The 4319** [sqlite3_value_dup()] interface can be used to construct a new 4320** protected sqlite3_value from an unprotected sqlite3_value. 4321** 4322** The terms "protected" and "unprotected" refer to whether or not 4323** a mutex is held. An internal mutex is held for a protected 4324** sqlite3_value object but no mutex is held for an unprotected 4325** sqlite3_value object. If SQLite is compiled to be single-threaded 4326** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4327** or if SQLite is run in one of reduced mutex modes 4328** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4329** then there is no distinction between protected and unprotected 4330** sqlite3_value objects and they can be used interchangeably. However, 4331** for maximum code portability it is recommended that applications 4332** still make the distinction between protected and unprotected 4333** sqlite3_value objects even when not strictly required. 4334** 4335** ^The sqlite3_value objects that are passed as parameters into the 4336** implementation of [application-defined SQL functions] are protected. 4337** ^The sqlite3_value object returned by 4338** [sqlite3_column_value()] is unprotected. 4339** Unprotected sqlite3_value objects may only be used as arguments 4340** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4341** [sqlite3_value_dup()]. 4342** The [sqlite3_value_blob | sqlite3_value_type()] family of 4343** interfaces require protected sqlite3_value objects. 4344*/ 4345typedef struct sqlite3_value sqlite3_value; 4346 4347/* 4348** CAPI3REF: SQL Function Context Object 4349** 4350** The context in which an SQL function executes is stored in an 4351** sqlite3_context object. ^A pointer to an sqlite3_context object 4352** is always first parameter to [application-defined SQL functions]. 4353** The application-defined SQL function implementation will pass this 4354** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4355** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4356** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4357** and/or [sqlite3_set_auxdata()]. 4358*/ 4359typedef struct sqlite3_context sqlite3_context; 4360 4361/* 4362** CAPI3REF: Binding Values To Prepared Statements 4363** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4364** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4365** METHOD: sqlite3_stmt 4366** 4367** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4368** literals may be replaced by a [parameter] that matches one of following 4369** templates: 4370** 4371** <ul> 4372** <li> ? 4373** <li> ?NNN 4374** <li> :VVV 4375** <li> @VVV 4376** <li> $VVV 4377** </ul> 4378** 4379** In the templates above, NNN represents an integer literal, 4380** and VVV represents an alphanumeric identifier.)^ ^The values of these 4381** parameters (also called "host parameter names" or "SQL parameters") 4382** can be set using the sqlite3_bind_*() routines defined here. 4383** 4384** ^The first argument to the sqlite3_bind_*() routines is always 4385** a pointer to the [sqlite3_stmt] object returned from 4386** [sqlite3_prepare_v2()] or its variants. 4387** 4388** ^The second argument is the index of the SQL parameter to be set. 4389** ^The leftmost SQL parameter has an index of 1. ^When the same named 4390** SQL parameter is used more than once, second and subsequent 4391** occurrences have the same index as the first occurrence. 4392** ^The index for named parameters can be looked up using the 4393** [sqlite3_bind_parameter_index()] API if desired. ^The index 4394** for "?NNN" parameters is the value of NNN. 4395** ^The NNN value must be between 1 and the [sqlite3_limit()] 4396** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4397** 4398** ^The third argument is the value to bind to the parameter. 4399** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4400** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4401** is ignored and the end result is the same as sqlite3_bind_null(). 4402** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4403** it should be a pointer to well-formed UTF8 text. 4404** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4405** it should be a pointer to well-formed UTF16 text. 4406** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4407** it should be a pointer to a well-formed unicode string that is 4408** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4409** otherwise. 4410** 4411** [[byte-order determination rules]] ^The byte-order of 4412** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4413** found in first character, which is removed, or in the absence of a BOM 4414** the byte order is the native byte order of the host 4415** machine for sqlite3_bind_text16() or the byte order specified in 4416** the 6th parameter for sqlite3_bind_text64().)^ 4417** ^If UTF16 input text contains invalid unicode 4418** characters, then SQLite might change those invalid characters 4419** into the unicode replacement character: U+FFFD. 4420** 4421** ^(In those routines that have a fourth argument, its value is the 4422** number of bytes in the parameter. To be clear: the value is the 4423** number of <u>bytes</u> in the value, not the number of characters.)^ 4424** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4425** is negative, then the length of the string is 4426** the number of bytes up to the first zero terminator. 4427** If the fourth parameter to sqlite3_bind_blob() is negative, then 4428** the behavior is undefined. 4429** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4430** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4431** that parameter must be the byte offset 4432** where the NUL terminator would occur assuming the string were NUL 4433** terminated. If any NUL characters occurs at byte offsets less than 4434** the value of the fourth parameter then the resulting string value will 4435** contain embedded NULs. The result of expressions involving strings 4436** with embedded NULs is undefined. 4437** 4438** ^The fifth argument to the BLOB and string binding interfaces controls 4439** or indicates the lifetime of the object referenced by the third parameter. 4440** These three options exist: 4441** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4442** with it may be passed. ^It is called to dispose of the BLOB or string even 4443** if the call to the bind API fails, except the destructor is not called if 4444** the third parameter is a NULL pointer or the fourth parameter is negative. 4445** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that 4446** the application remains responsible for disposing of the object. ^In this 4447** case, the object and the provided pointer to it must remain valid until 4448** either the prepared statement is finalized or the same SQL parameter is 4449** bound to something else, whichever occurs sooner. 4450** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4451** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4452** object and pointer to it must remain valid until then. ^SQLite will then 4453** manage the lifetime of its private copy. 4454** 4455** ^The sixth argument to sqlite3_bind_text64() must be one of 4456** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4457** to specify the encoding of the text in the third parameter. If 4458** the sixth argument to sqlite3_bind_text64() is not one of the 4459** allowed values shown above, or if the text encoding is different 4460** from the encoding specified by the sixth parameter, then the behavior 4461** is undefined. 4462** 4463** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4464** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4465** (just an integer to hold its size) while it is being processed. 4466** Zeroblobs are intended to serve as placeholders for BLOBs whose 4467** content is later written using 4468** [sqlite3_blob_open | incremental BLOB I/O] routines. 4469** ^A negative value for the zeroblob results in a zero-length BLOB. 4470** 4471** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4472** [prepared statement] S to have an SQL value of NULL, but to also be 4473** associated with the pointer P of type T. ^D is either a NULL pointer or 4474** a pointer to a destructor function for P. ^SQLite will invoke the 4475** destructor D with a single argument of P when it is finished using 4476** P. The T parameter should be a static string, preferably a string 4477** literal. The sqlite3_bind_pointer() routine is part of the 4478** [pointer passing interface] added for SQLite 3.20.0. 4479** 4480** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4481** for the [prepared statement] or with a prepared statement for which 4482** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4483** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4484** routine is passed a [prepared statement] that has been finalized, the 4485** result is undefined and probably harmful. 4486** 4487** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4488** ^Unbound parameters are interpreted as NULL. 4489** 4490** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4491** [error code] if anything goes wrong. 4492** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4493** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4494** [SQLITE_MAX_LENGTH]. 4495** ^[SQLITE_RANGE] is returned if the parameter 4496** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4497** 4498** See also: [sqlite3_bind_parameter_count()], 4499** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4500*/ 4501int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4502int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4503 void(*)(void*)); 4504int sqlite3_bind_double(sqlite3_stmt*, int, double); 4505int sqlite3_bind_int(sqlite3_stmt*, int, int); 4506int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4507int sqlite3_bind_null(sqlite3_stmt*, int); 4508int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4509int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4510int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4511 void(*)(void*), unsigned char encoding); 4512int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4513int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4514int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4515int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4516 4517/* 4518** CAPI3REF: Number Of SQL Parameters 4519** METHOD: sqlite3_stmt 4520** 4521** ^This routine can be used to find the number of [SQL parameters] 4522** in a [prepared statement]. SQL parameters are tokens of the 4523** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4524** placeholders for values that are [sqlite3_bind_blob | bound] 4525** to the parameters at a later time. 4526** 4527** ^(This routine actually returns the index of the largest (rightmost) 4528** parameter. For all forms except ?NNN, this will correspond to the 4529** number of unique parameters. If parameters of the ?NNN form are used, 4530** there may be gaps in the list.)^ 4531** 4532** See also: [sqlite3_bind_blob|sqlite3_bind()], 4533** [sqlite3_bind_parameter_name()], and 4534** [sqlite3_bind_parameter_index()]. 4535*/ 4536int sqlite3_bind_parameter_count(sqlite3_stmt*); 4537 4538/* 4539** CAPI3REF: Name Of A Host Parameter 4540** METHOD: sqlite3_stmt 4541** 4542** ^The sqlite3_bind_parameter_name(P,N) interface returns 4543** the name of the N-th [SQL parameter] in the [prepared statement] P. 4544** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4545** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4546** respectively. 4547** In other words, the initial ":" or "$" or "@" or "?" 4548** is included as part of the name.)^ 4549** ^Parameters of the form "?" without a following integer have no name 4550** and are referred to as "nameless" or "anonymous parameters". 4551** 4552** ^The first host parameter has an index of 1, not 0. 4553** 4554** ^If the value N is out of range or if the N-th parameter is 4555** nameless, then NULL is returned. ^The returned string is 4556** always in UTF-8 encoding even if the named parameter was 4557** originally specified as UTF-16 in [sqlite3_prepare16()], 4558** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4559** 4560** See also: [sqlite3_bind_blob|sqlite3_bind()], 4561** [sqlite3_bind_parameter_count()], and 4562** [sqlite3_bind_parameter_index()]. 4563*/ 4564const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4565 4566/* 4567** CAPI3REF: Index Of A Parameter With A Given Name 4568** METHOD: sqlite3_stmt 4569** 4570** ^Return the index of an SQL parameter given its name. ^The 4571** index value returned is suitable for use as the second 4572** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4573** is returned if no matching parameter is found. ^The parameter 4574** name must be given in UTF-8 even if the original statement 4575** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4576** [sqlite3_prepare16_v3()]. 4577** 4578** See also: [sqlite3_bind_blob|sqlite3_bind()], 4579** [sqlite3_bind_parameter_count()], and 4580** [sqlite3_bind_parameter_name()]. 4581*/ 4582int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4583 4584/* 4585** CAPI3REF: Reset All Bindings On A Prepared Statement 4586** METHOD: sqlite3_stmt 4587** 4588** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4589** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4590** ^Use this routine to reset all host parameters to NULL. 4591*/ 4592int sqlite3_clear_bindings(sqlite3_stmt*); 4593 4594/* 4595** CAPI3REF: Number Of Columns In A Result Set 4596** METHOD: sqlite3_stmt 4597** 4598** ^Return the number of columns in the result set returned by the 4599** [prepared statement]. ^If this routine returns 0, that means the 4600** [prepared statement] returns no data (for example an [UPDATE]). 4601** ^However, just because this routine returns a positive number does not 4602** mean that one or more rows of data will be returned. ^A SELECT statement 4603** will always have a positive sqlite3_column_count() but depending on the 4604** WHERE clause constraints and the table content, it might return no rows. 4605** 4606** See also: [sqlite3_data_count()] 4607*/ 4608int sqlite3_column_count(sqlite3_stmt *pStmt); 4609 4610/* 4611** CAPI3REF: Column Names In A Result Set 4612** METHOD: sqlite3_stmt 4613** 4614** ^These routines return the name assigned to a particular column 4615** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4616** interface returns a pointer to a zero-terminated UTF-8 string 4617** and sqlite3_column_name16() returns a pointer to a zero-terminated 4618** UTF-16 string. ^The first parameter is the [prepared statement] 4619** that implements the [SELECT] statement. ^The second parameter is the 4620** column number. ^The leftmost column is number 0. 4621** 4622** ^The returned string pointer is valid until either the [prepared statement] 4623** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4624** reprepared by the first call to [sqlite3_step()] for a particular run 4625** or until the next call to 4626** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4627** 4628** ^If sqlite3_malloc() fails during the processing of either routine 4629** (for example during a conversion from UTF-8 to UTF-16) then a 4630** NULL pointer is returned. 4631** 4632** ^The name of a result column is the value of the "AS" clause for 4633** that column, if there is an AS clause. If there is no AS clause 4634** then the name of the column is unspecified and may change from 4635** one release of SQLite to the next. 4636*/ 4637const char *sqlite3_column_name(sqlite3_stmt*, int N); 4638const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4639 4640/* 4641** CAPI3REF: Source Of Data In A Query Result 4642** METHOD: sqlite3_stmt 4643** 4644** ^These routines provide a means to determine the database, table, and 4645** table column that is the origin of a particular result column in 4646** [SELECT] statement. 4647** ^The name of the database or table or column can be returned as 4648** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4649** the database name, the _table_ routines return the table name, and 4650** the origin_ routines return the column name. 4651** ^The returned string is valid until the [prepared statement] is destroyed 4652** using [sqlite3_finalize()] or until the statement is automatically 4653** reprepared by the first call to [sqlite3_step()] for a particular run 4654** or until the same information is requested 4655** again in a different encoding. 4656** 4657** ^The names returned are the original un-aliased names of the 4658** database, table, and column. 4659** 4660** ^The first argument to these interfaces is a [prepared statement]. 4661** ^These functions return information about the Nth result column returned by 4662** the statement, where N is the second function argument. 4663** ^The left-most column is column 0 for these routines. 4664** 4665** ^If the Nth column returned by the statement is an expression or 4666** subquery and is not a column value, then all of these functions return 4667** NULL. ^These routines might also return NULL if a memory allocation error 4668** occurs. ^Otherwise, they return the name of the attached database, table, 4669** or column that query result column was extracted from. 4670** 4671** ^As with all other SQLite APIs, those whose names end with "16" return 4672** UTF-16 encoded strings and the other functions return UTF-8. 4673** 4674** ^These APIs are only available if the library was compiled with the 4675** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4676** 4677** If two or more threads call one or more 4678** [sqlite3_column_database_name | column metadata interfaces] 4679** for the same [prepared statement] and result column 4680** at the same time then the results are undefined. 4681*/ 4682const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4683const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4684const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4685const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4686const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4687const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4688 4689/* 4690** CAPI3REF: Declared Datatype Of A Query Result 4691** METHOD: sqlite3_stmt 4692** 4693** ^(The first parameter is a [prepared statement]. 4694** If this statement is a [SELECT] statement and the Nth column of the 4695** returned result set of that [SELECT] is a table column (not an 4696** expression or subquery) then the declared type of the table 4697** column is returned.)^ ^If the Nth column of the result set is an 4698** expression or subquery, then a NULL pointer is returned. 4699** ^The returned string is always UTF-8 encoded. 4700** 4701** ^(For example, given the database schema: 4702** 4703** CREATE TABLE t1(c1 VARIANT); 4704** 4705** and the following statement to be compiled: 4706** 4707** SELECT c1 + 1, c1 FROM t1; 4708** 4709** this routine would return the string "VARIANT" for the second result 4710** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4711** 4712** ^SQLite uses dynamic run-time typing. ^So just because a column 4713** is declared to contain a particular type does not mean that the 4714** data stored in that column is of the declared type. SQLite is 4715** strongly typed, but the typing is dynamic not static. ^Type 4716** is associated with individual values, not with the containers 4717** used to hold those values. 4718*/ 4719const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4720const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4721 4722/* 4723** CAPI3REF: Evaluate An SQL Statement 4724** METHOD: sqlite3_stmt 4725** 4726** After a [prepared statement] has been prepared using any of 4727** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4728** or [sqlite3_prepare16_v3()] or one of the legacy 4729** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4730** must be called one or more times to evaluate the statement. 4731** 4732** The details of the behavior of the sqlite3_step() interface depend 4733** on whether the statement was prepared using the newer "vX" interfaces 4734** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4735** [sqlite3_prepare16_v2()] or the older legacy 4736** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4737** new "vX" interface is recommended for new applications but the legacy 4738** interface will continue to be supported. 4739** 4740** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4741** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4742** ^With the "v2" interface, any of the other [result codes] or 4743** [extended result codes] might be returned as well. 4744** 4745** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4746** database locks it needs to do its job. ^If the statement is a [COMMIT] 4747** or occurs outside of an explicit transaction, then you can retry the 4748** statement. If the statement is not a [COMMIT] and occurs within an 4749** explicit transaction then you should rollback the transaction before 4750** continuing. 4751** 4752** ^[SQLITE_DONE] means that the statement has finished executing 4753** successfully. sqlite3_step() should not be called again on this virtual 4754** machine without first calling [sqlite3_reset()] to reset the virtual 4755** machine back to its initial state. 4756** 4757** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4758** is returned each time a new row of data is ready for processing by the 4759** caller. The values may be accessed using the [column access functions]. 4760** sqlite3_step() is called again to retrieve the next row of data. 4761** 4762** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4763** violation) has occurred. sqlite3_step() should not be called again on 4764** the VM. More information may be found by calling [sqlite3_errmsg()]. 4765** ^With the legacy interface, a more specific error code (for example, 4766** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4767** can be obtained by calling [sqlite3_reset()] on the 4768** [prepared statement]. ^In the "v2" interface, 4769** the more specific error code is returned directly by sqlite3_step(). 4770** 4771** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4772** Perhaps it was called on a [prepared statement] that has 4773** already been [sqlite3_finalize | finalized] or on one that had 4774** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4775** be the case that the same database connection is being used by two or 4776** more threads at the same moment in time. 4777** 4778** For all versions of SQLite up to and including 3.6.23.1, a call to 4779** [sqlite3_reset()] was required after sqlite3_step() returned anything 4780** other than [SQLITE_ROW] before any subsequent invocation of 4781** sqlite3_step(). Failure to reset the prepared statement using 4782** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4783** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4784** sqlite3_step() began 4785** calling [sqlite3_reset()] automatically in this circumstance rather 4786** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4787** break because any application that ever receives an SQLITE_MISUSE error 4788** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4789** can be used to restore the legacy behavior. 4790** 4791** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4792** API always returns a generic error code, [SQLITE_ERROR], following any 4793** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4794** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4795** specific [error codes] that better describes the error. 4796** We admit that this is a goofy design. The problem has been fixed 4797** with the "v2" interface. If you prepare all of your SQL statements 4798** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4799** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4800** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4801** then the more specific [error codes] are returned directly 4802** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4803*/ 4804int sqlite3_step(sqlite3_stmt*); 4805 4806/* 4807** CAPI3REF: Number of columns in a result set 4808** METHOD: sqlite3_stmt 4809** 4810** ^The sqlite3_data_count(P) interface returns the number of columns in the 4811** current row of the result set of [prepared statement] P. 4812** ^If prepared statement P does not have results ready to return 4813** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4814** interfaces) then sqlite3_data_count(P) returns 0. 4815** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4816** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4817** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4818** will return non-zero if previous call to [sqlite3_step](P) returned 4819** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4820** where it always returns zero since each step of that multi-step 4821** pragma returns 0 columns of data. 4822** 4823** See also: [sqlite3_column_count()] 4824*/ 4825int sqlite3_data_count(sqlite3_stmt *pStmt); 4826 4827/* 4828** CAPI3REF: Fundamental Datatypes 4829** KEYWORDS: SQLITE_TEXT 4830** 4831** ^(Every value in SQLite has one of five fundamental datatypes: 4832** 4833** <ul> 4834** <li> 64-bit signed integer 4835** <li> 64-bit IEEE floating point number 4836** <li> string 4837** <li> BLOB 4838** <li> NULL 4839** </ul>)^ 4840** 4841** These constants are codes for each of those types. 4842** 4843** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4844** for a completely different meaning. Software that links against both 4845** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4846** SQLITE_TEXT. 4847*/ 4848#define SQLITE_INTEGER 1 4849#define SQLITE_FLOAT 2 4850#define SQLITE_BLOB 4 4851#define SQLITE_NULL 5 4852#ifdef SQLITE_TEXT 4853# undef SQLITE_TEXT 4854#else 4855# define SQLITE_TEXT 3 4856#endif 4857#define SQLITE3_TEXT 3 4858 4859/* 4860** CAPI3REF: Result Values From A Query 4861** KEYWORDS: {column access functions} 4862** METHOD: sqlite3_stmt 4863** 4864** <b>Summary:</b> 4865** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4866** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4867** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4868** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4869** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4870** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4871** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4872** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4873** [sqlite3_value|unprotected sqlite3_value] object. 4874** <tr><td> <td> <td> 4875** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4876** or a UTF-8 TEXT result in bytes 4877** <tr><td><b>sqlite3_column_bytes16 </b> 4878** <td>→ <td>Size of UTF-16 4879** TEXT in bytes 4880** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4881** datatype of the result 4882** </table></blockquote> 4883** 4884** <b>Details:</b> 4885** 4886** ^These routines return information about a single column of the current 4887** result row of a query. ^In every case the first argument is a pointer 4888** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4889** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4890** and the second argument is the index of the column for which information 4891** should be returned. ^The leftmost column of the result set has the index 0. 4892** ^The number of columns in the result can be determined using 4893** [sqlite3_column_count()]. 4894** 4895** If the SQL statement does not currently point to a valid row, or if the 4896** column index is out of range, the result is undefined. 4897** These routines may only be called when the most recent call to 4898** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4899** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4900** If any of these routines are called after [sqlite3_reset()] or 4901** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4902** something other than [SQLITE_ROW], the results are undefined. 4903** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4904** are called from a different thread while any of these routines 4905** are pending, then the results are undefined. 4906** 4907** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4908** each return the value of a result column in a specific data format. If 4909** the result column is not initially in the requested format (for example, 4910** if the query returns an integer but the sqlite3_column_text() interface 4911** is used to extract the value) then an automatic type conversion is performed. 4912** 4913** ^The sqlite3_column_type() routine returns the 4914** [SQLITE_INTEGER | datatype code] for the initial data type 4915** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4916** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4917** The return value of sqlite3_column_type() can be used to decide which 4918** of the first six interface should be used to extract the column value. 4919** The value returned by sqlite3_column_type() is only meaningful if no 4920** automatic type conversions have occurred for the value in question. 4921** After a type conversion, the result of calling sqlite3_column_type() 4922** is undefined, though harmless. Future 4923** versions of SQLite may change the behavior of sqlite3_column_type() 4924** following a type conversion. 4925** 4926** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4927** or sqlite3_column_bytes16() interfaces can be used to determine the size 4928** of that BLOB or string. 4929** 4930** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4931** routine returns the number of bytes in that BLOB or string. 4932** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4933** the string to UTF-8 and then returns the number of bytes. 4934** ^If the result is a numeric value then sqlite3_column_bytes() uses 4935** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4936** the number of bytes in that string. 4937** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4938** 4939** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4940** routine returns the number of bytes in that BLOB or string. 4941** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4942** the string to UTF-16 and then returns the number of bytes. 4943** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4944** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4945** the number of bytes in that string. 4946** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4947** 4948** ^The values returned by [sqlite3_column_bytes()] and 4949** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4950** of the string. ^For clarity: the values returned by 4951** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4952** bytes in the string, not the number of characters. 4953** 4954** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4955** even empty strings, are always zero-terminated. ^The return 4956** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4957** 4958** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4959** [unprotected sqlite3_value] object. In a multithreaded environment, 4960** an unprotected sqlite3_value object may only be used safely with 4961** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4962** If the [unprotected sqlite3_value] object returned by 4963** [sqlite3_column_value()] is used in any other way, including calls 4964** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4965** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4966** Hence, the sqlite3_column_value() interface 4967** is normally only useful within the implementation of 4968** [application-defined SQL functions] or [virtual tables], not within 4969** top-level application code. 4970** 4971** The these routines may attempt to convert the datatype of the result. 4972** ^For example, if the internal representation is FLOAT and a text result 4973** is requested, [sqlite3_snprintf()] is used internally to perform the 4974** conversion automatically. ^(The following table details the conversions 4975** that are applied: 4976** 4977** <blockquote> 4978** <table border="1"> 4979** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4980** 4981** <tr><td> NULL <td> INTEGER <td> Result is 0 4982** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4983** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4984** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4985** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4986** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4987** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4988** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4989** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4990** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4991** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4992** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4993** <tr><td> TEXT <td> BLOB <td> No change 4994** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4995** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4996** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4997** </table> 4998** </blockquote>)^ 4999** 5000** Note that when type conversions occur, pointers returned by prior 5001** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5002** sqlite3_column_text16() may be invalidated. 5003** Type conversions and pointer invalidations might occur 5004** in the following cases: 5005** 5006** <ul> 5007** <li> The initial content is a BLOB and sqlite3_column_text() or 5008** sqlite3_column_text16() is called. A zero-terminator might 5009** need to be added to the string.</li> 5010** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5011** sqlite3_column_text16() is called. The content must be converted 5012** to UTF-16.</li> 5013** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5014** sqlite3_column_text() is called. The content must be converted 5015** to UTF-8.</li> 5016** </ul> 5017** 5018** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5019** not invalidate a prior pointer, though of course the content of the buffer 5020** that the prior pointer references will have been modified. Other kinds 5021** of conversion are done in place when it is possible, but sometimes they 5022** are not possible and in those cases prior pointers are invalidated. 5023** 5024** The safest policy is to invoke these routines 5025** in one of the following ways: 5026** 5027** <ul> 5028** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5029** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5030** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5031** </ul> 5032** 5033** In other words, you should call sqlite3_column_text(), 5034** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5035** into the desired format, then invoke sqlite3_column_bytes() or 5036** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5037** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5038** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5039** with calls to sqlite3_column_bytes(). 5040** 5041** ^The pointers returned are valid until a type conversion occurs as 5042** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5043** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5044** and BLOBs is freed automatically. Do not pass the pointers returned 5045** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5046** [sqlite3_free()]. 5047** 5048** As long as the input parameters are correct, these routines will only 5049** fail if an out-of-memory error occurs during a format conversion. 5050** Only the following subset of interfaces are subject to out-of-memory 5051** errors: 5052** 5053** <ul> 5054** <li> sqlite3_column_blob() 5055** <li> sqlite3_column_text() 5056** <li> sqlite3_column_text16() 5057** <li> sqlite3_column_bytes() 5058** <li> sqlite3_column_bytes16() 5059** </ul> 5060** 5061** If an out-of-memory error occurs, then the return value from these 5062** routines is the same as if the column had contained an SQL NULL value. 5063** Valid SQL NULL returns can be distinguished from out-of-memory errors 5064** by invoking the [sqlite3_errcode()] immediately after the suspect 5065** return value is obtained and before any 5066** other SQLite interface is called on the same [database connection]. 5067*/ 5068const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5069double sqlite3_column_double(sqlite3_stmt*, int iCol); 5070int sqlite3_column_int(sqlite3_stmt*, int iCol); 5071sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5072const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5073const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5074sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5075int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5076int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5077int sqlite3_column_type(sqlite3_stmt*, int iCol); 5078 5079/* 5080** CAPI3REF: Destroy A Prepared Statement Object 5081** DESTRUCTOR: sqlite3_stmt 5082** 5083** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5084** ^If the most recent evaluation of the statement encountered no errors 5085** or if the statement is never been evaluated, then sqlite3_finalize() returns 5086** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5087** sqlite3_finalize(S) returns the appropriate [error code] or 5088** [extended error code]. 5089** 5090** ^The sqlite3_finalize(S) routine can be called at any point during 5091** the life cycle of [prepared statement] S: 5092** before statement S is ever evaluated, after 5093** one or more calls to [sqlite3_reset()], or after any call 5094** to [sqlite3_step()] regardless of whether or not the statement has 5095** completed execution. 5096** 5097** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5098** 5099** The application must finalize every [prepared statement] in order to avoid 5100** resource leaks. It is a grievous error for the application to try to use 5101** a prepared statement after it has been finalized. Any use of a prepared 5102** statement after it has been finalized can result in undefined and 5103** undesirable behavior such as segfaults and heap corruption. 5104*/ 5105int sqlite3_finalize(sqlite3_stmt *pStmt); 5106 5107/* 5108** CAPI3REF: Reset A Prepared Statement Object 5109** METHOD: sqlite3_stmt 5110** 5111** The sqlite3_reset() function is called to reset a [prepared statement] 5112** object back to its initial state, ready to be re-executed. 5113** ^Any SQL statement variables that had values bound to them using 5114** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5115** Use [sqlite3_clear_bindings()] to reset the bindings. 5116** 5117** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5118** back to the beginning of its program. 5119** 5120** ^If the most recent call to [sqlite3_step(S)] for the 5121** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5122** or if [sqlite3_step(S)] has never before been called on S, 5123** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5124** 5125** ^If the most recent call to [sqlite3_step(S)] for the 5126** [prepared statement] S indicated an error, then 5127** [sqlite3_reset(S)] returns an appropriate [error code]. 5128** 5129** ^The [sqlite3_reset(S)] interface does not change the values 5130** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5131*/ 5132int sqlite3_reset(sqlite3_stmt *pStmt); 5133 5134/* 5135** CAPI3REF: Create Or Redefine SQL Functions 5136** KEYWORDS: {function creation routines} 5137** METHOD: sqlite3 5138** 5139** ^These functions (collectively known as "function creation routines") 5140** are used to add SQL functions or aggregates or to redefine the behavior 5141** of existing SQL functions or aggregates. The only differences between 5142** the three "sqlite3_create_function*" routines are the text encoding 5143** expected for the second parameter (the name of the function being 5144** created) and the presence or absence of a destructor callback for 5145** the application data pointer. Function sqlite3_create_window_function() 5146** is similar, but allows the user to supply the extra callback functions 5147** needed by [aggregate window functions]. 5148** 5149** ^The first parameter is the [database connection] to which the SQL 5150** function is to be added. ^If an application uses more than one database 5151** connection then application-defined SQL functions must be added 5152** to each database connection separately. 5153** 5154** ^The second parameter is the name of the SQL function to be created or 5155** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5156** representation, exclusive of the zero-terminator. ^Note that the name 5157** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5158** ^Any attempt to create a function with a longer name 5159** will result in [SQLITE_MISUSE] being returned. 5160** 5161** ^The third parameter (nArg) 5162** is the number of arguments that the SQL function or 5163** aggregate takes. ^If this parameter is -1, then the SQL function or 5164** aggregate may take any number of arguments between 0 and the limit 5165** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5166** parameter is less than -1 or greater than 127 then the behavior is 5167** undefined. 5168** 5169** ^The fourth parameter, eTextRep, specifies what 5170** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5171** its parameters. The application should set this parameter to 5172** [SQLITE_UTF16LE] if the function implementation invokes 5173** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5174** implementation invokes [sqlite3_value_text16be()] on an input, or 5175** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5176** otherwise. ^The same SQL function may be registered multiple times using 5177** different preferred text encodings, with different implementations for 5178** each encoding. 5179** ^When multiple implementations of the same function are available, SQLite 5180** will pick the one that involves the least amount of data conversion. 5181** 5182** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5183** to signal that the function will always return the same result given 5184** the same inputs within a single SQL statement. Most SQL functions are 5185** deterministic. The built-in [random()] SQL function is an example of a 5186** function that is not deterministic. The SQLite query planner is able to 5187** perform additional optimizations on deterministic functions, so use 5188** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5189** 5190** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5191** flag, which if present prevents the function from being invoked from 5192** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5193** index expressions, or the WHERE clause of partial indexes. 5194** 5195** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5196** all application-defined SQL functions that do not need to be 5197** used inside of triggers, view, CHECK constraints, or other elements of 5198** the database schema. This flags is especially recommended for SQL 5199** functions that have side effects or reveal internal application state. 5200** Without this flag, an attacker might be able to modify the schema of 5201** a database file to include invocations of the function with parameters 5202** chosen by the attacker, which the application will then execute when 5203** the database file is opened and read. 5204** 5205** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5206** function can gain access to this pointer using [sqlite3_user_data()].)^ 5207** 5208** ^The sixth, seventh and eighth parameters passed to the three 5209** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5210** pointers to C-language functions that implement the SQL function or 5211** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5212** callback only; NULL pointers must be passed as the xStep and xFinal 5213** parameters. ^An aggregate SQL function requires an implementation of xStep 5214** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5215** SQL function or aggregate, pass NULL pointers for all three function 5216** callbacks. 5217** 5218** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5219** and xInverse) passed to sqlite3_create_window_function are pointers to 5220** C-language callbacks that implement the new function. xStep and xFinal 5221** must both be non-NULL. xValue and xInverse may either both be NULL, in 5222** which case a regular aggregate function is created, or must both be 5223** non-NULL, in which case the new function may be used as either an aggregate 5224** or aggregate window function. More details regarding the implementation 5225** of aggregate window functions are 5226** [user-defined window functions|available here]. 5227** 5228** ^(If the final parameter to sqlite3_create_function_v2() or 5229** sqlite3_create_window_function() is not NULL, then it is destructor for 5230** the application data pointer. The destructor is invoked when the function 5231** is deleted, either by being overloaded or when the database connection 5232** closes.)^ ^The destructor is also invoked if the call to 5233** sqlite3_create_function_v2() fails. ^When the destructor callback is 5234** invoked, it is passed a single argument which is a copy of the application 5235** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5236** 5237** ^It is permitted to register multiple implementations of the same 5238** functions with the same name but with either differing numbers of 5239** arguments or differing preferred text encodings. ^SQLite will use 5240** the implementation that most closely matches the way in which the 5241** SQL function is used. ^A function implementation with a non-negative 5242** nArg parameter is a better match than a function implementation with 5243** a negative nArg. ^A function where the preferred text encoding 5244** matches the database encoding is a better 5245** match than a function where the encoding is different. 5246** ^A function where the encoding difference is between UTF16le and UTF16be 5247** is a closer match than a function where the encoding difference is 5248** between UTF8 and UTF16. 5249** 5250** ^Built-in functions may be overloaded by new application-defined functions. 5251** 5252** ^An application-defined function is permitted to call other 5253** SQLite interfaces. However, such calls must not 5254** close the database connection nor finalize or reset the prepared 5255** statement in which the function is running. 5256*/ 5257int sqlite3_create_function( 5258 sqlite3 *db, 5259 const char *zFunctionName, 5260 int nArg, 5261 int eTextRep, 5262 void *pApp, 5263 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5264 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5265 void (*xFinal)(sqlite3_context*) 5266); 5267int sqlite3_create_function16( 5268 sqlite3 *db, 5269 const void *zFunctionName, 5270 int nArg, 5271 int eTextRep, 5272 void *pApp, 5273 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5274 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5275 void (*xFinal)(sqlite3_context*) 5276); 5277int sqlite3_create_function_v2( 5278 sqlite3 *db, 5279 const char *zFunctionName, 5280 int nArg, 5281 int eTextRep, 5282 void *pApp, 5283 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5284 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5285 void (*xFinal)(sqlite3_context*), 5286 void(*xDestroy)(void*) 5287); 5288int sqlite3_create_window_function( 5289 sqlite3 *db, 5290 const char *zFunctionName, 5291 int nArg, 5292 int eTextRep, 5293 void *pApp, 5294 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5295 void (*xFinal)(sqlite3_context*), 5296 void (*xValue)(sqlite3_context*), 5297 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5298 void(*xDestroy)(void*) 5299); 5300 5301/* 5302** CAPI3REF: Text Encodings 5303** 5304** These constant define integer codes that represent the various 5305** text encodings supported by SQLite. 5306*/ 5307#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5308#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5309#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5310#define SQLITE_UTF16 4 /* Use native byte order */ 5311#define SQLITE_ANY 5 /* Deprecated */ 5312#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5313 5314/* 5315** CAPI3REF: Function Flags 5316** 5317** These constants may be ORed together with the 5318** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5319** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5320** [sqlite3_create_function_v2()]. 5321** 5322** <dl> 5323** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5324** The SQLITE_DETERMINISTIC flag means that the new function always gives 5325** the same output when the input parameters are the same. 5326** The [abs|abs() function] is deterministic, for example, but 5327** [randomblob|randomblob()] is not. Functions must 5328** be deterministic in order to be used in certain contexts such as 5329** with the WHERE clause of [partial indexes] or in [generated columns]. 5330** SQLite might also optimize deterministic functions by factoring them 5331** out of inner loops. 5332** </dd> 5333** 5334** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5335** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5336** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5337** schema structures such as [CHECK constraints], [DEFAULT clauses], 5338** [expression indexes], [partial indexes], or [generated columns]. 5339** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5340** for all [application-defined SQL functions], and especially for functions 5341** that have side-effects or that could potentially leak sensitive 5342** information. 5343** </dd> 5344** 5345** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5346** The SQLITE_INNOCUOUS flag means that the function is unlikely 5347** to cause problems even if misused. An innocuous function should have 5348** no side effects and should not depend on any values other than its 5349** input parameters. The [abs|abs() function] is an example of an 5350** innocuous function. 5351** The [load_extension() SQL function] is not innocuous because of its 5352** side effects. 5353** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5354** exactly the same. The [random|random() function] is an example of a 5355** function that is innocuous but not deterministic. 5356** <p>Some heightened security settings 5357** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5358** disable the use of SQL functions inside views and triggers and in 5359** schema structures such as [CHECK constraints], [DEFAULT clauses], 5360** [expression indexes], [partial indexes], and [generated columns] unless 5361** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5362** are innocuous. Developers are advised to avoid using the 5363** SQLITE_INNOCUOUS flag for application-defined functions unless the 5364** function has been carefully audited and found to be free of potentially 5365** security-adverse side-effects and information-leaks. 5366** </dd> 5367** 5368** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5369** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5370** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5371** Specifying this flag makes no difference for scalar or aggregate user 5372** functions. However, if it is not specified for a user-defined window 5373** function, then any sub-types belonging to arguments passed to the window 5374** function may be discarded before the window function is called (i.e. 5375** sqlite3_value_subtype() will always return 0). 5376** </dd> 5377** </dl> 5378*/ 5379#define SQLITE_DETERMINISTIC 0x000000800 5380#define SQLITE_DIRECTONLY 0x000080000 5381#define SQLITE_SUBTYPE 0x000100000 5382#define SQLITE_INNOCUOUS 0x000200000 5383 5384/* 5385** CAPI3REF: Deprecated Functions 5386** DEPRECATED 5387** 5388** These functions are [deprecated]. In order to maintain 5389** backwards compatibility with older code, these functions continue 5390** to be supported. However, new applications should avoid 5391** the use of these functions. To encourage programmers to avoid 5392** these functions, we will not explain what they do. 5393*/ 5394#ifndef SQLITE_OMIT_DEPRECATED 5395SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5396SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5397SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5398SQLITE_DEPRECATED int sqlite3_global_recover(void); 5399SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5400SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5401 void*,sqlite3_int64); 5402#endif 5403 5404/* 5405** CAPI3REF: Obtaining SQL Values 5406** METHOD: sqlite3_value 5407** 5408** <b>Summary:</b> 5409** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5410** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5411** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5412** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5413** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5414** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5415** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5416** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5417** the native byteorder 5418** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5419** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5420** <tr><td> <td> <td> 5421** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5422** or a UTF-8 TEXT in bytes 5423** <tr><td><b>sqlite3_value_bytes16 </b> 5424** <td>→ <td>Size of UTF-16 5425** TEXT in bytes 5426** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5427** datatype of the value 5428** <tr><td><b>sqlite3_value_numeric_type </b> 5429** <td>→ <td>Best numeric datatype of the value 5430** <tr><td><b>sqlite3_value_nochange </b> 5431** <td>→ <td>True if the column is unchanged in an UPDATE 5432** against a virtual table. 5433** <tr><td><b>sqlite3_value_frombind </b> 5434** <td>→ <td>True if value originated from a [bound parameter] 5435** </table></blockquote> 5436** 5437** <b>Details:</b> 5438** 5439** These routines extract type, size, and content information from 5440** [protected sqlite3_value] objects. Protected sqlite3_value objects 5441** are used to pass parameter information into the functions that 5442** implement [application-defined SQL functions] and [virtual tables]. 5443** 5444** These routines work only with [protected sqlite3_value] objects. 5445** Any attempt to use these routines on an [unprotected sqlite3_value] 5446** is not threadsafe. 5447** 5448** ^These routines work just like the corresponding [column access functions] 5449** except that these routines take a single [protected sqlite3_value] object 5450** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5451** 5452** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5453** in the native byte-order of the host machine. ^The 5454** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5455** extract UTF-16 strings as big-endian and little-endian respectively. 5456** 5457** ^If [sqlite3_value] object V was initialized 5458** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5459** and if X and Y are strings that compare equal according to strcmp(X,Y), 5460** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5461** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5462** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5463** 5464** ^(The sqlite3_value_type(V) interface returns the 5465** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5466** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5467** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5468** Other interfaces might change the datatype for an sqlite3_value object. 5469** For example, if the datatype is initially SQLITE_INTEGER and 5470** sqlite3_value_text(V) is called to extract a text value for that 5471** integer, then subsequent calls to sqlite3_value_type(V) might return 5472** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5473** occurs is undefined and may change from one release of SQLite to the next. 5474** 5475** ^(The sqlite3_value_numeric_type() interface attempts to apply 5476** numeric affinity to the value. This means that an attempt is 5477** made to convert the value to an integer or floating point. If 5478** such a conversion is possible without loss of information (in other 5479** words, if the value is a string that looks like a number) 5480** then the conversion is performed. Otherwise no conversion occurs. 5481** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5482** 5483** ^Within the [xUpdate] method of a [virtual table], the 5484** sqlite3_value_nochange(X) interface returns true if and only if 5485** the column corresponding to X is unchanged by the UPDATE operation 5486** that the xUpdate method call was invoked to implement and if 5487** and the prior [xColumn] method call that was invoked to extracted 5488** the value for that column returned without setting a result (probably 5489** because it queried [sqlite3_vtab_nochange()] and found that the column 5490** was unchanging). ^Within an [xUpdate] method, any value for which 5491** sqlite3_value_nochange(X) is true will in all other respects appear 5492** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5493** than within an [xUpdate] method call for an UPDATE statement, then 5494** the return value is arbitrary and meaningless. 5495** 5496** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5497** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5498** interfaces. ^If X comes from an SQL literal value, or a table column, 5499** or an expression, then sqlite3_value_frombind(X) returns zero. 5500** 5501** Please pay particular attention to the fact that the pointer returned 5502** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5503** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5504** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5505** or [sqlite3_value_text16()]. 5506** 5507** These routines must be called from the same thread as 5508** the SQL function that supplied the [sqlite3_value*] parameters. 5509** 5510** As long as the input parameter is correct, these routines can only 5511** fail if an out-of-memory error occurs during a format conversion. 5512** Only the following subset of interfaces are subject to out-of-memory 5513** errors: 5514** 5515** <ul> 5516** <li> sqlite3_value_blob() 5517** <li> sqlite3_value_text() 5518** <li> sqlite3_value_text16() 5519** <li> sqlite3_value_text16le() 5520** <li> sqlite3_value_text16be() 5521** <li> sqlite3_value_bytes() 5522** <li> sqlite3_value_bytes16() 5523** </ul> 5524** 5525** If an out-of-memory error occurs, then the return value from these 5526** routines is the same as if the column had contained an SQL NULL value. 5527** Valid SQL NULL returns can be distinguished from out-of-memory errors 5528** by invoking the [sqlite3_errcode()] immediately after the suspect 5529** return value is obtained and before any 5530** other SQLite interface is called on the same [database connection]. 5531*/ 5532const void *sqlite3_value_blob(sqlite3_value*); 5533double sqlite3_value_double(sqlite3_value*); 5534int sqlite3_value_int(sqlite3_value*); 5535sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5536void *sqlite3_value_pointer(sqlite3_value*, const char*); 5537const unsigned char *sqlite3_value_text(sqlite3_value*); 5538const void *sqlite3_value_text16(sqlite3_value*); 5539const void *sqlite3_value_text16le(sqlite3_value*); 5540const void *sqlite3_value_text16be(sqlite3_value*); 5541int sqlite3_value_bytes(sqlite3_value*); 5542int sqlite3_value_bytes16(sqlite3_value*); 5543int sqlite3_value_type(sqlite3_value*); 5544int sqlite3_value_numeric_type(sqlite3_value*); 5545int sqlite3_value_nochange(sqlite3_value*); 5546int sqlite3_value_frombind(sqlite3_value*); 5547 5548/* 5549** CAPI3REF: Finding The Subtype Of SQL Values 5550** METHOD: sqlite3_value 5551** 5552** The sqlite3_value_subtype(V) function returns the subtype for 5553** an [application-defined SQL function] argument V. The subtype 5554** information can be used to pass a limited amount of context from 5555** one SQL function to another. Use the [sqlite3_result_subtype()] 5556** routine to set the subtype for the return value of an SQL function. 5557*/ 5558unsigned int sqlite3_value_subtype(sqlite3_value*); 5559 5560/* 5561** CAPI3REF: Copy And Free SQL Values 5562** METHOD: sqlite3_value 5563** 5564** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5565** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5566** is a [protected sqlite3_value] object even if the input is not. 5567** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5568** memory allocation fails. 5569** 5570** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5571** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5572** then sqlite3_value_free(V) is a harmless no-op. 5573*/ 5574sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5575void sqlite3_value_free(sqlite3_value*); 5576 5577/* 5578** CAPI3REF: Obtain Aggregate Function Context 5579** METHOD: sqlite3_context 5580** 5581** Implementations of aggregate SQL functions use this 5582** routine to allocate memory for storing their state. 5583** 5584** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5585** for a particular aggregate function, SQLite allocates 5586** N bytes of memory, zeroes out that memory, and returns a pointer 5587** to the new memory. ^On second and subsequent calls to 5588** sqlite3_aggregate_context() for the same aggregate function instance, 5589** the same buffer is returned. Sqlite3_aggregate_context() is normally 5590** called once for each invocation of the xStep callback and then one 5591** last time when the xFinal callback is invoked. ^(When no rows match 5592** an aggregate query, the xStep() callback of the aggregate function 5593** implementation is never called and xFinal() is called exactly once. 5594** In those cases, sqlite3_aggregate_context() might be called for the 5595** first time from within xFinal().)^ 5596** 5597** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5598** when first called if N is less than or equal to zero or if a memory 5599** allocate error occurs. 5600** 5601** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5602** determined by the N parameter on first successful call. Changing the 5603** value of N in any subsequent call to sqlite3_aggregate_context() within 5604** the same aggregate function instance will not resize the memory 5605** allocation.)^ Within the xFinal callback, it is customary to set 5606** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5607** pointless memory allocations occur. 5608** 5609** ^SQLite automatically frees the memory allocated by 5610** sqlite3_aggregate_context() when the aggregate query concludes. 5611** 5612** The first parameter must be a copy of the 5613** [sqlite3_context | SQL function context] that is the first parameter 5614** to the xStep or xFinal callback routine that implements the aggregate 5615** function. 5616** 5617** This routine must be called from the same thread in which 5618** the aggregate SQL function is running. 5619*/ 5620void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5621 5622/* 5623** CAPI3REF: User Data For Functions 5624** METHOD: sqlite3_context 5625** 5626** ^The sqlite3_user_data() interface returns a copy of 5627** the pointer that was the pUserData parameter (the 5th parameter) 5628** of the [sqlite3_create_function()] 5629** and [sqlite3_create_function16()] routines that originally 5630** registered the application defined function. 5631** 5632** This routine must be called from the same thread in which 5633** the application-defined function is running. 5634*/ 5635void *sqlite3_user_data(sqlite3_context*); 5636 5637/* 5638** CAPI3REF: Database Connection For Functions 5639** METHOD: sqlite3_context 5640** 5641** ^The sqlite3_context_db_handle() interface returns a copy of 5642** the pointer to the [database connection] (the 1st parameter) 5643** of the [sqlite3_create_function()] 5644** and [sqlite3_create_function16()] routines that originally 5645** registered the application defined function. 5646*/ 5647sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5648 5649/* 5650** CAPI3REF: Function Auxiliary Data 5651** METHOD: sqlite3_context 5652** 5653** These functions may be used by (non-aggregate) SQL functions to 5654** associate metadata with argument values. If the same value is passed to 5655** multiple invocations of the same SQL function during query execution, under 5656** some circumstances the associated metadata may be preserved. An example 5657** of where this might be useful is in a regular-expression matching 5658** function. The compiled version of the regular expression can be stored as 5659** metadata associated with the pattern string. 5660** Then as long as the pattern string remains the same, 5661** the compiled regular expression can be reused on multiple 5662** invocations of the same function. 5663** 5664** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5665** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5666** value to the application-defined function. ^N is zero for the left-most 5667** function argument. ^If there is no metadata 5668** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5669** returns a NULL pointer. 5670** 5671** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5672** argument of the application-defined function. ^Subsequent 5673** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5674** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5675** NULL if the metadata has been discarded. 5676** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5677** SQLite will invoke the destructor function X with parameter P exactly 5678** once, when the metadata is discarded. 5679** SQLite is free to discard the metadata at any time, including: <ul> 5680** <li> ^(when the corresponding function parameter changes)^, or 5681** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5682** SQL statement)^, or 5683** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5684** parameter)^, or 5685** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5686** allocation error occurs.)^ </ul> 5687** 5688** Note the last bullet in particular. The destructor X in 5689** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5690** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5691** should be called near the end of the function implementation and the 5692** function implementation should not make any use of P after 5693** sqlite3_set_auxdata() has been called. 5694** 5695** ^(In practice, metadata is preserved between function calls for 5696** function parameters that are compile-time constants, including literal 5697** values and [parameters] and expressions composed from the same.)^ 5698** 5699** The value of the N parameter to these interfaces should be non-negative. 5700** Future enhancements may make use of negative N values to define new 5701** kinds of function caching behavior. 5702** 5703** These routines must be called from the same thread in which 5704** the SQL function is running. 5705*/ 5706void *sqlite3_get_auxdata(sqlite3_context*, int N); 5707void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5708 5709 5710/* 5711** CAPI3REF: Constants Defining Special Destructor Behavior 5712** 5713** These are special values for the destructor that is passed in as the 5714** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5715** argument is SQLITE_STATIC, it means that the content pointer is constant 5716** and will never change. It does not need to be destroyed. ^The 5717** SQLITE_TRANSIENT value means that the content will likely change in 5718** the near future and that SQLite should make its own private copy of 5719** the content before returning. 5720** 5721** The typedef is necessary to work around problems in certain 5722** C++ compilers. 5723*/ 5724typedef void (*sqlite3_destructor_type)(void*); 5725#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5726#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5727 5728/* 5729** CAPI3REF: Setting The Result Of An SQL Function 5730** METHOD: sqlite3_context 5731** 5732** These routines are used by the xFunc or xFinal callbacks that 5733** implement SQL functions and aggregates. See 5734** [sqlite3_create_function()] and [sqlite3_create_function16()] 5735** for additional information. 5736** 5737** These functions work very much like the [parameter binding] family of 5738** functions used to bind values to host parameters in prepared statements. 5739** Refer to the [SQL parameter] documentation for additional information. 5740** 5741** ^The sqlite3_result_blob() interface sets the result from 5742** an application-defined function to be the BLOB whose content is pointed 5743** to by the second parameter and which is N bytes long where N is the 5744** third parameter. 5745** 5746** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5747** interfaces set the result of the application-defined function to be 5748** a BLOB containing all zero bytes and N bytes in size. 5749** 5750** ^The sqlite3_result_double() interface sets the result from 5751** an application-defined function to be a floating point value specified 5752** by its 2nd argument. 5753** 5754** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5755** cause the implemented SQL function to throw an exception. 5756** ^SQLite uses the string pointed to by the 5757** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5758** as the text of an error message. ^SQLite interprets the error 5759** message string from sqlite3_result_error() as UTF-8. ^SQLite 5760** interprets the string from sqlite3_result_error16() as UTF-16 using 5761** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5762** ^If the third parameter to sqlite3_result_error() 5763** or sqlite3_result_error16() is negative then SQLite takes as the error 5764** message all text up through the first zero character. 5765** ^If the third parameter to sqlite3_result_error() or 5766** sqlite3_result_error16() is non-negative then SQLite takes that many 5767** bytes (not characters) from the 2nd parameter as the error message. 5768** ^The sqlite3_result_error() and sqlite3_result_error16() 5769** routines make a private copy of the error message text before 5770** they return. Hence, the calling function can deallocate or 5771** modify the text after they return without harm. 5772** ^The sqlite3_result_error_code() function changes the error code 5773** returned by SQLite as a result of an error in a function. ^By default, 5774** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5775** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5776** 5777** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5778** error indicating that a string or BLOB is too long to represent. 5779** 5780** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5781** error indicating that a memory allocation failed. 5782** 5783** ^The sqlite3_result_int() interface sets the return value 5784** of the application-defined function to be the 32-bit signed integer 5785** value given in the 2nd argument. 5786** ^The sqlite3_result_int64() interface sets the return value 5787** of the application-defined function to be the 64-bit signed integer 5788** value given in the 2nd argument. 5789** 5790** ^The sqlite3_result_null() interface sets the return value 5791** of the application-defined function to be NULL. 5792** 5793** ^The sqlite3_result_text(), sqlite3_result_text16(), 5794** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5795** set the return value of the application-defined function to be 5796** a text string which is represented as UTF-8, UTF-16 native byte order, 5797** UTF-16 little endian, or UTF-16 big endian, respectively. 5798** ^The sqlite3_result_text64() interface sets the return value of an 5799** application-defined function to be a text string in an encoding 5800** specified by the fifth (and last) parameter, which must be one 5801** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5802** ^SQLite takes the text result from the application from 5803** the 2nd parameter of the sqlite3_result_text* interfaces. 5804** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5805** is negative, then SQLite takes result text from the 2nd parameter 5806** through the first zero character. 5807** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5808** is non-negative, then as many bytes (not characters) of the text 5809** pointed to by the 2nd parameter are taken as the application-defined 5810** function result. If the 3rd parameter is non-negative, then it 5811** must be the byte offset into the string where the NUL terminator would 5812** appear if the string where NUL terminated. If any NUL characters occur 5813** in the string at a byte offset that is less than the value of the 3rd 5814** parameter, then the resulting string will contain embedded NULs and the 5815** result of expressions operating on strings with embedded NULs is undefined. 5816** ^If the 4th parameter to the sqlite3_result_text* interfaces 5817** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5818** function as the destructor on the text or BLOB result when it has 5819** finished using that result. 5820** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5821** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5822** assumes that the text or BLOB result is in constant space and does not 5823** copy the content of the parameter nor call a destructor on the content 5824** when it has finished using that result. 5825** ^If the 4th parameter to the sqlite3_result_text* interfaces 5826** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5827** then SQLite makes a copy of the result into space obtained 5828** from [sqlite3_malloc()] before it returns. 5829** 5830** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5831** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5832** when the encoding is not UTF8, if the input UTF16 begins with a 5833** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5834** string and the rest of the string is interpreted according to the 5835** byte-order specified by the BOM. ^The byte-order specified by 5836** the BOM at the beginning of the text overrides the byte-order 5837** specified by the interface procedure. ^So, for example, if 5838** sqlite3_result_text16le() is invoked with text that begins 5839** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5840** first two bytes of input are skipped and the remaining input 5841** is interpreted as UTF16BE text. 5842** 5843** ^For UTF16 input text to the sqlite3_result_text16(), 5844** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5845** sqlite3_result_text64() routines, if the text contains invalid 5846** UTF16 characters, the invalid characters might be converted 5847** into the unicode replacement character, U+FFFD. 5848** 5849** ^The sqlite3_result_value() interface sets the result of 5850** the application-defined function to be a copy of the 5851** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5852** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5853** so that the [sqlite3_value] specified in the parameter may change or 5854** be deallocated after sqlite3_result_value() returns without harm. 5855** ^A [protected sqlite3_value] object may always be used where an 5856** [unprotected sqlite3_value] object is required, so either 5857** kind of [sqlite3_value] object can be used with this interface. 5858** 5859** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5860** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5861** also associates the host-language pointer P or type T with that 5862** NULL value such that the pointer can be retrieved within an 5863** [application-defined SQL function] using [sqlite3_value_pointer()]. 5864** ^If the D parameter is not NULL, then it is a pointer to a destructor 5865** for the P parameter. ^SQLite invokes D with P as its only argument 5866** when SQLite is finished with P. The T parameter should be a static 5867** string and preferably a string literal. The sqlite3_result_pointer() 5868** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5869** 5870** If these routines are called from within the different thread 5871** than the one containing the application-defined function that received 5872** the [sqlite3_context] pointer, the results are undefined. 5873*/ 5874void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5875void sqlite3_result_blob64(sqlite3_context*,const void*, 5876 sqlite3_uint64,void(*)(void*)); 5877void sqlite3_result_double(sqlite3_context*, double); 5878void sqlite3_result_error(sqlite3_context*, const char*, int); 5879void sqlite3_result_error16(sqlite3_context*, const void*, int); 5880void sqlite3_result_error_toobig(sqlite3_context*); 5881void sqlite3_result_error_nomem(sqlite3_context*); 5882void sqlite3_result_error_code(sqlite3_context*, int); 5883void sqlite3_result_int(sqlite3_context*, int); 5884void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5885void sqlite3_result_null(sqlite3_context*); 5886void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5887void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5888 void(*)(void*), unsigned char encoding); 5889void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5890void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5891void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5892void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5893void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5894void sqlite3_result_zeroblob(sqlite3_context*, int n); 5895int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5896 5897 5898/* 5899** CAPI3REF: Setting The Subtype Of An SQL Function 5900** METHOD: sqlite3_context 5901** 5902** The sqlite3_result_subtype(C,T) function causes the subtype of 5903** the result from the [application-defined SQL function] with 5904** [sqlite3_context] C to be the value T. Only the lower 8 bits 5905** of the subtype T are preserved in current versions of SQLite; 5906** higher order bits are discarded. 5907** The number of subtype bytes preserved by SQLite might increase 5908** in future releases of SQLite. 5909*/ 5910void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5911 5912/* 5913** CAPI3REF: Define New Collating Sequences 5914** METHOD: sqlite3 5915** 5916** ^These functions add, remove, or modify a [collation] associated 5917** with the [database connection] specified as the first argument. 5918** 5919** ^The name of the collation is a UTF-8 string 5920** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5921** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5922** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5923** considered to be the same name. 5924** 5925** ^(The third argument (eTextRep) must be one of the constants: 5926** <ul> 5927** <li> [SQLITE_UTF8], 5928** <li> [SQLITE_UTF16LE], 5929** <li> [SQLITE_UTF16BE], 5930** <li> [SQLITE_UTF16], or 5931** <li> [SQLITE_UTF16_ALIGNED]. 5932** </ul>)^ 5933** ^The eTextRep argument determines the encoding of strings passed 5934** to the collating function callback, xCompare. 5935** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5936** force strings to be UTF16 with native byte order. 5937** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5938** on an even byte address. 5939** 5940** ^The fourth argument, pArg, is an application data pointer that is passed 5941** through as the first argument to the collating function callback. 5942** 5943** ^The fifth argument, xCompare, is a pointer to the collating function. 5944** ^Multiple collating functions can be registered using the same name but 5945** with different eTextRep parameters and SQLite will use whichever 5946** function requires the least amount of data transformation. 5947** ^If the xCompare argument is NULL then the collating function is 5948** deleted. ^When all collating functions having the same name are deleted, 5949** that collation is no longer usable. 5950** 5951** ^The collating function callback is invoked with a copy of the pArg 5952** application data pointer and with two strings in the encoding specified 5953** by the eTextRep argument. The two integer parameters to the collating 5954** function callback are the length of the two strings, in bytes. The collating 5955** function must return an integer that is negative, zero, or positive 5956** if the first string is less than, equal to, or greater than the second, 5957** respectively. A collating function must always return the same answer 5958** given the same inputs. If two or more collating functions are registered 5959** to the same collation name (using different eTextRep values) then all 5960** must give an equivalent answer when invoked with equivalent strings. 5961** The collating function must obey the following properties for all 5962** strings A, B, and C: 5963** 5964** <ol> 5965** <li> If A==B then B==A. 5966** <li> If A==B and B==C then A==C. 5967** <li> If A<B THEN B>A. 5968** <li> If A<B and B<C then A<C. 5969** </ol> 5970** 5971** If a collating function fails any of the above constraints and that 5972** collating function is registered and used, then the behavior of SQLite 5973** is undefined. 5974** 5975** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5976** with the addition that the xDestroy callback is invoked on pArg when 5977** the collating function is deleted. 5978** ^Collating functions are deleted when they are overridden by later 5979** calls to the collation creation functions or when the 5980** [database connection] is closed using [sqlite3_close()]. 5981** 5982** ^The xDestroy callback is <u>not</u> called if the 5983** sqlite3_create_collation_v2() function fails. Applications that invoke 5984** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5985** check the return code and dispose of the application data pointer 5986** themselves rather than expecting SQLite to deal with it for them. 5987** This is different from every other SQLite interface. The inconsistency 5988** is unfortunate but cannot be changed without breaking backwards 5989** compatibility. 5990** 5991** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5992*/ 5993int sqlite3_create_collation( 5994 sqlite3*, 5995 const char *zName, 5996 int eTextRep, 5997 void *pArg, 5998 int(*xCompare)(void*,int,const void*,int,const void*) 5999); 6000int sqlite3_create_collation_v2( 6001 sqlite3*, 6002 const char *zName, 6003 int eTextRep, 6004 void *pArg, 6005 int(*xCompare)(void*,int,const void*,int,const void*), 6006 void(*xDestroy)(void*) 6007); 6008int sqlite3_create_collation16( 6009 sqlite3*, 6010 const void *zName, 6011 int eTextRep, 6012 void *pArg, 6013 int(*xCompare)(void*,int,const void*,int,const void*) 6014); 6015 6016/* 6017** CAPI3REF: Collation Needed Callbacks 6018** METHOD: sqlite3 6019** 6020** ^To avoid having to register all collation sequences before a database 6021** can be used, a single callback function may be registered with the 6022** [database connection] to be invoked whenever an undefined collation 6023** sequence is required. 6024** 6025** ^If the function is registered using the sqlite3_collation_needed() API, 6026** then it is passed the names of undefined collation sequences as strings 6027** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6028** the names are passed as UTF-16 in machine native byte order. 6029** ^A call to either function replaces the existing collation-needed callback. 6030** 6031** ^(When the callback is invoked, the first argument passed is a copy 6032** of the second argument to sqlite3_collation_needed() or 6033** sqlite3_collation_needed16(). The second argument is the database 6034** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6035** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6036** sequence function required. The fourth parameter is the name of the 6037** required collation sequence.)^ 6038** 6039** The callback function should register the desired collation using 6040** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6041** [sqlite3_create_collation_v2()]. 6042*/ 6043int sqlite3_collation_needed( 6044 sqlite3*, 6045 void*, 6046 void(*)(void*,sqlite3*,int eTextRep,const char*) 6047); 6048int sqlite3_collation_needed16( 6049 sqlite3*, 6050 void*, 6051 void(*)(void*,sqlite3*,int eTextRep,const void*) 6052); 6053 6054#ifdef SQLITE_ENABLE_CEROD 6055/* 6056** Specify the activation key for a CEROD database. Unless 6057** activated, none of the CEROD routines will work. 6058*/ 6059void sqlite3_activate_cerod( 6060 const char *zPassPhrase /* Activation phrase */ 6061); 6062#endif 6063 6064/* 6065** CAPI3REF: Suspend Execution For A Short Time 6066** 6067** The sqlite3_sleep() function causes the current thread to suspend execution 6068** for at least a number of milliseconds specified in its parameter. 6069** 6070** If the operating system does not support sleep requests with 6071** millisecond time resolution, then the time will be rounded up to 6072** the nearest second. The number of milliseconds of sleep actually 6073** requested from the operating system is returned. 6074** 6075** ^SQLite implements this interface by calling the xSleep() 6076** method of the default [sqlite3_vfs] object. If the xSleep() method 6077** of the default VFS is not implemented correctly, or not implemented at 6078** all, then the behavior of sqlite3_sleep() may deviate from the description 6079** in the previous paragraphs. 6080*/ 6081int sqlite3_sleep(int); 6082 6083/* 6084** CAPI3REF: Name Of The Folder Holding Temporary Files 6085** 6086** ^(If this global variable is made to point to a string which is 6087** the name of a folder (a.k.a. directory), then all temporary files 6088** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6089** will be placed in that directory.)^ ^If this variable 6090** is a NULL pointer, then SQLite performs a search for an appropriate 6091** temporary file directory. 6092** 6093** Applications are strongly discouraged from using this global variable. 6094** It is required to set a temporary folder on Windows Runtime (WinRT). 6095** But for all other platforms, it is highly recommended that applications 6096** neither read nor write this variable. This global variable is a relic 6097** that exists for backwards compatibility of legacy applications and should 6098** be avoided in new projects. 6099** 6100** It is not safe to read or modify this variable in more than one 6101** thread at a time. It is not safe to read or modify this variable 6102** if a [database connection] is being used at the same time in a separate 6103** thread. 6104** It is intended that this variable be set once 6105** as part of process initialization and before any SQLite interface 6106** routines have been called and that this variable remain unchanged 6107** thereafter. 6108** 6109** ^The [temp_store_directory pragma] may modify this variable and cause 6110** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6111** the [temp_store_directory pragma] always assumes that any string 6112** that this variable points to is held in memory obtained from 6113** [sqlite3_malloc] and the pragma may attempt to free that memory 6114** using [sqlite3_free]. 6115** Hence, if this variable is modified directly, either it should be 6116** made NULL or made to point to memory obtained from [sqlite3_malloc] 6117** or else the use of the [temp_store_directory pragma] should be avoided. 6118** Except when requested by the [temp_store_directory pragma], SQLite 6119** does not free the memory that sqlite3_temp_directory points to. If 6120** the application wants that memory to be freed, it must do 6121** so itself, taking care to only do so after all [database connection] 6122** objects have been destroyed. 6123** 6124** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6125** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6126** features that require the use of temporary files may fail. Here is an 6127** example of how to do this using C++ with the Windows Runtime: 6128** 6129** <blockquote><pre> 6130** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6131** TemporaryFolder->Path->Data(); 6132** char zPathBuf[MAX_PATH + 1]; 6133** memset(zPathBuf, 0, sizeof(zPathBuf)); 6134** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6135** NULL, NULL); 6136** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6137** </pre></blockquote> 6138*/ 6139SQLITE_EXTERN char *sqlite3_temp_directory; 6140 6141/* 6142** CAPI3REF: Name Of The Folder Holding Database Files 6143** 6144** ^(If this global variable is made to point to a string which is 6145** the name of a folder (a.k.a. directory), then all database files 6146** specified with a relative pathname and created or accessed by 6147** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6148** to be relative to that directory.)^ ^If this variable is a NULL 6149** pointer, then SQLite assumes that all database files specified 6150** with a relative pathname are relative to the current directory 6151** for the process. Only the windows VFS makes use of this global 6152** variable; it is ignored by the unix VFS. 6153** 6154** Changing the value of this variable while a database connection is 6155** open can result in a corrupt database. 6156** 6157** It is not safe to read or modify this variable in more than one 6158** thread at a time. It is not safe to read or modify this variable 6159** if a [database connection] is being used at the same time in a separate 6160** thread. 6161** It is intended that this variable be set once 6162** as part of process initialization and before any SQLite interface 6163** routines have been called and that this variable remain unchanged 6164** thereafter. 6165** 6166** ^The [data_store_directory pragma] may modify this variable and cause 6167** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6168** the [data_store_directory pragma] always assumes that any string 6169** that this variable points to is held in memory obtained from 6170** [sqlite3_malloc] and the pragma may attempt to free that memory 6171** using [sqlite3_free]. 6172** Hence, if this variable is modified directly, either it should be 6173** made NULL or made to point to memory obtained from [sqlite3_malloc] 6174** or else the use of the [data_store_directory pragma] should be avoided. 6175*/ 6176SQLITE_EXTERN char *sqlite3_data_directory; 6177 6178/* 6179** CAPI3REF: Win32 Specific Interface 6180** 6181** These interfaces are available only on Windows. The 6182** [sqlite3_win32_set_directory] interface is used to set the value associated 6183** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6184** zValue, depending on the value of the type parameter. The zValue parameter 6185** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6186** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6187** prior to being used. The [sqlite3_win32_set_directory] interface returns 6188** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6189** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6190** [sqlite3_data_directory] variable is intended to act as a replacement for 6191** the current directory on the sub-platforms of Win32 where that concept is 6192** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6193** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6194** sqlite3_win32_set_directory interface except the string parameter must be 6195** UTF-8 or UTF-16, respectively. 6196*/ 6197int sqlite3_win32_set_directory( 6198 unsigned long type, /* Identifier for directory being set or reset */ 6199 void *zValue /* New value for directory being set or reset */ 6200); 6201int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6202int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6203 6204/* 6205** CAPI3REF: Win32 Directory Types 6206** 6207** These macros are only available on Windows. They define the allowed values 6208** for the type argument to the [sqlite3_win32_set_directory] interface. 6209*/ 6210#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6211#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6212 6213/* 6214** CAPI3REF: Test For Auto-Commit Mode 6215** KEYWORDS: {autocommit mode} 6216** METHOD: sqlite3 6217** 6218** ^The sqlite3_get_autocommit() interface returns non-zero or 6219** zero if the given database connection is or is not in autocommit mode, 6220** respectively. ^Autocommit mode is on by default. 6221** ^Autocommit mode is disabled by a [BEGIN] statement. 6222** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6223** 6224** If certain kinds of errors occur on a statement within a multi-statement 6225** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6226** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6227** transaction might be rolled back automatically. The only way to 6228** find out whether SQLite automatically rolled back the transaction after 6229** an error is to use this function. 6230** 6231** If another thread changes the autocommit status of the database 6232** connection while this routine is running, then the return value 6233** is undefined. 6234*/ 6235int sqlite3_get_autocommit(sqlite3*); 6236 6237/* 6238** CAPI3REF: Find The Database Handle Of A Prepared Statement 6239** METHOD: sqlite3_stmt 6240** 6241** ^The sqlite3_db_handle interface returns the [database connection] handle 6242** to which a [prepared statement] belongs. ^The [database connection] 6243** returned by sqlite3_db_handle is the same [database connection] 6244** that was the first argument 6245** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6246** create the statement in the first place. 6247*/ 6248sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6249 6250/* 6251** CAPI3REF: Return The Filename For A Database Connection 6252** METHOD: sqlite3 6253** 6254** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6255** associated with database N of connection D. 6256** ^If there is no attached database N on the database 6257** connection D, or if database N is a temporary or in-memory database, then 6258** this function will return either a NULL pointer or an empty string. 6259** 6260** ^The string value returned by this routine is owned and managed by 6261** the database connection. ^The value will be valid until the database N 6262** is [DETACH]-ed or until the database connection closes. 6263** 6264** ^The filename returned by this function is the output of the 6265** xFullPathname method of the [VFS]. ^In other words, the filename 6266** will be an absolute pathname, even if the filename used 6267** to open the database originally was a URI or relative pathname. 6268** 6269** If the filename pointer returned by this routine is not NULL, then it 6270** can be used as the filename input parameter to these routines: 6271** <ul> 6272** <li> [sqlite3_uri_parameter()] 6273** <li> [sqlite3_uri_boolean()] 6274** <li> [sqlite3_uri_int64()] 6275** <li> [sqlite3_filename_database()] 6276** <li> [sqlite3_filename_journal()] 6277** <li> [sqlite3_filename_wal()] 6278** </ul> 6279*/ 6280const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6281 6282/* 6283** CAPI3REF: Determine if a database is read-only 6284** METHOD: sqlite3 6285** 6286** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6287** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6288** the name of a database on connection D. 6289*/ 6290int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6291 6292/* 6293** CAPI3REF: Determine the transaction state of a database 6294** METHOD: sqlite3 6295** 6296** ^The sqlite3_txn_state(D,S) interface returns the current 6297** [transaction state] of schema S in database connection D. ^If S is NULL, 6298** then the highest transaction state of any schema on database connection D 6299** is returned. Transaction states are (in order of lowest to highest): 6300** <ol> 6301** <li value="0"> SQLITE_TXN_NONE 6302** <li value="1"> SQLITE_TXN_READ 6303** <li value="2"> SQLITE_TXN_WRITE 6304** </ol> 6305** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6306** a valid schema, then -1 is returned. 6307*/ 6308int sqlite3_txn_state(sqlite3*,const char *zSchema); 6309 6310/* 6311** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6312** KEYWORDS: {transaction state} 6313** 6314** These constants define the current transaction state of a database file. 6315** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6316** constants in order to describe the transaction state of schema S 6317** in [database connection] D. 6318** 6319** <dl> 6320** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6321** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6322** pending.</dd> 6323** 6324** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6325** <dd>The SQLITE_TXN_READ state means that the database is currently 6326** in a read transaction. Content has been read from the database file 6327** but nothing in the database file has changed. The transaction state 6328** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6329** no other conflicting concurrent write transactions. The transaction 6330** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6331** [COMMIT].</dd> 6332** 6333** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6334** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6335** in a write transaction. Content has been written to the database file 6336** but has not yet committed. The transaction state will change to 6337** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6338*/ 6339#define SQLITE_TXN_NONE 0 6340#define SQLITE_TXN_READ 1 6341#define SQLITE_TXN_WRITE 2 6342 6343/* 6344** CAPI3REF: Find the next prepared statement 6345** METHOD: sqlite3 6346** 6347** ^This interface returns a pointer to the next [prepared statement] after 6348** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6349** then this interface returns a pointer to the first prepared statement 6350** associated with the database connection pDb. ^If no prepared statement 6351** satisfies the conditions of this routine, it returns NULL. 6352** 6353** The [database connection] pointer D in a call to 6354** [sqlite3_next_stmt(D,S)] must refer to an open database 6355** connection and in particular must not be a NULL pointer. 6356*/ 6357sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6358 6359/* 6360** CAPI3REF: Commit And Rollback Notification Callbacks 6361** METHOD: sqlite3 6362** 6363** ^The sqlite3_commit_hook() interface registers a callback 6364** function to be invoked whenever a transaction is [COMMIT | committed]. 6365** ^Any callback set by a previous call to sqlite3_commit_hook() 6366** for the same database connection is overridden. 6367** ^The sqlite3_rollback_hook() interface registers a callback 6368** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6369** ^Any callback set by a previous call to sqlite3_rollback_hook() 6370** for the same database connection is overridden. 6371** ^The pArg argument is passed through to the callback. 6372** ^If the callback on a commit hook function returns non-zero, 6373** then the commit is converted into a rollback. 6374** 6375** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6376** return the P argument from the previous call of the same function 6377** on the same [database connection] D, or NULL for 6378** the first call for each function on D. 6379** 6380** The commit and rollback hook callbacks are not reentrant. 6381** The callback implementation must not do anything that will modify 6382** the database connection that invoked the callback. Any actions 6383** to modify the database connection must be deferred until after the 6384** completion of the [sqlite3_step()] call that triggered the commit 6385** or rollback hook in the first place. 6386** Note that running any other SQL statements, including SELECT statements, 6387** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6388** the database connections for the meaning of "modify" in this paragraph. 6389** 6390** ^Registering a NULL function disables the callback. 6391** 6392** ^When the commit hook callback routine returns zero, the [COMMIT] 6393** operation is allowed to continue normally. ^If the commit hook 6394** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6395** ^The rollback hook is invoked on a rollback that results from a commit 6396** hook returning non-zero, just as it would be with any other rollback. 6397** 6398** ^For the purposes of this API, a transaction is said to have been 6399** rolled back if an explicit "ROLLBACK" statement is executed, or 6400** an error or constraint causes an implicit rollback to occur. 6401** ^The rollback callback is not invoked if a transaction is 6402** automatically rolled back because the database connection is closed. 6403** 6404** See also the [sqlite3_update_hook()] interface. 6405*/ 6406void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6407void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6408 6409/* 6410** CAPI3REF: Data Change Notification Callbacks 6411** METHOD: sqlite3 6412** 6413** ^The sqlite3_update_hook() interface registers a callback function 6414** with the [database connection] identified by the first argument 6415** to be invoked whenever a row is updated, inserted or deleted in 6416** a [rowid table]. 6417** ^Any callback set by a previous call to this function 6418** for the same database connection is overridden. 6419** 6420** ^The second argument is a pointer to the function to invoke when a 6421** row is updated, inserted or deleted in a rowid table. 6422** ^The first argument to the callback is a copy of the third argument 6423** to sqlite3_update_hook(). 6424** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6425** or [SQLITE_UPDATE], depending on the operation that caused the callback 6426** to be invoked. 6427** ^The third and fourth arguments to the callback contain pointers to the 6428** database and table name containing the affected row. 6429** ^The final callback parameter is the [rowid] of the row. 6430** ^In the case of an update, this is the [rowid] after the update takes place. 6431** 6432** ^(The update hook is not invoked when internal system tables are 6433** modified (i.e. sqlite_sequence).)^ 6434** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6435** 6436** ^In the current implementation, the update hook 6437** is not invoked when conflicting rows are deleted because of an 6438** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6439** invoked when rows are deleted using the [truncate optimization]. 6440** The exceptions defined in this paragraph might change in a future 6441** release of SQLite. 6442** 6443** The update hook implementation must not do anything that will modify 6444** the database connection that invoked the update hook. Any actions 6445** to modify the database connection must be deferred until after the 6446** completion of the [sqlite3_step()] call that triggered the update hook. 6447** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6448** database connections for the meaning of "modify" in this paragraph. 6449** 6450** ^The sqlite3_update_hook(D,C,P) function 6451** returns the P argument from the previous call 6452** on the same [database connection] D, or NULL for 6453** the first call on D. 6454** 6455** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6456** and [sqlite3_preupdate_hook()] interfaces. 6457*/ 6458void *sqlite3_update_hook( 6459 sqlite3*, 6460 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6461 void* 6462); 6463 6464/* 6465** CAPI3REF: Enable Or Disable Shared Pager Cache 6466** 6467** ^(This routine enables or disables the sharing of the database cache 6468** and schema data structures between [database connection | connections] 6469** to the same database. Sharing is enabled if the argument is true 6470** and disabled if the argument is false.)^ 6471** 6472** ^Cache sharing is enabled and disabled for an entire process. 6473** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6474** In prior versions of SQLite, 6475** sharing was enabled or disabled for each thread separately. 6476** 6477** ^(The cache sharing mode set by this interface effects all subsequent 6478** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6479** Existing database connections continue to use the sharing mode 6480** that was in effect at the time they were opened.)^ 6481** 6482** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6483** successfully. An [error code] is returned otherwise.)^ 6484** 6485** ^Shared cache is disabled by default. It is recommended that it stay 6486** that way. In other words, do not use this routine. This interface 6487** continues to be provided for historical compatibility, but its use is 6488** discouraged. Any use of shared cache is discouraged. If shared cache 6489** must be used, it is recommended that shared cache only be enabled for 6490** individual database connections using the [sqlite3_open_v2()] interface 6491** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6492** 6493** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6494** and will always return SQLITE_MISUSE. On those systems, 6495** shared cache mode should be enabled per-database connection via 6496** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6497** 6498** This interface is threadsafe on processors where writing a 6499** 32-bit integer is atomic. 6500** 6501** See Also: [SQLite Shared-Cache Mode] 6502*/ 6503int sqlite3_enable_shared_cache(int); 6504 6505/* 6506** CAPI3REF: Attempt To Free Heap Memory 6507** 6508** ^The sqlite3_release_memory() interface attempts to free N bytes 6509** of heap memory by deallocating non-essential memory allocations 6510** held by the database library. Memory used to cache database 6511** pages to improve performance is an example of non-essential memory. 6512** ^sqlite3_release_memory() returns the number of bytes actually freed, 6513** which might be more or less than the amount requested. 6514** ^The sqlite3_release_memory() routine is a no-op returning zero 6515** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6516** 6517** See also: [sqlite3_db_release_memory()] 6518*/ 6519int sqlite3_release_memory(int); 6520 6521/* 6522** CAPI3REF: Free Memory Used By A Database Connection 6523** METHOD: sqlite3 6524** 6525** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6526** memory as possible from database connection D. Unlike the 6527** [sqlite3_release_memory()] interface, this interface is in effect even 6528** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6529** omitted. 6530** 6531** See also: [sqlite3_release_memory()] 6532*/ 6533int sqlite3_db_release_memory(sqlite3*); 6534 6535/* 6536** CAPI3REF: Impose A Limit On Heap Size 6537** 6538** These interfaces impose limits on the amount of heap memory that will be 6539** by all database connections within a single process. 6540** 6541** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6542** soft limit on the amount of heap memory that may be allocated by SQLite. 6543** ^SQLite strives to keep heap memory utilization below the soft heap 6544** limit by reducing the number of pages held in the page cache 6545** as heap memory usages approaches the limit. 6546** ^The soft heap limit is "soft" because even though SQLite strives to stay 6547** below the limit, it will exceed the limit rather than generate 6548** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6549** is advisory only. 6550** 6551** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6552** N bytes on the amount of memory that will be allocated. ^The 6553** sqlite3_hard_heap_limit64(N) interface is similar to 6554** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6555** when the hard heap limit is reached. 6556** 6557** ^The return value from both sqlite3_soft_heap_limit64() and 6558** sqlite3_hard_heap_limit64() is the size of 6559** the heap limit prior to the call, or negative in the case of an 6560** error. ^If the argument N is negative 6561** then no change is made to the heap limit. Hence, the current 6562** size of heap limits can be determined by invoking 6563** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6564** 6565** ^Setting the heap limits to zero disables the heap limiter mechanism. 6566** 6567** ^The soft heap limit may not be greater than the hard heap limit. 6568** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6569** is invoked with a value of N that is greater than the hard heap limit, 6570** the the soft heap limit is set to the value of the hard heap limit. 6571** ^The soft heap limit is automatically enabled whenever the hard heap 6572** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6573** the soft heap limit is outside the range of 1..N, then the soft heap 6574** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6575** hard heap limit is enabled makes the soft heap limit equal to the 6576** hard heap limit. 6577** 6578** The memory allocation limits can also be adjusted using 6579** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6580** 6581** ^(The heap limits are not enforced in the current implementation 6582** if one or more of following conditions are true: 6583** 6584** <ul> 6585** <li> The limit value is set to zero. 6586** <li> Memory accounting is disabled using a combination of the 6587** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6588** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6589** <li> An alternative page cache implementation is specified using 6590** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6591** <li> The page cache allocates from its own memory pool supplied 6592** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6593** from the heap. 6594** </ul>)^ 6595** 6596** The circumstances under which SQLite will enforce the heap limits may 6597** changes in future releases of SQLite. 6598*/ 6599sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6600sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6601 6602/* 6603** CAPI3REF: Deprecated Soft Heap Limit Interface 6604** DEPRECATED 6605** 6606** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6607** interface. This routine is provided for historical compatibility 6608** only. All new applications should use the 6609** [sqlite3_soft_heap_limit64()] interface rather than this one. 6610*/ 6611SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6612 6613 6614/* 6615** CAPI3REF: Extract Metadata About A Column Of A Table 6616** METHOD: sqlite3 6617** 6618** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6619** information about column C of table T in database D 6620** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6621** interface returns SQLITE_OK and fills in the non-NULL pointers in 6622** the final five arguments with appropriate values if the specified 6623** column exists. ^The sqlite3_table_column_metadata() interface returns 6624** SQLITE_ERROR if the specified column does not exist. 6625** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6626** NULL pointer, then this routine simply checks for the existence of the 6627** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6628** does not. If the table name parameter T in a call to 6629** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6630** undefined behavior. 6631** 6632** ^The column is identified by the second, third and fourth parameters to 6633** this function. ^(The second parameter is either the name of the database 6634** (i.e. "main", "temp", or an attached database) containing the specified 6635** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6636** for the table using the same algorithm used by the database engine to 6637** resolve unqualified table references. 6638** 6639** ^The third and fourth parameters to this function are the table and column 6640** name of the desired column, respectively. 6641** 6642** ^Metadata is returned by writing to the memory locations passed as the 5th 6643** and subsequent parameters to this function. ^Any of these arguments may be 6644** NULL, in which case the corresponding element of metadata is omitted. 6645** 6646** ^(<blockquote> 6647** <table border="1"> 6648** <tr><th> Parameter <th> Output<br>Type <th> Description 6649** 6650** <tr><td> 5th <td> const char* <td> Data type 6651** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6652** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6653** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6654** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6655** </table> 6656** </blockquote>)^ 6657** 6658** ^The memory pointed to by the character pointers returned for the 6659** declaration type and collation sequence is valid until the next 6660** call to any SQLite API function. 6661** 6662** ^If the specified table is actually a view, an [error code] is returned. 6663** 6664** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6665** is not a [WITHOUT ROWID] table and an 6666** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6667** parameters are set for the explicitly declared column. ^(If there is no 6668** [INTEGER PRIMARY KEY] column, then the outputs 6669** for the [rowid] are set as follows: 6670** 6671** <pre> 6672** data type: "INTEGER" 6673** collation sequence: "BINARY" 6674** not null: 0 6675** primary key: 1 6676** auto increment: 0 6677** </pre>)^ 6678** 6679** ^This function causes all database schemas to be read from disk and 6680** parsed, if that has not already been done, and returns an error if 6681** any errors are encountered while loading the schema. 6682*/ 6683int sqlite3_table_column_metadata( 6684 sqlite3 *db, /* Connection handle */ 6685 const char *zDbName, /* Database name or NULL */ 6686 const char *zTableName, /* Table name */ 6687 const char *zColumnName, /* Column name */ 6688 char const **pzDataType, /* OUTPUT: Declared data type */ 6689 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6690 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6691 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6692 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6693); 6694 6695/* 6696** CAPI3REF: Load An Extension 6697** METHOD: sqlite3 6698** 6699** ^This interface loads an SQLite extension library from the named file. 6700** 6701** ^The sqlite3_load_extension() interface attempts to load an 6702** [SQLite extension] library contained in the file zFile. If 6703** the file cannot be loaded directly, attempts are made to load 6704** with various operating-system specific extensions added. 6705** So for example, if "samplelib" cannot be loaded, then names like 6706** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6707** be tried also. 6708** 6709** ^The entry point is zProc. 6710** ^(zProc may be 0, in which case SQLite will try to come up with an 6711** entry point name on its own. It first tries "sqlite3_extension_init". 6712** If that does not work, it constructs a name "sqlite3_X_init" where the 6713** X is consists of the lower-case equivalent of all ASCII alphabetic 6714** characters in the filename from the last "/" to the first following 6715** "." and omitting any initial "lib".)^ 6716** ^The sqlite3_load_extension() interface returns 6717** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6718** ^If an error occurs and pzErrMsg is not 0, then the 6719** [sqlite3_load_extension()] interface shall attempt to 6720** fill *pzErrMsg with error message text stored in memory 6721** obtained from [sqlite3_malloc()]. The calling function 6722** should free this memory by calling [sqlite3_free()]. 6723** 6724** ^Extension loading must be enabled using 6725** [sqlite3_enable_load_extension()] or 6726** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6727** prior to calling this API, 6728** otherwise an error will be returned. 6729** 6730** <b>Security warning:</b> It is recommended that the 6731** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6732** interface. The use of the [sqlite3_enable_load_extension()] interface 6733** should be avoided. This will keep the SQL function [load_extension()] 6734** disabled and prevent SQL injections from giving attackers 6735** access to extension loading capabilities. 6736** 6737** See also the [load_extension() SQL function]. 6738*/ 6739int sqlite3_load_extension( 6740 sqlite3 *db, /* Load the extension into this database connection */ 6741 const char *zFile, /* Name of the shared library containing extension */ 6742 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6743 char **pzErrMsg /* Put error message here if not 0 */ 6744); 6745 6746/* 6747** CAPI3REF: Enable Or Disable Extension Loading 6748** METHOD: sqlite3 6749** 6750** ^So as not to open security holes in older applications that are 6751** unprepared to deal with [extension loading], and as a means of disabling 6752** [extension loading] while evaluating user-entered SQL, the following API 6753** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6754** 6755** ^Extension loading is off by default. 6756** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6757** to turn extension loading on and call it with onoff==0 to turn 6758** it back off again. 6759** 6760** ^This interface enables or disables both the C-API 6761** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6762** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6763** to enable or disable only the C-API.)^ 6764** 6765** <b>Security warning:</b> It is recommended that extension loading 6766** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6767** rather than this interface, so the [load_extension()] SQL function 6768** remains disabled. This will prevent SQL injections from giving attackers 6769** access to extension loading capabilities. 6770*/ 6771int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6772 6773/* 6774** CAPI3REF: Automatically Load Statically Linked Extensions 6775** 6776** ^This interface causes the xEntryPoint() function to be invoked for 6777** each new [database connection] that is created. The idea here is that 6778** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6779** that is to be automatically loaded into all new database connections. 6780** 6781** ^(Even though the function prototype shows that xEntryPoint() takes 6782** no arguments and returns void, SQLite invokes xEntryPoint() with three 6783** arguments and expects an integer result as if the signature of the 6784** entry point where as follows: 6785** 6786** <blockquote><pre> 6787** int xEntryPoint( 6788** sqlite3 *db, 6789** const char **pzErrMsg, 6790** const struct sqlite3_api_routines *pThunk 6791** ); 6792** </pre></blockquote>)^ 6793** 6794** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6795** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6796** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6797** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6798** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6799** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6800** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6801** 6802** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6803** on the list of automatic extensions is a harmless no-op. ^No entry point 6804** will be called more than once for each database connection that is opened. 6805** 6806** See also: [sqlite3_reset_auto_extension()] 6807** and [sqlite3_cancel_auto_extension()] 6808*/ 6809int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6810 6811/* 6812** CAPI3REF: Cancel Automatic Extension Loading 6813** 6814** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6815** initialization routine X that was registered using a prior call to 6816** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6817** routine returns 1 if initialization routine X was successfully 6818** unregistered and it returns 0 if X was not on the list of initialization 6819** routines. 6820*/ 6821int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6822 6823/* 6824** CAPI3REF: Reset Automatic Extension Loading 6825** 6826** ^This interface disables all automatic extensions previously 6827** registered using [sqlite3_auto_extension()]. 6828*/ 6829void sqlite3_reset_auto_extension(void); 6830 6831/* 6832** The interface to the virtual-table mechanism is currently considered 6833** to be experimental. The interface might change in incompatible ways. 6834** If this is a problem for you, do not use the interface at this time. 6835** 6836** When the virtual-table mechanism stabilizes, we will declare the 6837** interface fixed, support it indefinitely, and remove this comment. 6838*/ 6839 6840/* 6841** Structures used by the virtual table interface 6842*/ 6843typedef struct sqlite3_vtab sqlite3_vtab; 6844typedef struct sqlite3_index_info sqlite3_index_info; 6845typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6846typedef struct sqlite3_module sqlite3_module; 6847 6848/* 6849** CAPI3REF: Virtual Table Object 6850** KEYWORDS: sqlite3_module {virtual table module} 6851** 6852** This structure, sometimes called a "virtual table module", 6853** defines the implementation of a [virtual table]. 6854** This structure consists mostly of methods for the module. 6855** 6856** ^A virtual table module is created by filling in a persistent 6857** instance of this structure and passing a pointer to that instance 6858** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6859** ^The registration remains valid until it is replaced by a different 6860** module or until the [database connection] closes. The content 6861** of this structure must not change while it is registered with 6862** any database connection. 6863*/ 6864struct sqlite3_module { 6865 int iVersion; 6866 int (*xCreate)(sqlite3*, void *pAux, 6867 int argc, const char *const*argv, 6868 sqlite3_vtab **ppVTab, char**); 6869 int (*xConnect)(sqlite3*, void *pAux, 6870 int argc, const char *const*argv, 6871 sqlite3_vtab **ppVTab, char**); 6872 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6873 int (*xDisconnect)(sqlite3_vtab *pVTab); 6874 int (*xDestroy)(sqlite3_vtab *pVTab); 6875 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6876 int (*xClose)(sqlite3_vtab_cursor*); 6877 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6878 int argc, sqlite3_value **argv); 6879 int (*xNext)(sqlite3_vtab_cursor*); 6880 int (*xEof)(sqlite3_vtab_cursor*); 6881 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6882 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6883 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6884 int (*xBegin)(sqlite3_vtab *pVTab); 6885 int (*xSync)(sqlite3_vtab *pVTab); 6886 int (*xCommit)(sqlite3_vtab *pVTab); 6887 int (*xRollback)(sqlite3_vtab *pVTab); 6888 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6889 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6890 void **ppArg); 6891 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6892 /* The methods above are in version 1 of the sqlite_module object. Those 6893 ** below are for version 2 and greater. */ 6894 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6895 int (*xRelease)(sqlite3_vtab *pVTab, int); 6896 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6897 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6898 ** Those below are for version 3 and greater. */ 6899 int (*xShadowName)(const char*); 6900}; 6901 6902/* 6903** CAPI3REF: Virtual Table Indexing Information 6904** KEYWORDS: sqlite3_index_info 6905** 6906** The sqlite3_index_info structure and its substructures is used as part 6907** of the [virtual table] interface to 6908** pass information into and receive the reply from the [xBestIndex] 6909** method of a [virtual table module]. The fields under **Inputs** are the 6910** inputs to xBestIndex and are read-only. xBestIndex inserts its 6911** results into the **Outputs** fields. 6912** 6913** ^(The aConstraint[] array records WHERE clause constraints of the form: 6914** 6915** <blockquote>column OP expr</blockquote> 6916** 6917** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6918** stored in aConstraint[].op using one of the 6919** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6920** ^(The index of the column is stored in 6921** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6922** expr on the right-hand side can be evaluated (and thus the constraint 6923** is usable) and false if it cannot.)^ 6924** 6925** ^The optimizer automatically inverts terms of the form "expr OP column" 6926** and makes other simplifications to the WHERE clause in an attempt to 6927** get as many WHERE clause terms into the form shown above as possible. 6928** ^The aConstraint[] array only reports WHERE clause terms that are 6929** relevant to the particular virtual table being queried. 6930** 6931** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6932** ^Each term of aOrderBy records a column of the ORDER BY clause. 6933** 6934** The colUsed field indicates which columns of the virtual table may be 6935** required by the current scan. Virtual table columns are numbered from 6936** zero in the order in which they appear within the CREATE TABLE statement 6937** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6938** the corresponding bit is set within the colUsed mask if the column may be 6939** required by SQLite. If the table has at least 64 columns and any column 6940** to the right of the first 63 is required, then bit 63 of colUsed is also 6941** set. In other words, column iCol may be required if the expression 6942** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6943** non-zero. 6944** 6945** The [xBestIndex] method must fill aConstraintUsage[] with information 6946** about what parameters to pass to xFilter. ^If argvIndex>0 then 6947** the right-hand side of the corresponding aConstraint[] is evaluated 6948** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6949** is true, then the constraint is assumed to be fully handled by the 6950** virtual table and might not be checked again by the byte code.)^ ^(The 6951** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6952** is left in its default setting of false, the constraint will always be 6953** checked separately in byte code. If the omit flag is change to true, then 6954** the constraint may or may not be checked in byte code. In other words, 6955** when the omit flag is true there is no guarantee that the constraint will 6956** not be checked again using byte code.)^ 6957** 6958** ^The idxNum and idxPtr values are recorded and passed into the 6959** [xFilter] method. 6960** ^[sqlite3_free()] is used to free idxPtr if and only if 6961** needToFreeIdxPtr is true. 6962** 6963** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6964** the correct order to satisfy the ORDER BY clause so that no separate 6965** sorting step is required. 6966** 6967** ^The estimatedCost value is an estimate of the cost of a particular 6968** strategy. A cost of N indicates that the cost of the strategy is similar 6969** to a linear scan of an SQLite table with N rows. A cost of log(N) 6970** indicates that the expense of the operation is similar to that of a 6971** binary search on a unique indexed field of an SQLite table with N rows. 6972** 6973** ^The estimatedRows value is an estimate of the number of rows that 6974** will be returned by the strategy. 6975** 6976** The xBestIndex method may optionally populate the idxFlags field with a 6977** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6978** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6979** assumes that the strategy may visit at most one row. 6980** 6981** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6982** SQLite also assumes that if a call to the xUpdate() method is made as 6983** part of the same statement to delete or update a virtual table row and the 6984** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6985** any database changes. In other words, if the xUpdate() returns 6986** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6987** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6988** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6989** the xUpdate method are automatically rolled back by SQLite. 6990** 6991** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6992** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6993** If a virtual table extension is 6994** used with an SQLite version earlier than 3.8.2, the results of attempting 6995** to read or write the estimatedRows field are undefined (but are likely 6996** to include crashing the application). The estimatedRows field should 6997** therefore only be used if [sqlite3_libversion_number()] returns a 6998** value greater than or equal to 3008002. Similarly, the idxFlags field 6999** was added for [version 3.9.0] ([dateof:3.9.0]). 7000** It may therefore only be used if 7001** sqlite3_libversion_number() returns a value greater than or equal to 7002** 3009000. 7003*/ 7004struct sqlite3_index_info { 7005 /* Inputs */ 7006 int nConstraint; /* Number of entries in aConstraint */ 7007 struct sqlite3_index_constraint { 7008 int iColumn; /* Column constrained. -1 for ROWID */ 7009 unsigned char op; /* Constraint operator */ 7010 unsigned char usable; /* True if this constraint is usable */ 7011 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7012 } *aConstraint; /* Table of WHERE clause constraints */ 7013 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7014 struct sqlite3_index_orderby { 7015 int iColumn; /* Column number */ 7016 unsigned char desc; /* True for DESC. False for ASC. */ 7017 } *aOrderBy; /* The ORDER BY clause */ 7018 /* Outputs */ 7019 struct sqlite3_index_constraint_usage { 7020 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7021 unsigned char omit; /* Do not code a test for this constraint */ 7022 } *aConstraintUsage; 7023 int idxNum; /* Number used to identify the index */ 7024 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7025 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7026 int orderByConsumed; /* True if output is already ordered */ 7027 double estimatedCost; /* Estimated cost of using this index */ 7028 /* Fields below are only available in SQLite 3.8.2 and later */ 7029 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7030 /* Fields below are only available in SQLite 3.9.0 and later */ 7031 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7032 /* Fields below are only available in SQLite 3.10.0 and later */ 7033 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7034}; 7035 7036/* 7037** CAPI3REF: Virtual Table Scan Flags 7038** 7039** Virtual table implementations are allowed to set the 7040** [sqlite3_index_info].idxFlags field to some combination of 7041** these bits. 7042*/ 7043#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7044 7045/* 7046** CAPI3REF: Virtual Table Constraint Operator Codes 7047** 7048** These macros define the allowed values for the 7049** [sqlite3_index_info].aConstraint[].op field. Each value represents 7050** an operator that is part of a constraint term in the wHERE clause of 7051** a query that uses a [virtual table]. 7052*/ 7053#define SQLITE_INDEX_CONSTRAINT_EQ 2 7054#define SQLITE_INDEX_CONSTRAINT_GT 4 7055#define SQLITE_INDEX_CONSTRAINT_LE 8 7056#define SQLITE_INDEX_CONSTRAINT_LT 16 7057#define SQLITE_INDEX_CONSTRAINT_GE 32 7058#define SQLITE_INDEX_CONSTRAINT_MATCH 64 7059#define SQLITE_INDEX_CONSTRAINT_LIKE 65 7060#define SQLITE_INDEX_CONSTRAINT_GLOB 66 7061#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7062#define SQLITE_INDEX_CONSTRAINT_NE 68 7063#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7064#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7065#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7066#define SQLITE_INDEX_CONSTRAINT_IS 72 7067#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7068 7069/* 7070** CAPI3REF: Register A Virtual Table Implementation 7071** METHOD: sqlite3 7072** 7073** ^These routines are used to register a new [virtual table module] name. 7074** ^Module names must be registered before 7075** creating a new [virtual table] using the module and before using a 7076** preexisting [virtual table] for the module. 7077** 7078** ^The module name is registered on the [database connection] specified 7079** by the first parameter. ^The name of the module is given by the 7080** second parameter. ^The third parameter is a pointer to 7081** the implementation of the [virtual table module]. ^The fourth 7082** parameter is an arbitrary client data pointer that is passed through 7083** into the [xCreate] and [xConnect] methods of the virtual table module 7084** when a new virtual table is be being created or reinitialized. 7085** 7086** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7087** is a pointer to a destructor for the pClientData. ^SQLite will 7088** invoke the destructor function (if it is not NULL) when SQLite 7089** no longer needs the pClientData pointer. ^The destructor will also 7090** be invoked if the call to sqlite3_create_module_v2() fails. 7091** ^The sqlite3_create_module() 7092** interface is equivalent to sqlite3_create_module_v2() with a NULL 7093** destructor. 7094** 7095** ^If the third parameter (the pointer to the sqlite3_module object) is 7096** NULL then no new module is create and any existing modules with the 7097** same name are dropped. 7098** 7099** See also: [sqlite3_drop_modules()] 7100*/ 7101int sqlite3_create_module( 7102 sqlite3 *db, /* SQLite connection to register module with */ 7103 const char *zName, /* Name of the module */ 7104 const sqlite3_module *p, /* Methods for the module */ 7105 void *pClientData /* Client data for xCreate/xConnect */ 7106); 7107int sqlite3_create_module_v2( 7108 sqlite3 *db, /* SQLite connection to register module with */ 7109 const char *zName, /* Name of the module */ 7110 const sqlite3_module *p, /* Methods for the module */ 7111 void *pClientData, /* Client data for xCreate/xConnect */ 7112 void(*xDestroy)(void*) /* Module destructor function */ 7113); 7114 7115/* 7116** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7117** METHOD: sqlite3 7118** 7119** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7120** table modules from database connection D except those named on list L. 7121** The L parameter must be either NULL or a pointer to an array of pointers 7122** to strings where the array is terminated by a single NULL pointer. 7123** ^If the L parameter is NULL, then all virtual table modules are removed. 7124** 7125** See also: [sqlite3_create_module()] 7126*/ 7127int sqlite3_drop_modules( 7128 sqlite3 *db, /* Remove modules from this connection */ 7129 const char **azKeep /* Except, do not remove the ones named here */ 7130); 7131 7132/* 7133** CAPI3REF: Virtual Table Instance Object 7134** KEYWORDS: sqlite3_vtab 7135** 7136** Every [virtual table module] implementation uses a subclass 7137** of this object to describe a particular instance 7138** of the [virtual table]. Each subclass will 7139** be tailored to the specific needs of the module implementation. 7140** The purpose of this superclass is to define certain fields that are 7141** common to all module implementations. 7142** 7143** ^Virtual tables methods can set an error message by assigning a 7144** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7145** take care that any prior string is freed by a call to [sqlite3_free()] 7146** prior to assigning a new string to zErrMsg. ^After the error message 7147** is delivered up to the client application, the string will be automatically 7148** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7149*/ 7150struct sqlite3_vtab { 7151 const sqlite3_module *pModule; /* The module for this virtual table */ 7152 int nRef; /* Number of open cursors */ 7153 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7154 /* Virtual table implementations will typically add additional fields */ 7155}; 7156 7157/* 7158** CAPI3REF: Virtual Table Cursor Object 7159** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7160** 7161** Every [virtual table module] implementation uses a subclass of the 7162** following structure to describe cursors that point into the 7163** [virtual table] and are used 7164** to loop through the virtual table. Cursors are created using the 7165** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7166** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7167** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7168** of the module. Each module implementation will define 7169** the content of a cursor structure to suit its own needs. 7170** 7171** This superclass exists in order to define fields of the cursor that 7172** are common to all implementations. 7173*/ 7174struct sqlite3_vtab_cursor { 7175 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7176 /* Virtual table implementations will typically add additional fields */ 7177}; 7178 7179/* 7180** CAPI3REF: Declare The Schema Of A Virtual Table 7181** 7182** ^The [xCreate] and [xConnect] methods of a 7183** [virtual table module] call this interface 7184** to declare the format (the names and datatypes of the columns) of 7185** the virtual tables they implement. 7186*/ 7187int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7188 7189/* 7190** CAPI3REF: Overload A Function For A Virtual Table 7191** METHOD: sqlite3 7192** 7193** ^(Virtual tables can provide alternative implementations of functions 7194** using the [xFindFunction] method of the [virtual table module]. 7195** But global versions of those functions 7196** must exist in order to be overloaded.)^ 7197** 7198** ^(This API makes sure a global version of a function with a particular 7199** name and number of parameters exists. If no such function exists 7200** before this API is called, a new function is created.)^ ^The implementation 7201** of the new function always causes an exception to be thrown. So 7202** the new function is not good for anything by itself. Its only 7203** purpose is to be a placeholder function that can be overloaded 7204** by a [virtual table]. 7205*/ 7206int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7207 7208/* 7209** The interface to the virtual-table mechanism defined above (back up 7210** to a comment remarkably similar to this one) is currently considered 7211** to be experimental. The interface might change in incompatible ways. 7212** If this is a problem for you, do not use the interface at this time. 7213** 7214** When the virtual-table mechanism stabilizes, we will declare the 7215** interface fixed, support it indefinitely, and remove this comment. 7216*/ 7217 7218/* 7219** CAPI3REF: A Handle To An Open BLOB 7220** KEYWORDS: {BLOB handle} {BLOB handles} 7221** 7222** An instance of this object represents an open BLOB on which 7223** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7224** ^Objects of this type are created by [sqlite3_blob_open()] 7225** and destroyed by [sqlite3_blob_close()]. 7226** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7227** can be used to read or write small subsections of the BLOB. 7228** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7229*/ 7230typedef struct sqlite3_blob sqlite3_blob; 7231 7232/* 7233** CAPI3REF: Open A BLOB For Incremental I/O 7234** METHOD: sqlite3 7235** CONSTRUCTOR: sqlite3_blob 7236** 7237** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7238** in row iRow, column zColumn, table zTable in database zDb; 7239** in other words, the same BLOB that would be selected by: 7240** 7241** <pre> 7242** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7243** </pre>)^ 7244** 7245** ^(Parameter zDb is not the filename that contains the database, but 7246** rather the symbolic name of the database. For attached databases, this is 7247** the name that appears after the AS keyword in the [ATTACH] statement. 7248** For the main database file, the database name is "main". For TEMP 7249** tables, the database name is "temp".)^ 7250** 7251** ^If the flags parameter is non-zero, then the BLOB is opened for read 7252** and write access. ^If the flags parameter is zero, the BLOB is opened for 7253** read-only access. 7254** 7255** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7256** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7257** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7258** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7259** on *ppBlob after this function it returns. 7260** 7261** This function fails with SQLITE_ERROR if any of the following are true: 7262** <ul> 7263** <li> ^(Database zDb does not exist)^, 7264** <li> ^(Table zTable does not exist within database zDb)^, 7265** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7266** <li> ^(Column zColumn does not exist)^, 7267** <li> ^(Row iRow is not present in the table)^, 7268** <li> ^(The specified column of row iRow contains a value that is not 7269** a TEXT or BLOB value)^, 7270** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7271** constraint and the blob is being opened for read/write access)^, 7272** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7273** column zColumn is part of a [child key] definition and the blob is 7274** being opened for read/write access)^. 7275** </ul> 7276** 7277** ^Unless it returns SQLITE_MISUSE, this function sets the 7278** [database connection] error code and message accessible via 7279** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7280** 7281** A BLOB referenced by sqlite3_blob_open() may be read using the 7282** [sqlite3_blob_read()] interface and modified by using 7283** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7284** different row of the same table using the [sqlite3_blob_reopen()] 7285** interface. However, the column, table, or database of a [BLOB handle] 7286** cannot be changed after the [BLOB handle] is opened. 7287** 7288** ^(If the row that a BLOB handle points to is modified by an 7289** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7290** then the BLOB handle is marked as "expired". 7291** This is true if any column of the row is changed, even a column 7292** other than the one the BLOB handle is open on.)^ 7293** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7294** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7295** ^(Changes written into a BLOB prior to the BLOB expiring are not 7296** rolled back by the expiration of the BLOB. Such changes will eventually 7297** commit if the transaction continues to completion.)^ 7298** 7299** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7300** the opened blob. ^The size of a blob may not be changed by this 7301** interface. Use the [UPDATE] SQL command to change the size of a 7302** blob. 7303** 7304** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7305** and the built-in [zeroblob] SQL function may be used to create a 7306** zero-filled blob to read or write using the incremental-blob interface. 7307** 7308** To avoid a resource leak, every open [BLOB handle] should eventually 7309** be released by a call to [sqlite3_blob_close()]. 7310** 7311** See also: [sqlite3_blob_close()], 7312** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7313** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7314*/ 7315int sqlite3_blob_open( 7316 sqlite3*, 7317 const char *zDb, 7318 const char *zTable, 7319 const char *zColumn, 7320 sqlite3_int64 iRow, 7321 int flags, 7322 sqlite3_blob **ppBlob 7323); 7324 7325/* 7326** CAPI3REF: Move a BLOB Handle to a New Row 7327** METHOD: sqlite3_blob 7328** 7329** ^This function is used to move an existing [BLOB handle] so that it points 7330** to a different row of the same database table. ^The new row is identified 7331** by the rowid value passed as the second argument. Only the row can be 7332** changed. ^The database, table and column on which the blob handle is open 7333** remain the same. Moving an existing [BLOB handle] to a new row is 7334** faster than closing the existing handle and opening a new one. 7335** 7336** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7337** it must exist and there must be either a blob or text value stored in 7338** the nominated column.)^ ^If the new row is not present in the table, or if 7339** it does not contain a blob or text value, or if another error occurs, an 7340** SQLite error code is returned and the blob handle is considered aborted. 7341** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7342** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7343** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7344** always returns zero. 7345** 7346** ^This function sets the database handle error code and message. 7347*/ 7348int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7349 7350/* 7351** CAPI3REF: Close A BLOB Handle 7352** DESTRUCTOR: sqlite3_blob 7353** 7354** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7355** unconditionally. Even if this routine returns an error code, the 7356** handle is still closed.)^ 7357** 7358** ^If the blob handle being closed was opened for read-write access, and if 7359** the database is in auto-commit mode and there are no other open read-write 7360** blob handles or active write statements, the current transaction is 7361** committed. ^If an error occurs while committing the transaction, an error 7362** code is returned and the transaction rolled back. 7363** 7364** Calling this function with an argument that is not a NULL pointer or an 7365** open blob handle results in undefined behaviour. ^Calling this routine 7366** with a null pointer (such as would be returned by a failed call to 7367** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7368** is passed a valid open blob handle, the values returned by the 7369** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7370*/ 7371int sqlite3_blob_close(sqlite3_blob *); 7372 7373/* 7374** CAPI3REF: Return The Size Of An Open BLOB 7375** METHOD: sqlite3_blob 7376** 7377** ^Returns the size in bytes of the BLOB accessible via the 7378** successfully opened [BLOB handle] in its only argument. ^The 7379** incremental blob I/O routines can only read or overwriting existing 7380** blob content; they cannot change the size of a blob. 7381** 7382** This routine only works on a [BLOB handle] which has been created 7383** by a prior successful call to [sqlite3_blob_open()] and which has not 7384** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7385** to this routine results in undefined and probably undesirable behavior. 7386*/ 7387int sqlite3_blob_bytes(sqlite3_blob *); 7388 7389/* 7390** CAPI3REF: Read Data From A BLOB Incrementally 7391** METHOD: sqlite3_blob 7392** 7393** ^(This function is used to read data from an open [BLOB handle] into a 7394** caller-supplied buffer. N bytes of data are copied into buffer Z 7395** from the open BLOB, starting at offset iOffset.)^ 7396** 7397** ^If offset iOffset is less than N bytes from the end of the BLOB, 7398** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7399** less than zero, [SQLITE_ERROR] is returned and no data is read. 7400** ^The size of the blob (and hence the maximum value of N+iOffset) 7401** can be determined using the [sqlite3_blob_bytes()] interface. 7402** 7403** ^An attempt to read from an expired [BLOB handle] fails with an 7404** error code of [SQLITE_ABORT]. 7405** 7406** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7407** Otherwise, an [error code] or an [extended error code] is returned.)^ 7408** 7409** This routine only works on a [BLOB handle] which has been created 7410** by a prior successful call to [sqlite3_blob_open()] and which has not 7411** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7412** to this routine results in undefined and probably undesirable behavior. 7413** 7414** See also: [sqlite3_blob_write()]. 7415*/ 7416int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7417 7418/* 7419** CAPI3REF: Write Data Into A BLOB Incrementally 7420** METHOD: sqlite3_blob 7421** 7422** ^(This function is used to write data into an open [BLOB handle] from a 7423** caller-supplied buffer. N bytes of data are copied from the buffer Z 7424** into the open BLOB, starting at offset iOffset.)^ 7425** 7426** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7427** Otherwise, an [error code] or an [extended error code] is returned.)^ 7428** ^Unless SQLITE_MISUSE is returned, this function sets the 7429** [database connection] error code and message accessible via 7430** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7431** 7432** ^If the [BLOB handle] passed as the first argument was not opened for 7433** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7434** this function returns [SQLITE_READONLY]. 7435** 7436** This function may only modify the contents of the BLOB; it is 7437** not possible to increase the size of a BLOB using this API. 7438** ^If offset iOffset is less than N bytes from the end of the BLOB, 7439** [SQLITE_ERROR] is returned and no data is written. The size of the 7440** BLOB (and hence the maximum value of N+iOffset) can be determined 7441** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7442** than zero [SQLITE_ERROR] is returned and no data is written. 7443** 7444** ^An attempt to write to an expired [BLOB handle] fails with an 7445** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7446** before the [BLOB handle] expired are not rolled back by the 7447** expiration of the handle, though of course those changes might 7448** have been overwritten by the statement that expired the BLOB handle 7449** or by other independent statements. 7450** 7451** This routine only works on a [BLOB handle] which has been created 7452** by a prior successful call to [sqlite3_blob_open()] and which has not 7453** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7454** to this routine results in undefined and probably undesirable behavior. 7455** 7456** See also: [sqlite3_blob_read()]. 7457*/ 7458int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7459 7460/* 7461** CAPI3REF: Virtual File System Objects 7462** 7463** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7464** that SQLite uses to interact 7465** with the underlying operating system. Most SQLite builds come with a 7466** single default VFS that is appropriate for the host computer. 7467** New VFSes can be registered and existing VFSes can be unregistered. 7468** The following interfaces are provided. 7469** 7470** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7471** ^Names are case sensitive. 7472** ^Names are zero-terminated UTF-8 strings. 7473** ^If there is no match, a NULL pointer is returned. 7474** ^If zVfsName is NULL then the default VFS is returned. 7475** 7476** ^New VFSes are registered with sqlite3_vfs_register(). 7477** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7478** ^The same VFS can be registered multiple times without injury. 7479** ^To make an existing VFS into the default VFS, register it again 7480** with the makeDflt flag set. If two different VFSes with the 7481** same name are registered, the behavior is undefined. If a 7482** VFS is registered with a name that is NULL or an empty string, 7483** then the behavior is undefined. 7484** 7485** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7486** ^(If the default VFS is unregistered, another VFS is chosen as 7487** the default. The choice for the new VFS is arbitrary.)^ 7488*/ 7489sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7490int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7491int sqlite3_vfs_unregister(sqlite3_vfs*); 7492 7493/* 7494** CAPI3REF: Mutexes 7495** 7496** The SQLite core uses these routines for thread 7497** synchronization. Though they are intended for internal 7498** use by SQLite, code that links against SQLite is 7499** permitted to use any of these routines. 7500** 7501** The SQLite source code contains multiple implementations 7502** of these mutex routines. An appropriate implementation 7503** is selected automatically at compile-time. The following 7504** implementations are available in the SQLite core: 7505** 7506** <ul> 7507** <li> SQLITE_MUTEX_PTHREADS 7508** <li> SQLITE_MUTEX_W32 7509** <li> SQLITE_MUTEX_NOOP 7510** </ul> 7511** 7512** The SQLITE_MUTEX_NOOP implementation is a set of routines 7513** that does no real locking and is appropriate for use in 7514** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7515** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7516** and Windows. 7517** 7518** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7519** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7520** implementation is included with the library. In this case the 7521** application must supply a custom mutex implementation using the 7522** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7523** before calling sqlite3_initialize() or any other public sqlite3_ 7524** function that calls sqlite3_initialize(). 7525** 7526** ^The sqlite3_mutex_alloc() routine allocates a new 7527** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7528** routine returns NULL if it is unable to allocate the requested 7529** mutex. The argument to sqlite3_mutex_alloc() must one of these 7530** integer constants: 7531** 7532** <ul> 7533** <li> SQLITE_MUTEX_FAST 7534** <li> SQLITE_MUTEX_RECURSIVE 7535** <li> SQLITE_MUTEX_STATIC_MAIN 7536** <li> SQLITE_MUTEX_STATIC_MEM 7537** <li> SQLITE_MUTEX_STATIC_OPEN 7538** <li> SQLITE_MUTEX_STATIC_PRNG 7539** <li> SQLITE_MUTEX_STATIC_LRU 7540** <li> SQLITE_MUTEX_STATIC_PMEM 7541** <li> SQLITE_MUTEX_STATIC_APP1 7542** <li> SQLITE_MUTEX_STATIC_APP2 7543** <li> SQLITE_MUTEX_STATIC_APP3 7544** <li> SQLITE_MUTEX_STATIC_VFS1 7545** <li> SQLITE_MUTEX_STATIC_VFS2 7546** <li> SQLITE_MUTEX_STATIC_VFS3 7547** </ul> 7548** 7549** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7550** cause sqlite3_mutex_alloc() to create 7551** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7552** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7553** The mutex implementation does not need to make a distinction 7554** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7555** not want to. SQLite will only request a recursive mutex in 7556** cases where it really needs one. If a faster non-recursive mutex 7557** implementation is available on the host platform, the mutex subsystem 7558** might return such a mutex in response to SQLITE_MUTEX_FAST. 7559** 7560** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7561** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7562** a pointer to a static preexisting mutex. ^Nine static mutexes are 7563** used by the current version of SQLite. Future versions of SQLite 7564** may add additional static mutexes. Static mutexes are for internal 7565** use by SQLite only. Applications that use SQLite mutexes should 7566** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7567** SQLITE_MUTEX_RECURSIVE. 7568** 7569** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7570** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7571** returns a different mutex on every call. ^For the static 7572** mutex types, the same mutex is returned on every call that has 7573** the same type number. 7574** 7575** ^The sqlite3_mutex_free() routine deallocates a previously 7576** allocated dynamic mutex. Attempting to deallocate a static 7577** mutex results in undefined behavior. 7578** 7579** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7580** to enter a mutex. ^If another thread is already within the mutex, 7581** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7582** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7583** upon successful entry. ^(Mutexes created using 7584** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7585** In such cases, the 7586** mutex must be exited an equal number of times before another thread 7587** can enter.)^ If the same thread tries to enter any mutex other 7588** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7589** 7590** ^(Some systems (for example, Windows 95) do not support the operation 7591** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7592** will always return SQLITE_BUSY. The SQLite core only ever uses 7593** sqlite3_mutex_try() as an optimization so this is acceptable 7594** behavior.)^ 7595** 7596** ^The sqlite3_mutex_leave() routine exits a mutex that was 7597** previously entered by the same thread. The behavior 7598** is undefined if the mutex is not currently entered by the 7599** calling thread or is not currently allocated. 7600** 7601** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7602** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7603** behave as no-ops. 7604** 7605** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7606*/ 7607sqlite3_mutex *sqlite3_mutex_alloc(int); 7608void sqlite3_mutex_free(sqlite3_mutex*); 7609void sqlite3_mutex_enter(sqlite3_mutex*); 7610int sqlite3_mutex_try(sqlite3_mutex*); 7611void sqlite3_mutex_leave(sqlite3_mutex*); 7612 7613/* 7614** CAPI3REF: Mutex Methods Object 7615** 7616** An instance of this structure defines the low-level routines 7617** used to allocate and use mutexes. 7618** 7619** Usually, the default mutex implementations provided by SQLite are 7620** sufficient, however the application has the option of substituting a custom 7621** implementation for specialized deployments or systems for which SQLite 7622** does not provide a suitable implementation. In this case, the application 7623** creates and populates an instance of this structure to pass 7624** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7625** Additionally, an instance of this structure can be used as an 7626** output variable when querying the system for the current mutex 7627** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7628** 7629** ^The xMutexInit method defined by this structure is invoked as 7630** part of system initialization by the sqlite3_initialize() function. 7631** ^The xMutexInit routine is called by SQLite exactly once for each 7632** effective call to [sqlite3_initialize()]. 7633** 7634** ^The xMutexEnd method defined by this structure is invoked as 7635** part of system shutdown by the sqlite3_shutdown() function. The 7636** implementation of this method is expected to release all outstanding 7637** resources obtained by the mutex methods implementation, especially 7638** those obtained by the xMutexInit method. ^The xMutexEnd() 7639** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7640** 7641** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7642** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7643** xMutexNotheld) implement the following interfaces (respectively): 7644** 7645** <ul> 7646** <li> [sqlite3_mutex_alloc()] </li> 7647** <li> [sqlite3_mutex_free()] </li> 7648** <li> [sqlite3_mutex_enter()] </li> 7649** <li> [sqlite3_mutex_try()] </li> 7650** <li> [sqlite3_mutex_leave()] </li> 7651** <li> [sqlite3_mutex_held()] </li> 7652** <li> [sqlite3_mutex_notheld()] </li> 7653** </ul>)^ 7654** 7655** The only difference is that the public sqlite3_XXX functions enumerated 7656** above silently ignore any invocations that pass a NULL pointer instead 7657** of a valid mutex handle. The implementations of the methods defined 7658** by this structure are not required to handle this case. The results 7659** of passing a NULL pointer instead of a valid mutex handle are undefined 7660** (i.e. it is acceptable to provide an implementation that segfaults if 7661** it is passed a NULL pointer). 7662** 7663** The xMutexInit() method must be threadsafe. It must be harmless to 7664** invoke xMutexInit() multiple times within the same process and without 7665** intervening calls to xMutexEnd(). Second and subsequent calls to 7666** xMutexInit() must be no-ops. 7667** 7668** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7669** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7670** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7671** memory allocation for a fast or recursive mutex. 7672** 7673** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7674** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7675** If xMutexInit fails in any way, it is expected to clean up after itself 7676** prior to returning. 7677*/ 7678typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7679struct sqlite3_mutex_methods { 7680 int (*xMutexInit)(void); 7681 int (*xMutexEnd)(void); 7682 sqlite3_mutex *(*xMutexAlloc)(int); 7683 void (*xMutexFree)(sqlite3_mutex *); 7684 void (*xMutexEnter)(sqlite3_mutex *); 7685 int (*xMutexTry)(sqlite3_mutex *); 7686 void (*xMutexLeave)(sqlite3_mutex *); 7687 int (*xMutexHeld)(sqlite3_mutex *); 7688 int (*xMutexNotheld)(sqlite3_mutex *); 7689}; 7690 7691/* 7692** CAPI3REF: Mutex Verification Routines 7693** 7694** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7695** are intended for use inside assert() statements. The SQLite core 7696** never uses these routines except inside an assert() and applications 7697** are advised to follow the lead of the core. The SQLite core only 7698** provides implementations for these routines when it is compiled 7699** with the SQLITE_DEBUG flag. External mutex implementations 7700** are only required to provide these routines if SQLITE_DEBUG is 7701** defined and if NDEBUG is not defined. 7702** 7703** These routines should return true if the mutex in their argument 7704** is held or not held, respectively, by the calling thread. 7705** 7706** The implementation is not required to provide versions of these 7707** routines that actually work. If the implementation does not provide working 7708** versions of these routines, it should at least provide stubs that always 7709** return true so that one does not get spurious assertion failures. 7710** 7711** If the argument to sqlite3_mutex_held() is a NULL pointer then 7712** the routine should return 1. This seems counter-intuitive since 7713** clearly the mutex cannot be held if it does not exist. But 7714** the reason the mutex does not exist is because the build is not 7715** using mutexes. And we do not want the assert() containing the 7716** call to sqlite3_mutex_held() to fail, so a non-zero return is 7717** the appropriate thing to do. The sqlite3_mutex_notheld() 7718** interface should also return 1 when given a NULL pointer. 7719*/ 7720#ifndef NDEBUG 7721int sqlite3_mutex_held(sqlite3_mutex*); 7722int sqlite3_mutex_notheld(sqlite3_mutex*); 7723#endif 7724 7725/* 7726** CAPI3REF: Mutex Types 7727** 7728** The [sqlite3_mutex_alloc()] interface takes a single argument 7729** which is one of these integer constants. 7730** 7731** The set of static mutexes may change from one SQLite release to the 7732** next. Applications that override the built-in mutex logic must be 7733** prepared to accommodate additional static mutexes. 7734*/ 7735#define SQLITE_MUTEX_FAST 0 7736#define SQLITE_MUTEX_RECURSIVE 1 7737#define SQLITE_MUTEX_STATIC_MAIN 2 7738#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7739#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7740#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7741#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7742#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7743#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7744#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7745#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7746#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7747#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7748#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7749#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7750#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7751 7752/* Legacy compatibility: */ 7753#define SQLITE_MUTEX_STATIC_MASTER 2 7754 7755 7756/* 7757** CAPI3REF: Retrieve the mutex for a database connection 7758** METHOD: sqlite3 7759** 7760** ^This interface returns a pointer the [sqlite3_mutex] object that 7761** serializes access to the [database connection] given in the argument 7762** when the [threading mode] is Serialized. 7763** ^If the [threading mode] is Single-thread or Multi-thread then this 7764** routine returns a NULL pointer. 7765*/ 7766sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7767 7768/* 7769** CAPI3REF: Low-Level Control Of Database Files 7770** METHOD: sqlite3 7771** KEYWORDS: {file control} 7772** 7773** ^The [sqlite3_file_control()] interface makes a direct call to the 7774** xFileControl method for the [sqlite3_io_methods] object associated 7775** with a particular database identified by the second argument. ^The 7776** name of the database is "main" for the main database or "temp" for the 7777** TEMP database, or the name that appears after the AS keyword for 7778** databases that are added using the [ATTACH] SQL command. 7779** ^A NULL pointer can be used in place of "main" to refer to the 7780** main database file. 7781** ^The third and fourth parameters to this routine 7782** are passed directly through to the second and third parameters of 7783** the xFileControl method. ^The return value of the xFileControl 7784** method becomes the return value of this routine. 7785** 7786** A few opcodes for [sqlite3_file_control()] are handled directly 7787** by the SQLite core and never invoke the 7788** sqlite3_io_methods.xFileControl method. 7789** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7790** a pointer to the underlying [sqlite3_file] object to be written into 7791** the space pointed to by the 4th parameter. The 7792** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7793** the [sqlite3_file] object associated with the journal file instead of 7794** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7795** a pointer to the underlying [sqlite3_vfs] object for the file. 7796** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7797** from the pager. 7798** 7799** ^If the second parameter (zDbName) does not match the name of any 7800** open database file, then SQLITE_ERROR is returned. ^This error 7801** code is not remembered and will not be recalled by [sqlite3_errcode()] 7802** or [sqlite3_errmsg()]. The underlying xFileControl method might 7803** also return SQLITE_ERROR. There is no way to distinguish between 7804** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7805** xFileControl method. 7806** 7807** See also: [file control opcodes] 7808*/ 7809int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7810 7811/* 7812** CAPI3REF: Testing Interface 7813** 7814** ^The sqlite3_test_control() interface is used to read out internal 7815** state of SQLite and to inject faults into SQLite for testing 7816** purposes. ^The first parameter is an operation code that determines 7817** the number, meaning, and operation of all subsequent parameters. 7818** 7819** This interface is not for use by applications. It exists solely 7820** for verifying the correct operation of the SQLite library. Depending 7821** on how the SQLite library is compiled, this interface might not exist. 7822** 7823** The details of the operation codes, their meanings, the parameters 7824** they take, and what they do are all subject to change without notice. 7825** Unlike most of the SQLite API, this function is not guaranteed to 7826** operate consistently from one release to the next. 7827*/ 7828int sqlite3_test_control(int op, ...); 7829 7830/* 7831** CAPI3REF: Testing Interface Operation Codes 7832** 7833** These constants are the valid operation code parameters used 7834** as the first argument to [sqlite3_test_control()]. 7835** 7836** These parameters and their meanings are subject to change 7837** without notice. These values are for testing purposes only. 7838** Applications should not use any of these parameters or the 7839** [sqlite3_test_control()] interface. 7840*/ 7841#define SQLITE_TESTCTRL_FIRST 5 7842#define SQLITE_TESTCTRL_PRNG_SAVE 5 7843#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7844#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7845#define SQLITE_TESTCTRL_BITVEC_TEST 8 7846#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7847#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7848#define SQLITE_TESTCTRL_PENDING_BYTE 11 7849#define SQLITE_TESTCTRL_ASSERT 12 7850#define SQLITE_TESTCTRL_ALWAYS 13 7851#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 7852#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7853#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7854#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7855#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7856#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7857#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7858#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7859#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7860#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7861#define SQLITE_TESTCTRL_BYTEORDER 22 7862#define SQLITE_TESTCTRL_ISINIT 23 7863#define SQLITE_TESTCTRL_SORTER_MMAP 24 7864#define SQLITE_TESTCTRL_IMPOSTER 25 7865#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7866#define SQLITE_TESTCTRL_RESULT_INTREAL 27 7867#define SQLITE_TESTCTRL_PRNG_SEED 28 7868#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7869#define SQLITE_TESTCTRL_SEEK_COUNT 30 7870#define SQLITE_TESTCTRL_TRACEFLAGS 31 7871#define SQLITE_TESTCTRL_TUNE 32 7872#define SQLITE_TESTCTRL_LAST 32 /* Largest TESTCTRL */ 7873 7874/* 7875** CAPI3REF: SQL Keyword Checking 7876** 7877** These routines provide access to the set of SQL language keywords 7878** recognized by SQLite. Applications can uses these routines to determine 7879** whether or not a specific identifier needs to be escaped (for example, 7880** by enclosing in double-quotes) so as not to confuse the parser. 7881** 7882** The sqlite3_keyword_count() interface returns the number of distinct 7883** keywords understood by SQLite. 7884** 7885** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7886** makes *Z point to that keyword expressed as UTF8 and writes the number 7887** of bytes in the keyword into *L. The string that *Z points to is not 7888** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7889** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7890** or L are NULL or invalid pointers then calls to 7891** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7892** 7893** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7894** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7895** if it is and zero if not. 7896** 7897** The parser used by SQLite is forgiving. It is often possible to use 7898** a keyword as an identifier as long as such use does not result in a 7899** parsing ambiguity. For example, the statement 7900** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7901** creates a new table named "BEGIN" with three columns named 7902** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7903** using keywords as identifiers. Common techniques used to avoid keyword 7904** name collisions include: 7905** <ul> 7906** <li> Put all identifier names inside double-quotes. This is the official 7907** SQL way to escape identifier names. 7908** <li> Put identifier names inside [...]. This is not standard SQL, 7909** but it is what SQL Server does and so lots of programmers use this 7910** technique. 7911** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7912** with "Z". 7913** <li> Include a digit somewhere in every identifier name. 7914** </ul> 7915** 7916** Note that the number of keywords understood by SQLite can depend on 7917** compile-time options. For example, "VACUUM" is not a keyword if 7918** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7919** new keywords may be added to future releases of SQLite. 7920*/ 7921int sqlite3_keyword_count(void); 7922int sqlite3_keyword_name(int,const char**,int*); 7923int sqlite3_keyword_check(const char*,int); 7924 7925/* 7926** CAPI3REF: Dynamic String Object 7927** KEYWORDS: {dynamic string} 7928** 7929** An instance of the sqlite3_str object contains a dynamically-sized 7930** string under construction. 7931** 7932** The lifecycle of an sqlite3_str object is as follows: 7933** <ol> 7934** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7935** <li> ^Text is appended to the sqlite3_str object using various 7936** methods, such as [sqlite3_str_appendf()]. 7937** <li> ^The sqlite3_str object is destroyed and the string it created 7938** is returned using the [sqlite3_str_finish()] interface. 7939** </ol> 7940*/ 7941typedef struct sqlite3_str sqlite3_str; 7942 7943/* 7944** CAPI3REF: Create A New Dynamic String Object 7945** CONSTRUCTOR: sqlite3_str 7946** 7947** ^The [sqlite3_str_new(D)] interface allocates and initializes 7948** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7949** [sqlite3_str_new()] must be freed by a subsequent call to 7950** [sqlite3_str_finish(X)]. 7951** 7952** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7953** valid [sqlite3_str] object, though in the event of an out-of-memory 7954** error the returned object might be a special singleton that will 7955** silently reject new text, always return SQLITE_NOMEM from 7956** [sqlite3_str_errcode()], always return 0 for 7957** [sqlite3_str_length()], and always return NULL from 7958** [sqlite3_str_finish(X)]. It is always safe to use the value 7959** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7960** to any of the other [sqlite3_str] methods. 7961** 7962** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7963** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7964** length of the string contained in the [sqlite3_str] object will be 7965** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7966** of [SQLITE_MAX_LENGTH]. 7967*/ 7968sqlite3_str *sqlite3_str_new(sqlite3*); 7969 7970/* 7971** CAPI3REF: Finalize A Dynamic String 7972** DESTRUCTOR: sqlite3_str 7973** 7974** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7975** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7976** that contains the constructed string. The calling application should 7977** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7978** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7979** errors were encountered during construction of the string. ^The 7980** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7981** string in [sqlite3_str] object X is zero bytes long. 7982*/ 7983char *sqlite3_str_finish(sqlite3_str*); 7984 7985/* 7986** CAPI3REF: Add Content To A Dynamic String 7987** METHOD: sqlite3_str 7988** 7989** These interfaces add content to an sqlite3_str object previously obtained 7990** from [sqlite3_str_new()]. 7991** 7992** ^The [sqlite3_str_appendf(X,F,...)] and 7993** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7994** functionality of SQLite to append formatted text onto the end of 7995** [sqlite3_str] object X. 7996** 7997** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7998** onto the end of the [sqlite3_str] object X. N must be non-negative. 7999** S must contain at least N non-zero bytes of content. To append a 8000** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8001** method instead. 8002** 8003** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8004** zero-terminated string S onto the end of [sqlite3_str] object X. 8005** 8006** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8007** single-byte character C onto the end of [sqlite3_str] object X. 8008** ^This method can be used, for example, to add whitespace indentation. 8009** 8010** ^The [sqlite3_str_reset(X)] method resets the string under construction 8011** inside [sqlite3_str] object X back to zero bytes in length. 8012** 8013** These methods do not return a result code. ^If an error occurs, that fact 8014** is recorded in the [sqlite3_str] object and can be recovered by a 8015** subsequent call to [sqlite3_str_errcode(X)]. 8016*/ 8017void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8018void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8019void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8020void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8021void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8022void sqlite3_str_reset(sqlite3_str*); 8023 8024/* 8025** CAPI3REF: Status Of A Dynamic String 8026** METHOD: sqlite3_str 8027** 8028** These interfaces return the current status of an [sqlite3_str] object. 8029** 8030** ^If any prior errors have occurred while constructing the dynamic string 8031** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8032** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8033** [SQLITE_NOMEM] following any out-of-memory error, or 8034** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8035** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8036** 8037** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8038** of the dynamic string under construction in [sqlite3_str] object X. 8039** ^The length returned by [sqlite3_str_length(X)] does not include the 8040** zero-termination byte. 8041** 8042** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8043** content of the dynamic string under construction in X. The value 8044** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8045** and might be freed or altered by any subsequent method on the same 8046** [sqlite3_str] object. Applications must not used the pointer returned 8047** [sqlite3_str_value(X)] after any subsequent method call on the same 8048** object. ^Applications may change the content of the string returned 8049** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8050** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8051** write any byte after any subsequent sqlite3_str method call. 8052*/ 8053int sqlite3_str_errcode(sqlite3_str*); 8054int sqlite3_str_length(sqlite3_str*); 8055char *sqlite3_str_value(sqlite3_str*); 8056 8057/* 8058** CAPI3REF: SQLite Runtime Status 8059** 8060** ^These interfaces are used to retrieve runtime status information 8061** about the performance of SQLite, and optionally to reset various 8062** highwater marks. ^The first argument is an integer code for 8063** the specific parameter to measure. ^(Recognized integer codes 8064** are of the form [status parameters | SQLITE_STATUS_...].)^ 8065** ^The current value of the parameter is returned into *pCurrent. 8066** ^The highest recorded value is returned in *pHighwater. ^If the 8067** resetFlag is true, then the highest record value is reset after 8068** *pHighwater is written. ^(Some parameters do not record the highest 8069** value. For those parameters 8070** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8071** ^(Other parameters record only the highwater mark and not the current 8072** value. For these latter parameters nothing is written into *pCurrent.)^ 8073** 8074** ^The sqlite3_status() and sqlite3_status64() routines return 8075** SQLITE_OK on success and a non-zero [error code] on failure. 8076** 8077** If either the current value or the highwater mark is too large to 8078** be represented by a 32-bit integer, then the values returned by 8079** sqlite3_status() are undefined. 8080** 8081** See also: [sqlite3_db_status()] 8082*/ 8083int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8084int sqlite3_status64( 8085 int op, 8086 sqlite3_int64 *pCurrent, 8087 sqlite3_int64 *pHighwater, 8088 int resetFlag 8089); 8090 8091 8092/* 8093** CAPI3REF: Status Parameters 8094** KEYWORDS: {status parameters} 8095** 8096** These integer constants designate various run-time status parameters 8097** that can be returned by [sqlite3_status()]. 8098** 8099** <dl> 8100** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8101** <dd>This parameter is the current amount of memory checked out 8102** using [sqlite3_malloc()], either directly or indirectly. The 8103** figure includes calls made to [sqlite3_malloc()] by the application 8104** and internal memory usage by the SQLite library. Auxiliary page-cache 8105** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8106** this parameter. The amount returned is the sum of the allocation 8107** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8108** 8109** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8110** <dd>This parameter records the largest memory allocation request 8111** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8112** internal equivalents). Only the value returned in the 8113** *pHighwater parameter to [sqlite3_status()] is of interest. 8114** The value written into the *pCurrent parameter is undefined.</dd>)^ 8115** 8116** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8117** <dd>This parameter records the number of separate memory allocations 8118** currently checked out.</dd>)^ 8119** 8120** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8121** <dd>This parameter returns the number of pages used out of the 8122** [pagecache memory allocator] that was configured using 8123** [SQLITE_CONFIG_PAGECACHE]. The 8124** value returned is in pages, not in bytes.</dd>)^ 8125** 8126** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8127** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8128** <dd>This parameter returns the number of bytes of page cache 8129** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8130** buffer and where forced to overflow to [sqlite3_malloc()]. The 8131** returned value includes allocations that overflowed because they 8132** where too large (they were larger than the "sz" parameter to 8133** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8134** no space was left in the page cache.</dd>)^ 8135** 8136** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8137** <dd>This parameter records the largest memory allocation request 8138** handed to the [pagecache memory allocator]. Only the value returned in the 8139** *pHighwater parameter to [sqlite3_status()] is of interest. 8140** The value written into the *pCurrent parameter is undefined.</dd>)^ 8141** 8142** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8143** <dd>No longer used.</dd> 8144** 8145** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8146** <dd>No longer used.</dd> 8147** 8148** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8149** <dd>No longer used.</dd> 8150** 8151** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8152** <dd>The *pHighwater parameter records the deepest parser stack. 8153** The *pCurrent value is undefined. The *pHighwater value is only 8154** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8155** </dl> 8156** 8157** New status parameters may be added from time to time. 8158*/ 8159#define SQLITE_STATUS_MEMORY_USED 0 8160#define SQLITE_STATUS_PAGECACHE_USED 1 8161#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8162#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8163#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8164#define SQLITE_STATUS_MALLOC_SIZE 5 8165#define SQLITE_STATUS_PARSER_STACK 6 8166#define SQLITE_STATUS_PAGECACHE_SIZE 7 8167#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8168#define SQLITE_STATUS_MALLOC_COUNT 9 8169 8170/* 8171** CAPI3REF: Database Connection Status 8172** METHOD: sqlite3 8173** 8174** ^This interface is used to retrieve runtime status information 8175** about a single [database connection]. ^The first argument is the 8176** database connection object to be interrogated. ^The second argument 8177** is an integer constant, taken from the set of 8178** [SQLITE_DBSTATUS options], that 8179** determines the parameter to interrogate. The set of 8180** [SQLITE_DBSTATUS options] is likely 8181** to grow in future releases of SQLite. 8182** 8183** ^The current value of the requested parameter is written into *pCur 8184** and the highest instantaneous value is written into *pHiwtr. ^If 8185** the resetFlg is true, then the highest instantaneous value is 8186** reset back down to the current value. 8187** 8188** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8189** non-zero [error code] on failure. 8190** 8191** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8192*/ 8193int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8194 8195/* 8196** CAPI3REF: Status Parameters for database connections 8197** KEYWORDS: {SQLITE_DBSTATUS options} 8198** 8199** These constants are the available integer "verbs" that can be passed as 8200** the second argument to the [sqlite3_db_status()] interface. 8201** 8202** New verbs may be added in future releases of SQLite. Existing verbs 8203** might be discontinued. Applications should check the return code from 8204** [sqlite3_db_status()] to make sure that the call worked. 8205** The [sqlite3_db_status()] interface will return a non-zero error code 8206** if a discontinued or unsupported verb is invoked. 8207** 8208** <dl> 8209** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8210** <dd>This parameter returns the number of lookaside memory slots currently 8211** checked out.</dd>)^ 8212** 8213** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8214** <dd>This parameter returns the number of malloc attempts that were 8215** satisfied using lookaside memory. Only the high-water value is meaningful; 8216** the current value is always zero.)^ 8217** 8218** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8219** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8220** <dd>This parameter returns the number malloc attempts that might have 8221** been satisfied using lookaside memory but failed due to the amount of 8222** memory requested being larger than the lookaside slot size. 8223** Only the high-water value is meaningful; 8224** the current value is always zero.)^ 8225** 8226** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8227** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8228** <dd>This parameter returns the number malloc attempts that might have 8229** been satisfied using lookaside memory but failed due to all lookaside 8230** memory already being in use. 8231** Only the high-water value is meaningful; 8232** the current value is always zero.)^ 8233** 8234** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8235** <dd>This parameter returns the approximate number of bytes of heap 8236** memory used by all pager caches associated with the database connection.)^ 8237** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8238** 8239** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8240** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8241** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8242** pager cache is shared between two or more connections the bytes of heap 8243** memory used by that pager cache is divided evenly between the attached 8244** connections.)^ In other words, if none of the pager caches associated 8245** with the database connection are shared, this request returns the same 8246** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8247** shared, the value returned by this call will be smaller than that returned 8248** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8249** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8250** 8251** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8252** <dd>This parameter returns the approximate number of bytes of heap 8253** memory used to store the schema for all databases associated 8254** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8255** ^The full amount of memory used by the schemas is reported, even if the 8256** schema memory is shared with other database connections due to 8257** [shared cache mode] being enabled. 8258** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8259** 8260** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8261** <dd>This parameter returns the approximate number of bytes of heap 8262** and lookaside memory used by all prepared statements associated with 8263** the database connection.)^ 8264** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8265** </dd> 8266** 8267** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8268** <dd>This parameter returns the number of pager cache hits that have 8269** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8270** is always 0. 8271** </dd> 8272** 8273** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8274** <dd>This parameter returns the number of pager cache misses that have 8275** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8276** is always 0. 8277** </dd> 8278** 8279** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8280** <dd>This parameter returns the number of dirty cache entries that have 8281** been written to disk. Specifically, the number of pages written to the 8282** wal file in wal mode databases, or the number of pages written to the 8283** database file in rollback mode databases. Any pages written as part of 8284** transaction rollback or database recovery operations are not included. 8285** If an IO or other error occurs while writing a page to disk, the effect 8286** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8287** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8288** </dd> 8289** 8290** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8291** <dd>This parameter returns the number of dirty cache entries that have 8292** been written to disk in the middle of a transaction due to the page 8293** cache overflowing. Transactions are more efficient if they are written 8294** to disk all at once. When pages spill mid-transaction, that introduces 8295** additional overhead. This parameter can be used help identify 8296** inefficiencies that can be resolved by increasing the cache size. 8297** </dd> 8298** 8299** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8300** <dd>This parameter returns zero for the current value if and only if 8301** all foreign key constraints (deferred or immediate) have been 8302** resolved.)^ ^The highwater mark is always 0. 8303** </dd> 8304** </dl> 8305*/ 8306#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8307#define SQLITE_DBSTATUS_CACHE_USED 1 8308#define SQLITE_DBSTATUS_SCHEMA_USED 2 8309#define SQLITE_DBSTATUS_STMT_USED 3 8310#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8311#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8312#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8313#define SQLITE_DBSTATUS_CACHE_HIT 7 8314#define SQLITE_DBSTATUS_CACHE_MISS 8 8315#define SQLITE_DBSTATUS_CACHE_WRITE 9 8316#define SQLITE_DBSTATUS_DEFERRED_FKS 10 8317#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8318#define SQLITE_DBSTATUS_CACHE_SPILL 12 8319#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8320 8321 8322/* 8323** CAPI3REF: Prepared Statement Status 8324** METHOD: sqlite3_stmt 8325** 8326** ^(Each prepared statement maintains various 8327** [SQLITE_STMTSTATUS counters] that measure the number 8328** of times it has performed specific operations.)^ These counters can 8329** be used to monitor the performance characteristics of the prepared 8330** statements. For example, if the number of table steps greatly exceeds 8331** the number of table searches or result rows, that would tend to indicate 8332** that the prepared statement is using a full table scan rather than 8333** an index. 8334** 8335** ^(This interface is used to retrieve and reset counter values from 8336** a [prepared statement]. The first argument is the prepared statement 8337** object to be interrogated. The second argument 8338** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8339** to be interrogated.)^ 8340** ^The current value of the requested counter is returned. 8341** ^If the resetFlg is true, then the counter is reset to zero after this 8342** interface call returns. 8343** 8344** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8345*/ 8346int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8347 8348/* 8349** CAPI3REF: Status Parameters for prepared statements 8350** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8351** 8352** These preprocessor macros define integer codes that name counter 8353** values associated with the [sqlite3_stmt_status()] interface. 8354** The meanings of the various counters are as follows: 8355** 8356** <dl> 8357** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8358** <dd>^This is the number of times that SQLite has stepped forward in 8359** a table as part of a full table scan. Large numbers for this counter 8360** may indicate opportunities for performance improvement through 8361** careful use of indices.</dd> 8362** 8363** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8364** <dd>^This is the number of sort operations that have occurred. 8365** A non-zero value in this counter may indicate an opportunity to 8366** improvement performance through careful use of indices.</dd> 8367** 8368** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8369** <dd>^This is the number of rows inserted into transient indices that 8370** were created automatically in order to help joins run faster. 8371** A non-zero value in this counter may indicate an opportunity to 8372** improvement performance by adding permanent indices that do not 8373** need to be reinitialized each time the statement is run.</dd> 8374** 8375** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8376** <dd>^This is the number of virtual machine operations executed 8377** by the prepared statement if that number is less than or equal 8378** to 2147483647. The number of virtual machine operations can be 8379** used as a proxy for the total work done by the prepared statement. 8380** If the number of virtual machine operations exceeds 2147483647 8381** then the value returned by this statement status code is undefined. 8382** 8383** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8384** <dd>^This is the number of times that the prepare statement has been 8385** automatically regenerated due to schema changes or changes to 8386** [bound parameters] that might affect the query plan. 8387** 8388** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8389** <dd>^This is the number of times that the prepared statement has 8390** been run. A single "run" for the purposes of this counter is one 8391** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8392** The counter is incremented on the first [sqlite3_step()] call of each 8393** cycle. 8394** 8395** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8396** <dd>^This is the approximate number of bytes of heap memory 8397** used to store the prepared statement. ^This value is not actually 8398** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8399** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8400** </dd> 8401** </dl> 8402*/ 8403#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8404#define SQLITE_STMTSTATUS_SORT 2 8405#define SQLITE_STMTSTATUS_AUTOINDEX 3 8406#define SQLITE_STMTSTATUS_VM_STEP 4 8407#define SQLITE_STMTSTATUS_REPREPARE 5 8408#define SQLITE_STMTSTATUS_RUN 6 8409#define SQLITE_STMTSTATUS_MEMUSED 99 8410 8411/* 8412** CAPI3REF: Custom Page Cache Object 8413** 8414** The sqlite3_pcache type is opaque. It is implemented by 8415** the pluggable module. The SQLite core has no knowledge of 8416** its size or internal structure and never deals with the 8417** sqlite3_pcache object except by holding and passing pointers 8418** to the object. 8419** 8420** See [sqlite3_pcache_methods2] for additional information. 8421*/ 8422typedef struct sqlite3_pcache sqlite3_pcache; 8423 8424/* 8425** CAPI3REF: Custom Page Cache Object 8426** 8427** The sqlite3_pcache_page object represents a single page in the 8428** page cache. The page cache will allocate instances of this 8429** object. Various methods of the page cache use pointers to instances 8430** of this object as parameters or as their return value. 8431** 8432** See [sqlite3_pcache_methods2] for additional information. 8433*/ 8434typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8435struct sqlite3_pcache_page { 8436 void *pBuf; /* The content of the page */ 8437 void *pExtra; /* Extra information associated with the page */ 8438}; 8439 8440/* 8441** CAPI3REF: Application Defined Page Cache. 8442** KEYWORDS: {page cache} 8443** 8444** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8445** register an alternative page cache implementation by passing in an 8446** instance of the sqlite3_pcache_methods2 structure.)^ 8447** In many applications, most of the heap memory allocated by 8448** SQLite is used for the page cache. 8449** By implementing a 8450** custom page cache using this API, an application can better control 8451** the amount of memory consumed by SQLite, the way in which 8452** that memory is allocated and released, and the policies used to 8453** determine exactly which parts of a database file are cached and for 8454** how long. 8455** 8456** The alternative page cache mechanism is an 8457** extreme measure that is only needed by the most demanding applications. 8458** The built-in page cache is recommended for most uses. 8459** 8460** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8461** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8462** the application may discard the parameter after the call to 8463** [sqlite3_config()] returns.)^ 8464** 8465** [[the xInit() page cache method]] 8466** ^(The xInit() method is called once for each effective 8467** call to [sqlite3_initialize()])^ 8468** (usually only once during the lifetime of the process). ^(The xInit() 8469** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8470** The intent of the xInit() method is to set up global data structures 8471** required by the custom page cache implementation. 8472** ^(If the xInit() method is NULL, then the 8473** built-in default page cache is used instead of the application defined 8474** page cache.)^ 8475** 8476** [[the xShutdown() page cache method]] 8477** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8478** It can be used to clean up 8479** any outstanding resources before process shutdown, if required. 8480** ^The xShutdown() method may be NULL. 8481** 8482** ^SQLite automatically serializes calls to the xInit method, 8483** so the xInit method need not be threadsafe. ^The 8484** xShutdown method is only called from [sqlite3_shutdown()] so it does 8485** not need to be threadsafe either. All other methods must be threadsafe 8486** in multithreaded applications. 8487** 8488** ^SQLite will never invoke xInit() more than once without an intervening 8489** call to xShutdown(). 8490** 8491** [[the xCreate() page cache methods]] 8492** ^SQLite invokes the xCreate() method to construct a new cache instance. 8493** SQLite will typically create one cache instance for each open database file, 8494** though this is not guaranteed. ^The 8495** first parameter, szPage, is the size in bytes of the pages that must 8496** be allocated by the cache. ^szPage will always a power of two. ^The 8497** second parameter szExtra is a number of bytes of extra storage 8498** associated with each page cache entry. ^The szExtra parameter will 8499** a number less than 250. SQLite will use the 8500** extra szExtra bytes on each page to store metadata about the underlying 8501** database page on disk. The value passed into szExtra depends 8502** on the SQLite version, the target platform, and how SQLite was compiled. 8503** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8504** created will be used to cache database pages of a file stored on disk, or 8505** false if it is used for an in-memory database. The cache implementation 8506** does not have to do anything special based with the value of bPurgeable; 8507** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8508** never invoke xUnpin() except to deliberately delete a page. 8509** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8510** false will always have the "discard" flag set to true. 8511** ^Hence, a cache created with bPurgeable false will 8512** never contain any unpinned pages. 8513** 8514** [[the xCachesize() page cache method]] 8515** ^(The xCachesize() method may be called at any time by SQLite to set the 8516** suggested maximum cache-size (number of pages stored by) the cache 8517** instance passed as the first argument. This is the value configured using 8518** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8519** parameter, the implementation is not required to do anything with this 8520** value; it is advisory only. 8521** 8522** [[the xPagecount() page cache methods]] 8523** The xPagecount() method must return the number of pages currently 8524** stored in the cache, both pinned and unpinned. 8525** 8526** [[the xFetch() page cache methods]] 8527** The xFetch() method locates a page in the cache and returns a pointer to 8528** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8529** The pBuf element of the returned sqlite3_pcache_page object will be a 8530** pointer to a buffer of szPage bytes used to store the content of a 8531** single database page. The pExtra element of sqlite3_pcache_page will be 8532** a pointer to the szExtra bytes of extra storage that SQLite has requested 8533** for each entry in the page cache. 8534** 8535** The page to be fetched is determined by the key. ^The minimum key value 8536** is 1. After it has been retrieved using xFetch, the page is considered 8537** to be "pinned". 8538** 8539** If the requested page is already in the page cache, then the page cache 8540** implementation must return a pointer to the page buffer with its content 8541** intact. If the requested page is not already in the cache, then the 8542** cache implementation should use the value of the createFlag 8543** parameter to help it determined what action to take: 8544** 8545** <table border=1 width=85% align=center> 8546** <tr><th> createFlag <th> Behavior when page is not already in cache 8547** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8548** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8549** Otherwise return NULL. 8550** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8551** NULL if allocating a new page is effectively impossible. 8552** </table> 8553** 8554** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8555** will only use a createFlag of 2 after a prior call with a createFlag of 1 8556** failed.)^ In between the xFetch() calls, SQLite may 8557** attempt to unpin one or more cache pages by spilling the content of 8558** pinned pages to disk and synching the operating system disk cache. 8559** 8560** [[the xUnpin() page cache method]] 8561** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8562** as its second argument. If the third parameter, discard, is non-zero, 8563** then the page must be evicted from the cache. 8564** ^If the discard parameter is 8565** zero, then the page may be discarded or retained at the discretion of 8566** page cache implementation. ^The page cache implementation 8567** may choose to evict unpinned pages at any time. 8568** 8569** The cache must not perform any reference counting. A single 8570** call to xUnpin() unpins the page regardless of the number of prior calls 8571** to xFetch(). 8572** 8573** [[the xRekey() page cache methods]] 8574** The xRekey() method is used to change the key value associated with the 8575** page passed as the second argument. If the cache 8576** previously contains an entry associated with newKey, it must be 8577** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8578** to be pinned. 8579** 8580** When SQLite calls the xTruncate() method, the cache must discard all 8581** existing cache entries with page numbers (keys) greater than or equal 8582** to the value of the iLimit parameter passed to xTruncate(). If any 8583** of these pages are pinned, they are implicitly unpinned, meaning that 8584** they can be safely discarded. 8585** 8586** [[the xDestroy() page cache method]] 8587** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8588** All resources associated with the specified cache should be freed. ^After 8589** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8590** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8591** functions. 8592** 8593** [[the xShrink() page cache method]] 8594** ^SQLite invokes the xShrink() method when it wants the page cache to 8595** free up as much of heap memory as possible. The page cache implementation 8596** is not obligated to free any memory, but well-behaved implementations should 8597** do their best. 8598*/ 8599typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8600struct sqlite3_pcache_methods2 { 8601 int iVersion; 8602 void *pArg; 8603 int (*xInit)(void*); 8604 void (*xShutdown)(void*); 8605 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8606 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8607 int (*xPagecount)(sqlite3_pcache*); 8608 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8609 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8610 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8611 unsigned oldKey, unsigned newKey); 8612 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8613 void (*xDestroy)(sqlite3_pcache*); 8614 void (*xShrink)(sqlite3_pcache*); 8615}; 8616 8617/* 8618** This is the obsolete pcache_methods object that has now been replaced 8619** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8620** retained in the header file for backwards compatibility only. 8621*/ 8622typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8623struct sqlite3_pcache_methods { 8624 void *pArg; 8625 int (*xInit)(void*); 8626 void (*xShutdown)(void*); 8627 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8628 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8629 int (*xPagecount)(sqlite3_pcache*); 8630 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8631 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8632 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8633 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8634 void (*xDestroy)(sqlite3_pcache*); 8635}; 8636 8637 8638/* 8639** CAPI3REF: Online Backup Object 8640** 8641** The sqlite3_backup object records state information about an ongoing 8642** online backup operation. ^The sqlite3_backup object is created by 8643** a call to [sqlite3_backup_init()] and is destroyed by a call to 8644** [sqlite3_backup_finish()]. 8645** 8646** See Also: [Using the SQLite Online Backup API] 8647*/ 8648typedef struct sqlite3_backup sqlite3_backup; 8649 8650/* 8651** CAPI3REF: Online Backup API. 8652** 8653** The backup API copies the content of one database into another. 8654** It is useful either for creating backups of databases or 8655** for copying in-memory databases to or from persistent files. 8656** 8657** See Also: [Using the SQLite Online Backup API] 8658** 8659** ^SQLite holds a write transaction open on the destination database file 8660** for the duration of the backup operation. 8661** ^The source database is read-locked only while it is being read; 8662** it is not locked continuously for the entire backup operation. 8663** ^Thus, the backup may be performed on a live source database without 8664** preventing other database connections from 8665** reading or writing to the source database while the backup is underway. 8666** 8667** ^(To perform a backup operation: 8668** <ol> 8669** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8670** backup, 8671** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8672** the data between the two databases, and finally 8673** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8674** associated with the backup operation. 8675** </ol>)^ 8676** There should be exactly one call to sqlite3_backup_finish() for each 8677** successful call to sqlite3_backup_init(). 8678** 8679** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8680** 8681** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8682** [database connection] associated with the destination database 8683** and the database name, respectively. 8684** ^The database name is "main" for the main database, "temp" for the 8685** temporary database, or the name specified after the AS keyword in 8686** an [ATTACH] statement for an attached database. 8687** ^The S and M arguments passed to 8688** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8689** and database name of the source database, respectively. 8690** ^The source and destination [database connections] (parameters S and D) 8691** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8692** an error. 8693** 8694** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8695** there is already a read or read-write transaction open on the 8696** destination database. 8697** 8698** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8699** returned and an error code and error message are stored in the 8700** destination [database connection] D. 8701** ^The error code and message for the failed call to sqlite3_backup_init() 8702** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8703** [sqlite3_errmsg16()] functions. 8704** ^A successful call to sqlite3_backup_init() returns a pointer to an 8705** [sqlite3_backup] object. 8706** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8707** sqlite3_backup_finish() functions to perform the specified backup 8708** operation. 8709** 8710** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8711** 8712** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8713** the source and destination databases specified by [sqlite3_backup] object B. 8714** ^If N is negative, all remaining source pages are copied. 8715** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8716** are still more pages to be copied, then the function returns [SQLITE_OK]. 8717** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8718** from source to destination, then it returns [SQLITE_DONE]. 8719** ^If an error occurs while running sqlite3_backup_step(B,N), 8720** then an [error code] is returned. ^As well as [SQLITE_OK] and 8721** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8722** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8723** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8724** 8725** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8726** <ol> 8727** <li> the destination database was opened read-only, or 8728** <li> the destination database is using write-ahead-log journaling 8729** and the destination and source page sizes differ, or 8730** <li> the destination database is an in-memory database and the 8731** destination and source page sizes differ. 8732** </ol>)^ 8733** 8734** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8735** the [sqlite3_busy_handler | busy-handler function] 8736** is invoked (if one is specified). ^If the 8737** busy-handler returns non-zero before the lock is available, then 8738** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8739** sqlite3_backup_step() can be retried later. ^If the source 8740** [database connection] 8741** is being used to write to the source database when sqlite3_backup_step() 8742** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8743** case the call to sqlite3_backup_step() can be retried later on. ^(If 8744** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8745** [SQLITE_READONLY] is returned, then 8746** there is no point in retrying the call to sqlite3_backup_step(). These 8747** errors are considered fatal.)^ The application must accept 8748** that the backup operation has failed and pass the backup operation handle 8749** to the sqlite3_backup_finish() to release associated resources. 8750** 8751** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8752** on the destination file. ^The exclusive lock is not released until either 8753** sqlite3_backup_finish() is called or the backup operation is complete 8754** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8755** sqlite3_backup_step() obtains a [shared lock] on the source database that 8756** lasts for the duration of the sqlite3_backup_step() call. 8757** ^Because the source database is not locked between calls to 8758** sqlite3_backup_step(), the source database may be modified mid-way 8759** through the backup process. ^If the source database is modified by an 8760** external process or via a database connection other than the one being 8761** used by the backup operation, then the backup will be automatically 8762** restarted by the next call to sqlite3_backup_step(). ^If the source 8763** database is modified by the using the same database connection as is used 8764** by the backup operation, then the backup database is automatically 8765** updated at the same time. 8766** 8767** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8768** 8769** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8770** application wishes to abandon the backup operation, the application 8771** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8772** ^The sqlite3_backup_finish() interfaces releases all 8773** resources associated with the [sqlite3_backup] object. 8774** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8775** active write-transaction on the destination database is rolled back. 8776** The [sqlite3_backup] object is invalid 8777** and may not be used following a call to sqlite3_backup_finish(). 8778** 8779** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8780** sqlite3_backup_step() errors occurred, regardless or whether or not 8781** sqlite3_backup_step() completed. 8782** ^If an out-of-memory condition or IO error occurred during any prior 8783** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8784** sqlite3_backup_finish() returns the corresponding [error code]. 8785** 8786** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8787** is not a permanent error and does not affect the return value of 8788** sqlite3_backup_finish(). 8789** 8790** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8791** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8792** 8793** ^The sqlite3_backup_remaining() routine returns the number of pages still 8794** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8795** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8796** in the source database at the conclusion of the most recent 8797** sqlite3_backup_step(). 8798** ^(The values returned by these functions are only updated by 8799** sqlite3_backup_step(). If the source database is modified in a way that 8800** changes the size of the source database or the number of pages remaining, 8801** those changes are not reflected in the output of sqlite3_backup_pagecount() 8802** and sqlite3_backup_remaining() until after the next 8803** sqlite3_backup_step().)^ 8804** 8805** <b>Concurrent Usage of Database Handles</b> 8806** 8807** ^The source [database connection] may be used by the application for other 8808** purposes while a backup operation is underway or being initialized. 8809** ^If SQLite is compiled and configured to support threadsafe database 8810** connections, then the source database connection may be used concurrently 8811** from within other threads. 8812** 8813** However, the application must guarantee that the destination 8814** [database connection] is not passed to any other API (by any thread) after 8815** sqlite3_backup_init() is called and before the corresponding call to 8816** sqlite3_backup_finish(). SQLite does not currently check to see 8817** if the application incorrectly accesses the destination [database connection] 8818** and so no error code is reported, but the operations may malfunction 8819** nevertheless. Use of the destination database connection while a 8820** backup is in progress might also also cause a mutex deadlock. 8821** 8822** If running in [shared cache mode], the application must 8823** guarantee that the shared cache used by the destination database 8824** is not accessed while the backup is running. In practice this means 8825** that the application must guarantee that the disk file being 8826** backed up to is not accessed by any connection within the process, 8827** not just the specific connection that was passed to sqlite3_backup_init(). 8828** 8829** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8830** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8831** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8832** APIs are not strictly speaking threadsafe. If they are invoked at the 8833** same time as another thread is invoking sqlite3_backup_step() it is 8834** possible that they return invalid values. 8835*/ 8836sqlite3_backup *sqlite3_backup_init( 8837 sqlite3 *pDest, /* Destination database handle */ 8838 const char *zDestName, /* Destination database name */ 8839 sqlite3 *pSource, /* Source database handle */ 8840 const char *zSourceName /* Source database name */ 8841); 8842int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8843int sqlite3_backup_finish(sqlite3_backup *p); 8844int sqlite3_backup_remaining(sqlite3_backup *p); 8845int sqlite3_backup_pagecount(sqlite3_backup *p); 8846 8847/* 8848** CAPI3REF: Unlock Notification 8849** METHOD: sqlite3 8850** 8851** ^When running in shared-cache mode, a database operation may fail with 8852** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8853** individual tables within the shared-cache cannot be obtained. See 8854** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8855** ^This API may be used to register a callback that SQLite will invoke 8856** when the connection currently holding the required lock relinquishes it. 8857** ^This API is only available if the library was compiled with the 8858** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8859** 8860** See Also: [Using the SQLite Unlock Notification Feature]. 8861** 8862** ^Shared-cache locks are released when a database connection concludes 8863** its current transaction, either by committing it or rolling it back. 8864** 8865** ^When a connection (known as the blocked connection) fails to obtain a 8866** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8867** identity of the database connection (the blocking connection) that 8868** has locked the required resource is stored internally. ^After an 8869** application receives an SQLITE_LOCKED error, it may call the 8870** sqlite3_unlock_notify() method with the blocked connection handle as 8871** the first argument to register for a callback that will be invoked 8872** when the blocking connections current transaction is concluded. ^The 8873** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8874** call that concludes the blocking connection's transaction. 8875** 8876** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8877** there is a chance that the blocking connection will have already 8878** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8879** If this happens, then the specified callback is invoked immediately, 8880** from within the call to sqlite3_unlock_notify().)^ 8881** 8882** ^If the blocked connection is attempting to obtain a write-lock on a 8883** shared-cache table, and more than one other connection currently holds 8884** a read-lock on the same table, then SQLite arbitrarily selects one of 8885** the other connections to use as the blocking connection. 8886** 8887** ^(There may be at most one unlock-notify callback registered by a 8888** blocked connection. If sqlite3_unlock_notify() is called when the 8889** blocked connection already has a registered unlock-notify callback, 8890** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8891** called with a NULL pointer as its second argument, then any existing 8892** unlock-notify callback is canceled. ^The blocked connections 8893** unlock-notify callback may also be canceled by closing the blocked 8894** connection using [sqlite3_close()]. 8895** 8896** The unlock-notify callback is not reentrant. If an application invokes 8897** any sqlite3_xxx API functions from within an unlock-notify callback, a 8898** crash or deadlock may be the result. 8899** 8900** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8901** returns SQLITE_OK. 8902** 8903** <b>Callback Invocation Details</b> 8904** 8905** When an unlock-notify callback is registered, the application provides a 8906** single void* pointer that is passed to the callback when it is invoked. 8907** However, the signature of the callback function allows SQLite to pass 8908** it an array of void* context pointers. The first argument passed to 8909** an unlock-notify callback is a pointer to an array of void* pointers, 8910** and the second is the number of entries in the array. 8911** 8912** When a blocking connection's transaction is concluded, there may be 8913** more than one blocked connection that has registered for an unlock-notify 8914** callback. ^If two or more such blocked connections have specified the 8915** same callback function, then instead of invoking the callback function 8916** multiple times, it is invoked once with the set of void* context pointers 8917** specified by the blocked connections bundled together into an array. 8918** This gives the application an opportunity to prioritize any actions 8919** related to the set of unblocked database connections. 8920** 8921** <b>Deadlock Detection</b> 8922** 8923** Assuming that after registering for an unlock-notify callback a 8924** database waits for the callback to be issued before taking any further 8925** action (a reasonable assumption), then using this API may cause the 8926** application to deadlock. For example, if connection X is waiting for 8927** connection Y's transaction to be concluded, and similarly connection 8928** Y is waiting on connection X's transaction, then neither connection 8929** will proceed and the system may remain deadlocked indefinitely. 8930** 8931** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8932** detection. ^If a given call to sqlite3_unlock_notify() would put the 8933** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8934** unlock-notify callback is registered. The system is said to be in 8935** a deadlocked state if connection A has registered for an unlock-notify 8936** callback on the conclusion of connection B's transaction, and connection 8937** B has itself registered for an unlock-notify callback when connection 8938** A's transaction is concluded. ^Indirect deadlock is also detected, so 8939** the system is also considered to be deadlocked if connection B has 8940** registered for an unlock-notify callback on the conclusion of connection 8941** C's transaction, where connection C is waiting on connection A. ^Any 8942** number of levels of indirection are allowed. 8943** 8944** <b>The "DROP TABLE" Exception</b> 8945** 8946** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8947** always appropriate to call sqlite3_unlock_notify(). There is however, 8948** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8949** SQLite checks if there are any currently executing SELECT statements 8950** that belong to the same connection. If there are, SQLITE_LOCKED is 8951** returned. In this case there is no "blocking connection", so invoking 8952** sqlite3_unlock_notify() results in the unlock-notify callback being 8953** invoked immediately. If the application then re-attempts the "DROP TABLE" 8954** or "DROP INDEX" query, an infinite loop might be the result. 8955** 8956** One way around this problem is to check the extended error code returned 8957** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8958** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8959** the special "DROP TABLE/INDEX" case, the extended error code is just 8960** SQLITE_LOCKED.)^ 8961*/ 8962int sqlite3_unlock_notify( 8963 sqlite3 *pBlocked, /* Waiting connection */ 8964 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8965 void *pNotifyArg /* Argument to pass to xNotify */ 8966); 8967 8968 8969/* 8970** CAPI3REF: String Comparison 8971** 8972** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8973** and extensions to compare the contents of two buffers containing UTF-8 8974** strings in a case-independent fashion, using the same definition of "case 8975** independence" that SQLite uses internally when comparing identifiers. 8976*/ 8977int sqlite3_stricmp(const char *, const char *); 8978int sqlite3_strnicmp(const char *, const char *, int); 8979 8980/* 8981** CAPI3REF: String Globbing 8982* 8983** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8984** string X matches the [GLOB] pattern P. 8985** ^The definition of [GLOB] pattern matching used in 8986** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8987** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8988** is case sensitive. 8989** 8990** Note that this routine returns zero on a match and non-zero if the strings 8991** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8992** 8993** See also: [sqlite3_strlike()]. 8994*/ 8995int sqlite3_strglob(const char *zGlob, const char *zStr); 8996 8997/* 8998** CAPI3REF: String LIKE Matching 8999* 9000** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9001** string X matches the [LIKE] pattern P with escape character E. 9002** ^The definition of [LIKE] pattern matching used in 9003** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9004** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9005** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9006** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9007** insensitive - equivalent upper and lower case ASCII characters match 9008** one another. 9009** 9010** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9011** only ASCII characters are case folded. 9012** 9013** Note that this routine returns zero on a match and non-zero if the strings 9014** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9015** 9016** See also: [sqlite3_strglob()]. 9017*/ 9018int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9019 9020/* 9021** CAPI3REF: Error Logging Interface 9022** 9023** ^The [sqlite3_log()] interface writes a message into the [error log] 9024** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9025** ^If logging is enabled, the zFormat string and subsequent arguments are 9026** used with [sqlite3_snprintf()] to generate the final output string. 9027** 9028** The sqlite3_log() interface is intended for use by extensions such as 9029** virtual tables, collating functions, and SQL functions. While there is 9030** nothing to prevent an application from calling sqlite3_log(), doing so 9031** is considered bad form. 9032** 9033** The zFormat string must not be NULL. 9034** 9035** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9036** will not use dynamically allocated memory. The log message is stored in 9037** a fixed-length buffer on the stack. If the log message is longer than 9038** a few hundred characters, it will be truncated to the length of the 9039** buffer. 9040*/ 9041void sqlite3_log(int iErrCode, const char *zFormat, ...); 9042 9043/* 9044** CAPI3REF: Write-Ahead Log Commit Hook 9045** METHOD: sqlite3 9046** 9047** ^The [sqlite3_wal_hook()] function is used to register a callback that 9048** is invoked each time data is committed to a database in wal mode. 9049** 9050** ^(The callback is invoked by SQLite after the commit has taken place and 9051** the associated write-lock on the database released)^, so the implementation 9052** may read, write or [checkpoint] the database as required. 9053** 9054** ^The first parameter passed to the callback function when it is invoked 9055** is a copy of the third parameter passed to sqlite3_wal_hook() when 9056** registering the callback. ^The second is a copy of the database handle. 9057** ^The third parameter is the name of the database that was written to - 9058** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9059** is the number of pages currently in the write-ahead log file, 9060** including those that were just committed. 9061** 9062** The callback function should normally return [SQLITE_OK]. ^If an error 9063** code is returned, that error will propagate back up through the 9064** SQLite code base to cause the statement that provoked the callback 9065** to report an error, though the commit will have still occurred. If the 9066** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9067** that does not correspond to any valid SQLite error code, the results 9068** are undefined. 9069** 9070** A single database handle may have at most a single write-ahead log callback 9071** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9072** previously registered write-ahead log callback. ^The return value is 9073** a copy of the third parameter from the previous call, if any, or 0. 9074** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9075** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9076** overwrite any prior [sqlite3_wal_hook()] settings. 9077*/ 9078void *sqlite3_wal_hook( 9079 sqlite3*, 9080 int(*)(void *,sqlite3*,const char*,int), 9081 void* 9082); 9083 9084/* 9085** CAPI3REF: Configure an auto-checkpoint 9086** METHOD: sqlite3 9087** 9088** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9089** [sqlite3_wal_hook()] that causes any database on [database connection] D 9090** to automatically [checkpoint] 9091** after committing a transaction if there are N or 9092** more frames in the [write-ahead log] file. ^Passing zero or 9093** a negative value as the nFrame parameter disables automatic 9094** checkpoints entirely. 9095** 9096** ^The callback registered by this function replaces any existing callback 9097** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9098** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9099** configured by this function. 9100** 9101** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9102** from SQL. 9103** 9104** ^Checkpoints initiated by this mechanism are 9105** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9106** 9107** ^Every new [database connection] defaults to having the auto-checkpoint 9108** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9109** pages. The use of this interface 9110** is only necessary if the default setting is found to be suboptimal 9111** for a particular application. 9112*/ 9113int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9114 9115/* 9116** CAPI3REF: Checkpoint a database 9117** METHOD: sqlite3 9118** 9119** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9120** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9121** 9122** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9123** [write-ahead log] for database X on [database connection] D to be 9124** transferred into the database file and for the write-ahead log to 9125** be reset. See the [checkpointing] documentation for addition 9126** information. 9127** 9128** This interface used to be the only way to cause a checkpoint to 9129** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9130** interface was added. This interface is retained for backwards 9131** compatibility and as a convenience for applications that need to manually 9132** start a callback but which do not need the full power (and corresponding 9133** complication) of [sqlite3_wal_checkpoint_v2()]. 9134*/ 9135int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9136 9137/* 9138** CAPI3REF: Checkpoint a database 9139** METHOD: sqlite3 9140** 9141** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9142** operation on database X of [database connection] D in mode M. Status 9143** information is written back into integers pointed to by L and C.)^ 9144** ^(The M parameter must be a valid [checkpoint mode]:)^ 9145** 9146** <dl> 9147** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9148** ^Checkpoint as many frames as possible without waiting for any database 9149** readers or writers to finish, then sync the database file if all frames 9150** in the log were checkpointed. ^The [busy-handler callback] 9151** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9152** ^On the other hand, passive mode might leave the checkpoint unfinished 9153** if there are concurrent readers or writers. 9154** 9155** <dt>SQLITE_CHECKPOINT_FULL<dd> 9156** ^This mode blocks (it invokes the 9157** [sqlite3_busy_handler|busy-handler callback]) until there is no 9158** database writer and all readers are reading from the most recent database 9159** snapshot. ^It then checkpoints all frames in the log file and syncs the 9160** database file. ^This mode blocks new database writers while it is pending, 9161** but new database readers are allowed to continue unimpeded. 9162** 9163** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9164** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9165** that after checkpointing the log file it blocks (calls the 9166** [busy-handler callback]) 9167** until all readers are reading from the database file only. ^This ensures 9168** that the next writer will restart the log file from the beginning. 9169** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9170** database writer attempts while it is pending, but does not impede readers. 9171** 9172** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9173** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9174** addition that it also truncates the log file to zero bytes just prior 9175** to a successful return. 9176** </dl> 9177** 9178** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9179** the log file or to -1 if the checkpoint could not run because 9180** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9181** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9182** log file (including any that were already checkpointed before the function 9183** was called) or to -1 if the checkpoint could not run due to an error or 9184** because the database is not in WAL mode. ^Note that upon successful 9185** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9186** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9187** 9188** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9189** any other process is running a checkpoint operation at the same time, the 9190** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9191** busy-handler configured, it will not be invoked in this case. 9192** 9193** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9194** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9195** obtained immediately, and a busy-handler is configured, it is invoked and 9196** the writer lock retried until either the busy-handler returns 0 or the lock 9197** is successfully obtained. ^The busy-handler is also invoked while waiting for 9198** database readers as described above. ^If the busy-handler returns 0 before 9199** the writer lock is obtained or while waiting for database readers, the 9200** checkpoint operation proceeds from that point in the same way as 9201** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9202** without blocking any further. ^SQLITE_BUSY is returned in this case. 9203** 9204** ^If parameter zDb is NULL or points to a zero length string, then the 9205** specified operation is attempted on all WAL databases [attached] to 9206** [database connection] db. In this case the 9207** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9208** an SQLITE_BUSY error is encountered when processing one or more of the 9209** attached WAL databases, the operation is still attempted on any remaining 9210** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9211** error occurs while processing an attached database, processing is abandoned 9212** and the error code is returned to the caller immediately. ^If no error 9213** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9214** databases, SQLITE_OK is returned. 9215** 9216** ^If database zDb is the name of an attached database that is not in WAL 9217** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9218** zDb is not NULL (or a zero length string) and is not the name of any 9219** attached database, SQLITE_ERROR is returned to the caller. 9220** 9221** ^Unless it returns SQLITE_MISUSE, 9222** the sqlite3_wal_checkpoint_v2() interface 9223** sets the error information that is queried by 9224** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9225** 9226** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9227** from SQL. 9228*/ 9229int sqlite3_wal_checkpoint_v2( 9230 sqlite3 *db, /* Database handle */ 9231 const char *zDb, /* Name of attached database (or NULL) */ 9232 int eMode, /* SQLITE_CHECKPOINT_* value */ 9233 int *pnLog, /* OUT: Size of WAL log in frames */ 9234 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9235); 9236 9237/* 9238** CAPI3REF: Checkpoint Mode Values 9239** KEYWORDS: {checkpoint mode} 9240** 9241** These constants define all valid values for the "checkpoint mode" passed 9242** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9243** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9244** meaning of each of these checkpoint modes. 9245*/ 9246#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9247#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9248#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9249#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9250 9251/* 9252** CAPI3REF: Virtual Table Interface Configuration 9253** 9254** This function may be called by either the [xConnect] or [xCreate] method 9255** of a [virtual table] implementation to configure 9256** various facets of the virtual table interface. 9257** 9258** If this interface is invoked outside the context of an xConnect or 9259** xCreate virtual table method then the behavior is undefined. 9260** 9261** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9262** [database connection] in which the virtual table is being created and 9263** which is passed in as the first argument to the [xConnect] or [xCreate] 9264** method that is invoking sqlite3_vtab_config(). The C parameter is one 9265** of the [virtual table configuration options]. The presence and meaning 9266** of parameters after C depend on which [virtual table configuration option] 9267** is used. 9268*/ 9269int sqlite3_vtab_config(sqlite3*, int op, ...); 9270 9271/* 9272** CAPI3REF: Virtual Table Configuration Options 9273** KEYWORDS: {virtual table configuration options} 9274** KEYWORDS: {virtual table configuration option} 9275** 9276** These macros define the various options to the 9277** [sqlite3_vtab_config()] interface that [virtual table] implementations 9278** can use to customize and optimize their behavior. 9279** 9280** <dl> 9281** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9282** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9283** <dd>Calls of the form 9284** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9285** where X is an integer. If X is zero, then the [virtual table] whose 9286** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9287** support constraints. In this configuration (which is the default) if 9288** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9289** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9290** specified as part of the users SQL statement, regardless of the actual 9291** ON CONFLICT mode specified. 9292** 9293** If X is non-zero, then the virtual table implementation guarantees 9294** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9295** any modifications to internal or persistent data structures have been made. 9296** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9297** is able to roll back a statement or database transaction, and abandon 9298** or continue processing the current SQL statement as appropriate. 9299** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9300** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9301** had been ABORT. 9302** 9303** Virtual table implementations that are required to handle OR REPLACE 9304** must do so within the [xUpdate] method. If a call to the 9305** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9306** CONFLICT policy is REPLACE, the virtual table implementation should 9307** silently replace the appropriate rows within the xUpdate callback and 9308** return SQLITE_OK. Or, if this is not possible, it may return 9309** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9310** constraint handling. 9311** </dd> 9312** 9313** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9314** <dd>Calls of the form 9315** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9316** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9317** prohibits that virtual table from being used from within triggers and 9318** views. 9319** </dd> 9320** 9321** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9322** <dd>Calls of the form 9323** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9324** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9325** identify that virtual table as being safe to use from within triggers 9326** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9327** virtual table can do no serious harm even if it is controlled by a 9328** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9329** flag unless absolutely necessary. 9330** </dd> 9331** </dl> 9332*/ 9333#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9334#define SQLITE_VTAB_INNOCUOUS 2 9335#define SQLITE_VTAB_DIRECTONLY 3 9336 9337/* 9338** CAPI3REF: Determine The Virtual Table Conflict Policy 9339** 9340** This function may only be called from within a call to the [xUpdate] method 9341** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9342** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9343** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9344** of the SQL statement that triggered the call to the [xUpdate] method of the 9345** [virtual table]. 9346*/ 9347int sqlite3_vtab_on_conflict(sqlite3 *); 9348 9349/* 9350** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9351** 9352** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9353** method of a [virtual table], then it might return true if the 9354** column is being fetched as part of an UPDATE operation during which the 9355** column value will not change. The virtual table implementation can use 9356** this hint as permission to substitute a return value that is less 9357** expensive to compute and that the corresponding 9358** [xUpdate] method understands as a "no-change" value. 9359** 9360** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9361** the column is not changed by the UPDATE statement, then the xColumn 9362** method can optionally return without setting a result, without calling 9363** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9364** In that case, [sqlite3_value_nochange(X)] will return true for the 9365** same column in the [xUpdate] method. 9366** 9367** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9368** implementations should continue to give a correct answer even if the 9369** sqlite3_vtab_nochange() interface were to always return false. In the 9370** current implementation, the sqlite3_vtab_nochange() interface does always 9371** returns false for the enhanced [UPDATE FROM] statement. 9372*/ 9373int sqlite3_vtab_nochange(sqlite3_context*); 9374 9375/* 9376** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9377** 9378** This function may only be called from within a call to the [xBestIndex] 9379** method of a [virtual table]. 9380** 9381** The first argument must be the sqlite3_index_info object that is the 9382** first parameter to the xBestIndex() method. The second argument must be 9383** an index into the aConstraint[] array belonging to the sqlite3_index_info 9384** structure passed to xBestIndex. This function returns a pointer to a buffer 9385** containing the name of the collation sequence for the corresponding 9386** constraint. 9387*/ 9388SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9389 9390/* 9391** CAPI3REF: Conflict resolution modes 9392** KEYWORDS: {conflict resolution mode} 9393** 9394** These constants are returned by [sqlite3_vtab_on_conflict()] to 9395** inform a [virtual table] implementation what the [ON CONFLICT] mode 9396** is for the SQL statement being evaluated. 9397** 9398** Note that the [SQLITE_IGNORE] constant is also used as a potential 9399** return value from the [sqlite3_set_authorizer()] callback and that 9400** [SQLITE_ABORT] is also a [result code]. 9401*/ 9402#define SQLITE_ROLLBACK 1 9403/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9404#define SQLITE_FAIL 3 9405/* #define SQLITE_ABORT 4 // Also an error code */ 9406#define SQLITE_REPLACE 5 9407 9408/* 9409** CAPI3REF: Prepared Statement Scan Status Opcodes 9410** KEYWORDS: {scanstatus options} 9411** 9412** The following constants can be used for the T parameter to the 9413** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9414** different metric for sqlite3_stmt_scanstatus() to return. 9415** 9416** When the value returned to V is a string, space to hold that string is 9417** managed by the prepared statement S and will be automatically freed when 9418** S is finalized. 9419** 9420** <dl> 9421** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9422** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9423** set to the total number of times that the X-th loop has run.</dd> 9424** 9425** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9426** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9427** to the total number of rows examined by all iterations of the X-th loop.</dd> 9428** 9429** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9430** <dd>^The "double" variable pointed to by the V parameter will be set to the 9431** query planner's estimate for the average number of rows output from each 9432** iteration of the X-th loop. If the query planner's estimates was accurate, 9433** then this value will approximate the quotient NVISIT/NLOOP and the 9434** product of this value for all prior loops with the same SELECTID will 9435** be the NLOOP value for the current loop. 9436** 9437** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9438** <dd>^The "const char *" variable pointed to by the V parameter will be set 9439** to a zero-terminated UTF-8 string containing the name of the index or table 9440** used for the X-th loop. 9441** 9442** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9443** <dd>^The "const char *" variable pointed to by the V parameter will be set 9444** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9445** description for the X-th loop. 9446** 9447** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9448** <dd>^The "int" variable pointed to by the V parameter will be set to the 9449** "select-id" for the X-th loop. The select-id identifies which query or 9450** subquery the loop is part of. The main query has a select-id of zero. 9451** The select-id is the same value as is output in the first column 9452** of an [EXPLAIN QUERY PLAN] query. 9453** </dl> 9454*/ 9455#define SQLITE_SCANSTAT_NLOOP 0 9456#define SQLITE_SCANSTAT_NVISIT 1 9457#define SQLITE_SCANSTAT_EST 2 9458#define SQLITE_SCANSTAT_NAME 3 9459#define SQLITE_SCANSTAT_EXPLAIN 4 9460#define SQLITE_SCANSTAT_SELECTID 5 9461 9462/* 9463** CAPI3REF: Prepared Statement Scan Status 9464** METHOD: sqlite3_stmt 9465** 9466** This interface returns information about the predicted and measured 9467** performance for pStmt. Advanced applications can use this 9468** interface to compare the predicted and the measured performance and 9469** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9470** 9471** Since this interface is expected to be rarely used, it is only 9472** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9473** compile-time option. 9474** 9475** The "iScanStatusOp" parameter determines which status information to return. 9476** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9477** of this interface is undefined. 9478** ^The requested measurement is written into a variable pointed to by 9479** the "pOut" parameter. 9480** Parameter "idx" identifies the specific loop to retrieve statistics for. 9481** Loops are numbered starting from zero. ^If idx is out of range - less than 9482** zero or greater than or equal to the total number of loops used to implement 9483** the statement - a non-zero value is returned and the variable that pOut 9484** points to is unchanged. 9485** 9486** ^Statistics might not be available for all loops in all statements. ^In cases 9487** where there exist loops with no available statistics, this function behaves 9488** as if the loop did not exist - it returns non-zero and leave the variable 9489** that pOut points to unchanged. 9490** 9491** See also: [sqlite3_stmt_scanstatus_reset()] 9492*/ 9493int sqlite3_stmt_scanstatus( 9494 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9495 int idx, /* Index of loop to report on */ 9496 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9497 void *pOut /* Result written here */ 9498); 9499 9500/* 9501** CAPI3REF: Zero Scan-Status Counters 9502** METHOD: sqlite3_stmt 9503** 9504** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9505** 9506** This API is only available if the library is built with pre-processor 9507** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9508*/ 9509void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9510 9511/* 9512** CAPI3REF: Flush caches to disk mid-transaction 9513** METHOD: sqlite3 9514** 9515** ^If a write-transaction is open on [database connection] D when the 9516** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9517** pages in the pager-cache that are not currently in use are written out 9518** to disk. A dirty page may be in use if a database cursor created by an 9519** active SQL statement is reading from it, or if it is page 1 of a database 9520** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9521** interface flushes caches for all schemas - "main", "temp", and 9522** any [attached] databases. 9523** 9524** ^If this function needs to obtain extra database locks before dirty pages 9525** can be flushed to disk, it does so. ^If those locks cannot be obtained 9526** immediately and there is a busy-handler callback configured, it is invoked 9527** in the usual manner. ^If the required lock still cannot be obtained, then 9528** the database is skipped and an attempt made to flush any dirty pages 9529** belonging to the next (if any) database. ^If any databases are skipped 9530** because locks cannot be obtained, but no other error occurs, this 9531** function returns SQLITE_BUSY. 9532** 9533** ^If any other error occurs while flushing dirty pages to disk (for 9534** example an IO error or out-of-memory condition), then processing is 9535** abandoned and an SQLite [error code] is returned to the caller immediately. 9536** 9537** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9538** 9539** ^This function does not set the database handle error code or message 9540** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9541*/ 9542int sqlite3_db_cacheflush(sqlite3*); 9543 9544/* 9545** CAPI3REF: The pre-update hook. 9546** METHOD: sqlite3 9547** 9548** ^These interfaces are only available if SQLite is compiled using the 9549** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9550** 9551** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9552** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9553** on a database table. 9554** ^At most one preupdate hook may be registered at a time on a single 9555** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9556** the previous setting. 9557** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9558** with a NULL pointer as the second parameter. 9559** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9560** the first parameter to callbacks. 9561** 9562** ^The preupdate hook only fires for changes to real database tables; the 9563** preupdate hook is not invoked for changes to [virtual tables] or to 9564** system tables like sqlite_sequence or sqlite_stat1. 9565** 9566** ^The second parameter to the preupdate callback is a pointer to 9567** the [database connection] that registered the preupdate hook. 9568** ^The third parameter to the preupdate callback is one of the constants 9569** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9570** kind of update operation that is about to occur. 9571** ^(The fourth parameter to the preupdate callback is the name of the 9572** database within the database connection that is being modified. This 9573** will be "main" for the main database or "temp" for TEMP tables or 9574** the name given after the AS keyword in the [ATTACH] statement for attached 9575** databases.)^ 9576** ^The fifth parameter to the preupdate callback is the name of the 9577** table that is being modified. 9578** 9579** For an UPDATE or DELETE operation on a [rowid table], the sixth 9580** parameter passed to the preupdate callback is the initial [rowid] of the 9581** row being modified or deleted. For an INSERT operation on a rowid table, 9582** or any operation on a WITHOUT ROWID table, the value of the sixth 9583** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9584** seventh parameter is the final rowid value of the row being inserted 9585** or updated. The value of the seventh parameter passed to the callback 9586** function is not defined for operations on WITHOUT ROWID tables, or for 9587** DELETE operations on rowid tables. 9588** 9589** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9590** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9591** provide additional information about a preupdate event. These routines 9592** may only be called from within a preupdate callback. Invoking any of 9593** these routines from outside of a preupdate callback or with a 9594** [database connection] pointer that is different from the one supplied 9595** to the preupdate callback results in undefined and probably undesirable 9596** behavior. 9597** 9598** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9599** in the row that is being inserted, updated, or deleted. 9600** 9601** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9602** a [protected sqlite3_value] that contains the value of the Nth column of 9603** the table row before it is updated. The N parameter must be between 0 9604** and one less than the number of columns or the behavior will be 9605** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9606** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9607** behavior is undefined. The [sqlite3_value] that P points to 9608** will be destroyed when the preupdate callback returns. 9609** 9610** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9611** a [protected sqlite3_value] that contains the value of the Nth column of 9612** the table row after it is updated. The N parameter must be between 0 9613** and one less than the number of columns or the behavior will be 9614** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9615** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9616** behavior is undefined. The [sqlite3_value] that P points to 9617** will be destroyed when the preupdate callback returns. 9618** 9619** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9620** callback was invoked as a result of a direct insert, update, or delete 9621** operation; or 1 for inserts, updates, or deletes invoked by top-level 9622** triggers; or 2 for changes resulting from triggers called by top-level 9623** triggers; and so forth. 9624** 9625** When the [sqlite3_blob_write()] API is used to update a blob column, 9626** the pre-update hook is invoked with SQLITE_DELETE. This is because the 9627** in this case the new values are not available. In this case, when a 9628** callback made with op==SQLITE_DELETE is actuall a write using the 9629** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 9630** the index of the column being written. In other cases, where the 9631** pre-update hook is being invoked for some other reason, including a 9632** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 9633** 9634** See also: [sqlite3_update_hook()] 9635*/ 9636#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9637void *sqlite3_preupdate_hook( 9638 sqlite3 *db, 9639 void(*xPreUpdate)( 9640 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9641 sqlite3 *db, /* Database handle */ 9642 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9643 char const *zDb, /* Database name */ 9644 char const *zName, /* Table name */ 9645 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9646 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9647 ), 9648 void* 9649); 9650int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9651int sqlite3_preupdate_count(sqlite3 *); 9652int sqlite3_preupdate_depth(sqlite3 *); 9653int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9654int sqlite3_preupdate_blobwrite(sqlite3 *); 9655#endif 9656 9657/* 9658** CAPI3REF: Low-level system error code 9659** METHOD: sqlite3 9660** 9661** ^Attempt to return the underlying operating system error code or error 9662** number that caused the most recent I/O error or failure to open a file. 9663** The return value is OS-dependent. For example, on unix systems, after 9664** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9665** called to get back the underlying "errno" that caused the problem, such 9666** as ENOSPC, EAUTH, EISDIR, and so forth. 9667*/ 9668int sqlite3_system_errno(sqlite3*); 9669 9670/* 9671** CAPI3REF: Database Snapshot 9672** KEYWORDS: {snapshot} {sqlite3_snapshot} 9673** 9674** An instance of the snapshot object records the state of a [WAL mode] 9675** database for some specific point in history. 9676** 9677** In [WAL mode], multiple [database connections] that are open on the 9678** same database file can each be reading a different historical version 9679** of the database file. When a [database connection] begins a read 9680** transaction, that connection sees an unchanging copy of the database 9681** as it existed for the point in time when the transaction first started. 9682** Subsequent changes to the database from other connections are not seen 9683** by the reader until a new read transaction is started. 9684** 9685** The sqlite3_snapshot object records state information about an historical 9686** version of the database file so that it is possible to later open a new read 9687** transaction that sees that historical version of the database rather than 9688** the most recent version. 9689*/ 9690typedef struct sqlite3_snapshot { 9691 unsigned char hidden[48]; 9692} sqlite3_snapshot; 9693 9694/* 9695** CAPI3REF: Record A Database Snapshot 9696** CONSTRUCTOR: sqlite3_snapshot 9697** 9698** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9699** new [sqlite3_snapshot] object that records the current state of 9700** schema S in database connection D. ^On success, the 9701** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9702** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9703** If there is not already a read-transaction open on schema S when 9704** this function is called, one is opened automatically. 9705** 9706** The following must be true for this function to succeed. If any of 9707** the following statements are false when sqlite3_snapshot_get() is 9708** called, SQLITE_ERROR is returned. The final value of *P is undefined 9709** in this case. 9710** 9711** <ul> 9712** <li> The database handle must not be in [autocommit mode]. 9713** 9714** <li> Schema S of [database connection] D must be a [WAL mode] database. 9715** 9716** <li> There must not be a write transaction open on schema S of database 9717** connection D. 9718** 9719** <li> One or more transactions must have been written to the current wal 9720** file since it was created on disk (by any connection). This means 9721** that a snapshot cannot be taken on a wal mode database with no wal 9722** file immediately after it is first opened. At least one transaction 9723** must be written to it first. 9724** </ul> 9725** 9726** This function may also return SQLITE_NOMEM. If it is called with the 9727** database handle in autocommit mode but fails for some other reason, 9728** whether or not a read transaction is opened on schema S is undefined. 9729** 9730** The [sqlite3_snapshot] object returned from a successful call to 9731** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9732** to avoid a memory leak. 9733** 9734** The [sqlite3_snapshot_get()] interface is only available when the 9735** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9736*/ 9737SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9738 sqlite3 *db, 9739 const char *zSchema, 9740 sqlite3_snapshot **ppSnapshot 9741); 9742 9743/* 9744** CAPI3REF: Start a read transaction on an historical snapshot 9745** METHOD: sqlite3_snapshot 9746** 9747** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9748** transaction or upgrades an existing one for schema S of 9749** [database connection] D such that the read transaction refers to 9750** historical [snapshot] P, rather than the most recent change to the 9751** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9752** on success or an appropriate [error code] if it fails. 9753** 9754** ^In order to succeed, the database connection must not be in 9755** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9756** is already a read transaction open on schema S, then the database handle 9757** must have no active statements (SELECT statements that have been passed 9758** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9759** SQLITE_ERROR is returned if either of these conditions is violated, or 9760** if schema S does not exist, or if the snapshot object is invalid. 9761** 9762** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9763** snapshot has been overwritten by a [checkpoint]. In this case 9764** SQLITE_ERROR_SNAPSHOT is returned. 9765** 9766** If there is already a read transaction open when this function is 9767** invoked, then the same read transaction remains open (on the same 9768** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9769** is returned. If another error code - for example SQLITE_PROTOCOL or an 9770** SQLITE_IOERR error code - is returned, then the final state of the 9771** read transaction is undefined. If SQLITE_OK is returned, then the 9772** read transaction is now open on database snapshot P. 9773** 9774** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9775** database connection D does not know that the database file for 9776** schema S is in [WAL mode]. A database connection might not know 9777** that the database file is in [WAL mode] if there has been no prior 9778** I/O on that database connection, or if the database entered [WAL mode] 9779** after the most recent I/O on the database connection.)^ 9780** (Hint: Run "[PRAGMA application_id]" against a newly opened 9781** database connection in order to make it ready to use snapshots.) 9782** 9783** The [sqlite3_snapshot_open()] interface is only available when the 9784** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9785*/ 9786SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9787 sqlite3 *db, 9788 const char *zSchema, 9789 sqlite3_snapshot *pSnapshot 9790); 9791 9792/* 9793** CAPI3REF: Destroy a snapshot 9794** DESTRUCTOR: sqlite3_snapshot 9795** 9796** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9797** The application must eventually free every [sqlite3_snapshot] object 9798** using this routine to avoid a memory leak. 9799** 9800** The [sqlite3_snapshot_free()] interface is only available when the 9801** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9802*/ 9803SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9804 9805/* 9806** CAPI3REF: Compare the ages of two snapshot handles. 9807** METHOD: sqlite3_snapshot 9808** 9809** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9810** of two valid snapshot handles. 9811** 9812** If the two snapshot handles are not associated with the same database 9813** file, the result of the comparison is undefined. 9814** 9815** Additionally, the result of the comparison is only valid if both of the 9816** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9817** last time the wal file was deleted. The wal file is deleted when the 9818** database is changed back to rollback mode or when the number of database 9819** clients drops to zero. If either snapshot handle was obtained before the 9820** wal file was last deleted, the value returned by this function 9821** is undefined. 9822** 9823** Otherwise, this API returns a negative value if P1 refers to an older 9824** snapshot than P2, zero if the two handles refer to the same database 9825** snapshot, and a positive value if P1 is a newer snapshot than P2. 9826** 9827** This interface is only available if SQLite is compiled with the 9828** [SQLITE_ENABLE_SNAPSHOT] option. 9829*/ 9830SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9831 sqlite3_snapshot *p1, 9832 sqlite3_snapshot *p2 9833); 9834 9835/* 9836** CAPI3REF: Recover snapshots from a wal file 9837** METHOD: sqlite3_snapshot 9838** 9839** If a [WAL file] remains on disk after all database connections close 9840** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9841** or because the last process to have the database opened exited without 9842** calling [sqlite3_close()]) and a new connection is subsequently opened 9843** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9844** will only be able to open the last transaction added to the WAL file 9845** even though the WAL file contains other valid transactions. 9846** 9847** This function attempts to scan the WAL file associated with database zDb 9848** of database handle db and make all valid snapshots available to 9849** sqlite3_snapshot_open(). It is an error if there is already a read 9850** transaction open on the database, or if the database is not a WAL mode 9851** database. 9852** 9853** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9854** 9855** This interface is only available if SQLite is compiled with the 9856** [SQLITE_ENABLE_SNAPSHOT] option. 9857*/ 9858SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9859 9860/* 9861** CAPI3REF: Serialize a database 9862** 9863** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9864** that is a serialization of the S database on [database connection] D. 9865** If P is not a NULL pointer, then the size of the database in bytes 9866** is written into *P. 9867** 9868** For an ordinary on-disk database file, the serialization is just a 9869** copy of the disk file. For an in-memory database or a "TEMP" database, 9870** the serialization is the same sequence of bytes which would be written 9871** to disk if that database where backed up to disk. 9872** 9873** The usual case is that sqlite3_serialize() copies the serialization of 9874** the database into memory obtained from [sqlite3_malloc64()] and returns 9875** a pointer to that memory. The caller is responsible for freeing the 9876** returned value to avoid a memory leak. However, if the F argument 9877** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9878** are made, and the sqlite3_serialize() function will return a pointer 9879** to the contiguous memory representation of the database that SQLite 9880** is currently using for that database, or NULL if the no such contiguous 9881** memory representation of the database exists. A contiguous memory 9882** representation of the database will usually only exist if there has 9883** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9884** values of D and S. 9885** The size of the database is written into *P even if the 9886** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9887** of the database exists. 9888** 9889** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9890** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9891** allocation error occurs. 9892** 9893** This interface is omitted if SQLite is compiled with the 9894** [SQLITE_OMIT_DESERIALIZE] option. 9895*/ 9896unsigned char *sqlite3_serialize( 9897 sqlite3 *db, /* The database connection */ 9898 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9899 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9900 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9901); 9902 9903/* 9904** CAPI3REF: Flags for sqlite3_serialize 9905** 9906** Zero or more of the following constants can be OR-ed together for 9907** the F argument to [sqlite3_serialize(D,S,P,F)]. 9908** 9909** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9910** a pointer to contiguous in-memory database that it is currently using, 9911** without making a copy of the database. If SQLite is not currently using 9912** a contiguous in-memory database, then this option causes 9913** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9914** using a contiguous in-memory database if it has been initialized by a 9915** prior call to [sqlite3_deserialize()]. 9916*/ 9917#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9918 9919/* 9920** CAPI3REF: Deserialize a database 9921** 9922** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9923** [database connection] D to disconnect from database S and then 9924** reopen S as an in-memory database based on the serialization contained 9925** in P. The serialized database P is N bytes in size. M is the size of 9926** the buffer P, which might be larger than N. If M is larger than N, and 9927** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9928** permitted to add content to the in-memory database as long as the total 9929** size does not exceed M bytes. 9930** 9931** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9932** invoke sqlite3_free() on the serialization buffer when the database 9933** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9934** SQLite will try to increase the buffer size using sqlite3_realloc64() 9935** if writes on the database cause it to grow larger than M bytes. 9936** 9937** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9938** database is currently in a read transaction or is involved in a backup 9939** operation. 9940** 9941** It is not possible to deserialized into the TEMP database. If the 9942** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 9943** function returns SQLITE_ERROR. 9944** 9945** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9946** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9947** [sqlite3_free()] is invoked on argument P prior to returning. 9948** 9949** This interface is omitted if SQLite is compiled with the 9950** [SQLITE_OMIT_DESERIALIZE] option. 9951*/ 9952int sqlite3_deserialize( 9953 sqlite3 *db, /* The database connection */ 9954 const char *zSchema, /* Which DB to reopen with the deserialization */ 9955 unsigned char *pData, /* The serialized database content */ 9956 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9957 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9958 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9959); 9960 9961/* 9962** CAPI3REF: Flags for sqlite3_deserialize() 9963** 9964** The following are allowed values for 6th argument (the F argument) to 9965** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9966** 9967** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9968** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9969** and that SQLite should take ownership of this memory and automatically 9970** free it when it has finished using it. Without this flag, the caller 9971** is responsible for freeing any dynamically allocated memory. 9972** 9973** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9974** grow the size of the database using calls to [sqlite3_realloc64()]. This 9975** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9976** Without this flag, the deserialized database cannot increase in size beyond 9977** the number of bytes specified by the M parameter. 9978** 9979** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9980** should be treated as read-only. 9981*/ 9982#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9983#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9984#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9985 9986/* 9987** Undo the hack that converts floating point types to integer for 9988** builds on processors without floating point support. 9989*/ 9990#ifdef SQLITE_OMIT_FLOATING_POINT 9991# undef double 9992#endif 9993 9994#ifdef __cplusplus 9995} /* End of the 'extern "C"' block */ 9996#endif 9997#endif /* SQLITE3_H */ 9998