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** Provide the ability to override linkage features of the interface. 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51#ifndef SQLITE_API 52# define SQLITE_API 53#endif 54#ifndef SQLITE_CDECL 55# define SQLITE_CDECL 56#endif 57#ifndef SQLITE_APICALL 58# define SQLITE_APICALL 59#endif 60#ifndef SQLITE_STDCALL 61# define SQLITE_STDCALL SQLITE_APICALL 62#endif 63#ifndef SQLITE_CALLBACK 64# define SQLITE_CALLBACK 65#endif 66#ifndef SQLITE_SYSAPI 67# define SQLITE_SYSAPI 68#endif 69 70/* 71** These no-op macros are used in front of interfaces to mark those 72** interfaces as either deprecated or experimental. New applications 73** should not use deprecated interfaces - they are supported for backwards 74** compatibility only. Application writers should be aware that 75** experimental interfaces are subject to change in point releases. 76** 77** These macros used to resolve to various kinds of compiler magic that 78** would generate warning messages when they were used. But that 79** compiler magic ended up generating such a flurry of bug reports 80** that we have taken it all out and gone back to using simple 81** noop macros. 82*/ 83#define SQLITE_DEPRECATED 84#define SQLITE_EXPERIMENTAL 85 86/* 87** Ensure these symbols were not defined by some previous header file. 88*/ 89#ifdef SQLITE_VERSION 90# undef SQLITE_VERSION 91#endif 92#ifdef SQLITE_VERSION_NUMBER 93# undef SQLITE_VERSION_NUMBER 94#endif 95 96/* 97** CAPI3REF: Compile-Time Library Version Numbers 98** 99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100** evaluates to a string literal that is the SQLite version in the 101** format "X.Y.Z" where X is the major version number (always 3 for 102** SQLite3) and Y is the minor version number and Z is the release number.)^ 103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105** numbers used in [SQLITE_VERSION].)^ 106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107** be larger than the release from which it is derived. Either Y will 108** be held constant and Z will be incremented or else Y will be incremented 109** and Z will be reset to zero. 110** 111** Since [version 3.6.18] ([dateof:3.6.18]), 112** SQLite source code has been stored in the 113** <a href="http://www.fossil-scm.org/">Fossil configuration management 114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115** a string which identifies a particular check-in of SQLite 116** within its configuration management system. ^The SQLITE_SOURCE_ID 117** string contains the date and time of the check-in (UTC) and a SHA1 118** or SHA3-256 hash of the entire source tree. If the source code has 119** been edited in any way since it was last checked in, then the last 120** four hexadecimal digits of the hash may be modified. 121** 122** See also: [sqlite3_libversion()], 123** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124** [sqlite_version()] and [sqlite_source_id()]. 125*/ 126#define SQLITE_VERSION "--VERS--" 127#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 128#define SQLITE_SOURCE_ID "--SOURCE-ID--" 129 130/* 131** CAPI3REF: Run-Time Library Version Numbers 132** KEYWORDS: sqlite3_version sqlite3_sourceid 133** 134** These interfaces provide the same information as the [SQLITE_VERSION], 135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136** but are associated with the library instead of the header file. ^(Cautious 137** programmers might include assert() statements in their application to 138** verify that values returned by these interfaces match the macros in 139** the header, and thus ensure that the application is 140** compiled with matching library and header files. 141** 142** <blockquote><pre> 143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146** </pre></blockquote>)^ 147** 148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149** macro. ^The sqlite3_libversion() function returns a pointer to the 150** to the sqlite3_version[] string constant. The sqlite3_libversion() 151** function is provided for use in DLLs since DLL users usually do not have 152** direct access to string constants within the DLL. ^The 153** sqlite3_libversion_number() function returns an integer equal to 154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155** a pointer to a string constant whose value is the same as the 156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157** using an edited copy of [the amalgamation], then the last four characters 158** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159** 160** See also: [sqlite_version()] and [sqlite_source_id()]. 161*/ 162SQLITE_EXTERN const char sqlite3_version[]; 163const char *sqlite3_libversion(void); 164const char *sqlite3_sourceid(void); 165int sqlite3_libversion_number(void); 166 167/* 168** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169** 170** ^The sqlite3_compileoption_used() function returns 0 or 1 171** indicating whether the specified option was defined at 172** compile time. ^The SQLITE_ prefix may be omitted from the 173** option name passed to sqlite3_compileoption_used(). 174** 175** ^The sqlite3_compileoption_get() function allows iterating 176** over the list of options that were defined at compile time by 177** returning the N-th compile time option string. ^If N is out of range, 178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179** prefix is omitted from any strings returned by 180** sqlite3_compileoption_get(). 181** 182** ^Support for the diagnostic functions sqlite3_compileoption_used() 183** and sqlite3_compileoption_get() may be omitted by specifying the 184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185** 186** See also: SQL functions [sqlite_compileoption_used()] and 187** [sqlite_compileoption_get()] and the [compile_options pragma]. 188*/ 189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190int sqlite3_compileoption_used(const char *zOptName); 191const char *sqlite3_compileoption_get(int N); 192#else 193# define sqlite3_compileoption_used(X) 0 194# define sqlite3_compileoption_get(X) ((void*)0) 195#endif 196 197/* 198** CAPI3REF: Test To See If The Library Is Threadsafe 199** 200** ^The sqlite3_threadsafe() function returns zero if and only if 201** SQLite was compiled with mutexing code omitted due to the 202** [SQLITE_THREADSAFE] compile-time option being set to 0. 203** 204** SQLite can be compiled with or without mutexes. When 205** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206** are enabled and SQLite is threadsafe. When the 207** [SQLITE_THREADSAFE] macro is 0, 208** the mutexes are omitted. Without the mutexes, it is not safe 209** to use SQLite concurrently from more than one thread. 210** 211** Enabling mutexes incurs a measurable performance penalty. 212** So if speed is of utmost importance, it makes sense to disable 213** the mutexes. But for maximum safety, mutexes should be enabled. 214** ^The default behavior is for mutexes to be enabled. 215** 216** This interface can be used by an application to make sure that the 217** version of SQLite that it is linking against was compiled with 218** the desired setting of the [SQLITE_THREADSAFE] macro. 219** 220** This interface only reports on the compile-time mutex setting 221** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223** can be fully or partially disabled using a call to [sqlite3_config()] 224** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226** sqlite3_threadsafe() function shows only the compile-time setting of 227** thread safety, not any run-time changes to that setting made by 228** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229** is unchanged by calls to sqlite3_config().)^ 230** 231** See the [threading mode] documentation for additional information. 232*/ 233int sqlite3_threadsafe(void); 234 235/* 236** CAPI3REF: Database Connection Handle 237** KEYWORDS: {database connection} {database connections} 238** 239** Each open SQLite database is represented by a pointer to an instance of 240** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243** and [sqlite3_close_v2()] are its destructors. There are many other 244** interfaces (such as 245** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246** [sqlite3_busy_timeout()] to name but three) that are methods on an 247** sqlite3 object. 248*/ 249typedef struct sqlite3 sqlite3; 250 251/* 252** CAPI3REF: 64-Bit Integer Types 253** KEYWORDS: sqlite_int64 sqlite_uint64 254** 255** Because there is no cross-platform way to specify 64-bit integer types 256** SQLite includes typedefs for 64-bit signed and unsigned integers. 257** 258** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260** compatibility only. 261** 262** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264** sqlite3_uint64 and sqlite_uint64 types can store integer values 265** between 0 and +18446744073709551615 inclusive. 266*/ 267#ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269# ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271# else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273# endif 274#elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277#else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280#endif 281typedef sqlite_int64 sqlite3_int64; 282typedef sqlite_uint64 sqlite3_uint64; 283 284/* 285** If compiling for a processor that lacks floating point support, 286** substitute integer for floating-point. 287*/ 288#ifdef SQLITE_OMIT_FLOATING_POINT 289# define double sqlite3_int64 290#endif 291 292/* 293** CAPI3REF: Closing A Database Connection 294** DESTRUCTOR: sqlite3 295** 296** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297** for the [sqlite3] object. 298** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299** the [sqlite3] object is successfully destroyed and all associated 300** resources are deallocated. 301** 302** Ideally, applications should [sqlite3_finalize | finalize] all 303** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 304** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 305** with the [sqlite3] object prior to attempting to close the object. 306** ^If the database connection is associated with unfinalized prepared 307** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 308** sqlite3_close() will leave the database connection open and return 309** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 310** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 311** it returns [SQLITE_OK] regardless, but instead of deallocating the database 312** connection immediately, it marks the database connection as an unusable 313** "zombie" and makes arrangements to automatically deallocate the database 314** connection after all prepared statements are finalized, all BLOB handles 315** are closed, and all backups have finished. The sqlite3_close_v2() interface 316** is intended for use with host languages that are garbage collected, and 317** where the order in which destructors are called is arbitrary. 318** 319** ^If an [sqlite3] object is destroyed while a transaction is open, 320** the transaction is automatically rolled back. 321** 322** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 323** must be either a NULL 324** pointer or an [sqlite3] object pointer obtained 325** from [sqlite3_open()], [sqlite3_open16()], or 326** [sqlite3_open_v2()], and not previously closed. 327** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 328** argument is a harmless no-op. 329*/ 330int sqlite3_close(sqlite3*); 331int sqlite3_close_v2(sqlite3*); 332 333/* 334** The type for a callback function. 335** This is legacy and deprecated. It is included for historical 336** compatibility and is not documented. 337*/ 338typedef int (*sqlite3_callback)(void*,int,char**, char**); 339 340/* 341** CAPI3REF: One-Step Query Execution Interface 342** METHOD: sqlite3 343** 344** The sqlite3_exec() interface is a convenience wrapper around 345** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 346** that allows an application to run multiple statements of SQL 347** without having to use a lot of C code. 348** 349** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 350** semicolon-separate SQL statements passed into its 2nd argument, 351** in the context of the [database connection] passed in as its 1st 352** argument. ^If the callback function of the 3rd argument to 353** sqlite3_exec() is not NULL, then it is invoked for each result row 354** coming out of the evaluated SQL statements. ^The 4th argument to 355** sqlite3_exec() is relayed through to the 1st argument of each 356** callback invocation. ^If the callback pointer to sqlite3_exec() 357** is NULL, then no callback is ever invoked and result rows are 358** ignored. 359** 360** ^If an error occurs while evaluating the SQL statements passed into 361** sqlite3_exec(), then execution of the current statement stops and 362** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 363** is not NULL then any error message is written into memory obtained 364** from [sqlite3_malloc()] and passed back through the 5th parameter. 365** To avoid memory leaks, the application should invoke [sqlite3_free()] 366** on error message strings returned through the 5th parameter of 367** sqlite3_exec() after the error message string is no longer needed. 368** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 369** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 370** NULL before returning. 371** 372** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 373** routine returns SQLITE_ABORT without invoking the callback again and 374** without running any subsequent SQL statements. 375** 376** ^The 2nd argument to the sqlite3_exec() callback function is the 377** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 378** callback is an array of pointers to strings obtained as if from 379** [sqlite3_column_text()], one for each column. ^If an element of a 380** result row is NULL then the corresponding string pointer for the 381** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 382** sqlite3_exec() callback is an array of pointers to strings where each 383** entry represents the name of corresponding result column as obtained 384** from [sqlite3_column_name()]. 385** 386** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 387** to an empty string, or a pointer that contains only whitespace and/or 388** SQL comments, then no SQL statements are evaluated and the database 389** is not changed. 390** 391** Restrictions: 392** 393** <ul> 394** <li> The application must ensure that the 1st parameter to sqlite3_exec() 395** is a valid and open [database connection]. 396** <li> The application must not close the [database connection] specified by 397** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 398** <li> The application must not modify the SQL statement text passed into 399** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 400** </ul> 401*/ 402int sqlite3_exec( 403 sqlite3*, /* An open database */ 404 const char *sql, /* SQL to be evaluated */ 405 int (*callback)(void*,int,char**,char**), /* Callback function */ 406 void *, /* 1st argument to callback */ 407 char **errmsg /* Error msg written here */ 408); 409 410/* 411** CAPI3REF: Result Codes 412** KEYWORDS: {result code definitions} 413** 414** Many SQLite functions return an integer result code from the set shown 415** here in order to indicate success or failure. 416** 417** New error codes may be added in future versions of SQLite. 418** 419** See also: [extended result code definitions] 420*/ 421#define SQLITE_OK 0 /* Successful result */ 422/* beginning-of-error-codes */ 423#define SQLITE_ERROR 1 /* Generic error */ 424#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 425#define SQLITE_PERM 3 /* Access permission denied */ 426#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 427#define SQLITE_BUSY 5 /* The database file is locked */ 428#define SQLITE_LOCKED 6 /* A table in the database is locked */ 429#define SQLITE_NOMEM 7 /* A malloc() failed */ 430#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 431#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 432#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 433#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 434#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 435#define SQLITE_FULL 13 /* Insertion failed because database is full */ 436#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 437#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 438#define SQLITE_EMPTY 16 /* Internal use only */ 439#define SQLITE_SCHEMA 17 /* The database schema changed */ 440#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 441#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 442#define SQLITE_MISMATCH 20 /* Data type mismatch */ 443#define SQLITE_MISUSE 21 /* Library used incorrectly */ 444#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 445#define SQLITE_AUTH 23 /* Authorization denied */ 446#define SQLITE_FORMAT 24 /* Not used */ 447#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 448#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 449#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 450#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 451#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 452#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 453/* end-of-error-codes */ 454 455/* 456** CAPI3REF: Extended Result Codes 457** KEYWORDS: {extended result code definitions} 458** 459** In its default configuration, SQLite API routines return one of 30 integer 460** [result codes]. However, experience has shown that many of 461** these result codes are too coarse-grained. They do not provide as 462** much information about problems as programmers might like. In an effort to 463** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 464** and later) include 465** support for additional result codes that provide more detailed information 466** about errors. These [extended result codes] are enabled or disabled 467** on a per database connection basis using the 468** [sqlite3_extended_result_codes()] API. Or, the extended code for 469** the most recent error can be obtained using 470** [sqlite3_extended_errcode()]. 471*/ 472#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 473#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 474#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 475#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 476#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 477#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 478#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 479#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 480#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 481#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 482#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 483#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 484#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 485#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 486#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 487#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 488#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 489#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 490#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 491#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 492#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 493#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 494#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 495#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 496#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 497#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 498#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 499#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 500#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 501#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 502#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 503#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 504#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 505#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 506#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 507#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 508#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 509#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 510#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 511#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 512#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 513#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 514#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 515#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 516#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 517#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 518#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 519#define SQLITE_CANTOPEN_EXISTS (SQLITE_CANTOPEN | (7<<8)) 520#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 521#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 522#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 523#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 524#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 525#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 526#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 527#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 528#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 529#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 530#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 531#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 532#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 533#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 534#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 535#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 536#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 537#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 538#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 539#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 540#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 541#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 542#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 543#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 544#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 545#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 546#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 547 548/* 549** CAPI3REF: Flags For File Open Operations 550** 551** These bit values are intended for use in the 552** 3rd parameter to the [sqlite3_open_v2()] interface and 553** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 554*/ 555#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 556#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 557#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 558#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 559#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 560#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 561#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 562#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 563#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 564#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 565#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 566#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 567#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 568#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 569#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 570#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 571#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 572#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 573#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 574#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 575#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 576 577/* Reserved: 0x00F00000 */ 578/* Legacy compatibility: */ 579#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 580 581 582/* 583** CAPI3REF: Device Characteristics 584** 585** The xDeviceCharacteristics method of the [sqlite3_io_methods] 586** object returns an integer which is a vector of these 587** bit values expressing I/O characteristics of the mass storage 588** device that holds the file that the [sqlite3_io_methods] 589** refers to. 590** 591** The SQLITE_IOCAP_ATOMIC property means that all writes of 592** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 593** mean that writes of blocks that are nnn bytes in size and 594** are aligned to an address which is an integer multiple of 595** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 596** that when data is appended to a file, the data is appended 597** first then the size of the file is extended, never the other 598** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 599** information is written to disk in the same order as calls 600** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 601** after reboot following a crash or power loss, the only bytes in a 602** file that were written at the application level might have changed 603** and that adjacent bytes, even bytes within the same sector are 604** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 605** flag indicates that a file cannot be deleted when open. The 606** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 607** read-only media and cannot be changed even by processes with 608** elevated privileges. 609** 610** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 611** filesystem supports doing multiple write operations atomically when those 612** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 613** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 614*/ 615#define SQLITE_IOCAP_ATOMIC 0x00000001 616#define SQLITE_IOCAP_ATOMIC512 0x00000002 617#define SQLITE_IOCAP_ATOMIC1K 0x00000004 618#define SQLITE_IOCAP_ATOMIC2K 0x00000008 619#define SQLITE_IOCAP_ATOMIC4K 0x00000010 620#define SQLITE_IOCAP_ATOMIC8K 0x00000020 621#define SQLITE_IOCAP_ATOMIC16K 0x00000040 622#define SQLITE_IOCAP_ATOMIC32K 0x00000080 623#define SQLITE_IOCAP_ATOMIC64K 0x00000100 624#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 625#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 626#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 627#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 628#define SQLITE_IOCAP_IMMUTABLE 0x00002000 629#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 630 631/* 632** CAPI3REF: File Locking Levels 633** 634** SQLite uses one of these integer values as the second 635** argument to calls it makes to the xLock() and xUnlock() methods 636** of an [sqlite3_io_methods] object. 637*/ 638#define SQLITE_LOCK_NONE 0 639#define SQLITE_LOCK_SHARED 1 640#define SQLITE_LOCK_RESERVED 2 641#define SQLITE_LOCK_PENDING 3 642#define SQLITE_LOCK_EXCLUSIVE 4 643 644/* 645** CAPI3REF: Synchronization Type Flags 646** 647** When SQLite invokes the xSync() method of an 648** [sqlite3_io_methods] object it uses a combination of 649** these integer values as the second argument. 650** 651** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 652** sync operation only needs to flush data to mass storage. Inode 653** information need not be flushed. If the lower four bits of the flag 654** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 655** If the lower four bits equal SQLITE_SYNC_FULL, that means 656** to use Mac OS X style fullsync instead of fsync(). 657** 658** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 659** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 660** settings. The [synchronous pragma] determines when calls to the 661** xSync VFS method occur and applies uniformly across all platforms. 662** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 663** energetic or rigorous or forceful the sync operations are and 664** only make a difference on Mac OSX for the default SQLite code. 665** (Third-party VFS implementations might also make the distinction 666** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 667** operating systems natively supported by SQLite, only Mac OSX 668** cares about the difference.) 669*/ 670#define SQLITE_SYNC_NORMAL 0x00002 671#define SQLITE_SYNC_FULL 0x00003 672#define SQLITE_SYNC_DATAONLY 0x00010 673 674/* 675** CAPI3REF: OS Interface Open File Handle 676** 677** An [sqlite3_file] object represents an open file in the 678** [sqlite3_vfs | OS interface layer]. Individual OS interface 679** implementations will 680** want to subclass this object by appending additional fields 681** for their own use. The pMethods entry is a pointer to an 682** [sqlite3_io_methods] object that defines methods for performing 683** I/O operations on the open file. 684*/ 685typedef struct sqlite3_file sqlite3_file; 686struct sqlite3_file { 687 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 688}; 689 690/* 691** CAPI3REF: OS Interface File Virtual Methods Object 692** 693** Every file opened by the [sqlite3_vfs.xOpen] method populates an 694** [sqlite3_file] object (or, more commonly, a subclass of the 695** [sqlite3_file] object) with a pointer to an instance of this object. 696** This object defines the methods used to perform various operations 697** against the open file represented by the [sqlite3_file] object. 698** 699** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 700** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 701** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 702** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 703** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 704** to NULL. 705** 706** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 707** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 708** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 709** flag may be ORed in to indicate that only the data of the file 710** and not its inode needs to be synced. 711** 712** The integer values to xLock() and xUnlock() are one of 713** <ul> 714** <li> [SQLITE_LOCK_NONE], 715** <li> [SQLITE_LOCK_SHARED], 716** <li> [SQLITE_LOCK_RESERVED], 717** <li> [SQLITE_LOCK_PENDING], or 718** <li> [SQLITE_LOCK_EXCLUSIVE]. 719** </ul> 720** xLock() increases the lock. xUnlock() decreases the lock. 721** The xCheckReservedLock() method checks whether any database connection, 722** either in this process or in some other process, is holding a RESERVED, 723** PENDING, or EXCLUSIVE lock on the file. It returns true 724** if such a lock exists and false otherwise. 725** 726** The xFileControl() method is a generic interface that allows custom 727** VFS implementations to directly control an open file using the 728** [sqlite3_file_control()] interface. The second "op" argument is an 729** integer opcode. The third argument is a generic pointer intended to 730** point to a structure that may contain arguments or space in which to 731** write return values. Potential uses for xFileControl() might be 732** functions to enable blocking locks with timeouts, to change the 733** locking strategy (for example to use dot-file locks), to inquire 734** about the status of a lock, or to break stale locks. The SQLite 735** core reserves all opcodes less than 100 for its own use. 736** A [file control opcodes | list of opcodes] less than 100 is available. 737** Applications that define a custom xFileControl method should use opcodes 738** greater than 100 to avoid conflicts. VFS implementations should 739** return [SQLITE_NOTFOUND] for file control opcodes that they do not 740** recognize. 741** 742** The xSectorSize() method returns the sector size of the 743** device that underlies the file. The sector size is the 744** minimum write that can be performed without disturbing 745** other bytes in the file. The xDeviceCharacteristics() 746** method returns a bit vector describing behaviors of the 747** underlying device: 748** 749** <ul> 750** <li> [SQLITE_IOCAP_ATOMIC] 751** <li> [SQLITE_IOCAP_ATOMIC512] 752** <li> [SQLITE_IOCAP_ATOMIC1K] 753** <li> [SQLITE_IOCAP_ATOMIC2K] 754** <li> [SQLITE_IOCAP_ATOMIC4K] 755** <li> [SQLITE_IOCAP_ATOMIC8K] 756** <li> [SQLITE_IOCAP_ATOMIC16K] 757** <li> [SQLITE_IOCAP_ATOMIC32K] 758** <li> [SQLITE_IOCAP_ATOMIC64K] 759** <li> [SQLITE_IOCAP_SAFE_APPEND] 760** <li> [SQLITE_IOCAP_SEQUENTIAL] 761** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 762** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 763** <li> [SQLITE_IOCAP_IMMUTABLE] 764** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 765** </ul> 766** 767** The SQLITE_IOCAP_ATOMIC property means that all writes of 768** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 769** mean that writes of blocks that are nnn bytes in size and 770** are aligned to an address which is an integer multiple of 771** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 772** that when data is appended to a file, the data is appended 773** first then the size of the file is extended, never the other 774** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 775** information is written to disk in the same order as calls 776** to xWrite(). 777** 778** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 779** in the unread portions of the buffer with zeros. A VFS that 780** fails to zero-fill short reads might seem to work. However, 781** failure to zero-fill short reads will eventually lead to 782** database corruption. 783*/ 784typedef struct sqlite3_io_methods sqlite3_io_methods; 785struct sqlite3_io_methods { 786 int iVersion; 787 int (*xClose)(sqlite3_file*); 788 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 789 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 790 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 791 int (*xSync)(sqlite3_file*, int flags); 792 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 793 int (*xLock)(sqlite3_file*, int); 794 int (*xUnlock)(sqlite3_file*, int); 795 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 796 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 797 int (*xSectorSize)(sqlite3_file*); 798 int (*xDeviceCharacteristics)(sqlite3_file*); 799 /* Methods above are valid for version 1 */ 800 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 801 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 802 void (*xShmBarrier)(sqlite3_file*); 803 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 804 /* Methods above are valid for version 2 */ 805 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 806 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 807 /* Methods above are valid for version 3 */ 808 /* Additional methods may be added in future releases */ 809}; 810 811/* 812** CAPI3REF: Standard File Control Opcodes 813** KEYWORDS: {file control opcodes} {file control opcode} 814** 815** These integer constants are opcodes for the xFileControl method 816** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 817** interface. 818** 819** <ul> 820** <li>[[SQLITE_FCNTL_LOCKSTATE]] 821** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 822** opcode causes the xFileControl method to write the current state of 823** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 824** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 825** into an integer that the pArg argument points to. This capability 826** is used during testing and is only available when the SQLITE_TEST 827** compile-time option is used. 828** 829** <li>[[SQLITE_FCNTL_SIZE_HINT]] 830** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 831** layer a hint of how large the database file will grow to be during the 832** current transaction. This hint is not guaranteed to be accurate but it 833** is often close. The underlying VFS might choose to preallocate database 834** file space based on this hint in order to help writes to the database 835** file run faster. 836** 837** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 838** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 839** implements [sqlite3_deserialize()] to set an upper bound on the size 840** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 841** If the integer pointed to is negative, then it is filled in with the 842** current limit. Otherwise the limit is set to the larger of the value 843** of the integer pointed to and the current database size. The integer 844** pointed to is set to the new limit. 845** 846** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 847** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 848** extends and truncates the database file in chunks of a size specified 849** by the user. The fourth argument to [sqlite3_file_control()] should 850** point to an integer (type int) containing the new chunk-size to use 851** for the nominated database. Allocating database file space in large 852** chunks (say 1MB at a time), may reduce file-system fragmentation and 853** improve performance on some systems. 854** 855** <li>[[SQLITE_FCNTL_FILE_POINTER]] 856** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 857** to the [sqlite3_file] object associated with a particular database 858** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 859** 860** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 861** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 862** to the [sqlite3_file] object associated with the journal file (either 863** the [rollback journal] or the [write-ahead log]) for a particular database 864** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 865** 866** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 867** No longer in use. 868** 869** <li>[[SQLITE_FCNTL_SYNC]] 870** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 871** sent to the VFS immediately before the xSync method is invoked on a 872** database file descriptor. Or, if the xSync method is not invoked 873** because the user has configured SQLite with 874** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 875** of the xSync method. In most cases, the pointer argument passed with 876** this file-control is NULL. However, if the database file is being synced 877** as part of a multi-database commit, the argument points to a nul-terminated 878** string containing the transactions super-journal file name. VFSes that 879** do not need this signal should silently ignore this opcode. Applications 880** should not call [sqlite3_file_control()] with this opcode as doing so may 881** disrupt the operation of the specialized VFSes that do require it. 882** 883** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 884** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 885** and sent to the VFS after a transaction has been committed immediately 886** but before the database is unlocked. VFSes that do not need this signal 887** should silently ignore this opcode. Applications should not call 888** [sqlite3_file_control()] with this opcode as doing so may disrupt the 889** operation of the specialized VFSes that do require it. 890** 891** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 892** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 893** retry counts and intervals for certain disk I/O operations for the 894** windows [VFS] in order to provide robustness in the presence of 895** anti-virus programs. By default, the windows VFS will retry file read, 896** file write, and file delete operations up to 10 times, with a delay 897** of 25 milliseconds before the first retry and with the delay increasing 898** by an additional 25 milliseconds with each subsequent retry. This 899** opcode allows these two values (10 retries and 25 milliseconds of delay) 900** to be adjusted. The values are changed for all database connections 901** within the same process. The argument is a pointer to an array of two 902** integers where the first integer is the new retry count and the second 903** integer is the delay. If either integer is negative, then the setting 904** is not changed but instead the prior value of that setting is written 905** into the array entry, allowing the current retry settings to be 906** interrogated. The zDbName parameter is ignored. 907** 908** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 909** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 910** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 911** write ahead log ([WAL file]) and shared memory 912** files used for transaction control 913** are automatically deleted when the latest connection to the database 914** closes. Setting persistent WAL mode causes those files to persist after 915** close. Persisting the files is useful when other processes that do not 916** have write permission on the directory containing the database file want 917** to read the database file, as the WAL and shared memory files must exist 918** in order for the database to be readable. The fourth parameter to 919** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 920** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 921** WAL mode. If the integer is -1, then it is overwritten with the current 922** WAL persistence setting. 923** 924** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 925** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 926** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 927** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 928** xDeviceCharacteristics methods. The fourth parameter to 929** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 930** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 931** mode. If the integer is -1, then it is overwritten with the current 932** zero-damage mode setting. 933** 934** <li>[[SQLITE_FCNTL_OVERWRITE]] 935** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 936** a write transaction to indicate that, unless it is rolled back for some 937** reason, the entire database file will be overwritten by the current 938** transaction. This is used by VACUUM operations. 939** 940** <li>[[SQLITE_FCNTL_VFSNAME]] 941** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 942** all [VFSes] in the VFS stack. The names are of all VFS shims and the 943** final bottom-level VFS are written into memory obtained from 944** [sqlite3_malloc()] and the result is stored in the char* variable 945** that the fourth parameter of [sqlite3_file_control()] points to. 946** The caller is responsible for freeing the memory when done. As with 947** all file-control actions, there is no guarantee that this will actually 948** do anything. Callers should initialize the char* variable to a NULL 949** pointer in case this file-control is not implemented. This file-control 950** is intended for diagnostic use only. 951** 952** <li>[[SQLITE_FCNTL_VFS_POINTER]] 953** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 954** [VFSes] currently in use. ^(The argument X in 955** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 956** of type "[sqlite3_vfs] **". This opcodes will set *X 957** to a pointer to the top-level VFS.)^ 958** ^When there are multiple VFS shims in the stack, this opcode finds the 959** upper-most shim only. 960** 961** <li>[[SQLITE_FCNTL_PRAGMA]] 962** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 963** file control is sent to the open [sqlite3_file] object corresponding 964** to the database file to which the pragma statement refers. ^The argument 965** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 966** pointers to strings (char**) in which the second element of the array 967** is the name of the pragma and the third element is the argument to the 968** pragma or NULL if the pragma has no argument. ^The handler for an 969** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 970** of the char** argument point to a string obtained from [sqlite3_mprintf()] 971** or the equivalent and that string will become the result of the pragma or 972** the error message if the pragma fails. ^If the 973** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 974** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 975** file control returns [SQLITE_OK], then the parser assumes that the 976** VFS has handled the PRAGMA itself and the parser generates a no-op 977** prepared statement if result string is NULL, or that returns a copy 978** of the result string if the string is non-NULL. 979** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 980** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 981** that the VFS encountered an error while handling the [PRAGMA] and the 982** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 983** file control occurs at the beginning of pragma statement analysis and so 984** it is able to override built-in [PRAGMA] statements. 985** 986** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 987** ^The [SQLITE_FCNTL_BUSYHANDLER] 988** file-control may be invoked by SQLite on the database file handle 989** shortly after it is opened in order to provide a custom VFS with access 990** to the connection's busy-handler callback. The argument is of type (void**) 991** - an array of two (void *) values. The first (void *) actually points 992** to a function of type (int (*)(void *)). In order to invoke the connection's 993** busy-handler, this function should be invoked with the second (void *) in 994** the array as the only argument. If it returns non-zero, then the operation 995** should be retried. If it returns zero, the custom VFS should abandon the 996** current operation. 997** 998** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 999** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1000** to have SQLite generate a 1001** temporary filename using the same algorithm that is followed to generate 1002** temporary filenames for TEMP tables and other internal uses. The 1003** argument should be a char** which will be filled with the filename 1004** written into memory obtained from [sqlite3_malloc()]. The caller should 1005** invoke [sqlite3_free()] on the result to avoid a memory leak. 1006** 1007** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1008** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1009** maximum number of bytes that will be used for memory-mapped I/O. 1010** The argument is a pointer to a value of type sqlite3_int64 that 1011** is an advisory maximum number of bytes in the file to memory map. The 1012** pointer is overwritten with the old value. The limit is not changed if 1013** the value originally pointed to is negative, and so the current limit 1014** can be queried by passing in a pointer to a negative number. This 1015** file-control is used internally to implement [PRAGMA mmap_size]. 1016** 1017** <li>[[SQLITE_FCNTL_TRACE]] 1018** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1019** to the VFS about what the higher layers of the SQLite stack are doing. 1020** This file control is used by some VFS activity tracing [shims]. 1021** The argument is a zero-terminated string. Higher layers in the 1022** SQLite stack may generate instances of this file control if 1023** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1024** 1025** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1026** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1027** pointer to an integer and it writes a boolean into that integer depending 1028** on whether or not the file has been renamed, moved, or deleted since it 1029** was first opened. 1030** 1031** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1032** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1033** underlying native file handle associated with a file handle. This file 1034** control interprets its argument as a pointer to a native file handle and 1035** writes the resulting value there. 1036** 1037** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1038** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1039** opcode causes the xFileControl method to swap the file handle with the one 1040** pointed to by the pArg argument. This capability is used during testing 1041** and only needs to be supported when SQLITE_TEST is defined. 1042** 1043** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1044** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1045** be advantageous to block on the next WAL lock if the lock is not immediately 1046** available. The WAL subsystem issues this signal during rare 1047** circumstances in order to fix a problem with priority inversion. 1048** Applications should <em>not</em> use this file-control. 1049** 1050** <li>[[SQLITE_FCNTL_ZIPVFS]] 1051** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1052** VFS should return SQLITE_NOTFOUND for this opcode. 1053** 1054** <li>[[SQLITE_FCNTL_RBU]] 1055** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1056** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1057** this opcode. 1058** 1059** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1060** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1061** the file descriptor is placed in "batch write mode", which 1062** means all subsequent write operations will be deferred and done 1063** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1064** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1065** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1066** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1067** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1068** no VFS interface calls on the same [sqlite3_file] file descriptor 1069** except for calls to the xWrite method and the xFileControl method 1070** with [SQLITE_FCNTL_SIZE_HINT]. 1071** 1072** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1073** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1074** operations since the previous successful call to 1075** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1076** This file control returns [SQLITE_OK] if and only if the writes were 1077** all performed successfully and have been committed to persistent storage. 1078** ^Regardless of whether or not it is successful, this file control takes 1079** the file descriptor out of batch write mode so that all subsequent 1080** write operations are independent. 1081** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1082** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1083** 1084** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1085** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1086** operations since the previous successful call to 1087** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1088** ^This file control takes the file descriptor out of batch write mode 1089** so that all subsequent write operations are independent. 1090** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1091** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1092** 1093** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1094** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1095** to block for up to M milliseconds before failing when attempting to 1096** obtain a file lock using the xLock or xShmLock methods of the VFS. 1097** The parameter is a pointer to a 32-bit signed integer that contains 1098** the value that M is to be set to. Before returning, the 32-bit signed 1099** integer is overwritten with the previous value of M. 1100** 1101** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1102** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1103** a database file. The argument is a pointer to a 32-bit unsigned integer. 1104** The "data version" for the pager is written into the pointer. The 1105** "data version" changes whenever any change occurs to the corresponding 1106** database file, either through SQL statements on the same database 1107** connection or through transactions committed by separate database 1108** connections possibly in other processes. The [sqlite3_total_changes()] 1109** interface can be used to find if any database on the connection has changed, 1110** but that interface responds to changes on TEMP as well as MAIN and does 1111** not provide a mechanism to detect changes to MAIN only. Also, the 1112** [sqlite3_total_changes()] interface responds to internal changes only and 1113** omits changes made by other database connections. The 1114** [PRAGMA data_version] command provides a mechanism to detect changes to 1115** a single attached database that occur due to other database connections, 1116** but omits changes implemented by the database connection on which it is 1117** called. This file control is the only mechanism to detect changes that 1118** happen either internally or externally and that are associated with 1119** a particular attached database. 1120** 1121** <li>[[SQLITE_FCNTL_CKPT_START]] 1122** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1123** in wal mode before the client starts to copy pages from the wal 1124** file to the database file. 1125** 1126** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1127** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1128** in wal mode after the client has finished copying pages from the wal 1129** file to the database file, but before the *-shm file is updated to 1130** record the fact that the pages have been checkpointed. 1131** </ul> 1132** 1133** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1134** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1135** whether or not there is a database client in another process with a wal-mode 1136** transaction open on the database or not. It is only available on unix.The 1137** (void*) argument passed with this file-control should be a pointer to a 1138** value of type (int). The integer value is set to 1 if the database is a wal 1139** mode database and there exists at least one client in another process that 1140** currently has an SQL transaction open on the database. It is set to 0 if 1141** the database is not a wal-mode db, or if there is no such connection in any 1142** other process. This opcode cannot be used to detect transactions opened 1143** by clients within the current process, only within other processes. 1144** </ul> 1145** 1146** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1147** Used by the cksmvfs VFS module only. 1148** </ul> 1149*/ 1150#define SQLITE_FCNTL_LOCKSTATE 1 1151#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1152#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1153#define SQLITE_FCNTL_LAST_ERRNO 4 1154#define SQLITE_FCNTL_SIZE_HINT 5 1155#define SQLITE_FCNTL_CHUNK_SIZE 6 1156#define SQLITE_FCNTL_FILE_POINTER 7 1157#define SQLITE_FCNTL_SYNC_OMITTED 8 1158#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1159#define SQLITE_FCNTL_PERSIST_WAL 10 1160#define SQLITE_FCNTL_OVERWRITE 11 1161#define SQLITE_FCNTL_VFSNAME 12 1162#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1163#define SQLITE_FCNTL_PRAGMA 14 1164#define SQLITE_FCNTL_BUSYHANDLER 15 1165#define SQLITE_FCNTL_TEMPFILENAME 16 1166#define SQLITE_FCNTL_MMAP_SIZE 18 1167#define SQLITE_FCNTL_TRACE 19 1168#define SQLITE_FCNTL_HAS_MOVED 20 1169#define SQLITE_FCNTL_SYNC 21 1170#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1171#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1172#define SQLITE_FCNTL_WAL_BLOCK 24 1173#define SQLITE_FCNTL_ZIPVFS 25 1174#define SQLITE_FCNTL_RBU 26 1175#define SQLITE_FCNTL_VFS_POINTER 27 1176#define SQLITE_FCNTL_JOURNAL_POINTER 28 1177#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1178#define SQLITE_FCNTL_PDB 30 1179#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1180#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1181#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1182#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1183#define SQLITE_FCNTL_DATA_VERSION 35 1184#define SQLITE_FCNTL_SIZE_LIMIT 36 1185#define SQLITE_FCNTL_CKPT_DONE 37 1186#define SQLITE_FCNTL_RESERVE_BYTES 38 1187#define SQLITE_FCNTL_CKPT_START 39 1188#define SQLITE_FCNTL_EXTERNAL_READER 40 1189#define SQLITE_FCNTL_CKSM_FILE 41 1190 1191/* deprecated names */ 1192#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1193#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1194#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1195 1196 1197/* 1198** CAPI3REF: Mutex Handle 1199** 1200** The mutex module within SQLite defines [sqlite3_mutex] to be an 1201** abstract type for a mutex object. The SQLite core never looks 1202** at the internal representation of an [sqlite3_mutex]. It only 1203** deals with pointers to the [sqlite3_mutex] object. 1204** 1205** Mutexes are created using [sqlite3_mutex_alloc()]. 1206*/ 1207typedef struct sqlite3_mutex sqlite3_mutex; 1208 1209/* 1210** CAPI3REF: Loadable Extension Thunk 1211** 1212** A pointer to the opaque sqlite3_api_routines structure is passed as 1213** the third parameter to entry points of [loadable extensions]. This 1214** structure must be typedefed in order to work around compiler warnings 1215** on some platforms. 1216*/ 1217typedef struct sqlite3_api_routines sqlite3_api_routines; 1218 1219/* 1220** CAPI3REF: OS Interface Object 1221** 1222** An instance of the sqlite3_vfs object defines the interface between 1223** the SQLite core and the underlying operating system. The "vfs" 1224** in the name of the object stands for "virtual file system". See 1225** the [VFS | VFS documentation] for further information. 1226** 1227** The VFS interface is sometimes extended by adding new methods onto 1228** the end. Each time such an extension occurs, the iVersion field 1229** is incremented. The iVersion value started out as 1 in 1230** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1231** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1232** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1233** may be appended to the sqlite3_vfs object and the iVersion value 1234** may increase again in future versions of SQLite. 1235** Note that due to an oversight, the structure 1236** of the sqlite3_vfs object changed in the transition from 1237** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1238** and yet the iVersion field was not increased. 1239** 1240** The szOsFile field is the size of the subclassed [sqlite3_file] 1241** structure used by this VFS. mxPathname is the maximum length of 1242** a pathname in this VFS. 1243** 1244** Registered sqlite3_vfs objects are kept on a linked list formed by 1245** the pNext pointer. The [sqlite3_vfs_register()] 1246** and [sqlite3_vfs_unregister()] interfaces manage this list 1247** in a thread-safe way. The [sqlite3_vfs_find()] interface 1248** searches the list. Neither the application code nor the VFS 1249** implementation should use the pNext pointer. 1250** 1251** The pNext field is the only field in the sqlite3_vfs 1252** structure that SQLite will ever modify. SQLite will only access 1253** or modify this field while holding a particular static mutex. 1254** The application should never modify anything within the sqlite3_vfs 1255** object once the object has been registered. 1256** 1257** The zName field holds the name of the VFS module. The name must 1258** be unique across all VFS modules. 1259** 1260** [[sqlite3_vfs.xOpen]] 1261** ^SQLite guarantees that the zFilename parameter to xOpen 1262** is either a NULL pointer or string obtained 1263** from xFullPathname() with an optional suffix added. 1264** ^If a suffix is added to the zFilename parameter, it will 1265** consist of a single "-" character followed by no more than 1266** 11 alphanumeric and/or "-" characters. 1267** ^SQLite further guarantees that 1268** the string will be valid and unchanged until xClose() is 1269** called. Because of the previous sentence, 1270** the [sqlite3_file] can safely store a pointer to the 1271** filename if it needs to remember the filename for some reason. 1272** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1273** must invent its own temporary name for the file. ^Whenever the 1274** xFilename parameter is NULL it will also be the case that the 1275** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1276** 1277** The flags argument to xOpen() includes all bits set in 1278** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1279** or [sqlite3_open16()] is used, then flags includes at least 1280** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1281** If xOpen() opens a file read-only then it sets *pOutFlags to 1282** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1283** 1284** ^(SQLite will also add one of the following flags to the xOpen() 1285** call, depending on the object being opened: 1286** 1287** <ul> 1288** <li> [SQLITE_OPEN_MAIN_DB] 1289** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1290** <li> [SQLITE_OPEN_TEMP_DB] 1291** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1292** <li> [SQLITE_OPEN_TRANSIENT_DB] 1293** <li> [SQLITE_OPEN_SUBJOURNAL] 1294** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1295** <li> [SQLITE_OPEN_WAL] 1296** </ul>)^ 1297** 1298** The file I/O implementation can use the object type flags to 1299** change the way it deals with files. For example, an application 1300** that does not care about crash recovery or rollback might make 1301** the open of a journal file a no-op. Writes to this journal would 1302** also be no-ops, and any attempt to read the journal would return 1303** SQLITE_IOERR. Or the implementation might recognize that a database 1304** file will be doing page-aligned sector reads and writes in a random 1305** order and set up its I/O subsystem accordingly. 1306** 1307** SQLite might also add one of the following flags to the xOpen method: 1308** 1309** <ul> 1310** <li> [SQLITE_OPEN_DELETEONCLOSE] 1311** <li> [SQLITE_OPEN_EXCLUSIVE] 1312** </ul> 1313** 1314** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1315** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1316** will be set for TEMP databases and their journals, transient 1317** databases, and subjournals. 1318** 1319** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1320** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1321** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1322** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1323** SQLITE_OPEN_CREATE, is used to indicate that file should always 1324** be created, and that it is an error if it already exists. 1325** It is <i>not</i> used to indicate the file should be opened 1326** for exclusive access. 1327** 1328** ^At least szOsFile bytes of memory are allocated by SQLite 1329** to hold the [sqlite3_file] structure passed as the third 1330** argument to xOpen. The xOpen method does not have to 1331** allocate the structure; it should just fill it in. Note that 1332** the xOpen method must set the sqlite3_file.pMethods to either 1333** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1334** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1335** element will be valid after xOpen returns regardless of the success 1336** or failure of the xOpen call. 1337** 1338** [[sqlite3_vfs.xAccess]] 1339** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1340** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1341** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1342** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1343** flag is never actually used and is not implemented in the built-in 1344** VFSes of SQLite. The file is named by the second argument and can be a 1345** directory. The xAccess method returns [SQLITE_OK] on success or some 1346** non-zero error code if there is an I/O error or if the name of 1347** the file given in the second argument is illegal. If SQLITE_OK 1348** is returned, then non-zero or zero is written into *pResOut to indicate 1349** whether or not the file is accessible. 1350** 1351** ^SQLite will always allocate at least mxPathname+1 bytes for the 1352** output buffer xFullPathname. The exact size of the output buffer 1353** is also passed as a parameter to both methods. If the output buffer 1354** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1355** handled as a fatal error by SQLite, vfs implementations should endeavor 1356** to prevent this by setting mxPathname to a sufficiently large value. 1357** 1358** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1359** interfaces are not strictly a part of the filesystem, but they are 1360** included in the VFS structure for completeness. 1361** The xRandomness() function attempts to return nBytes bytes 1362** of good-quality randomness into zOut. The return value is 1363** the actual number of bytes of randomness obtained. 1364** The xSleep() method causes the calling thread to sleep for at 1365** least the number of microseconds given. ^The xCurrentTime() 1366** method returns a Julian Day Number for the current date and time as 1367** a floating point value. 1368** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1369** Day Number multiplied by 86400000 (the number of milliseconds in 1370** a 24-hour day). 1371** ^SQLite will use the xCurrentTimeInt64() method to get the current 1372** date and time if that method is available (if iVersion is 2 or 1373** greater and the function pointer is not NULL) and will fall back 1374** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1375** 1376** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1377** are not used by the SQLite core. These optional interfaces are provided 1378** by some VFSes to facilitate testing of the VFS code. By overriding 1379** system calls with functions under its control, a test program can 1380** simulate faults and error conditions that would otherwise be difficult 1381** or impossible to induce. The set of system calls that can be overridden 1382** varies from one VFS to another, and from one version of the same VFS to the 1383** next. Applications that use these interfaces must be prepared for any 1384** or all of these interfaces to be NULL or for their behavior to change 1385** from one release to the next. Applications must not attempt to access 1386** any of these methods if the iVersion of the VFS is less than 3. 1387*/ 1388typedef struct sqlite3_vfs sqlite3_vfs; 1389typedef void (*sqlite3_syscall_ptr)(void); 1390struct sqlite3_vfs { 1391 int iVersion; /* Structure version number (currently 3) */ 1392 int szOsFile; /* Size of subclassed sqlite3_file */ 1393 int mxPathname; /* Maximum file pathname length */ 1394 sqlite3_vfs *pNext; /* Next registered VFS */ 1395 const char *zName; /* Name of this virtual file system */ 1396 void *pAppData; /* Pointer to application-specific data */ 1397 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1398 int flags, int *pOutFlags); 1399 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1400 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1401 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1402 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1403 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1404 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1405 void (*xDlClose)(sqlite3_vfs*, void*); 1406 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1407 int (*xSleep)(sqlite3_vfs*, int microseconds); 1408 int (*xCurrentTime)(sqlite3_vfs*, double*); 1409 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1410 /* 1411 ** The methods above are in version 1 of the sqlite_vfs object 1412 ** definition. Those that follow are added in version 2 or later 1413 */ 1414 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1415 /* 1416 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1417 ** Those below are for version 3 and greater. 1418 */ 1419 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1420 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1421 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1422 /* 1423 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1424 ** New fields may be appended in future versions. The iVersion 1425 ** value will increment whenever this happens. 1426 */ 1427}; 1428 1429/* 1430** CAPI3REF: Flags for the xAccess VFS method 1431** 1432** These integer constants can be used as the third parameter to 1433** the xAccess method of an [sqlite3_vfs] object. They determine 1434** what kind of permissions the xAccess method is looking for. 1435** With SQLITE_ACCESS_EXISTS, the xAccess method 1436** simply checks whether the file exists. 1437** With SQLITE_ACCESS_READWRITE, the xAccess method 1438** checks whether the named directory is both readable and writable 1439** (in other words, if files can be added, removed, and renamed within 1440** the directory). 1441** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1442** [temp_store_directory pragma], though this could change in a future 1443** release of SQLite. 1444** With SQLITE_ACCESS_READ, the xAccess method 1445** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1446** currently unused, though it might be used in a future release of 1447** SQLite. 1448*/ 1449#define SQLITE_ACCESS_EXISTS 0 1450#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1451#define SQLITE_ACCESS_READ 2 /* Unused */ 1452 1453/* 1454** CAPI3REF: Flags for the xShmLock VFS method 1455** 1456** These integer constants define the various locking operations 1457** allowed by the xShmLock method of [sqlite3_io_methods]. The 1458** following are the only legal combinations of flags to the 1459** xShmLock method: 1460** 1461** <ul> 1462** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1463** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1464** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1465** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1466** </ul> 1467** 1468** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1469** was given on the corresponding lock. 1470** 1471** The xShmLock method can transition between unlocked and SHARED or 1472** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1473** and EXCLUSIVE. 1474*/ 1475#define SQLITE_SHM_UNLOCK 1 1476#define SQLITE_SHM_LOCK 2 1477#define SQLITE_SHM_SHARED 4 1478#define SQLITE_SHM_EXCLUSIVE 8 1479 1480/* 1481** CAPI3REF: Maximum xShmLock index 1482** 1483** The xShmLock method on [sqlite3_io_methods] may use values 1484** between 0 and this upper bound as its "offset" argument. 1485** The SQLite core will never attempt to acquire or release a 1486** lock outside of this range 1487*/ 1488#define SQLITE_SHM_NLOCK 8 1489 1490 1491/* 1492** CAPI3REF: Initialize The SQLite Library 1493** 1494** ^The sqlite3_initialize() routine initializes the 1495** SQLite library. ^The sqlite3_shutdown() routine 1496** deallocates any resources that were allocated by sqlite3_initialize(). 1497** These routines are designed to aid in process initialization and 1498** shutdown on embedded systems. Workstation applications using 1499** SQLite normally do not need to invoke either of these routines. 1500** 1501** A call to sqlite3_initialize() is an "effective" call if it is 1502** the first time sqlite3_initialize() is invoked during the lifetime of 1503** the process, or if it is the first time sqlite3_initialize() is invoked 1504** following a call to sqlite3_shutdown(). ^(Only an effective call 1505** of sqlite3_initialize() does any initialization. All other calls 1506** are harmless no-ops.)^ 1507** 1508** A call to sqlite3_shutdown() is an "effective" call if it is the first 1509** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1510** an effective call to sqlite3_shutdown() does any deinitialization. 1511** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1512** 1513** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1514** is not. The sqlite3_shutdown() interface must only be called from a 1515** single thread. All open [database connections] must be closed and all 1516** other SQLite resources must be deallocated prior to invoking 1517** sqlite3_shutdown(). 1518** 1519** Among other things, ^sqlite3_initialize() will invoke 1520** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1521** will invoke sqlite3_os_end(). 1522** 1523** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1524** ^If for some reason, sqlite3_initialize() is unable to initialize 1525** the library (perhaps it is unable to allocate a needed resource such 1526** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1527** 1528** ^The sqlite3_initialize() routine is called internally by many other 1529** SQLite interfaces so that an application usually does not need to 1530** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1531** calls sqlite3_initialize() so the SQLite library will be automatically 1532** initialized when [sqlite3_open()] is called if it has not be initialized 1533** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1534** compile-time option, then the automatic calls to sqlite3_initialize() 1535** are omitted and the application must call sqlite3_initialize() directly 1536** prior to using any other SQLite interface. For maximum portability, 1537** it is recommended that applications always invoke sqlite3_initialize() 1538** directly prior to using any other SQLite interface. Future releases 1539** of SQLite may require this. In other words, the behavior exhibited 1540** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1541** default behavior in some future release of SQLite. 1542** 1543** The sqlite3_os_init() routine does operating-system specific 1544** initialization of the SQLite library. The sqlite3_os_end() 1545** routine undoes the effect of sqlite3_os_init(). Typical tasks 1546** performed by these routines include allocation or deallocation 1547** of static resources, initialization of global variables, 1548** setting up a default [sqlite3_vfs] module, or setting up 1549** a default configuration using [sqlite3_config()]. 1550** 1551** The application should never invoke either sqlite3_os_init() 1552** or sqlite3_os_end() directly. The application should only invoke 1553** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1554** interface is called automatically by sqlite3_initialize() and 1555** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1556** implementations for sqlite3_os_init() and sqlite3_os_end() 1557** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1558** When [custom builds | built for other platforms] 1559** (using the [SQLITE_OS_OTHER=1] compile-time 1560** option) the application must supply a suitable implementation for 1561** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1562** implementation of sqlite3_os_init() or sqlite3_os_end() 1563** must return [SQLITE_OK] on success and some other [error code] upon 1564** failure. 1565*/ 1566int sqlite3_initialize(void); 1567int sqlite3_shutdown(void); 1568int sqlite3_os_init(void); 1569int sqlite3_os_end(void); 1570 1571/* 1572** CAPI3REF: Configuring The SQLite Library 1573** 1574** The sqlite3_config() interface is used to make global configuration 1575** changes to SQLite in order to tune SQLite to the specific needs of 1576** the application. The default configuration is recommended for most 1577** applications and so this routine is usually not necessary. It is 1578** provided to support rare applications with unusual needs. 1579** 1580** <b>The sqlite3_config() interface is not threadsafe. The application 1581** must ensure that no other SQLite interfaces are invoked by other 1582** threads while sqlite3_config() is running.</b> 1583** 1584** The sqlite3_config() interface 1585** may only be invoked prior to library initialization using 1586** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1587** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1588** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1589** Note, however, that ^sqlite3_config() can be called as part of the 1590** implementation of an application-defined [sqlite3_os_init()]. 1591** 1592** The first argument to sqlite3_config() is an integer 1593** [configuration option] that determines 1594** what property of SQLite is to be configured. Subsequent arguments 1595** vary depending on the [configuration option] 1596** in the first argument. 1597** 1598** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1599** ^If the option is unknown or SQLite is unable to set the option 1600** then this routine returns a non-zero [error code]. 1601*/ 1602int sqlite3_config(int, ...); 1603 1604/* 1605** CAPI3REF: Configure database connections 1606** METHOD: sqlite3 1607** 1608** The sqlite3_db_config() interface is used to make configuration 1609** changes to a [database connection]. The interface is similar to 1610** [sqlite3_config()] except that the changes apply to a single 1611** [database connection] (specified in the first argument). 1612** 1613** The second argument to sqlite3_db_config(D,V,...) is the 1614** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1615** that indicates what aspect of the [database connection] is being configured. 1616** Subsequent arguments vary depending on the configuration verb. 1617** 1618** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1619** the call is considered successful. 1620*/ 1621int sqlite3_db_config(sqlite3*, int op, ...); 1622 1623/* 1624** CAPI3REF: Memory Allocation Routines 1625** 1626** An instance of this object defines the interface between SQLite 1627** and low-level memory allocation routines. 1628** 1629** This object is used in only one place in the SQLite interface. 1630** A pointer to an instance of this object is the argument to 1631** [sqlite3_config()] when the configuration option is 1632** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1633** By creating an instance of this object 1634** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1635** during configuration, an application can specify an alternative 1636** memory allocation subsystem for SQLite to use for all of its 1637** dynamic memory needs. 1638** 1639** Note that SQLite comes with several [built-in memory allocators] 1640** that are perfectly adequate for the overwhelming majority of applications 1641** and that this object is only useful to a tiny minority of applications 1642** with specialized memory allocation requirements. This object is 1643** also used during testing of SQLite in order to specify an alternative 1644** memory allocator that simulates memory out-of-memory conditions in 1645** order to verify that SQLite recovers gracefully from such 1646** conditions. 1647** 1648** The xMalloc, xRealloc, and xFree methods must work like the 1649** malloc(), realloc() and free() functions from the standard C library. 1650** ^SQLite guarantees that the second argument to 1651** xRealloc is always a value returned by a prior call to xRoundup. 1652** 1653** xSize should return the allocated size of a memory allocation 1654** previously obtained from xMalloc or xRealloc. The allocated size 1655** is always at least as big as the requested size but may be larger. 1656** 1657** The xRoundup method returns what would be the allocated size of 1658** a memory allocation given a particular requested size. Most memory 1659** allocators round up memory allocations at least to the next multiple 1660** of 8. Some allocators round up to a larger multiple or to a power of 2. 1661** Every memory allocation request coming in through [sqlite3_malloc()] 1662** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1663** that causes the corresponding memory allocation to fail. 1664** 1665** The xInit method initializes the memory allocator. For example, 1666** it might allocate any required mutexes or initialize internal data 1667** structures. The xShutdown method is invoked (indirectly) by 1668** [sqlite3_shutdown()] and should deallocate any resources acquired 1669** by xInit. The pAppData pointer is used as the only parameter to 1670** xInit and xShutdown. 1671** 1672** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1673** the xInit method, so the xInit method need not be threadsafe. The 1674** xShutdown method is only called from [sqlite3_shutdown()] so it does 1675** not need to be threadsafe either. For all other methods, SQLite 1676** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1677** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1678** it is by default) and so the methods are automatically serialized. 1679** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1680** methods must be threadsafe or else make their own arrangements for 1681** serialization. 1682** 1683** SQLite will never invoke xInit() more than once without an intervening 1684** call to xShutdown(). 1685*/ 1686typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1687struct sqlite3_mem_methods { 1688 void *(*xMalloc)(int); /* Memory allocation function */ 1689 void (*xFree)(void*); /* Free a prior allocation */ 1690 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1691 int (*xSize)(void*); /* Return the size of an allocation */ 1692 int (*xRoundup)(int); /* Round up request size to allocation size */ 1693 int (*xInit)(void*); /* Initialize the memory allocator */ 1694 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1695 void *pAppData; /* Argument to xInit() and xShutdown() */ 1696}; 1697 1698/* 1699** CAPI3REF: Configuration Options 1700** KEYWORDS: {configuration option} 1701** 1702** These constants are the available integer configuration options that 1703** can be passed as the first argument to the [sqlite3_config()] interface. 1704** 1705** New configuration options may be added in future releases of SQLite. 1706** Existing configuration options might be discontinued. Applications 1707** should check the return code from [sqlite3_config()] to make sure that 1708** the call worked. The [sqlite3_config()] interface will return a 1709** non-zero [error code] if a discontinued or unsupported configuration option 1710** is invoked. 1711** 1712** <dl> 1713** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1714** <dd>There are no arguments to this option. ^This option sets the 1715** [threading mode] to Single-thread. In other words, it disables 1716** all mutexing and puts SQLite into a mode where it can only be used 1717** by a single thread. ^If SQLite is compiled with 1718** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1719** it is not possible to change the [threading mode] from its default 1720** value of Single-thread and so [sqlite3_config()] will return 1721** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1722** configuration option.</dd> 1723** 1724** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1725** <dd>There are no arguments to this option. ^This option sets the 1726** [threading mode] to Multi-thread. In other words, it disables 1727** mutexing on [database connection] and [prepared statement] objects. 1728** The application is responsible for serializing access to 1729** [database connections] and [prepared statements]. But other mutexes 1730** are enabled so that SQLite will be safe to use in a multi-threaded 1731** environment as long as no two threads attempt to use the same 1732** [database connection] at the same time. ^If SQLite is compiled with 1733** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1734** it is not possible to set the Multi-thread [threading mode] and 1735** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1736** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1737** 1738** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1739** <dd>There are no arguments to this option. ^This option sets the 1740** [threading mode] to Serialized. In other words, this option enables 1741** all mutexes including the recursive 1742** mutexes on [database connection] and [prepared statement] objects. 1743** In this mode (which is the default when SQLite is compiled with 1744** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1745** to [database connections] and [prepared statements] so that the 1746** application is free to use the same [database connection] or the 1747** same [prepared statement] in different threads at the same time. 1748** ^If SQLite is compiled with 1749** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1750** it is not possible to set the Serialized [threading mode] and 1751** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1752** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1753** 1754** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1755** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1756** a pointer to an instance of the [sqlite3_mem_methods] structure. 1757** The argument specifies 1758** alternative low-level memory allocation routines to be used in place of 1759** the memory allocation routines built into SQLite.)^ ^SQLite makes 1760** its own private copy of the content of the [sqlite3_mem_methods] structure 1761** before the [sqlite3_config()] call returns.</dd> 1762** 1763** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1764** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1765** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1766** The [sqlite3_mem_methods] 1767** structure is filled with the currently defined memory allocation routines.)^ 1768** This option can be used to overload the default memory allocation 1769** routines with a wrapper that simulations memory allocation failure or 1770** tracks memory usage, for example. </dd> 1771** 1772** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1773** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1774** type int, interpreted as a boolean, which if true provides a hint to 1775** SQLite that it should avoid large memory allocations if possible. 1776** SQLite will run faster if it is free to make large memory allocations, 1777** but some application might prefer to run slower in exchange for 1778** guarantees about memory fragmentation that are possible if large 1779** allocations are avoided. This hint is normally off. 1780** </dd> 1781** 1782** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1783** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1784** interpreted as a boolean, which enables or disables the collection of 1785** memory allocation statistics. ^(When memory allocation statistics are 1786** disabled, the following SQLite interfaces become non-operational: 1787** <ul> 1788** <li> [sqlite3_hard_heap_limit64()] 1789** <li> [sqlite3_memory_used()] 1790** <li> [sqlite3_memory_highwater()] 1791** <li> [sqlite3_soft_heap_limit64()] 1792** <li> [sqlite3_status64()] 1793** </ul>)^ 1794** ^Memory allocation statistics are enabled by default unless SQLite is 1795** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1796** allocation statistics are disabled by default. 1797** </dd> 1798** 1799** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1800** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1801** </dd> 1802** 1803** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1804** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1805** that SQLite can use for the database page cache with the default page 1806** cache implementation. 1807** This configuration option is a no-op if an application-defined page 1808** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1809** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1810** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1811** and the number of cache lines (N). 1812** The sz argument should be the size of the largest database page 1813** (a power of two between 512 and 65536) plus some extra bytes for each 1814** page header. ^The number of extra bytes needed by the page header 1815** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1816** ^It is harmless, apart from the wasted memory, 1817** for the sz parameter to be larger than necessary. The pMem 1818** argument must be either a NULL pointer or a pointer to an 8-byte 1819** aligned block of memory of at least sz*N bytes, otherwise 1820** subsequent behavior is undefined. 1821** ^When pMem is not NULL, SQLite will strive to use the memory provided 1822** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1823** a page cache line is larger than sz bytes or if all of the pMem buffer 1824** is exhausted. 1825** ^If pMem is NULL and N is non-zero, then each database connection 1826** does an initial bulk allocation for page cache memory 1827** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1828** of -1024*N bytes if N is negative, . ^If additional 1829** page cache memory is needed beyond what is provided by the initial 1830** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1831** additional cache line. </dd> 1832** 1833** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1834** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1835** that SQLite will use for all of its dynamic memory allocation needs 1836** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1837** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1838** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1839** [SQLITE_ERROR] if invoked otherwise. 1840** ^There are three arguments to SQLITE_CONFIG_HEAP: 1841** An 8-byte aligned pointer to the memory, 1842** the number of bytes in the memory buffer, and the minimum allocation size. 1843** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1844** to using its default memory allocator (the system malloc() implementation), 1845** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1846** memory pointer is not NULL then the alternative memory 1847** allocator is engaged to handle all of SQLites memory allocation needs. 1848** The first pointer (the memory pointer) must be aligned to an 8-byte 1849** boundary or subsequent behavior of SQLite will be undefined. 1850** The minimum allocation size is capped at 2**12. Reasonable values 1851** for the minimum allocation size are 2**5 through 2**8.</dd> 1852** 1853** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1854** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1855** pointer to an instance of the [sqlite3_mutex_methods] structure. 1856** The argument specifies alternative low-level mutex routines to be used 1857** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1858** the content of the [sqlite3_mutex_methods] structure before the call to 1859** [sqlite3_config()] returns. ^If SQLite is compiled with 1860** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1861** the entire mutexing subsystem is omitted from the build and hence calls to 1862** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1863** return [SQLITE_ERROR].</dd> 1864** 1865** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1866** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1867** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1868** [sqlite3_mutex_methods] 1869** structure is filled with the currently defined mutex routines.)^ 1870** This option can be used to overload the default mutex allocation 1871** routines with a wrapper used to track mutex usage for performance 1872** profiling or testing, for example. ^If SQLite is compiled with 1873** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1874** the entire mutexing subsystem is omitted from the build and hence calls to 1875** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1876** return [SQLITE_ERROR].</dd> 1877** 1878** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1879** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1880** the default size of lookaside memory on each [database connection]. 1881** The first argument is the 1882** size of each lookaside buffer slot and the second is the number of 1883** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1884** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1885** option to [sqlite3_db_config()] can be used to change the lookaside 1886** configuration on individual connections.)^ </dd> 1887** 1888** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1889** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1890** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1891** the interface to a custom page cache implementation.)^ 1892** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1893** 1894** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1895** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1896** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1897** the current page cache implementation into that object.)^ </dd> 1898** 1899** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1900** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1901** global [error log]. 1902** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1903** function with a call signature of void(*)(void*,int,const char*), 1904** and a pointer to void. ^If the function pointer is not NULL, it is 1905** invoked by [sqlite3_log()] to process each logging event. ^If the 1906** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1907** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1908** passed through as the first parameter to the application-defined logger 1909** function whenever that function is invoked. ^The second parameter to 1910** the logger function is a copy of the first parameter to the corresponding 1911** [sqlite3_log()] call and is intended to be a [result code] or an 1912** [extended result code]. ^The third parameter passed to the logger is 1913** log message after formatting via [sqlite3_snprintf()]. 1914** The SQLite logging interface is not reentrant; the logger function 1915** supplied by the application must not invoke any SQLite interface. 1916** In a multi-threaded application, the application-defined logger 1917** function must be threadsafe. </dd> 1918** 1919** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1920** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1921** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1922** then URI handling is globally disabled.)^ ^If URI handling is globally 1923** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1924** [sqlite3_open16()] or 1925** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1926** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1927** connection is opened. ^If it is globally disabled, filenames are 1928** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1929** database connection is opened. ^(By default, URI handling is globally 1930** disabled. The default value may be changed by compiling with the 1931** [SQLITE_USE_URI] symbol defined.)^ 1932** 1933** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1934** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1935** argument which is interpreted as a boolean in order to enable or disable 1936** the use of covering indices for full table scans in the query optimizer. 1937** ^The default setting is determined 1938** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1939** if that compile-time option is omitted. 1940** The ability to disable the use of covering indices for full table scans 1941** is because some incorrectly coded legacy applications might malfunction 1942** when the optimization is enabled. Providing the ability to 1943** disable the optimization allows the older, buggy application code to work 1944** without change even with newer versions of SQLite. 1945** 1946** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1947** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1948** <dd> These options are obsolete and should not be used by new code. 1949** They are retained for backwards compatibility but are now no-ops. 1950** </dd> 1951** 1952** [[SQLITE_CONFIG_SQLLOG]] 1953** <dt>SQLITE_CONFIG_SQLLOG 1954** <dd>This option is only available if sqlite is compiled with the 1955** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1956** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1957** The second should be of type (void*). The callback is invoked by the library 1958** in three separate circumstances, identified by the value passed as the 1959** fourth parameter. If the fourth parameter is 0, then the database connection 1960** passed as the second argument has just been opened. The third argument 1961** points to a buffer containing the name of the main database file. If the 1962** fourth parameter is 1, then the SQL statement that the third parameter 1963** points to has just been executed. Or, if the fourth parameter is 2, then 1964** the connection being passed as the second parameter is being closed. The 1965** third parameter is passed NULL In this case. An example of using this 1966** configuration option can be seen in the "test_sqllog.c" source file in 1967** the canonical SQLite source tree.</dd> 1968** 1969** [[SQLITE_CONFIG_MMAP_SIZE]] 1970** <dt>SQLITE_CONFIG_MMAP_SIZE 1971** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1972** that are the default mmap size limit (the default setting for 1973** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1974** ^The default setting can be overridden by each database connection using 1975** either the [PRAGMA mmap_size] command, or by using the 1976** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1977** will be silently truncated if necessary so that it does not exceed the 1978** compile-time maximum mmap size set by the 1979** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1980** ^If either argument to this option is negative, then that argument is 1981** changed to its compile-time default. 1982** 1983** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1984** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1985** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1986** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1987** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1988** that specifies the maximum size of the created heap. 1989** 1990** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1991** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1992** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1993** is a pointer to an integer and writes into that integer the number of extra 1994** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1995** The amount of extra space required can change depending on the compiler, 1996** target platform, and SQLite version. 1997** 1998** [[SQLITE_CONFIG_PMASZ]] 1999** <dt>SQLITE_CONFIG_PMASZ 2000** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2001** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2002** sorter to that integer. The default minimum PMA Size is set by the 2003** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2004** to help with sort operations when multithreaded sorting 2005** is enabled (using the [PRAGMA threads] command) and the amount of content 2006** to be sorted exceeds the page size times the minimum of the 2007** [PRAGMA cache_size] setting and this value. 2008** 2009** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2010** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2011** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2012** becomes the [statement journal] spill-to-disk threshold. 2013** [Statement journals] are held in memory until their size (in bytes) 2014** exceeds this threshold, at which point they are written to disk. 2015** Or if the threshold is -1, statement journals are always held 2016** exclusively in memory. 2017** Since many statement journals never become large, setting the spill 2018** threshold to a value such as 64KiB can greatly reduce the amount of 2019** I/O required to support statement rollback. 2020** The default value for this setting is controlled by the 2021** [SQLITE_STMTJRNL_SPILL] compile-time option. 2022** 2023** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2024** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2025** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2026** of type (int) - the new value of the sorter-reference size threshold. 2027** Usually, when SQLite uses an external sort to order records according 2028** to an ORDER BY clause, all fields required by the caller are present in the 2029** sorted records. However, if SQLite determines based on the declared type 2030** of a table column that its values are likely to be very large - larger 2031** than the configured sorter-reference size threshold - then a reference 2032** is stored in each sorted record and the required column values loaded 2033** from the database as records are returned in sorted order. The default 2034** value for this option is to never use this optimization. Specifying a 2035** negative value for this option restores the default behaviour. 2036** This option is only available if SQLite is compiled with the 2037** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2038** 2039** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2040** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2041** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2042** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2043** database created using [sqlite3_deserialize()]. This default maximum 2044** size can be adjusted up or down for individual databases using the 2045** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2046** configuration setting is never used, then the default maximum is determined 2047** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2048** compile-time option is not set, then the default maximum is 1073741824. 2049** </dl> 2050*/ 2051#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2052#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2053#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2054#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2055#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2056#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2057#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2058#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2059#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2060#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2061#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2062/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2063#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2064#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2065#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2066#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2067#define SQLITE_CONFIG_URI 17 /* int */ 2068#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2069#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2070#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2071#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2072#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2073#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2074#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2075#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2076#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2077#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2078#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2079#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2080 2081/* 2082** CAPI3REF: Database Connection Configuration Options 2083** 2084** These constants are the available integer configuration options that 2085** can be passed as the second argument to the [sqlite3_db_config()] interface. 2086** 2087** New configuration options may be added in future releases of SQLite. 2088** Existing configuration options might be discontinued. Applications 2089** should check the return code from [sqlite3_db_config()] to make sure that 2090** the call worked. ^The [sqlite3_db_config()] interface will return a 2091** non-zero [error code] if a discontinued or unsupported configuration option 2092** is invoked. 2093** 2094** <dl> 2095** [[SQLITE_DBCONFIG_LOOKASIDE]] 2096** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2097** <dd> ^This option takes three additional arguments that determine the 2098** [lookaside memory allocator] configuration for the [database connection]. 2099** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2100** pointer to a memory buffer to use for lookaside memory. 2101** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2102** may be NULL in which case SQLite will allocate the 2103** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2104** size of each lookaside buffer slot. ^The third argument is the number of 2105** slots. The size of the buffer in the first argument must be greater than 2106** or equal to the product of the second and third arguments. The buffer 2107** must be aligned to an 8-byte boundary. ^If the second argument to 2108** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2109** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2110** configuration for a database connection can only be changed when that 2111** connection is not currently using lookaside memory, or in other words 2112** when the "current value" returned by 2113** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2114** Any attempt to change the lookaside memory configuration when lookaside 2115** memory is in use leaves the configuration unchanged and returns 2116** [SQLITE_BUSY].)^</dd> 2117** 2118** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2119** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2120** <dd> ^This option is used to enable or disable the enforcement of 2121** [foreign key constraints]. There should be two additional arguments. 2122** The first argument is an integer which is 0 to disable FK enforcement, 2123** positive to enable FK enforcement or negative to leave FK enforcement 2124** unchanged. The second parameter is a pointer to an integer into which 2125** is written 0 or 1 to indicate whether FK enforcement is off or on 2126** following this call. The second parameter may be a NULL pointer, in 2127** which case the FK enforcement setting is not reported back. </dd> 2128** 2129** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2130** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2131** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2132** There should be two additional arguments. 2133** The first argument is an integer which is 0 to disable triggers, 2134** positive to enable triggers or negative to leave the setting unchanged. 2135** The second parameter is a pointer to an integer into which 2136** is written 0 or 1 to indicate whether triggers are disabled or enabled 2137** following this call. The second parameter may be a NULL pointer, in 2138** which case the trigger setting is not reported back. 2139** 2140** <p>Originally this option disabled all triggers. ^(However, since 2141** SQLite version 3.35.0, TEMP triggers are still allowed even if 2142** this option is off. So, in other words, this option now only disables 2143** triggers in the main database schema or in the schemas of ATTACH-ed 2144** databases.)^ </dd> 2145** 2146** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2147** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2148** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2149** There should be two additional arguments. 2150** The first argument is an integer which is 0 to disable views, 2151** positive to enable views or negative to leave the setting unchanged. 2152** The second parameter is a pointer to an integer into which 2153** is written 0 or 1 to indicate whether views are disabled or enabled 2154** following this call. The second parameter may be a NULL pointer, in 2155** which case the view setting is not reported back. 2156** 2157** <p>Originally this option disabled all views. ^(However, since 2158** SQLite version 3.35.0, TEMP views are still allowed even if 2159** this option is off. So, in other words, this option now only disables 2160** views in the main database schema or in the schemas of ATTACH-ed 2161** databases.)^ </dd> 2162** 2163** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2164** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2165** <dd> ^This option is used to enable or disable the 2166** [fts3_tokenizer()] function which is part of the 2167** [FTS3] full-text search engine extension. 2168** There should be two additional arguments. 2169** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2170** positive to enable fts3_tokenizer() or negative to leave the setting 2171** unchanged. 2172** The second parameter is a pointer to an integer into which 2173** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2174** following this call. The second parameter may be a NULL pointer, in 2175** which case the new setting is not reported back. </dd> 2176** 2177** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2178** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2179** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2180** interface independently of the [load_extension()] SQL function. 2181** The [sqlite3_enable_load_extension()] API enables or disables both the 2182** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2183** There should be two additional arguments. 2184** When the first argument to this interface is 1, then only the C-API is 2185** enabled and the SQL function remains disabled. If the first argument to 2186** this interface is 0, then both the C-API and the SQL function are disabled. 2187** If the first argument is -1, then no changes are made to state of either the 2188** C-API or the SQL function. 2189** The second parameter is a pointer to an integer into which 2190** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2191** is disabled or enabled following this call. The second parameter may 2192** be a NULL pointer, in which case the new setting is not reported back. 2193** </dd> 2194** 2195** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2196** <dd> ^This option is used to change the name of the "main" database 2197** schema. ^The sole argument is a pointer to a constant UTF8 string 2198** which will become the new schema name in place of "main". ^SQLite 2199** does not make a copy of the new main schema name string, so the application 2200** must ensure that the argument passed into this DBCONFIG option is unchanged 2201** until after the database connection closes. 2202** </dd> 2203** 2204** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2205** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2206** <dd> Usually, when a database in wal mode is closed or detached from a 2207** database handle, SQLite checks if this will mean that there are now no 2208** connections at all to the database. If so, it performs a checkpoint 2209** operation before closing the connection. This option may be used to 2210** override this behaviour. The first parameter passed to this operation 2211** is an integer - positive to disable checkpoints-on-close, or zero (the 2212** default) to enable them, and negative to leave the setting unchanged. 2213** The second parameter is a pointer to an integer 2214** into which is written 0 or 1 to indicate whether checkpoints-on-close 2215** have been disabled - 0 if they are not disabled, 1 if they are. 2216** </dd> 2217** 2218** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2219** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2220** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2221** a single SQL query statement will always use the same algorithm regardless 2222** of values of [bound parameters].)^ The QPSG disables some query optimizations 2223** that look at the values of bound parameters, which can make some queries 2224** slower. But the QPSG has the advantage of more predictable behavior. With 2225** the QPSG active, SQLite will always use the same query plan in the field as 2226** was used during testing in the lab. 2227** The first argument to this setting is an integer which is 0 to disable 2228** the QPSG, positive to enable QPSG, or negative to leave the setting 2229** unchanged. The second parameter is a pointer to an integer into which 2230** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2231** following this call. 2232** </dd> 2233** 2234** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2235** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2236** include output for any operations performed by trigger programs. This 2237** option is used to set or clear (the default) a flag that governs this 2238** behavior. The first parameter passed to this operation is an integer - 2239** positive to enable output for trigger programs, or zero to disable it, 2240** or negative to leave the setting unchanged. 2241** The second parameter is a pointer to an integer into which is written 2242** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2243** it is not disabled, 1 if it is. 2244** </dd> 2245** 2246** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2247** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2248** [VACUUM] in order to reset a database back to an empty database 2249** with no schema and no content. The following process works even for 2250** a badly corrupted database file: 2251** <ol> 2252** <li> If the database connection is newly opened, make sure it has read the 2253** database schema by preparing then discarding some query against the 2254** database, or calling sqlite3_table_column_metadata(), ignoring any 2255** errors. This step is only necessary if the application desires to keep 2256** the database in WAL mode after the reset if it was in WAL mode before 2257** the reset. 2258** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2259** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2260** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2261** </ol> 2262** Because resetting a database is destructive and irreversible, the 2263** process requires the use of this obscure API and multiple steps to help 2264** ensure that it does not happen by accident. 2265** 2266** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2267** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2268** "defensive" flag for a database connection. When the defensive 2269** flag is enabled, language features that allow ordinary SQL to 2270** deliberately corrupt the database file are disabled. The disabled 2271** features include but are not limited to the following: 2272** <ul> 2273** <li> The [PRAGMA writable_schema=ON] statement. 2274** <li> The [PRAGMA journal_mode=OFF] statement. 2275** <li> Writes to the [sqlite_dbpage] virtual table. 2276** <li> Direct writes to [shadow tables]. 2277** </ul> 2278** </dd> 2279** 2280** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2281** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2282** "writable_schema" flag. This has the same effect and is logically equivalent 2283** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2284** The first argument to this setting is an integer which is 0 to disable 2285** the writable_schema, positive to enable writable_schema, or negative to 2286** leave the setting unchanged. The second parameter is a pointer to an 2287** integer into which is written 0 or 1 to indicate whether the writable_schema 2288** is enabled or disabled following this call. 2289** </dd> 2290** 2291** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2292** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2293** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2294** the legacy behavior of the [ALTER TABLE RENAME] command such it 2295** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2296** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2297** additional information. This feature can also be turned on and off 2298** using the [PRAGMA legacy_alter_table] statement. 2299** </dd> 2300** 2301** [[SQLITE_DBCONFIG_DQS_DML]] 2302** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2303** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2304** the legacy [double-quoted string literal] misfeature for DML statements 2305** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2306** default value of this setting is determined by the [-DSQLITE_DQS] 2307** compile-time option. 2308** </dd> 2309** 2310** [[SQLITE_DBCONFIG_DQS_DDL]] 2311** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2312** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2313** the legacy [double-quoted string literal] misfeature for DDL statements, 2314** such as CREATE TABLE and CREATE INDEX. The 2315** default value of this setting is determined by the [-DSQLITE_DQS] 2316** compile-time option. 2317** </dd> 2318** 2319** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2320** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2321** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2322** assume that database schemas are untainted by malicious content. 2323** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2324** takes additional defensive steps to protect the application from harm 2325** including: 2326** <ul> 2327** <li> Prohibit the use of SQL functions inside triggers, views, 2328** CHECK constraints, DEFAULT clauses, expression indexes, 2329** partial indexes, or generated columns 2330** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2331** <li> Prohibit the use of virtual tables inside of triggers or views 2332** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2333** </ul> 2334** This setting defaults to "on" for legacy compatibility, however 2335** all applications are advised to turn it off if possible. This setting 2336** can also be controlled using the [PRAGMA trusted_schema] statement. 2337** </dd> 2338** 2339** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2340** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2341** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2342** the legacy file format flag. When activated, this flag causes all newly 2343** created database file to have a schema format version number (the 4-byte 2344** integer found at offset 44 into the database header) of 1. This in turn 2345** means that the resulting database file will be readable and writable by 2346** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2347** newly created databases are generally not understandable by SQLite versions 2348** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2349** is now scarcely any need to generated database files that are compatible 2350** all the way back to version 3.0.0, and so this setting is of little 2351** practical use, but is provided so that SQLite can continue to claim the 2352** ability to generate new database files that are compatible with version 2353** 3.0.0. 2354** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2355** the [VACUUM] command will fail with an obscure error when attempting to 2356** process a table with generated columns and a descending index. This is 2357** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2358** either generated columns or decending indexes. 2359** </dd> 2360** </dl> 2361*/ 2362#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2363#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2364#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2365#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2366#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2367#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2368#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2369#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2370#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2371#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2372#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2373#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2374#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2375#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2376#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2377#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2378#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2379#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2380#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2381 2382/* 2383** CAPI3REF: Enable Or Disable Extended Result Codes 2384** METHOD: sqlite3 2385** 2386** ^The sqlite3_extended_result_codes() routine enables or disables the 2387** [extended result codes] feature of SQLite. ^The extended result 2388** codes are disabled by default for historical compatibility. 2389*/ 2390int sqlite3_extended_result_codes(sqlite3*, int onoff); 2391 2392/* 2393** CAPI3REF: Last Insert Rowid 2394** METHOD: sqlite3 2395** 2396** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2397** has a unique 64-bit signed 2398** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2399** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2400** names are not also used by explicitly declared columns. ^If 2401** the table has a column of type [INTEGER PRIMARY KEY] then that column 2402** is another alias for the rowid. 2403** 2404** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2405** the most recent successful [INSERT] into a rowid table or [virtual table] 2406** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2407** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2408** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2409** zero. 2410** 2411** As well as being set automatically as rows are inserted into database 2412** tables, the value returned by this function may be set explicitly by 2413** [sqlite3_set_last_insert_rowid()] 2414** 2415** Some virtual table implementations may INSERT rows into rowid tables as 2416** part of committing a transaction (e.g. to flush data accumulated in memory 2417** to disk). In this case subsequent calls to this function return the rowid 2418** associated with these internal INSERT operations, which leads to 2419** unintuitive results. Virtual table implementations that do write to rowid 2420** tables in this way can avoid this problem by restoring the original 2421** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2422** control to the user. 2423** 2424** ^(If an [INSERT] occurs within a trigger then this routine will 2425** return the [rowid] of the inserted row as long as the trigger is 2426** running. Once the trigger program ends, the value returned 2427** by this routine reverts to what it was before the trigger was fired.)^ 2428** 2429** ^An [INSERT] that fails due to a constraint violation is not a 2430** successful [INSERT] and does not change the value returned by this 2431** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2432** and INSERT OR ABORT make no changes to the return value of this 2433** routine when their insertion fails. ^(When INSERT OR REPLACE 2434** encounters a constraint violation, it does not fail. The 2435** INSERT continues to completion after deleting rows that caused 2436** the constraint problem so INSERT OR REPLACE will always change 2437** the return value of this interface.)^ 2438** 2439** ^For the purposes of this routine, an [INSERT] is considered to 2440** be successful even if it is subsequently rolled back. 2441** 2442** This function is accessible to SQL statements via the 2443** [last_insert_rowid() SQL function]. 2444** 2445** If a separate thread performs a new [INSERT] on the same 2446** database connection while the [sqlite3_last_insert_rowid()] 2447** function is running and thus changes the last insert [rowid], 2448** then the value returned by [sqlite3_last_insert_rowid()] is 2449** unpredictable and might not equal either the old or the new 2450** last insert [rowid]. 2451*/ 2452sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2453 2454/* 2455** CAPI3REF: Set the Last Insert Rowid value. 2456** METHOD: sqlite3 2457** 2458** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2459** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2460** without inserting a row into the database. 2461*/ 2462void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2463 2464/* 2465** CAPI3REF: Count The Number Of Rows Modified 2466** METHOD: sqlite3 2467** 2468** ^These functions return the number of rows modified, inserted or 2469** deleted by the most recently completed INSERT, UPDATE or DELETE 2470** statement on the database connection specified by the only parameter. 2471** The two functions are identical except for the type of the return value 2472** and that if the number of rows modified by the most recent INSERT, UPDATE 2473** or DELETE is greater than the maximum value supported by type "int", then 2474** the return value of sqlite3_changes() is undefined. ^Executing any other 2475** type of SQL statement does not modify the value returned by these functions. 2476** 2477** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2478** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2479** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2480** 2481** Changes to a view that are intercepted by 2482** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2483** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2484** DELETE statement run on a view is always zero. Only changes made to real 2485** tables are counted. 2486** 2487** Things are more complicated if the sqlite3_changes() function is 2488** executed while a trigger program is running. This may happen if the 2489** program uses the [changes() SQL function], or if some other callback 2490** function invokes sqlite3_changes() directly. Essentially: 2491** 2492** <ul> 2493** <li> ^(Before entering a trigger program the value returned by 2494** sqlite3_changes() function is saved. After the trigger program 2495** has finished, the original value is restored.)^ 2496** 2497** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2498** statement sets the value returned by sqlite3_changes() 2499** upon completion as normal. Of course, this value will not include 2500** any changes performed by sub-triggers, as the sqlite3_changes() 2501** value will be saved and restored after each sub-trigger has run.)^ 2502** </ul> 2503** 2504** ^This means that if the changes() SQL function (or similar) is used 2505** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2506** returns the value as set when the calling statement began executing. 2507** ^If it is used by the second or subsequent such statement within a trigger 2508** program, the value returned reflects the number of rows modified by the 2509** previous INSERT, UPDATE or DELETE statement within the same trigger. 2510** 2511** If a separate thread makes changes on the same database connection 2512** while [sqlite3_changes()] is running then the value returned 2513** is unpredictable and not meaningful. 2514** 2515** See also: 2516** <ul> 2517** <li> the [sqlite3_total_changes()] interface 2518** <li> the [count_changes pragma] 2519** <li> the [changes() SQL function] 2520** <li> the [data_version pragma] 2521** </ul> 2522*/ 2523int sqlite3_changes(sqlite3*); 2524sqlite3_int64 sqlite3_changes64(sqlite3*); 2525 2526/* 2527** CAPI3REF: Total Number Of Rows Modified 2528** METHOD: sqlite3 2529** 2530** ^These functions return the total number of rows inserted, modified or 2531** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2532** since the database connection was opened, including those executed as 2533** part of trigger programs. The two functions are identical except for the 2534** type of the return value and that if the number of rows modified by the 2535** connection exceeds the maximum value supported by type "int", then 2536** the return value of sqlite3_total_changes() is undefined. ^Executing 2537** any other type of SQL statement does not affect the value returned by 2538** sqlite3_total_changes(). 2539** 2540** ^Changes made as part of [foreign key actions] are included in the 2541** count, but those made as part of REPLACE constraint resolution are 2542** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2543** are not counted. 2544** 2545** The [sqlite3_total_changes(D)] interface only reports the number 2546** of rows that changed due to SQL statement run against database 2547** connection D. Any changes by other database connections are ignored. 2548** To detect changes against a database file from other database 2549** connections use the [PRAGMA data_version] command or the 2550** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2551** 2552** If a separate thread makes changes on the same database connection 2553** while [sqlite3_total_changes()] is running then the value 2554** returned is unpredictable and not meaningful. 2555** 2556** See also: 2557** <ul> 2558** <li> the [sqlite3_changes()] interface 2559** <li> the [count_changes pragma] 2560** <li> the [changes() SQL function] 2561** <li> the [data_version pragma] 2562** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2563** </ul> 2564*/ 2565int sqlite3_total_changes(sqlite3*); 2566sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2567 2568/* 2569** CAPI3REF: Interrupt A Long-Running Query 2570** METHOD: sqlite3 2571** 2572** ^This function causes any pending database operation to abort and 2573** return at its earliest opportunity. This routine is typically 2574** called in response to a user action such as pressing "Cancel" 2575** or Ctrl-C where the user wants a long query operation to halt 2576** immediately. 2577** 2578** ^It is safe to call this routine from a thread different from the 2579** thread that is currently running the database operation. But it 2580** is not safe to call this routine with a [database connection] that 2581** is closed or might close before sqlite3_interrupt() returns. 2582** 2583** ^If an SQL operation is very nearly finished at the time when 2584** sqlite3_interrupt() is called, then it might not have an opportunity 2585** to be interrupted and might continue to completion. 2586** 2587** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2588** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2589** that is inside an explicit transaction, then the entire transaction 2590** will be rolled back automatically. 2591** 2592** ^The sqlite3_interrupt(D) call is in effect until all currently running 2593** SQL statements on [database connection] D complete. ^Any new SQL statements 2594** that are started after the sqlite3_interrupt() call and before the 2595** running statement count reaches zero are interrupted as if they had been 2596** running prior to the sqlite3_interrupt() call. ^New SQL statements 2597** that are started after the running statement count reaches zero are 2598** not effected by the sqlite3_interrupt(). 2599** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2600** SQL statements is a no-op and has no effect on SQL statements 2601** that are started after the sqlite3_interrupt() call returns. 2602*/ 2603void sqlite3_interrupt(sqlite3*); 2604 2605/* 2606** CAPI3REF: Determine If An SQL Statement Is Complete 2607** 2608** These routines are useful during command-line input to determine if the 2609** currently entered text seems to form a complete SQL statement or 2610** if additional input is needed before sending the text into 2611** SQLite for parsing. ^These routines return 1 if the input string 2612** appears to be a complete SQL statement. ^A statement is judged to be 2613** complete if it ends with a semicolon token and is not a prefix of a 2614** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2615** string literals or quoted identifier names or comments are not 2616** independent tokens (they are part of the token in which they are 2617** embedded) and thus do not count as a statement terminator. ^Whitespace 2618** and comments that follow the final semicolon are ignored. 2619** 2620** ^These routines return 0 if the statement is incomplete. ^If a 2621** memory allocation fails, then SQLITE_NOMEM is returned. 2622** 2623** ^These routines do not parse the SQL statements thus 2624** will not detect syntactically incorrect SQL. 2625** 2626** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2627** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2628** automatically by sqlite3_complete16(). If that initialization fails, 2629** then the return value from sqlite3_complete16() will be non-zero 2630** regardless of whether or not the input SQL is complete.)^ 2631** 2632** The input to [sqlite3_complete()] must be a zero-terminated 2633** UTF-8 string. 2634** 2635** The input to [sqlite3_complete16()] must be a zero-terminated 2636** UTF-16 string in native byte order. 2637*/ 2638int sqlite3_complete(const char *sql); 2639int sqlite3_complete16(const void *sql); 2640 2641/* 2642** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2643** KEYWORDS: {busy-handler callback} {busy handler} 2644** METHOD: sqlite3 2645** 2646** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2647** that might be invoked with argument P whenever 2648** an attempt is made to access a database table associated with 2649** [database connection] D when another thread 2650** or process has the table locked. 2651** The sqlite3_busy_handler() interface is used to implement 2652** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2653** 2654** ^If the busy callback is NULL, then [SQLITE_BUSY] 2655** is returned immediately upon encountering the lock. ^If the busy callback 2656** is not NULL, then the callback might be invoked with two arguments. 2657** 2658** ^The first argument to the busy handler is a copy of the void* pointer which 2659** is the third argument to sqlite3_busy_handler(). ^The second argument to 2660** the busy handler callback is the number of times that the busy handler has 2661** been invoked previously for the same locking event. ^If the 2662** busy callback returns 0, then no additional attempts are made to 2663** access the database and [SQLITE_BUSY] is returned 2664** to the application. 2665** ^If the callback returns non-zero, then another attempt 2666** is made to access the database and the cycle repeats. 2667** 2668** The presence of a busy handler does not guarantee that it will be invoked 2669** when there is lock contention. ^If SQLite determines that invoking the busy 2670** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2671** to the application instead of invoking the 2672** busy handler. 2673** Consider a scenario where one process is holding a read lock that 2674** it is trying to promote to a reserved lock and 2675** a second process is holding a reserved lock that it is trying 2676** to promote to an exclusive lock. The first process cannot proceed 2677** because it is blocked by the second and the second process cannot 2678** proceed because it is blocked by the first. If both processes 2679** invoke the busy handlers, neither will make any progress. Therefore, 2680** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2681** will induce the first process to release its read lock and allow 2682** the second process to proceed. 2683** 2684** ^The default busy callback is NULL. 2685** 2686** ^(There can only be a single busy handler defined for each 2687** [database connection]. Setting a new busy handler clears any 2688** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2689** or evaluating [PRAGMA busy_timeout=N] will change the 2690** busy handler and thus clear any previously set busy handler. 2691** 2692** The busy callback should not take any actions which modify the 2693** database connection that invoked the busy handler. In other words, 2694** the busy handler is not reentrant. Any such actions 2695** result in undefined behavior. 2696** 2697** A busy handler must not close the database connection 2698** or [prepared statement] that invoked the busy handler. 2699*/ 2700int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2701 2702/* 2703** CAPI3REF: Set A Busy Timeout 2704** METHOD: sqlite3 2705** 2706** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2707** for a specified amount of time when a table is locked. ^The handler 2708** will sleep multiple times until at least "ms" milliseconds of sleeping 2709** have accumulated. ^After at least "ms" milliseconds of sleeping, 2710** the handler returns 0 which causes [sqlite3_step()] to return 2711** [SQLITE_BUSY]. 2712** 2713** ^Calling this routine with an argument less than or equal to zero 2714** turns off all busy handlers. 2715** 2716** ^(There can only be a single busy handler for a particular 2717** [database connection] at any given moment. If another busy handler 2718** was defined (using [sqlite3_busy_handler()]) prior to calling 2719** this routine, that other busy handler is cleared.)^ 2720** 2721** See also: [PRAGMA busy_timeout] 2722*/ 2723int sqlite3_busy_timeout(sqlite3*, int ms); 2724 2725/* 2726** CAPI3REF: Convenience Routines For Running Queries 2727** METHOD: sqlite3 2728** 2729** This is a legacy interface that is preserved for backwards compatibility. 2730** Use of this interface is not recommended. 2731** 2732** Definition: A <b>result table</b> is memory data structure created by the 2733** [sqlite3_get_table()] interface. A result table records the 2734** complete query results from one or more queries. 2735** 2736** The table conceptually has a number of rows and columns. But 2737** these numbers are not part of the result table itself. These 2738** numbers are obtained separately. Let N be the number of rows 2739** and M be the number of columns. 2740** 2741** A result table is an array of pointers to zero-terminated UTF-8 strings. 2742** There are (N+1)*M elements in the array. The first M pointers point 2743** to zero-terminated strings that contain the names of the columns. 2744** The remaining entries all point to query results. NULL values result 2745** in NULL pointers. All other values are in their UTF-8 zero-terminated 2746** string representation as returned by [sqlite3_column_text()]. 2747** 2748** A result table might consist of one or more memory allocations. 2749** It is not safe to pass a result table directly to [sqlite3_free()]. 2750** A result table should be deallocated using [sqlite3_free_table()]. 2751** 2752** ^(As an example of the result table format, suppose a query result 2753** is as follows: 2754** 2755** <blockquote><pre> 2756** Name | Age 2757** ----------------------- 2758** Alice | 43 2759** Bob | 28 2760** Cindy | 21 2761** </pre></blockquote> 2762** 2763** There are two columns (M==2) and three rows (N==3). Thus the 2764** result table has 8 entries. Suppose the result table is stored 2765** in an array named azResult. Then azResult holds this content: 2766** 2767** <blockquote><pre> 2768** azResult[0] = "Name"; 2769** azResult[1] = "Age"; 2770** azResult[2] = "Alice"; 2771** azResult[3] = "43"; 2772** azResult[4] = "Bob"; 2773** azResult[5] = "28"; 2774** azResult[6] = "Cindy"; 2775** azResult[7] = "21"; 2776** </pre></blockquote>)^ 2777** 2778** ^The sqlite3_get_table() function evaluates one or more 2779** semicolon-separated SQL statements in the zero-terminated UTF-8 2780** string of its 2nd parameter and returns a result table to the 2781** pointer given in its 3rd parameter. 2782** 2783** After the application has finished with the result from sqlite3_get_table(), 2784** it must pass the result table pointer to sqlite3_free_table() in order to 2785** release the memory that was malloced. Because of the way the 2786** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2787** function must not try to call [sqlite3_free()] directly. Only 2788** [sqlite3_free_table()] is able to release the memory properly and safely. 2789** 2790** The sqlite3_get_table() interface is implemented as a wrapper around 2791** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2792** to any internal data structures of SQLite. It uses only the public 2793** interface defined here. As a consequence, errors that occur in the 2794** wrapper layer outside of the internal [sqlite3_exec()] call are not 2795** reflected in subsequent calls to [sqlite3_errcode()] or 2796** [sqlite3_errmsg()]. 2797*/ 2798int sqlite3_get_table( 2799 sqlite3 *db, /* An open database */ 2800 const char *zSql, /* SQL to be evaluated */ 2801 char ***pazResult, /* Results of the query */ 2802 int *pnRow, /* Number of result rows written here */ 2803 int *pnColumn, /* Number of result columns written here */ 2804 char **pzErrmsg /* Error msg written here */ 2805); 2806void sqlite3_free_table(char **result); 2807 2808/* 2809** CAPI3REF: Formatted String Printing Functions 2810** 2811** These routines are work-alikes of the "printf()" family of functions 2812** from the standard C library. 2813** These routines understand most of the common formatting options from 2814** the standard library printf() 2815** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2816** See the [built-in printf()] documentation for details. 2817** 2818** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2819** results into memory obtained from [sqlite3_malloc64()]. 2820** The strings returned by these two routines should be 2821** released by [sqlite3_free()]. ^Both routines return a 2822** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2823** memory to hold the resulting string. 2824** 2825** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2826** the standard C library. The result is written into the 2827** buffer supplied as the second parameter whose size is given by 2828** the first parameter. Note that the order of the 2829** first two parameters is reversed from snprintf().)^ This is an 2830** historical accident that cannot be fixed without breaking 2831** backwards compatibility. ^(Note also that sqlite3_snprintf() 2832** returns a pointer to its buffer instead of the number of 2833** characters actually written into the buffer.)^ We admit that 2834** the number of characters written would be a more useful return 2835** value but we cannot change the implementation of sqlite3_snprintf() 2836** now without breaking compatibility. 2837** 2838** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2839** guarantees that the buffer is always zero-terminated. ^The first 2840** parameter "n" is the total size of the buffer, including space for 2841** the zero terminator. So the longest string that can be completely 2842** written will be n-1 characters. 2843** 2844** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2845** 2846** See also: [built-in printf()], [printf() SQL function] 2847*/ 2848char *sqlite3_mprintf(const char*,...); 2849char *sqlite3_vmprintf(const char*, va_list); 2850char *sqlite3_snprintf(int,char*,const char*, ...); 2851char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2852 2853/* 2854** CAPI3REF: Memory Allocation Subsystem 2855** 2856** The SQLite core uses these three routines for all of its own 2857** internal memory allocation needs. "Core" in the previous sentence 2858** does not include operating-system specific [VFS] implementation. The 2859** Windows VFS uses native malloc() and free() for some operations. 2860** 2861** ^The sqlite3_malloc() routine returns a pointer to a block 2862** of memory at least N bytes in length, where N is the parameter. 2863** ^If sqlite3_malloc() is unable to obtain sufficient free 2864** memory, it returns a NULL pointer. ^If the parameter N to 2865** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2866** a NULL pointer. 2867** 2868** ^The sqlite3_malloc64(N) routine works just like 2869** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2870** of a signed 32-bit integer. 2871** 2872** ^Calling sqlite3_free() with a pointer previously returned 2873** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2874** that it might be reused. ^The sqlite3_free() routine is 2875** a no-op if is called with a NULL pointer. Passing a NULL pointer 2876** to sqlite3_free() is harmless. After being freed, memory 2877** should neither be read nor written. Even reading previously freed 2878** memory might result in a segmentation fault or other severe error. 2879** Memory corruption, a segmentation fault, or other severe error 2880** might result if sqlite3_free() is called with a non-NULL pointer that 2881** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2882** 2883** ^The sqlite3_realloc(X,N) interface attempts to resize a 2884** prior memory allocation X to be at least N bytes. 2885** ^If the X parameter to sqlite3_realloc(X,N) 2886** is a NULL pointer then its behavior is identical to calling 2887** sqlite3_malloc(N). 2888** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2889** negative then the behavior is exactly the same as calling 2890** sqlite3_free(X). 2891** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2892** of at least N bytes in size or NULL if insufficient memory is available. 2893** ^If M is the size of the prior allocation, then min(N,M) bytes 2894** of the prior allocation are copied into the beginning of buffer returned 2895** by sqlite3_realloc(X,N) and the prior allocation is freed. 2896** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2897** prior allocation is not freed. 2898** 2899** ^The sqlite3_realloc64(X,N) interfaces works the same as 2900** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2901** of a 32-bit signed integer. 2902** 2903** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2904** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2905** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2906** ^The value returned by sqlite3_msize(X) might be larger than the number 2907** of bytes requested when X was allocated. ^If X is a NULL pointer then 2908** sqlite3_msize(X) returns zero. If X points to something that is not 2909** the beginning of memory allocation, or if it points to a formerly 2910** valid memory allocation that has now been freed, then the behavior 2911** of sqlite3_msize(X) is undefined and possibly harmful. 2912** 2913** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2914** sqlite3_malloc64(), and sqlite3_realloc64() 2915** is always aligned to at least an 8 byte boundary, or to a 2916** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2917** option is used. 2918** 2919** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2920** must be either NULL or else pointers obtained from a prior 2921** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2922** not yet been released. 2923** 2924** The application must not read or write any part of 2925** a block of memory after it has been released using 2926** [sqlite3_free()] or [sqlite3_realloc()]. 2927*/ 2928void *sqlite3_malloc(int); 2929void *sqlite3_malloc64(sqlite3_uint64); 2930void *sqlite3_realloc(void*, int); 2931void *sqlite3_realloc64(void*, sqlite3_uint64); 2932void sqlite3_free(void*); 2933sqlite3_uint64 sqlite3_msize(void*); 2934 2935/* 2936** CAPI3REF: Memory Allocator Statistics 2937** 2938** SQLite provides these two interfaces for reporting on the status 2939** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2940** routines, which form the built-in memory allocation subsystem. 2941** 2942** ^The [sqlite3_memory_used()] routine returns the number of bytes 2943** of memory currently outstanding (malloced but not freed). 2944** ^The [sqlite3_memory_highwater()] routine returns the maximum 2945** value of [sqlite3_memory_used()] since the high-water mark 2946** was last reset. ^The values returned by [sqlite3_memory_used()] and 2947** [sqlite3_memory_highwater()] include any overhead 2948** added by SQLite in its implementation of [sqlite3_malloc()], 2949** but not overhead added by the any underlying system library 2950** routines that [sqlite3_malloc()] may call. 2951** 2952** ^The memory high-water mark is reset to the current value of 2953** [sqlite3_memory_used()] if and only if the parameter to 2954** [sqlite3_memory_highwater()] is true. ^The value returned 2955** by [sqlite3_memory_highwater(1)] is the high-water mark 2956** prior to the reset. 2957*/ 2958sqlite3_int64 sqlite3_memory_used(void); 2959sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2960 2961/* 2962** CAPI3REF: Pseudo-Random Number Generator 2963** 2964** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2965** select random [ROWID | ROWIDs] when inserting new records into a table that 2966** already uses the largest possible [ROWID]. The PRNG is also used for 2967** the built-in random() and randomblob() SQL functions. This interface allows 2968** applications to access the same PRNG for other purposes. 2969** 2970** ^A call to this routine stores N bytes of randomness into buffer P. 2971** ^The P parameter can be a NULL pointer. 2972** 2973** ^If this routine has not been previously called or if the previous 2974** call had N less than one or a NULL pointer for P, then the PRNG is 2975** seeded using randomness obtained from the xRandomness method of 2976** the default [sqlite3_vfs] object. 2977** ^If the previous call to this routine had an N of 1 or more and a 2978** non-NULL P then the pseudo-randomness is generated 2979** internally and without recourse to the [sqlite3_vfs] xRandomness 2980** method. 2981*/ 2982void sqlite3_randomness(int N, void *P); 2983 2984/* 2985** CAPI3REF: Compile-Time Authorization Callbacks 2986** METHOD: sqlite3 2987** KEYWORDS: {authorizer callback} 2988** 2989** ^This routine registers an authorizer callback with a particular 2990** [database connection], supplied in the first argument. 2991** ^The authorizer callback is invoked as SQL statements are being compiled 2992** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2993** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2994** and [sqlite3_prepare16_v3()]. ^At various 2995** points during the compilation process, as logic is being created 2996** to perform various actions, the authorizer callback is invoked to 2997** see if those actions are allowed. ^The authorizer callback should 2998** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2999** specific action but allow the SQL statement to continue to be 3000** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3001** rejected with an error. ^If the authorizer callback returns 3002** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3003** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3004** the authorizer will fail with an error message. 3005** 3006** When the callback returns [SQLITE_OK], that means the operation 3007** requested is ok. ^When the callback returns [SQLITE_DENY], the 3008** [sqlite3_prepare_v2()] or equivalent call that triggered the 3009** authorizer will fail with an error message explaining that 3010** access is denied. 3011** 3012** ^The first parameter to the authorizer callback is a copy of the third 3013** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3014** to the callback is an integer [SQLITE_COPY | action code] that specifies 3015** the particular action to be authorized. ^The third through sixth parameters 3016** to the callback are either NULL pointers or zero-terminated strings 3017** that contain additional details about the action to be authorized. 3018** Applications must always be prepared to encounter a NULL pointer in any 3019** of the third through the sixth parameters of the authorization callback. 3020** 3021** ^If the action code is [SQLITE_READ] 3022** and the callback returns [SQLITE_IGNORE] then the 3023** [prepared statement] statement is constructed to substitute 3024** a NULL value in place of the table column that would have 3025** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3026** return can be used to deny an untrusted user access to individual 3027** columns of a table. 3028** ^When a table is referenced by a [SELECT] but no column values are 3029** extracted from that table (for example in a query like 3030** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3031** is invoked once for that table with a column name that is an empty string. 3032** ^If the action code is [SQLITE_DELETE] and the callback returns 3033** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3034** [truncate optimization] is disabled and all rows are deleted individually. 3035** 3036** An authorizer is used when [sqlite3_prepare | preparing] 3037** SQL statements from an untrusted source, to ensure that the SQL statements 3038** do not try to access data they are not allowed to see, or that they do not 3039** try to execute malicious statements that damage the database. For 3040** example, an application may allow a user to enter arbitrary 3041** SQL queries for evaluation by a database. But the application does 3042** not want the user to be able to make arbitrary changes to the 3043** database. An authorizer could then be put in place while the 3044** user-entered SQL is being [sqlite3_prepare | prepared] that 3045** disallows everything except [SELECT] statements. 3046** 3047** Applications that need to process SQL from untrusted sources 3048** might also consider lowering resource limits using [sqlite3_limit()] 3049** and limiting database size using the [max_page_count] [PRAGMA] 3050** in addition to using an authorizer. 3051** 3052** ^(Only a single authorizer can be in place on a database connection 3053** at a time. Each call to sqlite3_set_authorizer overrides the 3054** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3055** The authorizer is disabled by default. 3056** 3057** The authorizer callback must not do anything that will modify 3058** the database connection that invoked the authorizer callback. 3059** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3060** database connections for the meaning of "modify" in this paragraph. 3061** 3062** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3063** statement might be re-prepared during [sqlite3_step()] due to a 3064** schema change. Hence, the application should ensure that the 3065** correct authorizer callback remains in place during the [sqlite3_step()]. 3066** 3067** ^Note that the authorizer callback is invoked only during 3068** [sqlite3_prepare()] or its variants. Authorization is not 3069** performed during statement evaluation in [sqlite3_step()], unless 3070** as stated in the previous paragraph, sqlite3_step() invokes 3071** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3072*/ 3073int sqlite3_set_authorizer( 3074 sqlite3*, 3075 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3076 void *pUserData 3077); 3078 3079/* 3080** CAPI3REF: Authorizer Return Codes 3081** 3082** The [sqlite3_set_authorizer | authorizer callback function] must 3083** return either [SQLITE_OK] or one of these two constants in order 3084** to signal SQLite whether or not the action is permitted. See the 3085** [sqlite3_set_authorizer | authorizer documentation] for additional 3086** information. 3087** 3088** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3089** returned from the [sqlite3_vtab_on_conflict()] interface. 3090*/ 3091#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3092#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3093 3094/* 3095** CAPI3REF: Authorizer Action Codes 3096** 3097** The [sqlite3_set_authorizer()] interface registers a callback function 3098** that is invoked to authorize certain SQL statement actions. The 3099** second parameter to the callback is an integer code that specifies 3100** what action is being authorized. These are the integer action codes that 3101** the authorizer callback may be passed. 3102** 3103** These action code values signify what kind of operation is to be 3104** authorized. The 3rd and 4th parameters to the authorization 3105** callback function will be parameters or NULL depending on which of these 3106** codes is used as the second parameter. ^(The 5th parameter to the 3107** authorizer callback is the name of the database ("main", "temp", 3108** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3109** is the name of the inner-most trigger or view that is responsible for 3110** the access attempt or NULL if this access attempt is directly from 3111** top-level SQL code. 3112*/ 3113/******************************************* 3rd ************ 4th ***********/ 3114#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3115#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3116#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3117#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3118#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3119#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3120#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3121#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3122#define SQLITE_DELETE 9 /* Table Name NULL */ 3123#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3124#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3125#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3126#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3127#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3128#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3129#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3130#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3131#define SQLITE_INSERT 18 /* Table Name NULL */ 3132#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3133#define SQLITE_READ 20 /* Table Name Column Name */ 3134#define SQLITE_SELECT 21 /* NULL NULL */ 3135#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3136#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3137#define SQLITE_ATTACH 24 /* Filename NULL */ 3138#define SQLITE_DETACH 25 /* Database Name NULL */ 3139#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3140#define SQLITE_REINDEX 27 /* Index Name NULL */ 3141#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3142#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3143#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3144#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3145#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3146#define SQLITE_COPY 0 /* No longer used */ 3147#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3148 3149/* 3150** CAPI3REF: Tracing And Profiling Functions 3151** METHOD: sqlite3 3152** 3153** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3154** instead of the routines described here. 3155** 3156** These routines register callback functions that can be used for 3157** tracing and profiling the execution of SQL statements. 3158** 3159** ^The callback function registered by sqlite3_trace() is invoked at 3160** various times when an SQL statement is being run by [sqlite3_step()]. 3161** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3162** SQL statement text as the statement first begins executing. 3163** ^(Additional sqlite3_trace() callbacks might occur 3164** as each triggered subprogram is entered. The callbacks for triggers 3165** contain a UTF-8 SQL comment that identifies the trigger.)^ 3166** 3167** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3168** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3169** 3170** ^The callback function registered by sqlite3_profile() is invoked 3171** as each SQL statement finishes. ^The profile callback contains 3172** the original statement text and an estimate of wall-clock time 3173** of how long that statement took to run. ^The profile callback 3174** time is in units of nanoseconds, however the current implementation 3175** is only capable of millisecond resolution so the six least significant 3176** digits in the time are meaningless. Future versions of SQLite 3177** might provide greater resolution on the profiler callback. Invoking 3178** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3179** profile callback. 3180*/ 3181SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3182 void(*xTrace)(void*,const char*), void*); 3183SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3184 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3185 3186/* 3187** CAPI3REF: SQL Trace Event Codes 3188** KEYWORDS: SQLITE_TRACE 3189** 3190** These constants identify classes of events that can be monitored 3191** using the [sqlite3_trace_v2()] tracing logic. The M argument 3192** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3193** the following constants. ^The first argument to the trace callback 3194** is one of the following constants. 3195** 3196** New tracing constants may be added in future releases. 3197** 3198** ^A trace callback has four arguments: xCallback(T,C,P,X). 3199** ^The T argument is one of the integer type codes above. 3200** ^The C argument is a copy of the context pointer passed in as the 3201** fourth argument to [sqlite3_trace_v2()]. 3202** The P and X arguments are pointers whose meanings depend on T. 3203** 3204** <dl> 3205** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3206** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3207** first begins running and possibly at other times during the 3208** execution of the prepared statement, such as at the start of each 3209** trigger subprogram. ^The P argument is a pointer to the 3210** [prepared statement]. ^The X argument is a pointer to a string which 3211** is the unexpanded SQL text of the prepared statement or an SQL comment 3212** that indicates the invocation of a trigger. ^The callback can compute 3213** the same text that would have been returned by the legacy [sqlite3_trace()] 3214** interface by using the X argument when X begins with "--" and invoking 3215** [sqlite3_expanded_sql(P)] otherwise. 3216** 3217** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3218** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3219** information as is provided by the [sqlite3_profile()] callback. 3220** ^The P argument is a pointer to the [prepared statement] and the 3221** X argument points to a 64-bit integer which is the estimated of 3222** the number of nanosecond that the prepared statement took to run. 3223** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3224** 3225** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3226** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3227** statement generates a single row of result. 3228** ^The P argument is a pointer to the [prepared statement] and the 3229** X argument is unused. 3230** 3231** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3232** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3233** connection closes. 3234** ^The P argument is a pointer to the [database connection] object 3235** and the X argument is unused. 3236** </dl> 3237*/ 3238#define SQLITE_TRACE_STMT 0x01 3239#define SQLITE_TRACE_PROFILE 0x02 3240#define SQLITE_TRACE_ROW 0x04 3241#define SQLITE_TRACE_CLOSE 0x08 3242 3243/* 3244** CAPI3REF: SQL Trace Hook 3245** METHOD: sqlite3 3246** 3247** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3248** function X against [database connection] D, using property mask M 3249** and context pointer P. ^If the X callback is 3250** NULL or if the M mask is zero, then tracing is disabled. The 3251** M argument should be the bitwise OR-ed combination of 3252** zero or more [SQLITE_TRACE] constants. 3253** 3254** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3255** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3256** 3257** ^The X callback is invoked whenever any of the events identified by 3258** mask M occur. ^The integer return value from the callback is currently 3259** ignored, though this may change in future releases. Callback 3260** implementations should return zero to ensure future compatibility. 3261** 3262** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3263** ^The T argument is one of the [SQLITE_TRACE] 3264** constants to indicate why the callback was invoked. 3265** ^The C argument is a copy of the context pointer. 3266** The P and X arguments are pointers whose meanings depend on T. 3267** 3268** The sqlite3_trace_v2() interface is intended to replace the legacy 3269** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3270** are deprecated. 3271*/ 3272int sqlite3_trace_v2( 3273 sqlite3*, 3274 unsigned uMask, 3275 int(*xCallback)(unsigned,void*,void*,void*), 3276 void *pCtx 3277); 3278 3279/* 3280** CAPI3REF: Query Progress Callbacks 3281** METHOD: sqlite3 3282** 3283** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3284** function X to be invoked periodically during long running calls to 3285** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3286** database connection D. An example use for this 3287** interface is to keep a GUI updated during a large query. 3288** 3289** ^The parameter P is passed through as the only parameter to the 3290** callback function X. ^The parameter N is the approximate number of 3291** [virtual machine instructions] that are evaluated between successive 3292** invocations of the callback X. ^If N is less than one then the progress 3293** handler is disabled. 3294** 3295** ^Only a single progress handler may be defined at one time per 3296** [database connection]; setting a new progress handler cancels the 3297** old one. ^Setting parameter X to NULL disables the progress handler. 3298** ^The progress handler is also disabled by setting N to a value less 3299** than 1. 3300** 3301** ^If the progress callback returns non-zero, the operation is 3302** interrupted. This feature can be used to implement a 3303** "Cancel" button on a GUI progress dialog box. 3304** 3305** The progress handler callback must not do anything that will modify 3306** the database connection that invoked the progress handler. 3307** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3308** database connections for the meaning of "modify" in this paragraph. 3309** 3310*/ 3311void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3312 3313/* 3314** CAPI3REF: Opening A New Database Connection 3315** CONSTRUCTOR: sqlite3 3316** 3317** ^These routines open an SQLite database file as specified by the 3318** filename argument. ^The filename argument is interpreted as UTF-8 for 3319** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3320** order for sqlite3_open16(). ^(A [database connection] handle is usually 3321** returned in *ppDb, even if an error occurs. The only exception is that 3322** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3323** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3324** object.)^ ^(If the database is opened (and/or created) successfully, then 3325** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3326** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3327** an English language description of the error following a failure of any 3328** of the sqlite3_open() routines. 3329** 3330** ^The default encoding will be UTF-8 for databases created using 3331** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3332** created using sqlite3_open16() will be UTF-16 in the native byte order. 3333** 3334** Whether or not an error occurs when it is opened, resources 3335** associated with the [database connection] handle should be released by 3336** passing it to [sqlite3_close()] when it is no longer required. 3337** 3338** The sqlite3_open_v2() interface works like sqlite3_open() 3339** except that it accepts two additional parameters for additional control 3340** over the new database connection. ^(The flags parameter to 3341** sqlite3_open_v2() must include, at a minimum, one of the following 3342** three flag combinations:)^ 3343** 3344** <dl> 3345** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3346** <dd>The database is opened in read-only mode. If the database does not 3347** already exist, an error is returned.</dd>)^ 3348** 3349** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3350** <dd>The database is opened for reading and writing if possible, or reading 3351** only if the file is write protected by the operating system. In either 3352** case the database must already exist, otherwise an error is returned.</dd>)^ 3353** 3354** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3355** <dd>The database is opened for reading and writing, and is created if 3356** it does not already exist. This is the behavior that is always used for 3357** sqlite3_open() and sqlite3_open16().</dd>)^ 3358** </dl> 3359** 3360** In addition to the required flags, the following optional flags are 3361** also supported: 3362** 3363** <dl> 3364** ^(<dt>[SQLITE_OPEN_URI]</dt> 3365** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3366** 3367** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3368** <dd>The database will be opened as an in-memory database. The database 3369** is named by the "filename" argument for the purposes of cache-sharing, 3370** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3371** </dd>)^ 3372** 3373** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3374** <dd>The new database connection will use the "multi-thread" 3375** [threading mode].)^ This means that separate threads are allowed 3376** to use SQLite at the same time, as long as each thread is using 3377** a different [database connection]. 3378** 3379** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3380** <dd>The new database connection will use the "serialized" 3381** [threading mode].)^ This means the multiple threads can safely 3382** attempt to use the same database connection at the same time. 3383** (Mutexes will block any actual concurrency, but in this mode 3384** there is no harm in trying.) 3385** 3386** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3387** <dd>The database is opened [shared cache] enabled, overriding 3388** the default shared cache setting provided by 3389** [sqlite3_enable_shared_cache()].)^ 3390** 3391** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3392** <dd>The database is opened [shared cache] disabled, overriding 3393** the default shared cache setting provided by 3394** [sqlite3_enable_shared_cache()].)^ 3395** 3396** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3397** <dd>The database filename is not allowed to be a symbolic link</dd> 3398** 3399** [[OPEN_EXCLUSIVE]] ^(<dt>[SQLITE_OPEN_EXCLUSIVE]</dt> 3400** <dd>This flag causes the open to fail if the database file already 3401** exists. The open will only be success if this flag is used in combination 3402** with the SQLITE_OPEN_CREATE and SQLITE_OPEN_READWRITE flags and if 3403** the file does not previously exist.</dd> 3404** </dl>)^ 3405** 3406** If the 3rd parameter to sqlite3_open_v2() is not one of the 3407** required combinations shown above optionally combined with other 3408** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3409** then the behavior is undefined. 3410** 3411** ^The fourth parameter to sqlite3_open_v2() is the name of the 3412** [sqlite3_vfs] object that defines the operating system interface that 3413** the new database connection should use. ^If the fourth parameter is 3414** a NULL pointer then the default [sqlite3_vfs] object is used. 3415** 3416** ^If the filename is ":memory:", then a private, temporary in-memory database 3417** is created for the connection. ^This in-memory database will vanish when 3418** the database connection is closed. Future versions of SQLite might 3419** make use of additional special filenames that begin with the ":" character. 3420** It is recommended that when a database filename actually does begin with 3421** a ":" character you should prefix the filename with a pathname such as 3422** "./" to avoid ambiguity. 3423** 3424** ^If the filename is an empty string, then a private, temporary 3425** on-disk database will be created. ^This private database will be 3426** automatically deleted as soon as the database connection is closed. 3427** 3428** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3429** 3430** ^If [URI filename] interpretation is enabled, and the filename argument 3431** begins with "file:", then the filename is interpreted as a URI. ^URI 3432** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3433** set in the third argument to sqlite3_open_v2(), or if it has 3434** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3435** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3436** URI filename interpretation is turned off 3437** by default, but future releases of SQLite might enable URI filename 3438** interpretation by default. See "[URI filenames]" for additional 3439** information. 3440** 3441** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3442** authority, then it must be either an empty string or the string 3443** "localhost". ^If the authority is not an empty string or "localhost", an 3444** error is returned to the caller. ^The fragment component of a URI, if 3445** present, is ignored. 3446** 3447** ^SQLite uses the path component of the URI as the name of the disk file 3448** which contains the database. ^If the path begins with a '/' character, 3449** then it is interpreted as an absolute path. ^If the path does not begin 3450** with a '/' (meaning that the authority section is omitted from the URI) 3451** then the path is interpreted as a relative path. 3452** ^(On windows, the first component of an absolute path 3453** is a drive specification (e.g. "C:").)^ 3454** 3455** [[core URI query parameters]] 3456** The query component of a URI may contain parameters that are interpreted 3457** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3458** SQLite and its built-in [VFSes] interpret the 3459** following query parameters: 3460** 3461** <ul> 3462** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3463** a VFS object that provides the operating system interface that should 3464** be used to access the database file on disk. ^If this option is set to 3465** an empty string the default VFS object is used. ^Specifying an unknown 3466** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3467** present, then the VFS specified by the option takes precedence over 3468** the value passed as the fourth parameter to sqlite3_open_v2(). 3469** 3470** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3471** "rwc", or "memory". Attempting to set it to any other value is 3472** an error)^. 3473** ^If "ro" is specified, then the database is opened for read-only 3474** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3475** third argument to sqlite3_open_v2(). ^If the mode option is set to 3476** "rw", then the database is opened for read-write (but not create) 3477** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3478** been set. ^Value "rwc" is equivalent to setting both 3479** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3480** set to "memory" then a pure [in-memory database] that never reads 3481** or writes from disk is used. ^It is an error to specify a value for 3482** the mode parameter that is less restrictive than that specified by 3483** the flags passed in the third parameter to sqlite3_open_v2(). 3484** 3485** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3486** "private". ^Setting it to "shared" is equivalent to setting the 3487** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3488** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3489** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3490** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3491** a URI filename, its value overrides any behavior requested by setting 3492** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3493** 3494** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3495** [powersafe overwrite] property does or does not apply to the 3496** storage media on which the database file resides. 3497** 3498** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3499** which if set disables file locking in rollback journal modes. This 3500** is useful for accessing a database on a filesystem that does not 3501** support locking. Caution: Database corruption might result if two 3502** or more processes write to the same database and any one of those 3503** processes uses nolock=1. 3504** 3505** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3506** parameter that indicates that the database file is stored on 3507** read-only media. ^When immutable is set, SQLite assumes that the 3508** database file cannot be changed, even by a process with higher 3509** privilege, and so the database is opened read-only and all locking 3510** and change detection is disabled. Caution: Setting the immutable 3511** property on a database file that does in fact change can result 3512** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3513** See also: [SQLITE_IOCAP_IMMUTABLE]. 3514** 3515** </ul> 3516** 3517** ^Specifying an unknown parameter in the query component of a URI is not an 3518** error. Future versions of SQLite might understand additional query 3519** parameters. See "[query parameters with special meaning to SQLite]" for 3520** additional information. 3521** 3522** [[URI filename examples]] <h3>URI filename examples</h3> 3523** 3524** <table border="1" align=center cellpadding=5> 3525** <tr><th> URI filenames <th> Results 3526** <tr><td> file:data.db <td> 3527** Open the file "data.db" in the current directory. 3528** <tr><td> file:/home/fred/data.db<br> 3529** file:///home/fred/data.db <br> 3530** file://localhost/home/fred/data.db <br> <td> 3531** Open the database file "/home/fred/data.db". 3532** <tr><td> file://darkstar/home/fred/data.db <td> 3533** An error. "darkstar" is not a recognized authority. 3534** <tr><td style="white-space:nowrap"> 3535** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3536** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3537** C:. Note that the %20 escaping in this example is not strictly 3538** necessary - space characters can be used literally 3539** in URI filenames. 3540** <tr><td> file:data.db?mode=ro&cache=private <td> 3541** Open file "data.db" in the current directory for read-only access. 3542** Regardless of whether or not shared-cache mode is enabled by 3543** default, use a private cache. 3544** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3545** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3546** that uses dot-files in place of posix advisory locking. 3547** <tr><td> file:data.db?mode=readonly <td> 3548** An error. "readonly" is not a valid option for the "mode" parameter. 3549** Use "ro" instead: "file:data.db?mode=ro". 3550** </table> 3551** 3552** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3553** query components of a URI. A hexadecimal escape sequence consists of a 3554** percent sign - "%" - followed by exactly two hexadecimal digits 3555** specifying an octet value. ^Before the path or query components of a 3556** URI filename are interpreted, they are encoded using UTF-8 and all 3557** hexadecimal escape sequences replaced by a single byte containing the 3558** corresponding octet. If this process generates an invalid UTF-8 encoding, 3559** the results are undefined. 3560** 3561** <b>Note to Windows users:</b> The encoding used for the filename argument 3562** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3563** codepage is currently defined. Filenames containing international 3564** characters must be converted to UTF-8 prior to passing them into 3565** sqlite3_open() or sqlite3_open_v2(). 3566** 3567** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3568** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3569** features that require the use of temporary files may fail. 3570** 3571** See also: [sqlite3_temp_directory] 3572*/ 3573int sqlite3_open( 3574 const char *filename, /* Database filename (UTF-8) */ 3575 sqlite3 **ppDb /* OUT: SQLite db handle */ 3576); 3577int sqlite3_open16( 3578 const void *filename, /* Database filename (UTF-16) */ 3579 sqlite3 **ppDb /* OUT: SQLite db handle */ 3580); 3581int sqlite3_open_v2( 3582 const char *filename, /* Database filename (UTF-8) */ 3583 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3584 int flags, /* Flags */ 3585 const char *zVfs /* Name of VFS module to use */ 3586); 3587 3588/* 3589** CAPI3REF: Obtain Values For URI Parameters 3590** 3591** These are utility routines, useful to [VFS|custom VFS implementations], 3592** that check if a database file was a URI that contained a specific query 3593** parameter, and if so obtains the value of that query parameter. 3594** 3595** The first parameter to these interfaces (hereafter referred to 3596** as F) must be one of: 3597** <ul> 3598** <li> A database filename pointer created by the SQLite core and 3599** passed into the xOpen() method of a VFS implemention, or 3600** <li> A filename obtained from [sqlite3_db_filename()], or 3601** <li> A new filename constructed using [sqlite3_create_filename()]. 3602** </ul> 3603** If the F parameter is not one of the above, then the behavior is 3604** undefined and probably undesirable. Older versions of SQLite were 3605** more tolerant of invalid F parameters than newer versions. 3606** 3607** If F is a suitable filename (as described in the previous paragraph) 3608** and if P is the name of the query parameter, then 3609** sqlite3_uri_parameter(F,P) returns the value of the P 3610** parameter if it exists or a NULL pointer if P does not appear as a 3611** query parameter on F. If P is a query parameter of F and it 3612** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3613** a pointer to an empty string. 3614** 3615** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3616** parameter and returns true (1) or false (0) according to the value 3617** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3618** value of query parameter P is one of "yes", "true", or "on" in any 3619** case or if the value begins with a non-zero number. The 3620** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3621** query parameter P is one of "no", "false", or "off" in any case or 3622** if the value begins with a numeric zero. If P is not a query 3623** parameter on F or if the value of P does not match any of the 3624** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3625** 3626** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3627** 64-bit signed integer and returns that integer, or D if P does not 3628** exist. If the value of P is something other than an integer, then 3629** zero is returned. 3630** 3631** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3632** the value) of the N-th query parameter for filename F, or a NULL 3633** pointer if N is less than zero or greater than the number of query 3634** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3635** the name of the first query parameter, 1 for the second parameter, and 3636** so forth. 3637** 3638** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3639** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3640** is not a database file pathname pointer that the SQLite core passed 3641** into the xOpen VFS method, then the behavior of this routine is undefined 3642** and probably undesirable. 3643** 3644** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3645** parameter can also be the name of a rollback journal file or WAL file 3646** in addition to the main database file. Prior to version 3.31.0, these 3647** routines would only work if F was the name of the main database file. 3648** When the F parameter is the name of the rollback journal or WAL file, 3649** it has access to all the same query parameters as were found on the 3650** main database file. 3651** 3652** See the [URI filename] documentation for additional information. 3653*/ 3654const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3655int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3656sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3657const char *sqlite3_uri_key(const char *zFilename, int N); 3658 3659/* 3660** CAPI3REF: Translate filenames 3661** 3662** These routines are available to [VFS|custom VFS implementations] for 3663** translating filenames between the main database file, the journal file, 3664** and the WAL file. 3665** 3666** If F is the name of an sqlite database file, journal file, or WAL file 3667** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3668** returns the name of the corresponding database file. 3669** 3670** If F is the name of an sqlite database file, journal file, or WAL file 3671** passed by the SQLite core into the VFS, or if F is a database filename 3672** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3673** returns the name of the corresponding rollback journal file. 3674** 3675** If F is the name of an sqlite database file, journal file, or WAL file 3676** that was passed by the SQLite core into the VFS, or if F is a database 3677** filename obtained from [sqlite3_db_filename()], then 3678** sqlite3_filename_wal(F) returns the name of the corresponding 3679** WAL file. 3680** 3681** In all of the above, if F is not the name of a database, journal or WAL 3682** filename passed into the VFS from the SQLite core and F is not the 3683** return value from [sqlite3_db_filename()], then the result is 3684** undefined and is likely a memory access violation. 3685*/ 3686const char *sqlite3_filename_database(const char*); 3687const char *sqlite3_filename_journal(const char*); 3688const char *sqlite3_filename_wal(const char*); 3689 3690/* 3691** CAPI3REF: Database File Corresponding To A Journal 3692** 3693** ^If X is the name of a rollback or WAL-mode journal file that is 3694** passed into the xOpen method of [sqlite3_vfs], then 3695** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3696** object that represents the main database file. 3697** 3698** This routine is intended for use in custom [VFS] implementations 3699** only. It is not a general-purpose interface. 3700** The argument sqlite3_file_object(X) must be a filename pointer that 3701** has been passed into [sqlite3_vfs].xOpen method where the 3702** flags parameter to xOpen contains one of the bits 3703** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3704** of this routine results in undefined and probably undesirable 3705** behavior. 3706*/ 3707sqlite3_file *sqlite3_database_file_object(const char*); 3708 3709/* 3710** CAPI3REF: Create and Destroy VFS Filenames 3711** 3712** These interfces are provided for use by [VFS shim] implementations and 3713** are not useful outside of that context. 3714** 3715** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3716** database filename D with corresponding journal file J and WAL file W and 3717** with N URI parameters key/values pairs in the array P. The result from 3718** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3719** is safe to pass to routines like: 3720** <ul> 3721** <li> [sqlite3_uri_parameter()], 3722** <li> [sqlite3_uri_boolean()], 3723** <li> [sqlite3_uri_int64()], 3724** <li> [sqlite3_uri_key()], 3725** <li> [sqlite3_filename_database()], 3726** <li> [sqlite3_filename_journal()], or 3727** <li> [sqlite3_filename_wal()]. 3728** </ul> 3729** If a memory allocation error occurs, sqlite3_create_filename() might 3730** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3731** must be released by a corresponding call to sqlite3_free_filename(Y). 3732** 3733** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3734** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3735** to a key and value for a query parameter. The P parameter may be a NULL 3736** pointer if N is zero. None of the 2*N pointers in the P array may be 3737** NULL pointers and key pointers should not be empty strings. 3738** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3739** be NULL pointers, though they can be empty strings. 3740** 3741** The sqlite3_free_filename(Y) routine releases a memory allocation 3742** previously obtained from sqlite3_create_filename(). Invoking 3743** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3744** 3745** If the Y parameter to sqlite3_free_filename(Y) is anything other 3746** than a NULL pointer or a pointer previously acquired from 3747** sqlite3_create_filename(), then bad things such as heap 3748** corruption or segfaults may occur. The value Y should not be 3749** used again after sqlite3_free_filename(Y) has been called. This means 3750** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3751** then the corresponding [sqlite3_module.xClose() method should also be 3752** invoked prior to calling sqlite3_free_filename(Y). 3753*/ 3754char *sqlite3_create_filename( 3755 const char *zDatabase, 3756 const char *zJournal, 3757 const char *zWal, 3758 int nParam, 3759 const char **azParam 3760); 3761void sqlite3_free_filename(char*); 3762 3763/* 3764** CAPI3REF: Error Codes And Messages 3765** METHOD: sqlite3 3766** 3767** ^If the most recent sqlite3_* API call associated with 3768** [database connection] D failed, then the sqlite3_errcode(D) interface 3769** returns the numeric [result code] or [extended result code] for that 3770** API call. 3771** ^The sqlite3_extended_errcode() 3772** interface is the same except that it always returns the 3773** [extended result code] even when extended result codes are 3774** disabled. 3775** 3776** The values returned by sqlite3_errcode() and/or 3777** sqlite3_extended_errcode() might change with each API call. 3778** Except, there are some interfaces that are guaranteed to never 3779** change the value of the error code. The error-code preserving 3780** interfaces are: 3781** 3782** <ul> 3783** <li> sqlite3_errcode() 3784** <li> sqlite3_extended_errcode() 3785** <li> sqlite3_errmsg() 3786** <li> sqlite3_errmsg16() 3787** </ul> 3788** 3789** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3790** text that describes the error, as either UTF-8 or UTF-16 respectively. 3791** ^(Memory to hold the error message string is managed internally. 3792** The application does not need to worry about freeing the result. 3793** However, the error string might be overwritten or deallocated by 3794** subsequent calls to other SQLite interface functions.)^ 3795** 3796** ^The sqlite3_errstr() interface returns the English-language text 3797** that describes the [result code], as UTF-8. 3798** ^(Memory to hold the error message string is managed internally 3799** and must not be freed by the application)^. 3800** 3801** When the serialized [threading mode] is in use, it might be the 3802** case that a second error occurs on a separate thread in between 3803** the time of the first error and the call to these interfaces. 3804** When that happens, the second error will be reported since these 3805** interfaces always report the most recent result. To avoid 3806** this, each thread can obtain exclusive use of the [database connection] D 3807** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3808** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3809** all calls to the interfaces listed here are completed. 3810** 3811** If an interface fails with SQLITE_MISUSE, that means the interface 3812** was invoked incorrectly by the application. In that case, the 3813** error code and message may or may not be set. 3814*/ 3815int sqlite3_errcode(sqlite3 *db); 3816int sqlite3_extended_errcode(sqlite3 *db); 3817const char *sqlite3_errmsg(sqlite3*); 3818const void *sqlite3_errmsg16(sqlite3*); 3819const char *sqlite3_errstr(int); 3820 3821/* 3822** CAPI3REF: Prepared Statement Object 3823** KEYWORDS: {prepared statement} {prepared statements} 3824** 3825** An instance of this object represents a single SQL statement that 3826** has been compiled into binary form and is ready to be evaluated. 3827** 3828** Think of each SQL statement as a separate computer program. The 3829** original SQL text is source code. A prepared statement object 3830** is the compiled object code. All SQL must be converted into a 3831** prepared statement before it can be run. 3832** 3833** The life-cycle of a prepared statement object usually goes like this: 3834** 3835** <ol> 3836** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3837** <li> Bind values to [parameters] using the sqlite3_bind_*() 3838** interfaces. 3839** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3840** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3841** to step 2. Do this zero or more times. 3842** <li> Destroy the object using [sqlite3_finalize()]. 3843** </ol> 3844*/ 3845typedef struct sqlite3_stmt sqlite3_stmt; 3846 3847/* 3848** CAPI3REF: Run-time Limits 3849** METHOD: sqlite3 3850** 3851** ^(This interface allows the size of various constructs to be limited 3852** on a connection by connection basis. The first parameter is the 3853** [database connection] whose limit is to be set or queried. The 3854** second parameter is one of the [limit categories] that define a 3855** class of constructs to be size limited. The third parameter is the 3856** new limit for that construct.)^ 3857** 3858** ^If the new limit is a negative number, the limit is unchanged. 3859** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3860** [limits | hard upper bound] 3861** set at compile-time by a C preprocessor macro called 3862** [limits | SQLITE_MAX_<i>NAME</i>]. 3863** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3864** ^Attempts to increase a limit above its hard upper bound are 3865** silently truncated to the hard upper bound. 3866** 3867** ^Regardless of whether or not the limit was changed, the 3868** [sqlite3_limit()] interface returns the prior value of the limit. 3869** ^Hence, to find the current value of a limit without changing it, 3870** simply invoke this interface with the third parameter set to -1. 3871** 3872** Run-time limits are intended for use in applications that manage 3873** both their own internal database and also databases that are controlled 3874** by untrusted external sources. An example application might be a 3875** web browser that has its own databases for storing history and 3876** separate databases controlled by JavaScript applications downloaded 3877** off the Internet. The internal databases can be given the 3878** large, default limits. Databases managed by external sources can 3879** be given much smaller limits designed to prevent a denial of service 3880** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3881** interface to further control untrusted SQL. The size of the database 3882** created by an untrusted script can be contained using the 3883** [max_page_count] [PRAGMA]. 3884** 3885** New run-time limit categories may be added in future releases. 3886*/ 3887int sqlite3_limit(sqlite3*, int id, int newVal); 3888 3889/* 3890** CAPI3REF: Run-Time Limit Categories 3891** KEYWORDS: {limit category} {*limit categories} 3892** 3893** These constants define various performance limits 3894** that can be lowered at run-time using [sqlite3_limit()]. 3895** The synopsis of the meanings of the various limits is shown below. 3896** Additional information is available at [limits | Limits in SQLite]. 3897** 3898** <dl> 3899** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3900** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3901** 3902** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3903** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3904** 3905** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3906** <dd>The maximum number of columns in a table definition or in the 3907** result set of a [SELECT] or the maximum number of columns in an index 3908** or in an ORDER BY or GROUP BY clause.</dd>)^ 3909** 3910** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3911** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3912** 3913** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3914** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3915** 3916** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3917** <dd>The maximum number of instructions in a virtual machine program 3918** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3919** the equivalent tries to allocate space for more than this many opcodes 3920** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3921** 3922** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3923** <dd>The maximum number of arguments on a function.</dd>)^ 3924** 3925** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3926** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3927** 3928** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3929** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3930** <dd>The maximum length of the pattern argument to the [LIKE] or 3931** [GLOB] operators.</dd>)^ 3932** 3933** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3934** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3935** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3936** 3937** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3938** <dd>The maximum depth of recursion for triggers.</dd>)^ 3939** 3940** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3941** <dd>The maximum number of auxiliary worker threads that a single 3942** [prepared statement] may start.</dd>)^ 3943** </dl> 3944*/ 3945#define SQLITE_LIMIT_LENGTH 0 3946#define SQLITE_LIMIT_SQL_LENGTH 1 3947#define SQLITE_LIMIT_COLUMN 2 3948#define SQLITE_LIMIT_EXPR_DEPTH 3 3949#define SQLITE_LIMIT_COMPOUND_SELECT 4 3950#define SQLITE_LIMIT_VDBE_OP 5 3951#define SQLITE_LIMIT_FUNCTION_ARG 6 3952#define SQLITE_LIMIT_ATTACHED 7 3953#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3954#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3955#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3956#define SQLITE_LIMIT_WORKER_THREADS 11 3957 3958/* 3959** CAPI3REF: Prepare Flags 3960** 3961** These constants define various flags that can be passed into 3962** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3963** [sqlite3_prepare16_v3()] interfaces. 3964** 3965** New flags may be added in future releases of SQLite. 3966** 3967** <dl> 3968** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3969** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3970** that the prepared statement will be retained for a long time and 3971** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3972** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3973** be used just once or at most a few times and then destroyed using 3974** [sqlite3_finalize()] relatively soon. The current implementation acts 3975** on this hint by avoiding the use of [lookaside memory] so as not to 3976** deplete the limited store of lookaside memory. Future versions of 3977** SQLite may act on this hint differently. 3978** 3979** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3980** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3981** to be required for any prepared statement that wanted to use the 3982** [sqlite3_normalized_sql()] interface. However, the 3983** [sqlite3_normalized_sql()] interface is now available to all 3984** prepared statements, regardless of whether or not they use this 3985** flag. 3986** 3987** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3988** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3989** to return an error (error code SQLITE_ERROR) if the statement uses 3990** any virtual tables. 3991** </dl> 3992*/ 3993#define SQLITE_PREPARE_PERSISTENT 0x01 3994#define SQLITE_PREPARE_NORMALIZE 0x02 3995#define SQLITE_PREPARE_NO_VTAB 0x04 3996 3997/* 3998** CAPI3REF: Compiling An SQL Statement 3999** KEYWORDS: {SQL statement compiler} 4000** METHOD: sqlite3 4001** CONSTRUCTOR: sqlite3_stmt 4002** 4003** To execute an SQL statement, it must first be compiled into a byte-code 4004** program using one of these routines. Or, in other words, these routines 4005** are constructors for the [prepared statement] object. 4006** 4007** The preferred routine to use is [sqlite3_prepare_v2()]. The 4008** [sqlite3_prepare()] interface is legacy and should be avoided. 4009** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4010** for special purposes. 4011** 4012** The use of the UTF-8 interfaces is preferred, as SQLite currently 4013** does all parsing using UTF-8. The UTF-16 interfaces are provided 4014** as a convenience. The UTF-16 interfaces work by converting the 4015** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4016** 4017** The first argument, "db", is a [database connection] obtained from a 4018** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4019** [sqlite3_open16()]. The database connection must not have been closed. 4020** 4021** The second argument, "zSql", is the statement to be compiled, encoded 4022** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4023** and sqlite3_prepare_v3() 4024** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4025** and sqlite3_prepare16_v3() use UTF-16. 4026** 4027** ^If the nByte argument is negative, then zSql is read up to the 4028** first zero terminator. ^If nByte is positive, then it is the 4029** number of bytes read from zSql. ^If nByte is zero, then no prepared 4030** statement is generated. 4031** If the caller knows that the supplied string is nul-terminated, then 4032** there is a small performance advantage to passing an nByte parameter that 4033** is the number of bytes in the input string <i>including</i> 4034** the nul-terminator. 4035** 4036** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4037** past the end of the first SQL statement in zSql. These routines only 4038** compile the first statement in zSql, so *pzTail is left pointing to 4039** what remains uncompiled. 4040** 4041** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4042** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4043** to NULL. ^If the input text contains no SQL (if the input is an empty 4044** string or a comment) then *ppStmt is set to NULL. 4045** The calling procedure is responsible for deleting the compiled 4046** SQL statement using [sqlite3_finalize()] after it has finished with it. 4047** ppStmt may not be NULL. 4048** 4049** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4050** otherwise an [error code] is returned. 4051** 4052** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4053** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4054** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4055** are retained for backwards compatibility, but their use is discouraged. 4056** ^In the "vX" interfaces, the prepared statement 4057** that is returned (the [sqlite3_stmt] object) contains a copy of the 4058** original SQL text. This causes the [sqlite3_step()] interface to 4059** behave differently in three ways: 4060** 4061** <ol> 4062** <li> 4063** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4064** always used to do, [sqlite3_step()] will automatically recompile the SQL 4065** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4066** retries will occur before sqlite3_step() gives up and returns an error. 4067** </li> 4068** 4069** <li> 4070** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4071** [error codes] or [extended error codes]. ^The legacy behavior was that 4072** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4073** and the application would have to make a second call to [sqlite3_reset()] 4074** in order to find the underlying cause of the problem. With the "v2" prepare 4075** interfaces, the underlying reason for the error is returned immediately. 4076** </li> 4077** 4078** <li> 4079** ^If the specific value bound to a [parameter | host parameter] in the 4080** WHERE clause might influence the choice of query plan for a statement, 4081** then the statement will be automatically recompiled, as if there had been 4082** a schema change, on the first [sqlite3_step()] call following any change 4083** to the [sqlite3_bind_text | bindings] of that [parameter]. 4084** ^The specific value of a WHERE-clause [parameter] might influence the 4085** choice of query plan if the parameter is the left-hand side of a [LIKE] 4086** or [GLOB] operator or if the parameter is compared to an indexed column 4087** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4088** </li> 4089** </ol> 4090** 4091** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4092** the extra prepFlags parameter, which is a bit array consisting of zero or 4093** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4094** sqlite3_prepare_v2() interface works exactly the same as 4095** sqlite3_prepare_v3() with a zero prepFlags parameter. 4096*/ 4097int sqlite3_prepare( 4098 sqlite3 *db, /* Database handle */ 4099 const char *zSql, /* SQL statement, UTF-8 encoded */ 4100 int nByte, /* Maximum length of zSql in bytes. */ 4101 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4102 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4103); 4104int sqlite3_prepare_v2( 4105 sqlite3 *db, /* Database handle */ 4106 const char *zSql, /* SQL statement, UTF-8 encoded */ 4107 int nByte, /* Maximum length of zSql in bytes. */ 4108 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4109 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4110); 4111int sqlite3_prepare_v3( 4112 sqlite3 *db, /* Database handle */ 4113 const char *zSql, /* SQL statement, UTF-8 encoded */ 4114 int nByte, /* Maximum length of zSql in bytes. */ 4115 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4116 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4117 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4118); 4119int sqlite3_prepare16( 4120 sqlite3 *db, /* Database handle */ 4121 const void *zSql, /* SQL statement, UTF-16 encoded */ 4122 int nByte, /* Maximum length of zSql in bytes. */ 4123 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4124 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4125); 4126int sqlite3_prepare16_v2( 4127 sqlite3 *db, /* Database handle */ 4128 const void *zSql, /* SQL statement, UTF-16 encoded */ 4129 int nByte, /* Maximum length of zSql in bytes. */ 4130 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4131 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4132); 4133int sqlite3_prepare16_v3( 4134 sqlite3 *db, /* Database handle */ 4135 const void *zSql, /* SQL statement, UTF-16 encoded */ 4136 int nByte, /* Maximum length of zSql in bytes. */ 4137 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4138 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4139 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4140); 4141 4142/* 4143** CAPI3REF: Retrieving Statement SQL 4144** METHOD: sqlite3_stmt 4145** 4146** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4147** SQL text used to create [prepared statement] P if P was 4148** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4149** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4150** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4151** string containing the SQL text of prepared statement P with 4152** [bound parameters] expanded. 4153** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4154** string containing the normalized SQL text of prepared statement P. The 4155** semantics used to normalize a SQL statement are unspecified and subject 4156** to change. At a minimum, literal values will be replaced with suitable 4157** placeholders. 4158** 4159** ^(For example, if a prepared statement is created using the SQL 4160** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4161** and parameter :xyz is unbound, then sqlite3_sql() will return 4162** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4163** will return "SELECT 2345,NULL".)^ 4164** 4165** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4166** is available to hold the result, or if the result would exceed the 4167** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4168** 4169** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4170** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4171** option causes sqlite3_expanded_sql() to always return NULL. 4172** 4173** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4174** are managed by SQLite and are automatically freed when the prepared 4175** statement is finalized. 4176** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4177** is obtained from [sqlite3_malloc()] and must be free by the application 4178** by passing it to [sqlite3_free()]. 4179** 4180** ^The sqlite3_normalized_sql() interface is only available if 4181** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4182*/ 4183const char *sqlite3_sql(sqlite3_stmt *pStmt); 4184char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4185#ifdef SQLITE_ENABLE_NORMALIZE 4186const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4187#endif 4188 4189/* 4190** CAPI3REF: Determine If An SQL Statement Writes The Database 4191** METHOD: sqlite3_stmt 4192** 4193** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4194** and only if the [prepared statement] X makes no direct changes to 4195** the content of the database file. 4196** 4197** Note that [application-defined SQL functions] or 4198** [virtual tables] might change the database indirectly as a side effect. 4199** ^(For example, if an application defines a function "eval()" that 4200** calls [sqlite3_exec()], then the following SQL statement would 4201** change the database file through side-effects: 4202** 4203** <blockquote><pre> 4204** SELECT eval('DELETE FROM t1') FROM t2; 4205** </pre></blockquote> 4206** 4207** But because the [SELECT] statement does not change the database file 4208** directly, sqlite3_stmt_readonly() would still return true.)^ 4209** 4210** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4211** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4212** since the statements themselves do not actually modify the database but 4213** rather they control the timing of when other statements modify the 4214** database. ^The [ATTACH] and [DETACH] statements also cause 4215** sqlite3_stmt_readonly() to return true since, while those statements 4216** change the configuration of a database connection, they do not make 4217** changes to the content of the database files on disk. 4218** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4219** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4220** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4221** sqlite3_stmt_readonly() returns false for those commands. 4222** 4223** ^This routine returns false if there is any possibility that the 4224** statement might change the database file. ^A false return does 4225** not guarantee that the statement will change the database file. 4226** ^For example, an UPDATE statement might have a WHERE clause that 4227** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4228** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4229** read-only no-op if the table already exists, but 4230** sqlite3_stmt_readonly() still returns false for such a statement. 4231*/ 4232int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4233 4234/* 4235** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4236** METHOD: sqlite3_stmt 4237** 4238** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4239** prepared statement S is an EXPLAIN statement, or 2 if the 4240** statement S is an EXPLAIN QUERY PLAN. 4241** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4242** an ordinary statement or a NULL pointer. 4243*/ 4244int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4245 4246/* 4247** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4248** METHOD: sqlite3_stmt 4249** 4250** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4251** [prepared statement] S has been stepped at least once using 4252** [sqlite3_step(S)] but has neither run to completion (returned 4253** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4254** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4255** interface returns false if S is a NULL pointer. If S is not a 4256** NULL pointer and is not a pointer to a valid [prepared statement] 4257** object, then the behavior is undefined and probably undesirable. 4258** 4259** This interface can be used in combination [sqlite3_next_stmt()] 4260** to locate all prepared statements associated with a database 4261** connection that are in need of being reset. This can be used, 4262** for example, in diagnostic routines to search for prepared 4263** statements that are holding a transaction open. 4264*/ 4265int sqlite3_stmt_busy(sqlite3_stmt*); 4266 4267/* 4268** CAPI3REF: Dynamically Typed Value Object 4269** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4270** 4271** SQLite uses the sqlite3_value object to represent all values 4272** that can be stored in a database table. SQLite uses dynamic typing 4273** for the values it stores. ^Values stored in sqlite3_value objects 4274** can be integers, floating point values, strings, BLOBs, or NULL. 4275** 4276** An sqlite3_value object may be either "protected" or "unprotected". 4277** Some interfaces require a protected sqlite3_value. Other interfaces 4278** will accept either a protected or an unprotected sqlite3_value. 4279** Every interface that accepts sqlite3_value arguments specifies 4280** whether or not it requires a protected sqlite3_value. The 4281** [sqlite3_value_dup()] interface can be used to construct a new 4282** protected sqlite3_value from an unprotected sqlite3_value. 4283** 4284** The terms "protected" and "unprotected" refer to whether or not 4285** a mutex is held. An internal mutex is held for a protected 4286** sqlite3_value object but no mutex is held for an unprotected 4287** sqlite3_value object. If SQLite is compiled to be single-threaded 4288** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4289** or if SQLite is run in one of reduced mutex modes 4290** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4291** then there is no distinction between protected and unprotected 4292** sqlite3_value objects and they can be used interchangeably. However, 4293** for maximum code portability it is recommended that applications 4294** still make the distinction between protected and unprotected 4295** sqlite3_value objects even when not strictly required. 4296** 4297** ^The sqlite3_value objects that are passed as parameters into the 4298** implementation of [application-defined SQL functions] are protected. 4299** ^The sqlite3_value object returned by 4300** [sqlite3_column_value()] is unprotected. 4301** Unprotected sqlite3_value objects may only be used as arguments 4302** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4303** [sqlite3_value_dup()]. 4304** The [sqlite3_value_blob | sqlite3_value_type()] family of 4305** interfaces require protected sqlite3_value objects. 4306*/ 4307typedef struct sqlite3_value sqlite3_value; 4308 4309/* 4310** CAPI3REF: SQL Function Context Object 4311** 4312** The context in which an SQL function executes is stored in an 4313** sqlite3_context object. ^A pointer to an sqlite3_context object 4314** is always first parameter to [application-defined SQL functions]. 4315** The application-defined SQL function implementation will pass this 4316** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4317** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4318** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4319** and/or [sqlite3_set_auxdata()]. 4320*/ 4321typedef struct sqlite3_context sqlite3_context; 4322 4323/* 4324** CAPI3REF: Binding Values To Prepared Statements 4325** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4326** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4327** METHOD: sqlite3_stmt 4328** 4329** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4330** literals may be replaced by a [parameter] that matches one of following 4331** templates: 4332** 4333** <ul> 4334** <li> ? 4335** <li> ?NNN 4336** <li> :VVV 4337** <li> @VVV 4338** <li> $VVV 4339** </ul> 4340** 4341** In the templates above, NNN represents an integer literal, 4342** and VVV represents an alphanumeric identifier.)^ ^The values of these 4343** parameters (also called "host parameter names" or "SQL parameters") 4344** can be set using the sqlite3_bind_*() routines defined here. 4345** 4346** ^The first argument to the sqlite3_bind_*() routines is always 4347** a pointer to the [sqlite3_stmt] object returned from 4348** [sqlite3_prepare_v2()] or its variants. 4349** 4350** ^The second argument is the index of the SQL parameter to be set. 4351** ^The leftmost SQL parameter has an index of 1. ^When the same named 4352** SQL parameter is used more than once, second and subsequent 4353** occurrences have the same index as the first occurrence. 4354** ^The index for named parameters can be looked up using the 4355** [sqlite3_bind_parameter_index()] API if desired. ^The index 4356** for "?NNN" parameters is the value of NNN. 4357** ^The NNN value must be between 1 and the [sqlite3_limit()] 4358** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4359** 4360** ^The third argument is the value to bind to the parameter. 4361** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4362** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4363** is ignored and the end result is the same as sqlite3_bind_null(). 4364** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4365** it should be a pointer to well-formed UTF8 text. 4366** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4367** it should be a pointer to well-formed UTF16 text. 4368** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4369** it should be a pointer to a well-formed unicode string that is 4370** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4371** otherwise. 4372** 4373** [[byte-order determination rules]] ^The byte-order of 4374** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4375** found in first character, which is removed, or in the absence of a BOM 4376** the byte order is the native byte order of the host 4377** machine for sqlite3_bind_text16() or the byte order specified in 4378** the 6th parameter for sqlite3_bind_text64().)^ 4379** ^If UTF16 input text contains invalid unicode 4380** characters, then SQLite might change those invalid characters 4381** into the unicode replacement character: U+FFFD. 4382** 4383** ^(In those routines that have a fourth argument, its value is the 4384** number of bytes in the parameter. To be clear: the value is the 4385** number of <u>bytes</u> in the value, not the number of characters.)^ 4386** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4387** is negative, then the length of the string is 4388** the number of bytes up to the first zero terminator. 4389** If the fourth parameter to sqlite3_bind_blob() is negative, then 4390** the behavior is undefined. 4391** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4392** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4393** that parameter must be the byte offset 4394** where the NUL terminator would occur assuming the string were NUL 4395** terminated. If any NUL characters occurs at byte offsets less than 4396** the value of the fourth parameter then the resulting string value will 4397** contain embedded NULs. The result of expressions involving strings 4398** with embedded NULs is undefined. 4399** 4400** ^The fifth argument to the BLOB and string binding interfaces controls 4401** or indicates the lifetime of the object referenced by the third parameter. 4402** These three options exist: 4403** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4404** with it may be passed. ^It is called to dispose of the BLOB or string even 4405** if the call to the bind API fails, except the destructor is not called if 4406** the third parameter is a NULL pointer or the fourth parameter is negative. 4407** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that 4408** the application remains responsible for disposing of the object. ^In this 4409** case, the object and the provided pointer to it must remain valid until 4410** either the prepared statement is finalized or the same SQL parameter is 4411** bound to something else, whichever occurs sooner. 4412** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4413** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4414** object and pointer to it must remain valid until then. ^SQLite will then 4415** manage the lifetime of its private copy. 4416** 4417** ^The sixth argument to sqlite3_bind_text64() must be one of 4418** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4419** to specify the encoding of the text in the third parameter. If 4420** the sixth argument to sqlite3_bind_text64() is not one of the 4421** allowed values shown above, or if the text encoding is different 4422** from the encoding specified by the sixth parameter, then the behavior 4423** is undefined. 4424** 4425** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4426** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4427** (just an integer to hold its size) while it is being processed. 4428** Zeroblobs are intended to serve as placeholders for BLOBs whose 4429** content is later written using 4430** [sqlite3_blob_open | incremental BLOB I/O] routines. 4431** ^A negative value for the zeroblob results in a zero-length BLOB. 4432** 4433** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4434** [prepared statement] S to have an SQL value of NULL, but to also be 4435** associated with the pointer P of type T. ^D is either a NULL pointer or 4436** a pointer to a destructor function for P. ^SQLite will invoke the 4437** destructor D with a single argument of P when it is finished using 4438** P. The T parameter should be a static string, preferably a string 4439** literal. The sqlite3_bind_pointer() routine is part of the 4440** [pointer passing interface] added for SQLite 3.20.0. 4441** 4442** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4443** for the [prepared statement] or with a prepared statement for which 4444** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4445** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4446** routine is passed a [prepared statement] that has been finalized, the 4447** result is undefined and probably harmful. 4448** 4449** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4450** ^Unbound parameters are interpreted as NULL. 4451** 4452** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4453** [error code] if anything goes wrong. 4454** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4455** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4456** [SQLITE_MAX_LENGTH]. 4457** ^[SQLITE_RANGE] is returned if the parameter 4458** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4459** 4460** See also: [sqlite3_bind_parameter_count()], 4461** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4462*/ 4463int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4464int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4465 void(*)(void*)); 4466int sqlite3_bind_double(sqlite3_stmt*, int, double); 4467int sqlite3_bind_int(sqlite3_stmt*, int, int); 4468int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4469int sqlite3_bind_null(sqlite3_stmt*, int); 4470int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4471int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4472int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4473 void(*)(void*), unsigned char encoding); 4474int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4475int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4476int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4477int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4478 4479/* 4480** CAPI3REF: Number Of SQL Parameters 4481** METHOD: sqlite3_stmt 4482** 4483** ^This routine can be used to find the number of [SQL parameters] 4484** in a [prepared statement]. SQL parameters are tokens of the 4485** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4486** placeholders for values that are [sqlite3_bind_blob | bound] 4487** to the parameters at a later time. 4488** 4489** ^(This routine actually returns the index of the largest (rightmost) 4490** parameter. For all forms except ?NNN, this will correspond to the 4491** number of unique parameters. If parameters of the ?NNN form are used, 4492** there may be gaps in the list.)^ 4493** 4494** See also: [sqlite3_bind_blob|sqlite3_bind()], 4495** [sqlite3_bind_parameter_name()], and 4496** [sqlite3_bind_parameter_index()]. 4497*/ 4498int sqlite3_bind_parameter_count(sqlite3_stmt*); 4499 4500/* 4501** CAPI3REF: Name Of A Host Parameter 4502** METHOD: sqlite3_stmt 4503** 4504** ^The sqlite3_bind_parameter_name(P,N) interface returns 4505** the name of the N-th [SQL parameter] in the [prepared statement] P. 4506** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4507** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4508** respectively. 4509** In other words, the initial ":" or "$" or "@" or "?" 4510** is included as part of the name.)^ 4511** ^Parameters of the form "?" without a following integer have no name 4512** and are referred to as "nameless" or "anonymous parameters". 4513** 4514** ^The first host parameter has an index of 1, not 0. 4515** 4516** ^If the value N is out of range or if the N-th parameter is 4517** nameless, then NULL is returned. ^The returned string is 4518** always in UTF-8 encoding even if the named parameter was 4519** originally specified as UTF-16 in [sqlite3_prepare16()], 4520** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4521** 4522** See also: [sqlite3_bind_blob|sqlite3_bind()], 4523** [sqlite3_bind_parameter_count()], and 4524** [sqlite3_bind_parameter_index()]. 4525*/ 4526const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4527 4528/* 4529** CAPI3REF: Index Of A Parameter With A Given Name 4530** METHOD: sqlite3_stmt 4531** 4532** ^Return the index of an SQL parameter given its name. ^The 4533** index value returned is suitable for use as the second 4534** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4535** is returned if no matching parameter is found. ^The parameter 4536** name must be given in UTF-8 even if the original statement 4537** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4538** [sqlite3_prepare16_v3()]. 4539** 4540** See also: [sqlite3_bind_blob|sqlite3_bind()], 4541** [sqlite3_bind_parameter_count()], and 4542** [sqlite3_bind_parameter_name()]. 4543*/ 4544int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4545 4546/* 4547** CAPI3REF: Reset All Bindings On A Prepared Statement 4548** METHOD: sqlite3_stmt 4549** 4550** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4551** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4552** ^Use this routine to reset all host parameters to NULL. 4553*/ 4554int sqlite3_clear_bindings(sqlite3_stmt*); 4555 4556/* 4557** CAPI3REF: Number Of Columns In A Result Set 4558** METHOD: sqlite3_stmt 4559** 4560** ^Return the number of columns in the result set returned by the 4561** [prepared statement]. ^If this routine returns 0, that means the 4562** [prepared statement] returns no data (for example an [UPDATE]). 4563** ^However, just because this routine returns a positive number does not 4564** mean that one or more rows of data will be returned. ^A SELECT statement 4565** will always have a positive sqlite3_column_count() but depending on the 4566** WHERE clause constraints and the table content, it might return no rows. 4567** 4568** See also: [sqlite3_data_count()] 4569*/ 4570int sqlite3_column_count(sqlite3_stmt *pStmt); 4571 4572/* 4573** CAPI3REF: Column Names In A Result Set 4574** METHOD: sqlite3_stmt 4575** 4576** ^These routines return the name assigned to a particular column 4577** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4578** interface returns a pointer to a zero-terminated UTF-8 string 4579** and sqlite3_column_name16() returns a pointer to a zero-terminated 4580** UTF-16 string. ^The first parameter is the [prepared statement] 4581** that implements the [SELECT] statement. ^The second parameter is the 4582** column number. ^The leftmost column is number 0. 4583** 4584** ^The returned string pointer is valid until either the [prepared statement] 4585** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4586** reprepared by the first call to [sqlite3_step()] for a particular run 4587** or until the next call to 4588** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4589** 4590** ^If sqlite3_malloc() fails during the processing of either routine 4591** (for example during a conversion from UTF-8 to UTF-16) then a 4592** NULL pointer is returned. 4593** 4594** ^The name of a result column is the value of the "AS" clause for 4595** that column, if there is an AS clause. If there is no AS clause 4596** then the name of the column is unspecified and may change from 4597** one release of SQLite to the next. 4598*/ 4599const char *sqlite3_column_name(sqlite3_stmt*, int N); 4600const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4601 4602/* 4603** CAPI3REF: Source Of Data In A Query Result 4604** METHOD: sqlite3_stmt 4605** 4606** ^These routines provide a means to determine the database, table, and 4607** table column that is the origin of a particular result column in 4608** [SELECT] statement. 4609** ^The name of the database or table or column can be returned as 4610** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4611** the database name, the _table_ routines return the table name, and 4612** the origin_ routines return the column name. 4613** ^The returned string is valid until the [prepared statement] is destroyed 4614** using [sqlite3_finalize()] or until the statement is automatically 4615** reprepared by the first call to [sqlite3_step()] for a particular run 4616** or until the same information is requested 4617** again in a different encoding. 4618** 4619** ^The names returned are the original un-aliased names of the 4620** database, table, and column. 4621** 4622** ^The first argument to these interfaces is a [prepared statement]. 4623** ^These functions return information about the Nth result column returned by 4624** the statement, where N is the second function argument. 4625** ^The left-most column is column 0 for these routines. 4626** 4627** ^If the Nth column returned by the statement is an expression or 4628** subquery and is not a column value, then all of these functions return 4629** NULL. ^These routines might also return NULL if a memory allocation error 4630** occurs. ^Otherwise, they return the name of the attached database, table, 4631** or column that query result column was extracted from. 4632** 4633** ^As with all other SQLite APIs, those whose names end with "16" return 4634** UTF-16 encoded strings and the other functions return UTF-8. 4635** 4636** ^These APIs are only available if the library was compiled with the 4637** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4638** 4639** If two or more threads call one or more 4640** [sqlite3_column_database_name | column metadata interfaces] 4641** for the same [prepared statement] and result column 4642** at the same time then the results are undefined. 4643*/ 4644const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4645const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4646const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4647const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4648const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4649const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4650 4651/* 4652** CAPI3REF: Declared Datatype Of A Query Result 4653** METHOD: sqlite3_stmt 4654** 4655** ^(The first parameter is a [prepared statement]. 4656** If this statement is a [SELECT] statement and the Nth column of the 4657** returned result set of that [SELECT] is a table column (not an 4658** expression or subquery) then the declared type of the table 4659** column is returned.)^ ^If the Nth column of the result set is an 4660** expression or subquery, then a NULL pointer is returned. 4661** ^The returned string is always UTF-8 encoded. 4662** 4663** ^(For example, given the database schema: 4664** 4665** CREATE TABLE t1(c1 VARIANT); 4666** 4667** and the following statement to be compiled: 4668** 4669** SELECT c1 + 1, c1 FROM t1; 4670** 4671** this routine would return the string "VARIANT" for the second result 4672** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4673** 4674** ^SQLite uses dynamic run-time typing. ^So just because a column 4675** is declared to contain a particular type does not mean that the 4676** data stored in that column is of the declared type. SQLite is 4677** strongly typed, but the typing is dynamic not static. ^Type 4678** is associated with individual values, not with the containers 4679** used to hold those values. 4680*/ 4681const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4682const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4683 4684/* 4685** CAPI3REF: Evaluate An SQL Statement 4686** METHOD: sqlite3_stmt 4687** 4688** After a [prepared statement] has been prepared using any of 4689** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4690** or [sqlite3_prepare16_v3()] or one of the legacy 4691** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4692** must be called one or more times to evaluate the statement. 4693** 4694** The details of the behavior of the sqlite3_step() interface depend 4695** on whether the statement was prepared using the newer "vX" interfaces 4696** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4697** [sqlite3_prepare16_v2()] or the older legacy 4698** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4699** new "vX" interface is recommended for new applications but the legacy 4700** interface will continue to be supported. 4701** 4702** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4703** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4704** ^With the "v2" interface, any of the other [result codes] or 4705** [extended result codes] might be returned as well. 4706** 4707** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4708** database locks it needs to do its job. ^If the statement is a [COMMIT] 4709** or occurs outside of an explicit transaction, then you can retry the 4710** statement. If the statement is not a [COMMIT] and occurs within an 4711** explicit transaction then you should rollback the transaction before 4712** continuing. 4713** 4714** ^[SQLITE_DONE] means that the statement has finished executing 4715** successfully. sqlite3_step() should not be called again on this virtual 4716** machine without first calling [sqlite3_reset()] to reset the virtual 4717** machine back to its initial state. 4718** 4719** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4720** is returned each time a new row of data is ready for processing by the 4721** caller. The values may be accessed using the [column access functions]. 4722** sqlite3_step() is called again to retrieve the next row of data. 4723** 4724** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4725** violation) has occurred. sqlite3_step() should not be called again on 4726** the VM. More information may be found by calling [sqlite3_errmsg()]. 4727** ^With the legacy interface, a more specific error code (for example, 4728** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4729** can be obtained by calling [sqlite3_reset()] on the 4730** [prepared statement]. ^In the "v2" interface, 4731** the more specific error code is returned directly by sqlite3_step(). 4732** 4733** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4734** Perhaps it was called on a [prepared statement] that has 4735** already been [sqlite3_finalize | finalized] or on one that had 4736** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4737** be the case that the same database connection is being used by two or 4738** more threads at the same moment in time. 4739** 4740** For all versions of SQLite up to and including 3.6.23.1, a call to 4741** [sqlite3_reset()] was required after sqlite3_step() returned anything 4742** other than [SQLITE_ROW] before any subsequent invocation of 4743** sqlite3_step(). Failure to reset the prepared statement using 4744** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4745** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4746** sqlite3_step() began 4747** calling [sqlite3_reset()] automatically in this circumstance rather 4748** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4749** break because any application that ever receives an SQLITE_MISUSE error 4750** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4751** can be used to restore the legacy behavior. 4752** 4753** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4754** API always returns a generic error code, [SQLITE_ERROR], following any 4755** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4756** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4757** specific [error codes] that better describes the error. 4758** We admit that this is a goofy design. The problem has been fixed 4759** with the "v2" interface. If you prepare all of your SQL statements 4760** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4761** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4762** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4763** then the more specific [error codes] are returned directly 4764** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4765*/ 4766int sqlite3_step(sqlite3_stmt*); 4767 4768/* 4769** CAPI3REF: Number of columns in a result set 4770** METHOD: sqlite3_stmt 4771** 4772** ^The sqlite3_data_count(P) interface returns the number of columns in the 4773** current row of the result set of [prepared statement] P. 4774** ^If prepared statement P does not have results ready to return 4775** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4776** interfaces) then sqlite3_data_count(P) returns 0. 4777** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4778** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4779** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4780** will return non-zero if previous call to [sqlite3_step](P) returned 4781** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4782** where it always returns zero since each step of that multi-step 4783** pragma returns 0 columns of data. 4784** 4785** See also: [sqlite3_column_count()] 4786*/ 4787int sqlite3_data_count(sqlite3_stmt *pStmt); 4788 4789/* 4790** CAPI3REF: Fundamental Datatypes 4791** KEYWORDS: SQLITE_TEXT 4792** 4793** ^(Every value in SQLite has one of five fundamental datatypes: 4794** 4795** <ul> 4796** <li> 64-bit signed integer 4797** <li> 64-bit IEEE floating point number 4798** <li> string 4799** <li> BLOB 4800** <li> NULL 4801** </ul>)^ 4802** 4803** These constants are codes for each of those types. 4804** 4805** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4806** for a completely different meaning. Software that links against both 4807** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4808** SQLITE_TEXT. 4809*/ 4810#define SQLITE_INTEGER 1 4811#define SQLITE_FLOAT 2 4812#define SQLITE_BLOB 4 4813#define SQLITE_NULL 5 4814#ifdef SQLITE_TEXT 4815# undef SQLITE_TEXT 4816#else 4817# define SQLITE_TEXT 3 4818#endif 4819#define SQLITE3_TEXT 3 4820 4821/* 4822** CAPI3REF: Result Values From A Query 4823** KEYWORDS: {column access functions} 4824** METHOD: sqlite3_stmt 4825** 4826** <b>Summary:</b> 4827** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4828** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4829** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4830** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4831** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4832** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4833** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4834** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4835** [sqlite3_value|unprotected sqlite3_value] object. 4836** <tr><td> <td> <td> 4837** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4838** or a UTF-8 TEXT result in bytes 4839** <tr><td><b>sqlite3_column_bytes16 </b> 4840** <td>→ <td>Size of UTF-16 4841** TEXT in bytes 4842** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4843** datatype of the result 4844** </table></blockquote> 4845** 4846** <b>Details:</b> 4847** 4848** ^These routines return information about a single column of the current 4849** result row of a query. ^In every case the first argument is a pointer 4850** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4851** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4852** and the second argument is the index of the column for which information 4853** should be returned. ^The leftmost column of the result set has the index 0. 4854** ^The number of columns in the result can be determined using 4855** [sqlite3_column_count()]. 4856** 4857** If the SQL statement does not currently point to a valid row, or if the 4858** column index is out of range, the result is undefined. 4859** These routines may only be called when the most recent call to 4860** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4861** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4862** If any of these routines are called after [sqlite3_reset()] or 4863** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4864** something other than [SQLITE_ROW], the results are undefined. 4865** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4866** are called from a different thread while any of these routines 4867** are pending, then the results are undefined. 4868** 4869** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4870** each return the value of a result column in a specific data format. If 4871** the result column is not initially in the requested format (for example, 4872** if the query returns an integer but the sqlite3_column_text() interface 4873** is used to extract the value) then an automatic type conversion is performed. 4874** 4875** ^The sqlite3_column_type() routine returns the 4876** [SQLITE_INTEGER | datatype code] for the initial data type 4877** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4878** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4879** The return value of sqlite3_column_type() can be used to decide which 4880** of the first six interface should be used to extract the column value. 4881** The value returned by sqlite3_column_type() is only meaningful if no 4882** automatic type conversions have occurred for the value in question. 4883** After a type conversion, the result of calling sqlite3_column_type() 4884** is undefined, though harmless. Future 4885** versions of SQLite may change the behavior of sqlite3_column_type() 4886** following a type conversion. 4887** 4888** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4889** or sqlite3_column_bytes16() interfaces can be used to determine the size 4890** of that BLOB or string. 4891** 4892** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4893** routine returns the number of bytes in that BLOB or string. 4894** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4895** the string to UTF-8 and then returns the number of bytes. 4896** ^If the result is a numeric value then sqlite3_column_bytes() uses 4897** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4898** the number of bytes in that string. 4899** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4900** 4901** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4902** routine returns the number of bytes in that BLOB or string. 4903** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4904** the string to UTF-16 and then returns the number of bytes. 4905** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4906** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4907** the number of bytes in that string. 4908** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4909** 4910** ^The values returned by [sqlite3_column_bytes()] and 4911** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4912** of the string. ^For clarity: the values returned by 4913** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4914** bytes in the string, not the number of characters. 4915** 4916** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4917** even empty strings, are always zero-terminated. ^The return 4918** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4919** 4920** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4921** [unprotected sqlite3_value] object. In a multithreaded environment, 4922** an unprotected sqlite3_value object may only be used safely with 4923** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4924** If the [unprotected sqlite3_value] object returned by 4925** [sqlite3_column_value()] is used in any other way, including calls 4926** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4927** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4928** Hence, the sqlite3_column_value() interface 4929** is normally only useful within the implementation of 4930** [application-defined SQL functions] or [virtual tables], not within 4931** top-level application code. 4932** 4933** The these routines may attempt to convert the datatype of the result. 4934** ^For example, if the internal representation is FLOAT and a text result 4935** is requested, [sqlite3_snprintf()] is used internally to perform the 4936** conversion automatically. ^(The following table details the conversions 4937** that are applied: 4938** 4939** <blockquote> 4940** <table border="1"> 4941** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4942** 4943** <tr><td> NULL <td> INTEGER <td> Result is 0 4944** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4945** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4946** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4947** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4948** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4949** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4950** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4951** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4952** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4953** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4954** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4955** <tr><td> TEXT <td> BLOB <td> No change 4956** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4957** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4958** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4959** </table> 4960** </blockquote>)^ 4961** 4962** Note that when type conversions occur, pointers returned by prior 4963** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4964** sqlite3_column_text16() may be invalidated. 4965** Type conversions and pointer invalidations might occur 4966** in the following cases: 4967** 4968** <ul> 4969** <li> The initial content is a BLOB and sqlite3_column_text() or 4970** sqlite3_column_text16() is called. A zero-terminator might 4971** need to be added to the string.</li> 4972** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4973** sqlite3_column_text16() is called. The content must be converted 4974** to UTF-16.</li> 4975** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4976** sqlite3_column_text() is called. The content must be converted 4977** to UTF-8.</li> 4978** </ul> 4979** 4980** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4981** not invalidate a prior pointer, though of course the content of the buffer 4982** that the prior pointer references will have been modified. Other kinds 4983** of conversion are done in place when it is possible, but sometimes they 4984** are not possible and in those cases prior pointers are invalidated. 4985** 4986** The safest policy is to invoke these routines 4987** in one of the following ways: 4988** 4989** <ul> 4990** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4991** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4992** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4993** </ul> 4994** 4995** In other words, you should call sqlite3_column_text(), 4996** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4997** into the desired format, then invoke sqlite3_column_bytes() or 4998** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4999** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5000** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5001** with calls to sqlite3_column_bytes(). 5002** 5003** ^The pointers returned are valid until a type conversion occurs as 5004** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5005** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5006** and BLOBs is freed automatically. Do not pass the pointers returned 5007** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5008** [sqlite3_free()]. 5009** 5010** As long as the input parameters are correct, these routines will only 5011** fail if an out-of-memory error occurs during a format conversion. 5012** Only the following subset of interfaces are subject to out-of-memory 5013** errors: 5014** 5015** <ul> 5016** <li> sqlite3_column_blob() 5017** <li> sqlite3_column_text() 5018** <li> sqlite3_column_text16() 5019** <li> sqlite3_column_bytes() 5020** <li> sqlite3_column_bytes16() 5021** </ul> 5022** 5023** If an out-of-memory error occurs, then the return value from these 5024** routines is the same as if the column had contained an SQL NULL value. 5025** Valid SQL NULL returns can be distinguished from out-of-memory errors 5026** by invoking the [sqlite3_errcode()] immediately after the suspect 5027** return value is obtained and before any 5028** other SQLite interface is called on the same [database connection]. 5029*/ 5030const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5031double sqlite3_column_double(sqlite3_stmt*, int iCol); 5032int sqlite3_column_int(sqlite3_stmt*, int iCol); 5033sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5034const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5035const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5036sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5037int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5038int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5039int sqlite3_column_type(sqlite3_stmt*, int iCol); 5040 5041/* 5042** CAPI3REF: Destroy A Prepared Statement Object 5043** DESTRUCTOR: sqlite3_stmt 5044** 5045** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5046** ^If the most recent evaluation of the statement encountered no errors 5047** or if the statement is never been evaluated, then sqlite3_finalize() returns 5048** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5049** sqlite3_finalize(S) returns the appropriate [error code] or 5050** [extended error code]. 5051** 5052** ^The sqlite3_finalize(S) routine can be called at any point during 5053** the life cycle of [prepared statement] S: 5054** before statement S is ever evaluated, after 5055** one or more calls to [sqlite3_reset()], or after any call 5056** to [sqlite3_step()] regardless of whether or not the statement has 5057** completed execution. 5058** 5059** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5060** 5061** The application must finalize every [prepared statement] in order to avoid 5062** resource leaks. It is a grievous error for the application to try to use 5063** a prepared statement after it has been finalized. Any use of a prepared 5064** statement after it has been finalized can result in undefined and 5065** undesirable behavior such as segfaults and heap corruption. 5066*/ 5067int sqlite3_finalize(sqlite3_stmt *pStmt); 5068 5069/* 5070** CAPI3REF: Reset A Prepared Statement Object 5071** METHOD: sqlite3_stmt 5072** 5073** The sqlite3_reset() function is called to reset a [prepared statement] 5074** object back to its initial state, ready to be re-executed. 5075** ^Any SQL statement variables that had values bound to them using 5076** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5077** Use [sqlite3_clear_bindings()] to reset the bindings. 5078** 5079** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5080** back to the beginning of its program. 5081** 5082** ^If the most recent call to [sqlite3_step(S)] for the 5083** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5084** or if [sqlite3_step(S)] has never before been called on S, 5085** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5086** 5087** ^If the most recent call to [sqlite3_step(S)] for the 5088** [prepared statement] S indicated an error, then 5089** [sqlite3_reset(S)] returns an appropriate [error code]. 5090** 5091** ^The [sqlite3_reset(S)] interface does not change the values 5092** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5093*/ 5094int sqlite3_reset(sqlite3_stmt *pStmt); 5095 5096/* 5097** CAPI3REF: Create Or Redefine SQL Functions 5098** KEYWORDS: {function creation routines} 5099** METHOD: sqlite3 5100** 5101** ^These functions (collectively known as "function creation routines") 5102** are used to add SQL functions or aggregates or to redefine the behavior 5103** of existing SQL functions or aggregates. The only differences between 5104** the three "sqlite3_create_function*" routines are the text encoding 5105** expected for the second parameter (the name of the function being 5106** created) and the presence or absence of a destructor callback for 5107** the application data pointer. Function sqlite3_create_window_function() 5108** is similar, but allows the user to supply the extra callback functions 5109** needed by [aggregate window functions]. 5110** 5111** ^The first parameter is the [database connection] to which the SQL 5112** function is to be added. ^If an application uses more than one database 5113** connection then application-defined SQL functions must be added 5114** to each database connection separately. 5115** 5116** ^The second parameter is the name of the SQL function to be created or 5117** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5118** representation, exclusive of the zero-terminator. ^Note that the name 5119** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5120** ^Any attempt to create a function with a longer name 5121** will result in [SQLITE_MISUSE] being returned. 5122** 5123** ^The third parameter (nArg) 5124** is the number of arguments that the SQL function or 5125** aggregate takes. ^If this parameter is -1, then the SQL function or 5126** aggregate may take any number of arguments between 0 and the limit 5127** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5128** parameter is less than -1 or greater than 127 then the behavior is 5129** undefined. 5130** 5131** ^The fourth parameter, eTextRep, specifies what 5132** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5133** its parameters. The application should set this parameter to 5134** [SQLITE_UTF16LE] if the function implementation invokes 5135** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5136** implementation invokes [sqlite3_value_text16be()] on an input, or 5137** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5138** otherwise. ^The same SQL function may be registered multiple times using 5139** different preferred text encodings, with different implementations for 5140** each encoding. 5141** ^When multiple implementations of the same function are available, SQLite 5142** will pick the one that involves the least amount of data conversion. 5143** 5144** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5145** to signal that the function will always return the same result given 5146** the same inputs within a single SQL statement. Most SQL functions are 5147** deterministic. The built-in [random()] SQL function is an example of a 5148** function that is not deterministic. The SQLite query planner is able to 5149** perform additional optimizations on deterministic functions, so use 5150** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5151** 5152** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5153** flag, which if present prevents the function from being invoked from 5154** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5155** index expressions, or the WHERE clause of partial indexes. 5156** 5157** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5158** all application-defined SQL functions that do not need to be 5159** used inside of triggers, view, CHECK constraints, or other elements of 5160** the database schema. This flags is especially recommended for SQL 5161** functions that have side effects or reveal internal application state. 5162** Without this flag, an attacker might be able to modify the schema of 5163** a database file to include invocations of the function with parameters 5164** chosen by the attacker, which the application will then execute when 5165** the database file is opened and read. 5166** 5167** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5168** function can gain access to this pointer using [sqlite3_user_data()].)^ 5169** 5170** ^The sixth, seventh and eighth parameters passed to the three 5171** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5172** pointers to C-language functions that implement the SQL function or 5173** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5174** callback only; NULL pointers must be passed as the xStep and xFinal 5175** parameters. ^An aggregate SQL function requires an implementation of xStep 5176** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5177** SQL function or aggregate, pass NULL pointers for all three function 5178** callbacks. 5179** 5180** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5181** and xInverse) passed to sqlite3_create_window_function are pointers to 5182** C-language callbacks that implement the new function. xStep and xFinal 5183** must both be non-NULL. xValue and xInverse may either both be NULL, in 5184** which case a regular aggregate function is created, or must both be 5185** non-NULL, in which case the new function may be used as either an aggregate 5186** or aggregate window function. More details regarding the implementation 5187** of aggregate window functions are 5188** [user-defined window functions|available here]. 5189** 5190** ^(If the final parameter to sqlite3_create_function_v2() or 5191** sqlite3_create_window_function() is not NULL, then it is destructor for 5192** the application data pointer. The destructor is invoked when the function 5193** is deleted, either by being overloaded or when the database connection 5194** closes.)^ ^The destructor is also invoked if the call to 5195** sqlite3_create_function_v2() fails. ^When the destructor callback is 5196** invoked, it is passed a single argument which is a copy of the application 5197** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5198** 5199** ^It is permitted to register multiple implementations of the same 5200** functions with the same name but with either differing numbers of 5201** arguments or differing preferred text encodings. ^SQLite will use 5202** the implementation that most closely matches the way in which the 5203** SQL function is used. ^A function implementation with a non-negative 5204** nArg parameter is a better match than a function implementation with 5205** a negative nArg. ^A function where the preferred text encoding 5206** matches the database encoding is a better 5207** match than a function where the encoding is different. 5208** ^A function where the encoding difference is between UTF16le and UTF16be 5209** is a closer match than a function where the encoding difference is 5210** between UTF8 and UTF16. 5211** 5212** ^Built-in functions may be overloaded by new application-defined functions. 5213** 5214** ^An application-defined function is permitted to call other 5215** SQLite interfaces. However, such calls must not 5216** close the database connection nor finalize or reset the prepared 5217** statement in which the function is running. 5218*/ 5219int sqlite3_create_function( 5220 sqlite3 *db, 5221 const char *zFunctionName, 5222 int nArg, 5223 int eTextRep, 5224 void *pApp, 5225 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5226 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5227 void (*xFinal)(sqlite3_context*) 5228); 5229int sqlite3_create_function16( 5230 sqlite3 *db, 5231 const void *zFunctionName, 5232 int nArg, 5233 int eTextRep, 5234 void *pApp, 5235 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5236 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5237 void (*xFinal)(sqlite3_context*) 5238); 5239int sqlite3_create_function_v2( 5240 sqlite3 *db, 5241 const char *zFunctionName, 5242 int nArg, 5243 int eTextRep, 5244 void *pApp, 5245 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5246 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5247 void (*xFinal)(sqlite3_context*), 5248 void(*xDestroy)(void*) 5249); 5250int sqlite3_create_window_function( 5251 sqlite3 *db, 5252 const char *zFunctionName, 5253 int nArg, 5254 int eTextRep, 5255 void *pApp, 5256 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5257 void (*xFinal)(sqlite3_context*), 5258 void (*xValue)(sqlite3_context*), 5259 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5260 void(*xDestroy)(void*) 5261); 5262 5263/* 5264** CAPI3REF: Text Encodings 5265** 5266** These constant define integer codes that represent the various 5267** text encodings supported by SQLite. 5268*/ 5269#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5270#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5271#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5272#define SQLITE_UTF16 4 /* Use native byte order */ 5273#define SQLITE_ANY 5 /* Deprecated */ 5274#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5275 5276/* 5277** CAPI3REF: Function Flags 5278** 5279** These constants may be ORed together with the 5280** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5281** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5282** [sqlite3_create_function_v2()]. 5283** 5284** <dl> 5285** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5286** The SQLITE_DETERMINISTIC flag means that the new function always gives 5287** the same output when the input parameters are the same. 5288** The [abs|abs() function] is deterministic, for example, but 5289** [randomblob|randomblob()] is not. Functions must 5290** be deterministic in order to be used in certain contexts such as 5291** with the WHERE clause of [partial indexes] or in [generated columns]. 5292** SQLite might also optimize deterministic functions by factoring them 5293** out of inner loops. 5294** </dd> 5295** 5296** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5297** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5298** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5299** schema structures such as [CHECK constraints], [DEFAULT clauses], 5300** [expression indexes], [partial indexes], or [generated columns]. 5301** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5302** for all [application-defined SQL functions], and especially for functions 5303** that have side-effects or that could potentially leak sensitive 5304** information. 5305** </dd> 5306** 5307** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5308** The SQLITE_INNOCUOUS flag means that the function is unlikely 5309** to cause problems even if misused. An innocuous function should have 5310** no side effects and should not depend on any values other than its 5311** input parameters. The [abs|abs() function] is an example of an 5312** innocuous function. 5313** The [load_extension() SQL function] is not innocuous because of its 5314** side effects. 5315** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5316** exactly the same. The [random|random() function] is an example of a 5317** function that is innocuous but not deterministic. 5318** <p>Some heightened security settings 5319** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5320** disable the use of SQL functions inside views and triggers and in 5321** schema structures such as [CHECK constraints], [DEFAULT clauses], 5322** [expression indexes], [partial indexes], and [generated columns] unless 5323** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5324** are innocuous. Developers are advised to avoid using the 5325** SQLITE_INNOCUOUS flag for application-defined functions unless the 5326** function has been carefully audited and found to be free of potentially 5327** security-adverse side-effects and information-leaks. 5328** </dd> 5329** 5330** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5331** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5332** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5333** Specifying this flag makes no difference for scalar or aggregate user 5334** functions. However, if it is not specified for a user-defined window 5335** function, then any sub-types belonging to arguments passed to the window 5336** function may be discarded before the window function is called (i.e. 5337** sqlite3_value_subtype() will always return 0). 5338** </dd> 5339** </dl> 5340*/ 5341#define SQLITE_DETERMINISTIC 0x000000800 5342#define SQLITE_DIRECTONLY 0x000080000 5343#define SQLITE_SUBTYPE 0x000100000 5344#define SQLITE_INNOCUOUS 0x000200000 5345 5346/* 5347** CAPI3REF: Deprecated Functions 5348** DEPRECATED 5349** 5350** These functions are [deprecated]. In order to maintain 5351** backwards compatibility with older code, these functions continue 5352** to be supported. However, new applications should avoid 5353** the use of these functions. To encourage programmers to avoid 5354** these functions, we will not explain what they do. 5355*/ 5356#ifndef SQLITE_OMIT_DEPRECATED 5357SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5358SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5359SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5360SQLITE_DEPRECATED int sqlite3_global_recover(void); 5361SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5362SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5363 void*,sqlite3_int64); 5364#endif 5365 5366/* 5367** CAPI3REF: Obtaining SQL Values 5368** METHOD: sqlite3_value 5369** 5370** <b>Summary:</b> 5371** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5372** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5373** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5374** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5375** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5376** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5377** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5378** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5379** the native byteorder 5380** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5381** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5382** <tr><td> <td> <td> 5383** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5384** or a UTF-8 TEXT in bytes 5385** <tr><td><b>sqlite3_value_bytes16 </b> 5386** <td>→ <td>Size of UTF-16 5387** TEXT in bytes 5388** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5389** datatype of the value 5390** <tr><td><b>sqlite3_value_numeric_type </b> 5391** <td>→ <td>Best numeric datatype of the value 5392** <tr><td><b>sqlite3_value_nochange </b> 5393** <td>→ <td>True if the column is unchanged in an UPDATE 5394** against a virtual table. 5395** <tr><td><b>sqlite3_value_frombind </b> 5396** <td>→ <td>True if value originated from a [bound parameter] 5397** </table></blockquote> 5398** 5399** <b>Details:</b> 5400** 5401** These routines extract type, size, and content information from 5402** [protected sqlite3_value] objects. Protected sqlite3_value objects 5403** are used to pass parameter information into the functions that 5404** implement [application-defined SQL functions] and [virtual tables]. 5405** 5406** These routines work only with [protected sqlite3_value] objects. 5407** Any attempt to use these routines on an [unprotected sqlite3_value] 5408** is not threadsafe. 5409** 5410** ^These routines work just like the corresponding [column access functions] 5411** except that these routines take a single [protected sqlite3_value] object 5412** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5413** 5414** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5415** in the native byte-order of the host machine. ^The 5416** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5417** extract UTF-16 strings as big-endian and little-endian respectively. 5418** 5419** ^If [sqlite3_value] object V was initialized 5420** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5421** and if X and Y are strings that compare equal according to strcmp(X,Y), 5422** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5423** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5424** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5425** 5426** ^(The sqlite3_value_type(V) interface returns the 5427** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5428** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5429** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5430** Other interfaces might change the datatype for an sqlite3_value object. 5431** For example, if the datatype is initially SQLITE_INTEGER and 5432** sqlite3_value_text(V) is called to extract a text value for that 5433** integer, then subsequent calls to sqlite3_value_type(V) might return 5434** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5435** occurs is undefined and may change from one release of SQLite to the next. 5436** 5437** ^(The sqlite3_value_numeric_type() interface attempts to apply 5438** numeric affinity to the value. This means that an attempt is 5439** made to convert the value to an integer or floating point. If 5440** such a conversion is possible without loss of information (in other 5441** words, if the value is a string that looks like a number) 5442** then the conversion is performed. Otherwise no conversion occurs. 5443** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5444** 5445** ^Within the [xUpdate] method of a [virtual table], the 5446** sqlite3_value_nochange(X) interface returns true if and only if 5447** the column corresponding to X is unchanged by the UPDATE operation 5448** that the xUpdate method call was invoked to implement and if 5449** and the prior [xColumn] method call that was invoked to extracted 5450** the value for that column returned without setting a result (probably 5451** because it queried [sqlite3_vtab_nochange()] and found that the column 5452** was unchanging). ^Within an [xUpdate] method, any value for which 5453** sqlite3_value_nochange(X) is true will in all other respects appear 5454** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5455** than within an [xUpdate] method call for an UPDATE statement, then 5456** the return value is arbitrary and meaningless. 5457** 5458** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5459** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5460** interfaces. ^If X comes from an SQL literal value, or a table column, 5461** or an expression, then sqlite3_value_frombind(X) returns zero. 5462** 5463** Please pay particular attention to the fact that the pointer returned 5464** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5465** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5466** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5467** or [sqlite3_value_text16()]. 5468** 5469** These routines must be called from the same thread as 5470** the SQL function that supplied the [sqlite3_value*] parameters. 5471** 5472** As long as the input parameter is correct, these routines can only 5473** fail if an out-of-memory error occurs during a format conversion. 5474** Only the following subset of interfaces are subject to out-of-memory 5475** errors: 5476** 5477** <ul> 5478** <li> sqlite3_value_blob() 5479** <li> sqlite3_value_text() 5480** <li> sqlite3_value_text16() 5481** <li> sqlite3_value_text16le() 5482** <li> sqlite3_value_text16be() 5483** <li> sqlite3_value_bytes() 5484** <li> sqlite3_value_bytes16() 5485** </ul> 5486** 5487** If an out-of-memory error occurs, then the return value from these 5488** routines is the same as if the column had contained an SQL NULL value. 5489** Valid SQL NULL returns can be distinguished from out-of-memory errors 5490** by invoking the [sqlite3_errcode()] immediately after the suspect 5491** return value is obtained and before any 5492** other SQLite interface is called on the same [database connection]. 5493*/ 5494const void *sqlite3_value_blob(sqlite3_value*); 5495double sqlite3_value_double(sqlite3_value*); 5496int sqlite3_value_int(sqlite3_value*); 5497sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5498void *sqlite3_value_pointer(sqlite3_value*, const char*); 5499const unsigned char *sqlite3_value_text(sqlite3_value*); 5500const void *sqlite3_value_text16(sqlite3_value*); 5501const void *sqlite3_value_text16le(sqlite3_value*); 5502const void *sqlite3_value_text16be(sqlite3_value*); 5503int sqlite3_value_bytes(sqlite3_value*); 5504int sqlite3_value_bytes16(sqlite3_value*); 5505int sqlite3_value_type(sqlite3_value*); 5506int sqlite3_value_numeric_type(sqlite3_value*); 5507int sqlite3_value_nochange(sqlite3_value*); 5508int sqlite3_value_frombind(sqlite3_value*); 5509 5510/* 5511** CAPI3REF: Finding The Subtype Of SQL Values 5512** METHOD: sqlite3_value 5513** 5514** The sqlite3_value_subtype(V) function returns the subtype for 5515** an [application-defined SQL function] argument V. The subtype 5516** information can be used to pass a limited amount of context from 5517** one SQL function to another. Use the [sqlite3_result_subtype()] 5518** routine to set the subtype for the return value of an SQL function. 5519*/ 5520unsigned int sqlite3_value_subtype(sqlite3_value*); 5521 5522/* 5523** CAPI3REF: Copy And Free SQL Values 5524** METHOD: sqlite3_value 5525** 5526** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5527** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5528** is a [protected sqlite3_value] object even if the input is not. 5529** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5530** memory allocation fails. 5531** 5532** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5533** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5534** then sqlite3_value_free(V) is a harmless no-op. 5535*/ 5536sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5537void sqlite3_value_free(sqlite3_value*); 5538 5539/* 5540** CAPI3REF: Obtain Aggregate Function Context 5541** METHOD: sqlite3_context 5542** 5543** Implementations of aggregate SQL functions use this 5544** routine to allocate memory for storing their state. 5545** 5546** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5547** for a particular aggregate function, SQLite allocates 5548** N bytes of memory, zeroes out that memory, and returns a pointer 5549** to the new memory. ^On second and subsequent calls to 5550** sqlite3_aggregate_context() for the same aggregate function instance, 5551** the same buffer is returned. Sqlite3_aggregate_context() is normally 5552** called once for each invocation of the xStep callback and then one 5553** last time when the xFinal callback is invoked. ^(When no rows match 5554** an aggregate query, the xStep() callback of the aggregate function 5555** implementation is never called and xFinal() is called exactly once. 5556** In those cases, sqlite3_aggregate_context() might be called for the 5557** first time from within xFinal().)^ 5558** 5559** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5560** when first called if N is less than or equal to zero or if a memory 5561** allocate error occurs. 5562** 5563** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5564** determined by the N parameter on first successful call. Changing the 5565** value of N in any subsequent call to sqlite3_aggregate_context() within 5566** the same aggregate function instance will not resize the memory 5567** allocation.)^ Within the xFinal callback, it is customary to set 5568** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5569** pointless memory allocations occur. 5570** 5571** ^SQLite automatically frees the memory allocated by 5572** sqlite3_aggregate_context() when the aggregate query concludes. 5573** 5574** The first parameter must be a copy of the 5575** [sqlite3_context | SQL function context] that is the first parameter 5576** to the xStep or xFinal callback routine that implements the aggregate 5577** function. 5578** 5579** This routine must be called from the same thread in which 5580** the aggregate SQL function is running. 5581*/ 5582void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5583 5584/* 5585** CAPI3REF: User Data For Functions 5586** METHOD: sqlite3_context 5587** 5588** ^The sqlite3_user_data() interface returns a copy of 5589** the pointer that was the pUserData parameter (the 5th parameter) 5590** of the [sqlite3_create_function()] 5591** and [sqlite3_create_function16()] routines that originally 5592** registered the application defined function. 5593** 5594** This routine must be called from the same thread in which 5595** the application-defined function is running. 5596*/ 5597void *sqlite3_user_data(sqlite3_context*); 5598 5599/* 5600** CAPI3REF: Database Connection For Functions 5601** METHOD: sqlite3_context 5602** 5603** ^The sqlite3_context_db_handle() interface returns a copy of 5604** the pointer to the [database connection] (the 1st parameter) 5605** of the [sqlite3_create_function()] 5606** and [sqlite3_create_function16()] routines that originally 5607** registered the application defined function. 5608*/ 5609sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5610 5611/* 5612** CAPI3REF: Function Auxiliary Data 5613** METHOD: sqlite3_context 5614** 5615** These functions may be used by (non-aggregate) SQL functions to 5616** associate metadata with argument values. If the same value is passed to 5617** multiple invocations of the same SQL function during query execution, under 5618** some circumstances the associated metadata may be preserved. An example 5619** of where this might be useful is in a regular-expression matching 5620** function. The compiled version of the regular expression can be stored as 5621** metadata associated with the pattern string. 5622** Then as long as the pattern string remains the same, 5623** the compiled regular expression can be reused on multiple 5624** invocations of the same function. 5625** 5626** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5627** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5628** value to the application-defined function. ^N is zero for the left-most 5629** function argument. ^If there is no metadata 5630** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5631** returns a NULL pointer. 5632** 5633** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5634** argument of the application-defined function. ^Subsequent 5635** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5636** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5637** NULL if the metadata has been discarded. 5638** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5639** SQLite will invoke the destructor function X with parameter P exactly 5640** once, when the metadata is discarded. 5641** SQLite is free to discard the metadata at any time, including: <ul> 5642** <li> ^(when the corresponding function parameter changes)^, or 5643** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5644** SQL statement)^, or 5645** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5646** parameter)^, or 5647** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5648** allocation error occurs.)^ </ul> 5649** 5650** Note the last bullet in particular. The destructor X in 5651** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5652** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5653** should be called near the end of the function implementation and the 5654** function implementation should not make any use of P after 5655** sqlite3_set_auxdata() has been called. 5656** 5657** ^(In practice, metadata is preserved between function calls for 5658** function parameters that are compile-time constants, including literal 5659** values and [parameters] and expressions composed from the same.)^ 5660** 5661** The value of the N parameter to these interfaces should be non-negative. 5662** Future enhancements may make use of negative N values to define new 5663** kinds of function caching behavior. 5664** 5665** These routines must be called from the same thread in which 5666** the SQL function is running. 5667*/ 5668void *sqlite3_get_auxdata(sqlite3_context*, int N); 5669void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5670 5671 5672/* 5673** CAPI3REF: Constants Defining Special Destructor Behavior 5674** 5675** These are special values for the destructor that is passed in as the 5676** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5677** argument is SQLITE_STATIC, it means that the content pointer is constant 5678** and will never change. It does not need to be destroyed. ^The 5679** SQLITE_TRANSIENT value means that the content will likely change in 5680** the near future and that SQLite should make its own private copy of 5681** the content before returning. 5682** 5683** The typedef is necessary to work around problems in certain 5684** C++ compilers. 5685*/ 5686typedef void (*sqlite3_destructor_type)(void*); 5687#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5688#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5689 5690/* 5691** CAPI3REF: Setting The Result Of An SQL Function 5692** METHOD: sqlite3_context 5693** 5694** These routines are used by the xFunc or xFinal callbacks that 5695** implement SQL functions and aggregates. See 5696** [sqlite3_create_function()] and [sqlite3_create_function16()] 5697** for additional information. 5698** 5699** These functions work very much like the [parameter binding] family of 5700** functions used to bind values to host parameters in prepared statements. 5701** Refer to the [SQL parameter] documentation for additional information. 5702** 5703** ^The sqlite3_result_blob() interface sets the result from 5704** an application-defined function to be the BLOB whose content is pointed 5705** to by the second parameter and which is N bytes long where N is the 5706** third parameter. 5707** 5708** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5709** interfaces set the result of the application-defined function to be 5710** a BLOB containing all zero bytes and N bytes in size. 5711** 5712** ^The sqlite3_result_double() interface sets the result from 5713** an application-defined function to be a floating point value specified 5714** by its 2nd argument. 5715** 5716** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5717** cause the implemented SQL function to throw an exception. 5718** ^SQLite uses the string pointed to by the 5719** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5720** as the text of an error message. ^SQLite interprets the error 5721** message string from sqlite3_result_error() as UTF-8. ^SQLite 5722** interprets the string from sqlite3_result_error16() as UTF-16 using 5723** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5724** ^If the third parameter to sqlite3_result_error() 5725** or sqlite3_result_error16() is negative then SQLite takes as the error 5726** message all text up through the first zero character. 5727** ^If the third parameter to sqlite3_result_error() or 5728** sqlite3_result_error16() is non-negative then SQLite takes that many 5729** bytes (not characters) from the 2nd parameter as the error message. 5730** ^The sqlite3_result_error() and sqlite3_result_error16() 5731** routines make a private copy of the error message text before 5732** they return. Hence, the calling function can deallocate or 5733** modify the text after they return without harm. 5734** ^The sqlite3_result_error_code() function changes the error code 5735** returned by SQLite as a result of an error in a function. ^By default, 5736** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5737** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5738** 5739** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5740** error indicating that a string or BLOB is too long to represent. 5741** 5742** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5743** error indicating that a memory allocation failed. 5744** 5745** ^The sqlite3_result_int() interface sets the return value 5746** of the application-defined function to be the 32-bit signed integer 5747** value given in the 2nd argument. 5748** ^The sqlite3_result_int64() interface sets the return value 5749** of the application-defined function to be the 64-bit signed integer 5750** value given in the 2nd argument. 5751** 5752** ^The sqlite3_result_null() interface sets the return value 5753** of the application-defined function to be NULL. 5754** 5755** ^The sqlite3_result_text(), sqlite3_result_text16(), 5756** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5757** set the return value of the application-defined function to be 5758** a text string which is represented as UTF-8, UTF-16 native byte order, 5759** UTF-16 little endian, or UTF-16 big endian, respectively. 5760** ^The sqlite3_result_text64() interface sets the return value of an 5761** application-defined function to be a text string in an encoding 5762** specified by the fifth (and last) parameter, which must be one 5763** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5764** ^SQLite takes the text result from the application from 5765** the 2nd parameter of the sqlite3_result_text* interfaces. 5766** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5767** is negative, then SQLite takes result text from the 2nd parameter 5768** through the first zero character. 5769** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5770** is non-negative, then as many bytes (not characters) of the text 5771** pointed to by the 2nd parameter are taken as the application-defined 5772** function result. If the 3rd parameter is non-negative, then it 5773** must be the byte offset into the string where the NUL terminator would 5774** appear if the string where NUL terminated. If any NUL characters occur 5775** in the string at a byte offset that is less than the value of the 3rd 5776** parameter, then the resulting string will contain embedded NULs and the 5777** result of expressions operating on strings with embedded NULs is undefined. 5778** ^If the 4th parameter to the sqlite3_result_text* interfaces 5779** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5780** function as the destructor on the text or BLOB result when it has 5781** finished using that result. 5782** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5783** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5784** assumes that the text or BLOB result is in constant space and does not 5785** copy the content of the parameter nor call a destructor on the content 5786** when it has finished using that result. 5787** ^If the 4th parameter to the sqlite3_result_text* interfaces 5788** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5789** then SQLite makes a copy of the result into space obtained 5790** from [sqlite3_malloc()] before it returns. 5791** 5792** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5793** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5794** when the encoding is not UTF8, if the input UTF16 begins with a 5795** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5796** string and the rest of the string is interpreted according to the 5797** byte-order specified by the BOM. ^The byte-order specified by 5798** the BOM at the beginning of the text overrides the byte-order 5799** specified by the interface procedure. ^So, for example, if 5800** sqlite3_result_text16le() is invoked with text that begins 5801** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5802** first two bytes of input are skipped and the remaining input 5803** is interpreted as UTF16BE text. 5804** 5805** ^For UTF16 input text to the sqlite3_result_text16(), 5806** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5807** sqlite3_result_text64() routines, if the text contains invalid 5808** UTF16 characters, the invalid characters might be converted 5809** into the unicode replacement character, U+FFFD. 5810** 5811** ^The sqlite3_result_value() interface sets the result of 5812** the application-defined function to be a copy of the 5813** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5814** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5815** so that the [sqlite3_value] specified in the parameter may change or 5816** be deallocated after sqlite3_result_value() returns without harm. 5817** ^A [protected sqlite3_value] object may always be used where an 5818** [unprotected sqlite3_value] object is required, so either 5819** kind of [sqlite3_value] object can be used with this interface. 5820** 5821** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5822** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5823** also associates the host-language pointer P or type T with that 5824** NULL value such that the pointer can be retrieved within an 5825** [application-defined SQL function] using [sqlite3_value_pointer()]. 5826** ^If the D parameter is not NULL, then it is a pointer to a destructor 5827** for the P parameter. ^SQLite invokes D with P as its only argument 5828** when SQLite is finished with P. The T parameter should be a static 5829** string and preferably a string literal. The sqlite3_result_pointer() 5830** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5831** 5832** If these routines are called from within the different thread 5833** than the one containing the application-defined function that received 5834** the [sqlite3_context] pointer, the results are undefined. 5835*/ 5836void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5837void sqlite3_result_blob64(sqlite3_context*,const void*, 5838 sqlite3_uint64,void(*)(void*)); 5839void sqlite3_result_double(sqlite3_context*, double); 5840void sqlite3_result_error(sqlite3_context*, const char*, int); 5841void sqlite3_result_error16(sqlite3_context*, const void*, int); 5842void sqlite3_result_error_toobig(sqlite3_context*); 5843void sqlite3_result_error_nomem(sqlite3_context*); 5844void sqlite3_result_error_code(sqlite3_context*, int); 5845void sqlite3_result_int(sqlite3_context*, int); 5846void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5847void sqlite3_result_null(sqlite3_context*); 5848void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5849void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5850 void(*)(void*), unsigned char encoding); 5851void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5852void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5853void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5854void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5855void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5856void sqlite3_result_zeroblob(sqlite3_context*, int n); 5857int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5858 5859 5860/* 5861** CAPI3REF: Setting The Subtype Of An SQL Function 5862** METHOD: sqlite3_context 5863** 5864** The sqlite3_result_subtype(C,T) function causes the subtype of 5865** the result from the [application-defined SQL function] with 5866** [sqlite3_context] C to be the value T. Only the lower 8 bits 5867** of the subtype T are preserved in current versions of SQLite; 5868** higher order bits are discarded. 5869** The number of subtype bytes preserved by SQLite might increase 5870** in future releases of SQLite. 5871*/ 5872void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5873 5874/* 5875** CAPI3REF: Define New Collating Sequences 5876** METHOD: sqlite3 5877** 5878** ^These functions add, remove, or modify a [collation] associated 5879** with the [database connection] specified as the first argument. 5880** 5881** ^The name of the collation is a UTF-8 string 5882** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5883** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5884** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5885** considered to be the same name. 5886** 5887** ^(The third argument (eTextRep) must be one of the constants: 5888** <ul> 5889** <li> [SQLITE_UTF8], 5890** <li> [SQLITE_UTF16LE], 5891** <li> [SQLITE_UTF16BE], 5892** <li> [SQLITE_UTF16], or 5893** <li> [SQLITE_UTF16_ALIGNED]. 5894** </ul>)^ 5895** ^The eTextRep argument determines the encoding of strings passed 5896** to the collating function callback, xCompare. 5897** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5898** force strings to be UTF16 with native byte order. 5899** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5900** on an even byte address. 5901** 5902** ^The fourth argument, pArg, is an application data pointer that is passed 5903** through as the first argument to the collating function callback. 5904** 5905** ^The fifth argument, xCompare, is a pointer to the collating function. 5906** ^Multiple collating functions can be registered using the same name but 5907** with different eTextRep parameters and SQLite will use whichever 5908** function requires the least amount of data transformation. 5909** ^If the xCompare argument is NULL then the collating function is 5910** deleted. ^When all collating functions having the same name are deleted, 5911** that collation is no longer usable. 5912** 5913** ^The collating function callback is invoked with a copy of the pArg 5914** application data pointer and with two strings in the encoding specified 5915** by the eTextRep argument. The two integer parameters to the collating 5916** function callback are the length of the two strings, in bytes. The collating 5917** function must return an integer that is negative, zero, or positive 5918** if the first string is less than, equal to, or greater than the second, 5919** respectively. A collating function must always return the same answer 5920** given the same inputs. If two or more collating functions are registered 5921** to the same collation name (using different eTextRep values) then all 5922** must give an equivalent answer when invoked with equivalent strings. 5923** The collating function must obey the following properties for all 5924** strings A, B, and C: 5925** 5926** <ol> 5927** <li> If A==B then B==A. 5928** <li> If A==B and B==C then A==C. 5929** <li> If A<B THEN B>A. 5930** <li> If A<B and B<C then A<C. 5931** </ol> 5932** 5933** If a collating function fails any of the above constraints and that 5934** collating function is registered and used, then the behavior of SQLite 5935** is undefined. 5936** 5937** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5938** with the addition that the xDestroy callback is invoked on pArg when 5939** the collating function is deleted. 5940** ^Collating functions are deleted when they are overridden by later 5941** calls to the collation creation functions or when the 5942** [database connection] is closed using [sqlite3_close()]. 5943** 5944** ^The xDestroy callback is <u>not</u> called if the 5945** sqlite3_create_collation_v2() function fails. Applications that invoke 5946** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5947** check the return code and dispose of the application data pointer 5948** themselves rather than expecting SQLite to deal with it for them. 5949** This is different from every other SQLite interface. The inconsistency 5950** is unfortunate but cannot be changed without breaking backwards 5951** compatibility. 5952** 5953** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5954*/ 5955int sqlite3_create_collation( 5956 sqlite3*, 5957 const char *zName, 5958 int eTextRep, 5959 void *pArg, 5960 int(*xCompare)(void*,int,const void*,int,const void*) 5961); 5962int sqlite3_create_collation_v2( 5963 sqlite3*, 5964 const char *zName, 5965 int eTextRep, 5966 void *pArg, 5967 int(*xCompare)(void*,int,const void*,int,const void*), 5968 void(*xDestroy)(void*) 5969); 5970int sqlite3_create_collation16( 5971 sqlite3*, 5972 const void *zName, 5973 int eTextRep, 5974 void *pArg, 5975 int(*xCompare)(void*,int,const void*,int,const void*) 5976); 5977 5978/* 5979** CAPI3REF: Collation Needed Callbacks 5980** METHOD: sqlite3 5981** 5982** ^To avoid having to register all collation sequences before a database 5983** can be used, a single callback function may be registered with the 5984** [database connection] to be invoked whenever an undefined collation 5985** sequence is required. 5986** 5987** ^If the function is registered using the sqlite3_collation_needed() API, 5988** then it is passed the names of undefined collation sequences as strings 5989** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5990** the names are passed as UTF-16 in machine native byte order. 5991** ^A call to either function replaces the existing collation-needed callback. 5992** 5993** ^(When the callback is invoked, the first argument passed is a copy 5994** of the second argument to sqlite3_collation_needed() or 5995** sqlite3_collation_needed16(). The second argument is the database 5996** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5997** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5998** sequence function required. The fourth parameter is the name of the 5999** required collation sequence.)^ 6000** 6001** The callback function should register the desired collation using 6002** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6003** [sqlite3_create_collation_v2()]. 6004*/ 6005int sqlite3_collation_needed( 6006 sqlite3*, 6007 void*, 6008 void(*)(void*,sqlite3*,int eTextRep,const char*) 6009); 6010int sqlite3_collation_needed16( 6011 sqlite3*, 6012 void*, 6013 void(*)(void*,sqlite3*,int eTextRep,const void*) 6014); 6015 6016#ifdef SQLITE_ENABLE_CEROD 6017/* 6018** Specify the activation key for a CEROD database. Unless 6019** activated, none of the CEROD routines will work. 6020*/ 6021void sqlite3_activate_cerod( 6022 const char *zPassPhrase /* Activation phrase */ 6023); 6024#endif 6025 6026/* 6027** CAPI3REF: Suspend Execution For A Short Time 6028** 6029** The sqlite3_sleep() function causes the current thread to suspend execution 6030** for at least a number of milliseconds specified in its parameter. 6031** 6032** If the operating system does not support sleep requests with 6033** millisecond time resolution, then the time will be rounded up to 6034** the nearest second. The number of milliseconds of sleep actually 6035** requested from the operating system is returned. 6036** 6037** ^SQLite implements this interface by calling the xSleep() 6038** method of the default [sqlite3_vfs] object. If the xSleep() method 6039** of the default VFS is not implemented correctly, or not implemented at 6040** all, then the behavior of sqlite3_sleep() may deviate from the description 6041** in the previous paragraphs. 6042*/ 6043int sqlite3_sleep(int); 6044 6045/* 6046** CAPI3REF: Name Of The Folder Holding Temporary Files 6047** 6048** ^(If this global variable is made to point to a string which is 6049** the name of a folder (a.k.a. directory), then all temporary files 6050** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6051** will be placed in that directory.)^ ^If this variable 6052** is a NULL pointer, then SQLite performs a search for an appropriate 6053** temporary file directory. 6054** 6055** Applications are strongly discouraged from using this global variable. 6056** It is required to set a temporary folder on Windows Runtime (WinRT). 6057** But for all other platforms, it is highly recommended that applications 6058** neither read nor write this variable. This global variable is a relic 6059** that exists for backwards compatibility of legacy applications and should 6060** be avoided in new projects. 6061** 6062** It is not safe to read or modify this variable in more than one 6063** thread at a time. It is not safe to read or modify this variable 6064** if a [database connection] is being used at the same time in a separate 6065** thread. 6066** It is intended that this variable be set once 6067** as part of process initialization and before any SQLite interface 6068** routines have been called and that this variable remain unchanged 6069** thereafter. 6070** 6071** ^The [temp_store_directory pragma] may modify this variable and cause 6072** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6073** the [temp_store_directory pragma] always assumes that any string 6074** that this variable points to is held in memory obtained from 6075** [sqlite3_malloc] and the pragma may attempt to free that memory 6076** using [sqlite3_free]. 6077** Hence, if this variable is modified directly, either it should be 6078** made NULL or made to point to memory obtained from [sqlite3_malloc] 6079** or else the use of the [temp_store_directory pragma] should be avoided. 6080** Except when requested by the [temp_store_directory pragma], SQLite 6081** does not free the memory that sqlite3_temp_directory points to. If 6082** the application wants that memory to be freed, it must do 6083** so itself, taking care to only do so after all [database connection] 6084** objects have been destroyed. 6085** 6086** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6087** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6088** features that require the use of temporary files may fail. Here is an 6089** example of how to do this using C++ with the Windows Runtime: 6090** 6091** <blockquote><pre> 6092** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6093** TemporaryFolder->Path->Data(); 6094** char zPathBuf[MAX_PATH + 1]; 6095** memset(zPathBuf, 0, sizeof(zPathBuf)); 6096** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6097** NULL, NULL); 6098** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6099** </pre></blockquote> 6100*/ 6101SQLITE_EXTERN char *sqlite3_temp_directory; 6102 6103/* 6104** CAPI3REF: Name Of The Folder Holding Database Files 6105** 6106** ^(If this global variable is made to point to a string which is 6107** the name of a folder (a.k.a. directory), then all database files 6108** specified with a relative pathname and created or accessed by 6109** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6110** to be relative to that directory.)^ ^If this variable is a NULL 6111** pointer, then SQLite assumes that all database files specified 6112** with a relative pathname are relative to the current directory 6113** for the process. Only the windows VFS makes use of this global 6114** variable; it is ignored by the unix VFS. 6115** 6116** Changing the value of this variable while a database connection is 6117** open can result in a corrupt database. 6118** 6119** It is not safe to read or modify this variable in more than one 6120** thread at a time. It is not safe to read or modify this variable 6121** if a [database connection] is being used at the same time in a separate 6122** thread. 6123** It is intended that this variable be set once 6124** as part of process initialization and before any SQLite interface 6125** routines have been called and that this variable remain unchanged 6126** thereafter. 6127** 6128** ^The [data_store_directory pragma] may modify this variable and cause 6129** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6130** the [data_store_directory pragma] always assumes that any string 6131** that this variable points to is held in memory obtained from 6132** [sqlite3_malloc] and the pragma may attempt to free that memory 6133** using [sqlite3_free]. 6134** Hence, if this variable is modified directly, either it should be 6135** made NULL or made to point to memory obtained from [sqlite3_malloc] 6136** or else the use of the [data_store_directory pragma] should be avoided. 6137*/ 6138SQLITE_EXTERN char *sqlite3_data_directory; 6139 6140/* 6141** CAPI3REF: Win32 Specific Interface 6142** 6143** These interfaces are available only on Windows. The 6144** [sqlite3_win32_set_directory] interface is used to set the value associated 6145** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6146** zValue, depending on the value of the type parameter. The zValue parameter 6147** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6148** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6149** prior to being used. The [sqlite3_win32_set_directory] interface returns 6150** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6151** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6152** [sqlite3_data_directory] variable is intended to act as a replacement for 6153** the current directory on the sub-platforms of Win32 where that concept is 6154** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6155** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6156** sqlite3_win32_set_directory interface except the string parameter must be 6157** UTF-8 or UTF-16, respectively. 6158*/ 6159int sqlite3_win32_set_directory( 6160 unsigned long type, /* Identifier for directory being set or reset */ 6161 void *zValue /* New value for directory being set or reset */ 6162); 6163int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6164int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6165 6166/* 6167** CAPI3REF: Win32 Directory Types 6168** 6169** These macros are only available on Windows. They define the allowed values 6170** for the type argument to the [sqlite3_win32_set_directory] interface. 6171*/ 6172#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6173#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6174 6175/* 6176** CAPI3REF: Test For Auto-Commit Mode 6177** KEYWORDS: {autocommit mode} 6178** METHOD: sqlite3 6179** 6180** ^The sqlite3_get_autocommit() interface returns non-zero or 6181** zero if the given database connection is or is not in autocommit mode, 6182** respectively. ^Autocommit mode is on by default. 6183** ^Autocommit mode is disabled by a [BEGIN] statement. 6184** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6185** 6186** If certain kinds of errors occur on a statement within a multi-statement 6187** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6188** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6189** transaction might be rolled back automatically. The only way to 6190** find out whether SQLite automatically rolled back the transaction after 6191** an error is to use this function. 6192** 6193** If another thread changes the autocommit status of the database 6194** connection while this routine is running, then the return value 6195** is undefined. 6196*/ 6197int sqlite3_get_autocommit(sqlite3*); 6198 6199/* 6200** CAPI3REF: Find The Database Handle Of A Prepared Statement 6201** METHOD: sqlite3_stmt 6202** 6203** ^The sqlite3_db_handle interface returns the [database connection] handle 6204** to which a [prepared statement] belongs. ^The [database connection] 6205** returned by sqlite3_db_handle is the same [database connection] 6206** that was the first argument 6207** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6208** create the statement in the first place. 6209*/ 6210sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6211 6212/* 6213** CAPI3REF: Return The Filename For A Database Connection 6214** METHOD: sqlite3 6215** 6216** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6217** associated with database N of connection D. 6218** ^If there is no attached database N on the database 6219** connection D, or if database N is a temporary or in-memory database, then 6220** this function will return either a NULL pointer or an empty string. 6221** 6222** ^The string value returned by this routine is owned and managed by 6223** the database connection. ^The value will be valid until the database N 6224** is [DETACH]-ed or until the database connection closes. 6225** 6226** ^The filename returned by this function is the output of the 6227** xFullPathname method of the [VFS]. ^In other words, the filename 6228** will be an absolute pathname, even if the filename used 6229** to open the database originally was a URI or relative pathname. 6230** 6231** If the filename pointer returned by this routine is not NULL, then it 6232** can be used as the filename input parameter to these routines: 6233** <ul> 6234** <li> [sqlite3_uri_parameter()] 6235** <li> [sqlite3_uri_boolean()] 6236** <li> [sqlite3_uri_int64()] 6237** <li> [sqlite3_filename_database()] 6238** <li> [sqlite3_filename_journal()] 6239** <li> [sqlite3_filename_wal()] 6240** </ul> 6241*/ 6242const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6243 6244/* 6245** CAPI3REF: Determine if a database is read-only 6246** METHOD: sqlite3 6247** 6248** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6249** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6250** the name of a database on connection D. 6251*/ 6252int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6253 6254/* 6255** CAPI3REF: Determine the transaction state of a database 6256** METHOD: sqlite3 6257** 6258** ^The sqlite3_txn_state(D,S) interface returns the current 6259** [transaction state] of schema S in database connection D. ^If S is NULL, 6260** then the highest transaction state of any schema on database connection D 6261** is returned. Transaction states are (in order of lowest to highest): 6262** <ol> 6263** <li value="0"> SQLITE_TXN_NONE 6264** <li value="1"> SQLITE_TXN_READ 6265** <li value="2"> SQLITE_TXN_WRITE 6266** </ol> 6267** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6268** a valid schema, then -1 is returned. 6269*/ 6270int sqlite3_txn_state(sqlite3*,const char *zSchema); 6271 6272/* 6273** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6274** KEYWORDS: {transaction state} 6275** 6276** These constants define the current transaction state of a database file. 6277** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6278** constants in order to describe the transaction state of schema S 6279** in [database connection] D. 6280** 6281** <dl> 6282** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6283** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6284** pending.</dd> 6285** 6286** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6287** <dd>The SQLITE_TXN_READ state means that the database is currently 6288** in a read transaction. Content has been read from the database file 6289** but nothing in the database file has changed. The transaction state 6290** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6291** no other conflicting concurrent write transactions. The transaction 6292** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6293** [COMMIT].</dd> 6294** 6295** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6296** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6297** in a write transaction. Content has been written to the database file 6298** but has not yet committed. The transaction state will change to 6299** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6300*/ 6301#define SQLITE_TXN_NONE 0 6302#define SQLITE_TXN_READ 1 6303#define SQLITE_TXN_WRITE 2 6304 6305/* 6306** CAPI3REF: Find the next prepared statement 6307** METHOD: sqlite3 6308** 6309** ^This interface returns a pointer to the next [prepared statement] after 6310** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6311** then this interface returns a pointer to the first prepared statement 6312** associated with the database connection pDb. ^If no prepared statement 6313** satisfies the conditions of this routine, it returns NULL. 6314** 6315** The [database connection] pointer D in a call to 6316** [sqlite3_next_stmt(D,S)] must refer to an open database 6317** connection and in particular must not be a NULL pointer. 6318*/ 6319sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6320 6321/* 6322** CAPI3REF: Commit And Rollback Notification Callbacks 6323** METHOD: sqlite3 6324** 6325** ^The sqlite3_commit_hook() interface registers a callback 6326** function to be invoked whenever a transaction is [COMMIT | committed]. 6327** ^Any callback set by a previous call to sqlite3_commit_hook() 6328** for the same database connection is overridden. 6329** ^The sqlite3_rollback_hook() interface registers a callback 6330** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6331** ^Any callback set by a previous call to sqlite3_rollback_hook() 6332** for the same database connection is overridden. 6333** ^The pArg argument is passed through to the callback. 6334** ^If the callback on a commit hook function returns non-zero, 6335** then the commit is converted into a rollback. 6336** 6337** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6338** return the P argument from the previous call of the same function 6339** on the same [database connection] D, or NULL for 6340** the first call for each function on D. 6341** 6342** The commit and rollback hook callbacks are not reentrant. 6343** The callback implementation must not do anything that will modify 6344** the database connection that invoked the callback. Any actions 6345** to modify the database connection must be deferred until after the 6346** completion of the [sqlite3_step()] call that triggered the commit 6347** or rollback hook in the first place. 6348** Note that running any other SQL statements, including SELECT statements, 6349** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6350** the database connections for the meaning of "modify" in this paragraph. 6351** 6352** ^Registering a NULL function disables the callback. 6353** 6354** ^When the commit hook callback routine returns zero, the [COMMIT] 6355** operation is allowed to continue normally. ^If the commit hook 6356** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6357** ^The rollback hook is invoked on a rollback that results from a commit 6358** hook returning non-zero, just as it would be with any other rollback. 6359** 6360** ^For the purposes of this API, a transaction is said to have been 6361** rolled back if an explicit "ROLLBACK" statement is executed, or 6362** an error or constraint causes an implicit rollback to occur. 6363** ^The rollback callback is not invoked if a transaction is 6364** automatically rolled back because the database connection is closed. 6365** 6366** See also the [sqlite3_update_hook()] interface. 6367*/ 6368void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6369void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6370 6371/* 6372** CAPI3REF: Data Change Notification Callbacks 6373** METHOD: sqlite3 6374** 6375** ^The sqlite3_update_hook() interface registers a callback function 6376** with the [database connection] identified by the first argument 6377** to be invoked whenever a row is updated, inserted or deleted in 6378** a [rowid table]. 6379** ^Any callback set by a previous call to this function 6380** for the same database connection is overridden. 6381** 6382** ^The second argument is a pointer to the function to invoke when a 6383** row is updated, inserted or deleted in a rowid table. 6384** ^The first argument to the callback is a copy of the third argument 6385** to sqlite3_update_hook(). 6386** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6387** or [SQLITE_UPDATE], depending on the operation that caused the callback 6388** to be invoked. 6389** ^The third and fourth arguments to the callback contain pointers to the 6390** database and table name containing the affected row. 6391** ^The final callback parameter is the [rowid] of the row. 6392** ^In the case of an update, this is the [rowid] after the update takes place. 6393** 6394** ^(The update hook is not invoked when internal system tables are 6395** modified (i.e. sqlite_sequence).)^ 6396** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6397** 6398** ^In the current implementation, the update hook 6399** is not invoked when conflicting rows are deleted because of an 6400** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6401** invoked when rows are deleted using the [truncate optimization]. 6402** The exceptions defined in this paragraph might change in a future 6403** release of SQLite. 6404** 6405** The update hook implementation must not do anything that will modify 6406** the database connection that invoked the update hook. Any actions 6407** to modify the database connection must be deferred until after the 6408** completion of the [sqlite3_step()] call that triggered the update hook. 6409** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6410** database connections for the meaning of "modify" in this paragraph. 6411** 6412** ^The sqlite3_update_hook(D,C,P) function 6413** returns the P argument from the previous call 6414** on the same [database connection] D, or NULL for 6415** the first call on D. 6416** 6417** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6418** and [sqlite3_preupdate_hook()] interfaces. 6419*/ 6420void *sqlite3_update_hook( 6421 sqlite3*, 6422 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6423 void* 6424); 6425 6426/* 6427** CAPI3REF: Enable Or Disable Shared Pager Cache 6428** 6429** ^(This routine enables or disables the sharing of the database cache 6430** and schema data structures between [database connection | connections] 6431** to the same database. Sharing is enabled if the argument is true 6432** and disabled if the argument is false.)^ 6433** 6434** ^Cache sharing is enabled and disabled for an entire process. 6435** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6436** In prior versions of SQLite, 6437** sharing was enabled or disabled for each thread separately. 6438** 6439** ^(The cache sharing mode set by this interface effects all subsequent 6440** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6441** Existing database connections continue to use the sharing mode 6442** that was in effect at the time they were opened.)^ 6443** 6444** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6445** successfully. An [error code] is returned otherwise.)^ 6446** 6447** ^Shared cache is disabled by default. It is recommended that it stay 6448** that way. In other words, do not use this routine. This interface 6449** continues to be provided for historical compatibility, but its use is 6450** discouraged. Any use of shared cache is discouraged. If shared cache 6451** must be used, it is recommended that shared cache only be enabled for 6452** individual database connections using the [sqlite3_open_v2()] interface 6453** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6454** 6455** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6456** and will always return SQLITE_MISUSE. On those systems, 6457** shared cache mode should be enabled per-database connection via 6458** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6459** 6460** This interface is threadsafe on processors where writing a 6461** 32-bit integer is atomic. 6462** 6463** See Also: [SQLite Shared-Cache Mode] 6464*/ 6465int sqlite3_enable_shared_cache(int); 6466 6467/* 6468** CAPI3REF: Attempt To Free Heap Memory 6469** 6470** ^The sqlite3_release_memory() interface attempts to free N bytes 6471** of heap memory by deallocating non-essential memory allocations 6472** held by the database library. Memory used to cache database 6473** pages to improve performance is an example of non-essential memory. 6474** ^sqlite3_release_memory() returns the number of bytes actually freed, 6475** which might be more or less than the amount requested. 6476** ^The sqlite3_release_memory() routine is a no-op returning zero 6477** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6478** 6479** See also: [sqlite3_db_release_memory()] 6480*/ 6481int sqlite3_release_memory(int); 6482 6483/* 6484** CAPI3REF: Free Memory Used By A Database Connection 6485** METHOD: sqlite3 6486** 6487** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6488** memory as possible from database connection D. Unlike the 6489** [sqlite3_release_memory()] interface, this interface is in effect even 6490** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6491** omitted. 6492** 6493** See also: [sqlite3_release_memory()] 6494*/ 6495int sqlite3_db_release_memory(sqlite3*); 6496 6497/* 6498** CAPI3REF: Impose A Limit On Heap Size 6499** 6500** These interfaces impose limits on the amount of heap memory that will be 6501** by all database connections within a single process. 6502** 6503** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6504** soft limit on the amount of heap memory that may be allocated by SQLite. 6505** ^SQLite strives to keep heap memory utilization below the soft heap 6506** limit by reducing the number of pages held in the page cache 6507** as heap memory usages approaches the limit. 6508** ^The soft heap limit is "soft" because even though SQLite strives to stay 6509** below the limit, it will exceed the limit rather than generate 6510** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6511** is advisory only. 6512** 6513** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6514** N bytes on the amount of memory that will be allocated. ^The 6515** sqlite3_hard_heap_limit64(N) interface is similar to 6516** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6517** when the hard heap limit is reached. 6518** 6519** ^The return value from both sqlite3_soft_heap_limit64() and 6520** sqlite3_hard_heap_limit64() is the size of 6521** the heap limit prior to the call, or negative in the case of an 6522** error. ^If the argument N is negative 6523** then no change is made to the heap limit. Hence, the current 6524** size of heap limits can be determined by invoking 6525** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6526** 6527** ^Setting the heap limits to zero disables the heap limiter mechanism. 6528** 6529** ^The soft heap limit may not be greater than the hard heap limit. 6530** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6531** is invoked with a value of N that is greater than the hard heap limit, 6532** the the soft heap limit is set to the value of the hard heap limit. 6533** ^The soft heap limit is automatically enabled whenever the hard heap 6534** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6535** the soft heap limit is outside the range of 1..N, then the soft heap 6536** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6537** hard heap limit is enabled makes the soft heap limit equal to the 6538** hard heap limit. 6539** 6540** The memory allocation limits can also be adjusted using 6541** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6542** 6543** ^(The heap limits are not enforced in the current implementation 6544** if one or more of following conditions are true: 6545** 6546** <ul> 6547** <li> The limit value is set to zero. 6548** <li> Memory accounting is disabled using a combination of the 6549** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6550** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6551** <li> An alternative page cache implementation is specified using 6552** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6553** <li> The page cache allocates from its own memory pool supplied 6554** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6555** from the heap. 6556** </ul>)^ 6557** 6558** The circumstances under which SQLite will enforce the heap limits may 6559** changes in future releases of SQLite. 6560*/ 6561sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6562sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6563 6564/* 6565** CAPI3REF: Deprecated Soft Heap Limit Interface 6566** DEPRECATED 6567** 6568** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6569** interface. This routine is provided for historical compatibility 6570** only. All new applications should use the 6571** [sqlite3_soft_heap_limit64()] interface rather than this one. 6572*/ 6573SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6574 6575 6576/* 6577** CAPI3REF: Extract Metadata About A Column Of A Table 6578** METHOD: sqlite3 6579** 6580** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6581** information about column C of table T in database D 6582** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6583** interface returns SQLITE_OK and fills in the non-NULL pointers in 6584** the final five arguments with appropriate values if the specified 6585** column exists. ^The sqlite3_table_column_metadata() interface returns 6586** SQLITE_ERROR if the specified column does not exist. 6587** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6588** NULL pointer, then this routine simply checks for the existence of the 6589** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6590** does not. If the table name parameter T in a call to 6591** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6592** undefined behavior. 6593** 6594** ^The column is identified by the second, third and fourth parameters to 6595** this function. ^(The second parameter is either the name of the database 6596** (i.e. "main", "temp", or an attached database) containing the specified 6597** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6598** for the table using the same algorithm used by the database engine to 6599** resolve unqualified table references. 6600** 6601** ^The third and fourth parameters to this function are the table and column 6602** name of the desired column, respectively. 6603** 6604** ^Metadata is returned by writing to the memory locations passed as the 5th 6605** and subsequent parameters to this function. ^Any of these arguments may be 6606** NULL, in which case the corresponding element of metadata is omitted. 6607** 6608** ^(<blockquote> 6609** <table border="1"> 6610** <tr><th> Parameter <th> Output<br>Type <th> Description 6611** 6612** <tr><td> 5th <td> const char* <td> Data type 6613** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6614** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6615** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6616** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6617** </table> 6618** </blockquote>)^ 6619** 6620** ^The memory pointed to by the character pointers returned for the 6621** declaration type and collation sequence is valid until the next 6622** call to any SQLite API function. 6623** 6624** ^If the specified table is actually a view, an [error code] is returned. 6625** 6626** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6627** is not a [WITHOUT ROWID] table and an 6628** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6629** parameters are set for the explicitly declared column. ^(If there is no 6630** [INTEGER PRIMARY KEY] column, then the outputs 6631** for the [rowid] are set as follows: 6632** 6633** <pre> 6634** data type: "INTEGER" 6635** collation sequence: "BINARY" 6636** not null: 0 6637** primary key: 1 6638** auto increment: 0 6639** </pre>)^ 6640** 6641** ^This function causes all database schemas to be read from disk and 6642** parsed, if that has not already been done, and returns an error if 6643** any errors are encountered while loading the schema. 6644*/ 6645int sqlite3_table_column_metadata( 6646 sqlite3 *db, /* Connection handle */ 6647 const char *zDbName, /* Database name or NULL */ 6648 const char *zTableName, /* Table name */ 6649 const char *zColumnName, /* Column name */ 6650 char const **pzDataType, /* OUTPUT: Declared data type */ 6651 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6652 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6653 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6654 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6655); 6656 6657/* 6658** CAPI3REF: Load An Extension 6659** METHOD: sqlite3 6660** 6661** ^This interface loads an SQLite extension library from the named file. 6662** 6663** ^The sqlite3_load_extension() interface attempts to load an 6664** [SQLite extension] library contained in the file zFile. If 6665** the file cannot be loaded directly, attempts are made to load 6666** with various operating-system specific extensions added. 6667** So for example, if "samplelib" cannot be loaded, then names like 6668** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6669** be tried also. 6670** 6671** ^The entry point is zProc. 6672** ^(zProc may be 0, in which case SQLite will try to come up with an 6673** entry point name on its own. It first tries "sqlite3_extension_init". 6674** If that does not work, it constructs a name "sqlite3_X_init" where the 6675** X is consists of the lower-case equivalent of all ASCII alphabetic 6676** characters in the filename from the last "/" to the first following 6677** "." and omitting any initial "lib".)^ 6678** ^The sqlite3_load_extension() interface returns 6679** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6680** ^If an error occurs and pzErrMsg is not 0, then the 6681** [sqlite3_load_extension()] interface shall attempt to 6682** fill *pzErrMsg with error message text stored in memory 6683** obtained from [sqlite3_malloc()]. The calling function 6684** should free this memory by calling [sqlite3_free()]. 6685** 6686** ^Extension loading must be enabled using 6687** [sqlite3_enable_load_extension()] or 6688** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6689** prior to calling this API, 6690** otherwise an error will be returned. 6691** 6692** <b>Security warning:</b> It is recommended that the 6693** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6694** interface. The use of the [sqlite3_enable_load_extension()] interface 6695** should be avoided. This will keep the SQL function [load_extension()] 6696** disabled and prevent SQL injections from giving attackers 6697** access to extension loading capabilities. 6698** 6699** See also the [load_extension() SQL function]. 6700*/ 6701int sqlite3_load_extension( 6702 sqlite3 *db, /* Load the extension into this database connection */ 6703 const char *zFile, /* Name of the shared library containing extension */ 6704 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6705 char **pzErrMsg /* Put error message here if not 0 */ 6706); 6707 6708/* 6709** CAPI3REF: Enable Or Disable Extension Loading 6710** METHOD: sqlite3 6711** 6712** ^So as not to open security holes in older applications that are 6713** unprepared to deal with [extension loading], and as a means of disabling 6714** [extension loading] while evaluating user-entered SQL, the following API 6715** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6716** 6717** ^Extension loading is off by default. 6718** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6719** to turn extension loading on and call it with onoff==0 to turn 6720** it back off again. 6721** 6722** ^This interface enables or disables both the C-API 6723** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6724** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6725** to enable or disable only the C-API.)^ 6726** 6727** <b>Security warning:</b> It is recommended that extension loading 6728** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6729** rather than this interface, so the [load_extension()] SQL function 6730** remains disabled. This will prevent SQL injections from giving attackers 6731** access to extension loading capabilities. 6732*/ 6733int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6734 6735/* 6736** CAPI3REF: Automatically Load Statically Linked Extensions 6737** 6738** ^This interface causes the xEntryPoint() function to be invoked for 6739** each new [database connection] that is created. The idea here is that 6740** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6741** that is to be automatically loaded into all new database connections. 6742** 6743** ^(Even though the function prototype shows that xEntryPoint() takes 6744** no arguments and returns void, SQLite invokes xEntryPoint() with three 6745** arguments and expects an integer result as if the signature of the 6746** entry point where as follows: 6747** 6748** <blockquote><pre> 6749** int xEntryPoint( 6750** sqlite3 *db, 6751** const char **pzErrMsg, 6752** const struct sqlite3_api_routines *pThunk 6753** ); 6754** </pre></blockquote>)^ 6755** 6756** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6757** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6758** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6759** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6760** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6761** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6762** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6763** 6764** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6765** on the list of automatic extensions is a harmless no-op. ^No entry point 6766** will be called more than once for each database connection that is opened. 6767** 6768** See also: [sqlite3_reset_auto_extension()] 6769** and [sqlite3_cancel_auto_extension()] 6770*/ 6771int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6772 6773/* 6774** CAPI3REF: Cancel Automatic Extension Loading 6775** 6776** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6777** initialization routine X that was registered using a prior call to 6778** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6779** routine returns 1 if initialization routine X was successfully 6780** unregistered and it returns 0 if X was not on the list of initialization 6781** routines. 6782*/ 6783int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6784 6785/* 6786** CAPI3REF: Reset Automatic Extension Loading 6787** 6788** ^This interface disables all automatic extensions previously 6789** registered using [sqlite3_auto_extension()]. 6790*/ 6791void sqlite3_reset_auto_extension(void); 6792 6793/* 6794** The interface to the virtual-table mechanism is currently considered 6795** to be experimental. The interface might change in incompatible ways. 6796** If this is a problem for you, do not use the interface at this time. 6797** 6798** When the virtual-table mechanism stabilizes, we will declare the 6799** interface fixed, support it indefinitely, and remove this comment. 6800*/ 6801 6802/* 6803** Structures used by the virtual table interface 6804*/ 6805typedef struct sqlite3_vtab sqlite3_vtab; 6806typedef struct sqlite3_index_info sqlite3_index_info; 6807typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6808typedef struct sqlite3_module sqlite3_module; 6809 6810/* 6811** CAPI3REF: Virtual Table Object 6812** KEYWORDS: sqlite3_module {virtual table module} 6813** 6814** This structure, sometimes called a "virtual table module", 6815** defines the implementation of a [virtual table]. 6816** This structure consists mostly of methods for the module. 6817** 6818** ^A virtual table module is created by filling in a persistent 6819** instance of this structure and passing a pointer to that instance 6820** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6821** ^The registration remains valid until it is replaced by a different 6822** module or until the [database connection] closes. The content 6823** of this structure must not change while it is registered with 6824** any database connection. 6825*/ 6826struct sqlite3_module { 6827 int iVersion; 6828 int (*xCreate)(sqlite3*, void *pAux, 6829 int argc, const char *const*argv, 6830 sqlite3_vtab **ppVTab, char**); 6831 int (*xConnect)(sqlite3*, void *pAux, 6832 int argc, const char *const*argv, 6833 sqlite3_vtab **ppVTab, char**); 6834 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6835 int (*xDisconnect)(sqlite3_vtab *pVTab); 6836 int (*xDestroy)(sqlite3_vtab *pVTab); 6837 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6838 int (*xClose)(sqlite3_vtab_cursor*); 6839 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6840 int argc, sqlite3_value **argv); 6841 int (*xNext)(sqlite3_vtab_cursor*); 6842 int (*xEof)(sqlite3_vtab_cursor*); 6843 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6844 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6845 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6846 int (*xBegin)(sqlite3_vtab *pVTab); 6847 int (*xSync)(sqlite3_vtab *pVTab); 6848 int (*xCommit)(sqlite3_vtab *pVTab); 6849 int (*xRollback)(sqlite3_vtab *pVTab); 6850 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6851 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6852 void **ppArg); 6853 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6854 /* The methods above are in version 1 of the sqlite_module object. Those 6855 ** below are for version 2 and greater. */ 6856 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6857 int (*xRelease)(sqlite3_vtab *pVTab, int); 6858 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6859 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6860 ** Those below are for version 3 and greater. */ 6861 int (*xShadowName)(const char*); 6862}; 6863 6864/* 6865** CAPI3REF: Virtual Table Indexing Information 6866** KEYWORDS: sqlite3_index_info 6867** 6868** The sqlite3_index_info structure and its substructures is used as part 6869** of the [virtual table] interface to 6870** pass information into and receive the reply from the [xBestIndex] 6871** method of a [virtual table module]. The fields under **Inputs** are the 6872** inputs to xBestIndex and are read-only. xBestIndex inserts its 6873** results into the **Outputs** fields. 6874** 6875** ^(The aConstraint[] array records WHERE clause constraints of the form: 6876** 6877** <blockquote>column OP expr</blockquote> 6878** 6879** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6880** stored in aConstraint[].op using one of the 6881** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6882** ^(The index of the column is stored in 6883** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6884** expr on the right-hand side can be evaluated (and thus the constraint 6885** is usable) and false if it cannot.)^ 6886** 6887** ^The optimizer automatically inverts terms of the form "expr OP column" 6888** and makes other simplifications to the WHERE clause in an attempt to 6889** get as many WHERE clause terms into the form shown above as possible. 6890** ^The aConstraint[] array only reports WHERE clause terms that are 6891** relevant to the particular virtual table being queried. 6892** 6893** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6894** ^Each term of aOrderBy records a column of the ORDER BY clause. 6895** 6896** The colUsed field indicates which columns of the virtual table may be 6897** required by the current scan. Virtual table columns are numbered from 6898** zero in the order in which they appear within the CREATE TABLE statement 6899** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6900** the corresponding bit is set within the colUsed mask if the column may be 6901** required by SQLite. If the table has at least 64 columns and any column 6902** to the right of the first 63 is required, then bit 63 of colUsed is also 6903** set. In other words, column iCol may be required if the expression 6904** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6905** non-zero. 6906** 6907** The [xBestIndex] method must fill aConstraintUsage[] with information 6908** about what parameters to pass to xFilter. ^If argvIndex>0 then 6909** the right-hand side of the corresponding aConstraint[] is evaluated 6910** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6911** is true, then the constraint is assumed to be fully handled by the 6912** virtual table and might not be checked again by the byte code.)^ ^(The 6913** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6914** is left in its default setting of false, the constraint will always be 6915** checked separately in byte code. If the omit flag is change to true, then 6916** the constraint may or may not be checked in byte code. In other words, 6917** when the omit flag is true there is no guarantee that the constraint will 6918** not be checked again using byte code.)^ 6919** 6920** ^The idxNum and idxPtr values are recorded and passed into the 6921** [xFilter] method. 6922** ^[sqlite3_free()] is used to free idxPtr if and only if 6923** needToFreeIdxPtr is true. 6924** 6925** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6926** the correct order to satisfy the ORDER BY clause so that no separate 6927** sorting step is required. 6928** 6929** ^The estimatedCost value is an estimate of the cost of a particular 6930** strategy. A cost of N indicates that the cost of the strategy is similar 6931** to a linear scan of an SQLite table with N rows. A cost of log(N) 6932** indicates that the expense of the operation is similar to that of a 6933** binary search on a unique indexed field of an SQLite table with N rows. 6934** 6935** ^The estimatedRows value is an estimate of the number of rows that 6936** will be returned by the strategy. 6937** 6938** The xBestIndex method may optionally populate the idxFlags field with a 6939** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6940** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6941** assumes that the strategy may visit at most one row. 6942** 6943** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6944** SQLite also assumes that if a call to the xUpdate() method is made as 6945** part of the same statement to delete or update a virtual table row and the 6946** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6947** any database changes. In other words, if the xUpdate() returns 6948** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6949** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6950** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6951** the xUpdate method are automatically rolled back by SQLite. 6952** 6953** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6954** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6955** If a virtual table extension is 6956** used with an SQLite version earlier than 3.8.2, the results of attempting 6957** to read or write the estimatedRows field are undefined (but are likely 6958** to include crashing the application). The estimatedRows field should 6959** therefore only be used if [sqlite3_libversion_number()] returns a 6960** value greater than or equal to 3008002. Similarly, the idxFlags field 6961** was added for [version 3.9.0] ([dateof:3.9.0]). 6962** It may therefore only be used if 6963** sqlite3_libversion_number() returns a value greater than or equal to 6964** 3009000. 6965*/ 6966struct sqlite3_index_info { 6967 /* Inputs */ 6968 int nConstraint; /* Number of entries in aConstraint */ 6969 struct sqlite3_index_constraint { 6970 int iColumn; /* Column constrained. -1 for ROWID */ 6971 unsigned char op; /* Constraint operator */ 6972 unsigned char usable; /* True if this constraint is usable */ 6973 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6974 } *aConstraint; /* Table of WHERE clause constraints */ 6975 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6976 struct sqlite3_index_orderby { 6977 int iColumn; /* Column number */ 6978 unsigned char desc; /* True for DESC. False for ASC. */ 6979 } *aOrderBy; /* The ORDER BY clause */ 6980 /* Outputs */ 6981 struct sqlite3_index_constraint_usage { 6982 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6983 unsigned char omit; /* Do not code a test for this constraint */ 6984 } *aConstraintUsage; 6985 int idxNum; /* Number used to identify the index */ 6986 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6987 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6988 int orderByConsumed; /* True if output is already ordered */ 6989 double estimatedCost; /* Estimated cost of using this index */ 6990 /* Fields below are only available in SQLite 3.8.2 and later */ 6991 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6992 /* Fields below are only available in SQLite 3.9.0 and later */ 6993 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6994 /* Fields below are only available in SQLite 3.10.0 and later */ 6995 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6996}; 6997 6998/* 6999** CAPI3REF: Virtual Table Scan Flags 7000** 7001** Virtual table implementations are allowed to set the 7002** [sqlite3_index_info].idxFlags field to some combination of 7003** these bits. 7004*/ 7005#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7006 7007/* 7008** CAPI3REF: Virtual Table Constraint Operator Codes 7009** 7010** These macros define the allowed values for the 7011** [sqlite3_index_info].aConstraint[].op field. Each value represents 7012** an operator that is part of a constraint term in the wHERE clause of 7013** a query that uses a [virtual table]. 7014*/ 7015#define SQLITE_INDEX_CONSTRAINT_EQ 2 7016#define SQLITE_INDEX_CONSTRAINT_GT 4 7017#define SQLITE_INDEX_CONSTRAINT_LE 8 7018#define SQLITE_INDEX_CONSTRAINT_LT 16 7019#define SQLITE_INDEX_CONSTRAINT_GE 32 7020#define SQLITE_INDEX_CONSTRAINT_MATCH 64 7021#define SQLITE_INDEX_CONSTRAINT_LIKE 65 7022#define SQLITE_INDEX_CONSTRAINT_GLOB 66 7023#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7024#define SQLITE_INDEX_CONSTRAINT_NE 68 7025#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7026#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7027#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7028#define SQLITE_INDEX_CONSTRAINT_IS 72 7029#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7030 7031/* 7032** CAPI3REF: Register A Virtual Table Implementation 7033** METHOD: sqlite3 7034** 7035** ^These routines are used to register a new [virtual table module] name. 7036** ^Module names must be registered before 7037** creating a new [virtual table] using the module and before using a 7038** preexisting [virtual table] for the module. 7039** 7040** ^The module name is registered on the [database connection] specified 7041** by the first parameter. ^The name of the module is given by the 7042** second parameter. ^The third parameter is a pointer to 7043** the implementation of the [virtual table module]. ^The fourth 7044** parameter is an arbitrary client data pointer that is passed through 7045** into the [xCreate] and [xConnect] methods of the virtual table module 7046** when a new virtual table is be being created or reinitialized. 7047** 7048** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7049** is a pointer to a destructor for the pClientData. ^SQLite will 7050** invoke the destructor function (if it is not NULL) when SQLite 7051** no longer needs the pClientData pointer. ^The destructor will also 7052** be invoked if the call to sqlite3_create_module_v2() fails. 7053** ^The sqlite3_create_module() 7054** interface is equivalent to sqlite3_create_module_v2() with a NULL 7055** destructor. 7056** 7057** ^If the third parameter (the pointer to the sqlite3_module object) is 7058** NULL then no new module is create and any existing modules with the 7059** same name are dropped. 7060** 7061** See also: [sqlite3_drop_modules()] 7062*/ 7063int sqlite3_create_module( 7064 sqlite3 *db, /* SQLite connection to register module with */ 7065 const char *zName, /* Name of the module */ 7066 const sqlite3_module *p, /* Methods for the module */ 7067 void *pClientData /* Client data for xCreate/xConnect */ 7068); 7069int sqlite3_create_module_v2( 7070 sqlite3 *db, /* SQLite connection to register module with */ 7071 const char *zName, /* Name of the module */ 7072 const sqlite3_module *p, /* Methods for the module */ 7073 void *pClientData, /* Client data for xCreate/xConnect */ 7074 void(*xDestroy)(void*) /* Module destructor function */ 7075); 7076 7077/* 7078** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7079** METHOD: sqlite3 7080** 7081** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7082** table modules from database connection D except those named on list L. 7083** The L parameter must be either NULL or a pointer to an array of pointers 7084** to strings where the array is terminated by a single NULL pointer. 7085** ^If the L parameter is NULL, then all virtual table modules are removed. 7086** 7087** See also: [sqlite3_create_module()] 7088*/ 7089int sqlite3_drop_modules( 7090 sqlite3 *db, /* Remove modules from this connection */ 7091 const char **azKeep /* Except, do not remove the ones named here */ 7092); 7093 7094/* 7095** CAPI3REF: Virtual Table Instance Object 7096** KEYWORDS: sqlite3_vtab 7097** 7098** Every [virtual table module] implementation uses a subclass 7099** of this object to describe a particular instance 7100** of the [virtual table]. Each subclass will 7101** be tailored to the specific needs of the module implementation. 7102** The purpose of this superclass is to define certain fields that are 7103** common to all module implementations. 7104** 7105** ^Virtual tables methods can set an error message by assigning a 7106** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7107** take care that any prior string is freed by a call to [sqlite3_free()] 7108** prior to assigning a new string to zErrMsg. ^After the error message 7109** is delivered up to the client application, the string will be automatically 7110** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7111*/ 7112struct sqlite3_vtab { 7113 const sqlite3_module *pModule; /* The module for this virtual table */ 7114 int nRef; /* Number of open cursors */ 7115 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7116 /* Virtual table implementations will typically add additional fields */ 7117}; 7118 7119/* 7120** CAPI3REF: Virtual Table Cursor Object 7121** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7122** 7123** Every [virtual table module] implementation uses a subclass of the 7124** following structure to describe cursors that point into the 7125** [virtual table] and are used 7126** to loop through the virtual table. Cursors are created using the 7127** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7128** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7129** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7130** of the module. Each module implementation will define 7131** the content of a cursor structure to suit its own needs. 7132** 7133** This superclass exists in order to define fields of the cursor that 7134** are common to all implementations. 7135*/ 7136struct sqlite3_vtab_cursor { 7137 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7138 /* Virtual table implementations will typically add additional fields */ 7139}; 7140 7141/* 7142** CAPI3REF: Declare The Schema Of A Virtual Table 7143** 7144** ^The [xCreate] and [xConnect] methods of a 7145** [virtual table module] call this interface 7146** to declare the format (the names and datatypes of the columns) of 7147** the virtual tables they implement. 7148*/ 7149int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7150 7151/* 7152** CAPI3REF: Overload A Function For A Virtual Table 7153** METHOD: sqlite3 7154** 7155** ^(Virtual tables can provide alternative implementations of functions 7156** using the [xFindFunction] method of the [virtual table module]. 7157** But global versions of those functions 7158** must exist in order to be overloaded.)^ 7159** 7160** ^(This API makes sure a global version of a function with a particular 7161** name and number of parameters exists. If no such function exists 7162** before this API is called, a new function is created.)^ ^The implementation 7163** of the new function always causes an exception to be thrown. So 7164** the new function is not good for anything by itself. Its only 7165** purpose is to be a placeholder function that can be overloaded 7166** by a [virtual table]. 7167*/ 7168int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7169 7170/* 7171** The interface to the virtual-table mechanism defined above (back up 7172** to a comment remarkably similar to this one) is currently considered 7173** to be experimental. The interface might change in incompatible ways. 7174** If this is a problem for you, do not use the interface at this time. 7175** 7176** When the virtual-table mechanism stabilizes, we will declare the 7177** interface fixed, support it indefinitely, and remove this comment. 7178*/ 7179 7180/* 7181** CAPI3REF: A Handle To An Open BLOB 7182** KEYWORDS: {BLOB handle} {BLOB handles} 7183** 7184** An instance of this object represents an open BLOB on which 7185** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7186** ^Objects of this type are created by [sqlite3_blob_open()] 7187** and destroyed by [sqlite3_blob_close()]. 7188** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7189** can be used to read or write small subsections of the BLOB. 7190** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7191*/ 7192typedef struct sqlite3_blob sqlite3_blob; 7193 7194/* 7195** CAPI3REF: Open A BLOB For Incremental I/O 7196** METHOD: sqlite3 7197** CONSTRUCTOR: sqlite3_blob 7198** 7199** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7200** in row iRow, column zColumn, table zTable in database zDb; 7201** in other words, the same BLOB that would be selected by: 7202** 7203** <pre> 7204** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7205** </pre>)^ 7206** 7207** ^(Parameter zDb is not the filename that contains the database, but 7208** rather the symbolic name of the database. For attached databases, this is 7209** the name that appears after the AS keyword in the [ATTACH] statement. 7210** For the main database file, the database name is "main". For TEMP 7211** tables, the database name is "temp".)^ 7212** 7213** ^If the flags parameter is non-zero, then the BLOB is opened for read 7214** and write access. ^If the flags parameter is zero, the BLOB is opened for 7215** read-only access. 7216** 7217** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7218** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7219** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7220** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7221** on *ppBlob after this function it returns. 7222** 7223** This function fails with SQLITE_ERROR if any of the following are true: 7224** <ul> 7225** <li> ^(Database zDb does not exist)^, 7226** <li> ^(Table zTable does not exist within database zDb)^, 7227** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7228** <li> ^(Column zColumn does not exist)^, 7229** <li> ^(Row iRow is not present in the table)^, 7230** <li> ^(The specified column of row iRow contains a value that is not 7231** a TEXT or BLOB value)^, 7232** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7233** constraint and the blob is being opened for read/write access)^, 7234** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7235** column zColumn is part of a [child key] definition and the blob is 7236** being opened for read/write access)^. 7237** </ul> 7238** 7239** ^Unless it returns SQLITE_MISUSE, this function sets the 7240** [database connection] error code and message accessible via 7241** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7242** 7243** A BLOB referenced by sqlite3_blob_open() may be read using the 7244** [sqlite3_blob_read()] interface and modified by using 7245** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7246** different row of the same table using the [sqlite3_blob_reopen()] 7247** interface. However, the column, table, or database of a [BLOB handle] 7248** cannot be changed after the [BLOB handle] is opened. 7249** 7250** ^(If the row that a BLOB handle points to is modified by an 7251** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7252** then the BLOB handle is marked as "expired". 7253** This is true if any column of the row is changed, even a column 7254** other than the one the BLOB handle is open on.)^ 7255** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7256** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7257** ^(Changes written into a BLOB prior to the BLOB expiring are not 7258** rolled back by the expiration of the BLOB. Such changes will eventually 7259** commit if the transaction continues to completion.)^ 7260** 7261** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7262** the opened blob. ^The size of a blob may not be changed by this 7263** interface. Use the [UPDATE] SQL command to change the size of a 7264** blob. 7265** 7266** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7267** and the built-in [zeroblob] SQL function may be used to create a 7268** zero-filled blob to read or write using the incremental-blob interface. 7269** 7270** To avoid a resource leak, every open [BLOB handle] should eventually 7271** be released by a call to [sqlite3_blob_close()]. 7272** 7273** See also: [sqlite3_blob_close()], 7274** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7275** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7276*/ 7277int sqlite3_blob_open( 7278 sqlite3*, 7279 const char *zDb, 7280 const char *zTable, 7281 const char *zColumn, 7282 sqlite3_int64 iRow, 7283 int flags, 7284 sqlite3_blob **ppBlob 7285); 7286 7287/* 7288** CAPI3REF: Move a BLOB Handle to a New Row 7289** METHOD: sqlite3_blob 7290** 7291** ^This function is used to move an existing [BLOB handle] so that it points 7292** to a different row of the same database table. ^The new row is identified 7293** by the rowid value passed as the second argument. Only the row can be 7294** changed. ^The database, table and column on which the blob handle is open 7295** remain the same. Moving an existing [BLOB handle] to a new row is 7296** faster than closing the existing handle and opening a new one. 7297** 7298** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7299** it must exist and there must be either a blob or text value stored in 7300** the nominated column.)^ ^If the new row is not present in the table, or if 7301** it does not contain a blob or text value, or if another error occurs, an 7302** SQLite error code is returned and the blob handle is considered aborted. 7303** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7304** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7305** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7306** always returns zero. 7307** 7308** ^This function sets the database handle error code and message. 7309*/ 7310int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7311 7312/* 7313** CAPI3REF: Close A BLOB Handle 7314** DESTRUCTOR: sqlite3_blob 7315** 7316** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7317** unconditionally. Even if this routine returns an error code, the 7318** handle is still closed.)^ 7319** 7320** ^If the blob handle being closed was opened for read-write access, and if 7321** the database is in auto-commit mode and there are no other open read-write 7322** blob handles or active write statements, the current transaction is 7323** committed. ^If an error occurs while committing the transaction, an error 7324** code is returned and the transaction rolled back. 7325** 7326** Calling this function with an argument that is not a NULL pointer or an 7327** open blob handle results in undefined behaviour. ^Calling this routine 7328** with a null pointer (such as would be returned by a failed call to 7329** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7330** is passed a valid open blob handle, the values returned by the 7331** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7332*/ 7333int sqlite3_blob_close(sqlite3_blob *); 7334 7335/* 7336** CAPI3REF: Return The Size Of An Open BLOB 7337** METHOD: sqlite3_blob 7338** 7339** ^Returns the size in bytes of the BLOB accessible via the 7340** successfully opened [BLOB handle] in its only argument. ^The 7341** incremental blob I/O routines can only read or overwriting existing 7342** blob content; they cannot change the size of a blob. 7343** 7344** This routine only works on a [BLOB handle] which has been created 7345** by a prior successful call to [sqlite3_blob_open()] and which has not 7346** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7347** to this routine results in undefined and probably undesirable behavior. 7348*/ 7349int sqlite3_blob_bytes(sqlite3_blob *); 7350 7351/* 7352** CAPI3REF: Read Data From A BLOB Incrementally 7353** METHOD: sqlite3_blob 7354** 7355** ^(This function is used to read data from an open [BLOB handle] into a 7356** caller-supplied buffer. N bytes of data are copied into buffer Z 7357** from the open BLOB, starting at offset iOffset.)^ 7358** 7359** ^If offset iOffset is less than N bytes from the end of the BLOB, 7360** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7361** less than zero, [SQLITE_ERROR] is returned and no data is read. 7362** ^The size of the blob (and hence the maximum value of N+iOffset) 7363** can be determined using the [sqlite3_blob_bytes()] interface. 7364** 7365** ^An attempt to read from an expired [BLOB handle] fails with an 7366** error code of [SQLITE_ABORT]. 7367** 7368** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7369** Otherwise, an [error code] or an [extended error code] is returned.)^ 7370** 7371** This routine only works on a [BLOB handle] which has been created 7372** by a prior successful call to [sqlite3_blob_open()] and which has not 7373** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7374** to this routine results in undefined and probably undesirable behavior. 7375** 7376** See also: [sqlite3_blob_write()]. 7377*/ 7378int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7379 7380/* 7381** CAPI3REF: Write Data Into A BLOB Incrementally 7382** METHOD: sqlite3_blob 7383** 7384** ^(This function is used to write data into an open [BLOB handle] from a 7385** caller-supplied buffer. N bytes of data are copied from the buffer Z 7386** into the open BLOB, starting at offset iOffset.)^ 7387** 7388** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7389** Otherwise, an [error code] or an [extended error code] is returned.)^ 7390** ^Unless SQLITE_MISUSE is returned, this function sets the 7391** [database connection] error code and message accessible via 7392** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7393** 7394** ^If the [BLOB handle] passed as the first argument was not opened for 7395** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7396** this function returns [SQLITE_READONLY]. 7397** 7398** This function may only modify the contents of the BLOB; it is 7399** not possible to increase the size of a BLOB using this API. 7400** ^If offset iOffset is less than N bytes from the end of the BLOB, 7401** [SQLITE_ERROR] is returned and no data is written. The size of the 7402** BLOB (and hence the maximum value of N+iOffset) can be determined 7403** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7404** than zero [SQLITE_ERROR] is returned and no data is written. 7405** 7406** ^An attempt to write to an expired [BLOB handle] fails with an 7407** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7408** before the [BLOB handle] expired are not rolled back by the 7409** expiration of the handle, though of course those changes might 7410** have been overwritten by the statement that expired the BLOB handle 7411** or by other independent statements. 7412** 7413** This routine only works on a [BLOB handle] which has been created 7414** by a prior successful call to [sqlite3_blob_open()] and which has not 7415** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7416** to this routine results in undefined and probably undesirable behavior. 7417** 7418** See also: [sqlite3_blob_read()]. 7419*/ 7420int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7421 7422/* 7423** CAPI3REF: Virtual File System Objects 7424** 7425** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7426** that SQLite uses to interact 7427** with the underlying operating system. Most SQLite builds come with a 7428** single default VFS that is appropriate for the host computer. 7429** New VFSes can be registered and existing VFSes can be unregistered. 7430** The following interfaces are provided. 7431** 7432** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7433** ^Names are case sensitive. 7434** ^Names are zero-terminated UTF-8 strings. 7435** ^If there is no match, a NULL pointer is returned. 7436** ^If zVfsName is NULL then the default VFS is returned. 7437** 7438** ^New VFSes are registered with sqlite3_vfs_register(). 7439** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7440** ^The same VFS can be registered multiple times without injury. 7441** ^To make an existing VFS into the default VFS, register it again 7442** with the makeDflt flag set. If two different VFSes with the 7443** same name are registered, the behavior is undefined. If a 7444** VFS is registered with a name that is NULL or an empty string, 7445** then the behavior is undefined. 7446** 7447** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7448** ^(If the default VFS is unregistered, another VFS is chosen as 7449** the default. The choice for the new VFS is arbitrary.)^ 7450*/ 7451sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7452int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7453int sqlite3_vfs_unregister(sqlite3_vfs*); 7454 7455/* 7456** CAPI3REF: Mutexes 7457** 7458** The SQLite core uses these routines for thread 7459** synchronization. Though they are intended for internal 7460** use by SQLite, code that links against SQLite is 7461** permitted to use any of these routines. 7462** 7463** The SQLite source code contains multiple implementations 7464** of these mutex routines. An appropriate implementation 7465** is selected automatically at compile-time. The following 7466** implementations are available in the SQLite core: 7467** 7468** <ul> 7469** <li> SQLITE_MUTEX_PTHREADS 7470** <li> SQLITE_MUTEX_W32 7471** <li> SQLITE_MUTEX_NOOP 7472** </ul> 7473** 7474** The SQLITE_MUTEX_NOOP implementation is a set of routines 7475** that does no real locking and is appropriate for use in 7476** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7477** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7478** and Windows. 7479** 7480** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7481** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7482** implementation is included with the library. In this case the 7483** application must supply a custom mutex implementation using the 7484** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7485** before calling sqlite3_initialize() or any other public sqlite3_ 7486** function that calls sqlite3_initialize(). 7487** 7488** ^The sqlite3_mutex_alloc() routine allocates a new 7489** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7490** routine returns NULL if it is unable to allocate the requested 7491** mutex. The argument to sqlite3_mutex_alloc() must one of these 7492** integer constants: 7493** 7494** <ul> 7495** <li> SQLITE_MUTEX_FAST 7496** <li> SQLITE_MUTEX_RECURSIVE 7497** <li> SQLITE_MUTEX_STATIC_MAIN 7498** <li> SQLITE_MUTEX_STATIC_MEM 7499** <li> SQLITE_MUTEX_STATIC_OPEN 7500** <li> SQLITE_MUTEX_STATIC_PRNG 7501** <li> SQLITE_MUTEX_STATIC_LRU 7502** <li> SQLITE_MUTEX_STATIC_PMEM 7503** <li> SQLITE_MUTEX_STATIC_APP1 7504** <li> SQLITE_MUTEX_STATIC_APP2 7505** <li> SQLITE_MUTEX_STATIC_APP3 7506** <li> SQLITE_MUTEX_STATIC_VFS1 7507** <li> SQLITE_MUTEX_STATIC_VFS2 7508** <li> SQLITE_MUTEX_STATIC_VFS3 7509** </ul> 7510** 7511** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7512** cause sqlite3_mutex_alloc() to create 7513** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7514** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7515** The mutex implementation does not need to make a distinction 7516** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7517** not want to. SQLite will only request a recursive mutex in 7518** cases where it really needs one. If a faster non-recursive mutex 7519** implementation is available on the host platform, the mutex subsystem 7520** might return such a mutex in response to SQLITE_MUTEX_FAST. 7521** 7522** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7523** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7524** a pointer to a static preexisting mutex. ^Nine static mutexes are 7525** used by the current version of SQLite. Future versions of SQLite 7526** may add additional static mutexes. Static mutexes are for internal 7527** use by SQLite only. Applications that use SQLite mutexes should 7528** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7529** SQLITE_MUTEX_RECURSIVE. 7530** 7531** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7532** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7533** returns a different mutex on every call. ^For the static 7534** mutex types, the same mutex is returned on every call that has 7535** the same type number. 7536** 7537** ^The sqlite3_mutex_free() routine deallocates a previously 7538** allocated dynamic mutex. Attempting to deallocate a static 7539** mutex results in undefined behavior. 7540** 7541** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7542** to enter a mutex. ^If another thread is already within the mutex, 7543** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7544** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7545** upon successful entry. ^(Mutexes created using 7546** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7547** In such cases, the 7548** mutex must be exited an equal number of times before another thread 7549** can enter.)^ If the same thread tries to enter any mutex other 7550** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7551** 7552** ^(Some systems (for example, Windows 95) do not support the operation 7553** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7554** will always return SQLITE_BUSY. The SQLite core only ever uses 7555** sqlite3_mutex_try() as an optimization so this is acceptable 7556** behavior.)^ 7557** 7558** ^The sqlite3_mutex_leave() routine exits a mutex that was 7559** previously entered by the same thread. The behavior 7560** is undefined if the mutex is not currently entered by the 7561** calling thread or is not currently allocated. 7562** 7563** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7564** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7565** behave as no-ops. 7566** 7567** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7568*/ 7569sqlite3_mutex *sqlite3_mutex_alloc(int); 7570void sqlite3_mutex_free(sqlite3_mutex*); 7571void sqlite3_mutex_enter(sqlite3_mutex*); 7572int sqlite3_mutex_try(sqlite3_mutex*); 7573void sqlite3_mutex_leave(sqlite3_mutex*); 7574 7575/* 7576** CAPI3REF: Mutex Methods Object 7577** 7578** An instance of this structure defines the low-level routines 7579** used to allocate and use mutexes. 7580** 7581** Usually, the default mutex implementations provided by SQLite are 7582** sufficient, however the application has the option of substituting a custom 7583** implementation for specialized deployments or systems for which SQLite 7584** does not provide a suitable implementation. In this case, the application 7585** creates and populates an instance of this structure to pass 7586** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7587** Additionally, an instance of this structure can be used as an 7588** output variable when querying the system for the current mutex 7589** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7590** 7591** ^The xMutexInit method defined by this structure is invoked as 7592** part of system initialization by the sqlite3_initialize() function. 7593** ^The xMutexInit routine is called by SQLite exactly once for each 7594** effective call to [sqlite3_initialize()]. 7595** 7596** ^The xMutexEnd method defined by this structure is invoked as 7597** part of system shutdown by the sqlite3_shutdown() function. The 7598** implementation of this method is expected to release all outstanding 7599** resources obtained by the mutex methods implementation, especially 7600** those obtained by the xMutexInit method. ^The xMutexEnd() 7601** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7602** 7603** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7604** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7605** xMutexNotheld) implement the following interfaces (respectively): 7606** 7607** <ul> 7608** <li> [sqlite3_mutex_alloc()] </li> 7609** <li> [sqlite3_mutex_free()] </li> 7610** <li> [sqlite3_mutex_enter()] </li> 7611** <li> [sqlite3_mutex_try()] </li> 7612** <li> [sqlite3_mutex_leave()] </li> 7613** <li> [sqlite3_mutex_held()] </li> 7614** <li> [sqlite3_mutex_notheld()] </li> 7615** </ul>)^ 7616** 7617** The only difference is that the public sqlite3_XXX functions enumerated 7618** above silently ignore any invocations that pass a NULL pointer instead 7619** of a valid mutex handle. The implementations of the methods defined 7620** by this structure are not required to handle this case. The results 7621** of passing a NULL pointer instead of a valid mutex handle are undefined 7622** (i.e. it is acceptable to provide an implementation that segfaults if 7623** it is passed a NULL pointer). 7624** 7625** The xMutexInit() method must be threadsafe. It must be harmless to 7626** invoke xMutexInit() multiple times within the same process and without 7627** intervening calls to xMutexEnd(). Second and subsequent calls to 7628** xMutexInit() must be no-ops. 7629** 7630** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7631** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7632** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7633** memory allocation for a fast or recursive mutex. 7634** 7635** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7636** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7637** If xMutexInit fails in any way, it is expected to clean up after itself 7638** prior to returning. 7639*/ 7640typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7641struct sqlite3_mutex_methods { 7642 int (*xMutexInit)(void); 7643 int (*xMutexEnd)(void); 7644 sqlite3_mutex *(*xMutexAlloc)(int); 7645 void (*xMutexFree)(sqlite3_mutex *); 7646 void (*xMutexEnter)(sqlite3_mutex *); 7647 int (*xMutexTry)(sqlite3_mutex *); 7648 void (*xMutexLeave)(sqlite3_mutex *); 7649 int (*xMutexHeld)(sqlite3_mutex *); 7650 int (*xMutexNotheld)(sqlite3_mutex *); 7651}; 7652 7653/* 7654** CAPI3REF: Mutex Verification Routines 7655** 7656** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7657** are intended for use inside assert() statements. The SQLite core 7658** never uses these routines except inside an assert() and applications 7659** are advised to follow the lead of the core. The SQLite core only 7660** provides implementations for these routines when it is compiled 7661** with the SQLITE_DEBUG flag. External mutex implementations 7662** are only required to provide these routines if SQLITE_DEBUG is 7663** defined and if NDEBUG is not defined. 7664** 7665** These routines should return true if the mutex in their argument 7666** is held or not held, respectively, by the calling thread. 7667** 7668** The implementation is not required to provide versions of these 7669** routines that actually work. If the implementation does not provide working 7670** versions of these routines, it should at least provide stubs that always 7671** return true so that one does not get spurious assertion failures. 7672** 7673** If the argument to sqlite3_mutex_held() is a NULL pointer then 7674** the routine should return 1. This seems counter-intuitive since 7675** clearly the mutex cannot be held if it does not exist. But 7676** the reason the mutex does not exist is because the build is not 7677** using mutexes. And we do not want the assert() containing the 7678** call to sqlite3_mutex_held() to fail, so a non-zero return is 7679** the appropriate thing to do. The sqlite3_mutex_notheld() 7680** interface should also return 1 when given a NULL pointer. 7681*/ 7682#ifndef NDEBUG 7683int sqlite3_mutex_held(sqlite3_mutex*); 7684int sqlite3_mutex_notheld(sqlite3_mutex*); 7685#endif 7686 7687/* 7688** CAPI3REF: Mutex Types 7689** 7690** The [sqlite3_mutex_alloc()] interface takes a single argument 7691** which is one of these integer constants. 7692** 7693** The set of static mutexes may change from one SQLite release to the 7694** next. Applications that override the built-in mutex logic must be 7695** prepared to accommodate additional static mutexes. 7696*/ 7697#define SQLITE_MUTEX_FAST 0 7698#define SQLITE_MUTEX_RECURSIVE 1 7699#define SQLITE_MUTEX_STATIC_MAIN 2 7700#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7701#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7702#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7703#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7704#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7705#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7706#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7707#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7708#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7709#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7710#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7711#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7712#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7713 7714/* Legacy compatibility: */ 7715#define SQLITE_MUTEX_STATIC_MASTER 2 7716 7717 7718/* 7719** CAPI3REF: Retrieve the mutex for a database connection 7720** METHOD: sqlite3 7721** 7722** ^This interface returns a pointer the [sqlite3_mutex] object that 7723** serializes access to the [database connection] given in the argument 7724** when the [threading mode] is Serialized. 7725** ^If the [threading mode] is Single-thread or Multi-thread then this 7726** routine returns a NULL pointer. 7727*/ 7728sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7729 7730/* 7731** CAPI3REF: Low-Level Control Of Database Files 7732** METHOD: sqlite3 7733** KEYWORDS: {file control} 7734** 7735** ^The [sqlite3_file_control()] interface makes a direct call to the 7736** xFileControl method for the [sqlite3_io_methods] object associated 7737** with a particular database identified by the second argument. ^The 7738** name of the database is "main" for the main database or "temp" for the 7739** TEMP database, or the name that appears after the AS keyword for 7740** databases that are added using the [ATTACH] SQL command. 7741** ^A NULL pointer can be used in place of "main" to refer to the 7742** main database file. 7743** ^The third and fourth parameters to this routine 7744** are passed directly through to the second and third parameters of 7745** the xFileControl method. ^The return value of the xFileControl 7746** method becomes the return value of this routine. 7747** 7748** A few opcodes for [sqlite3_file_control()] are handled directly 7749** by the SQLite core and never invoke the 7750** sqlite3_io_methods.xFileControl method. 7751** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7752** a pointer to the underlying [sqlite3_file] object to be written into 7753** the space pointed to by the 4th parameter. The 7754** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7755** the [sqlite3_file] object associated with the journal file instead of 7756** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7757** a pointer to the underlying [sqlite3_vfs] object for the file. 7758** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7759** from the pager. 7760** 7761** ^If the second parameter (zDbName) does not match the name of any 7762** open database file, then SQLITE_ERROR is returned. ^This error 7763** code is not remembered and will not be recalled by [sqlite3_errcode()] 7764** or [sqlite3_errmsg()]. The underlying xFileControl method might 7765** also return SQLITE_ERROR. There is no way to distinguish between 7766** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7767** xFileControl method. 7768** 7769** See also: [file control opcodes] 7770*/ 7771int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7772 7773/* 7774** CAPI3REF: Testing Interface 7775** 7776** ^The sqlite3_test_control() interface is used to read out internal 7777** state of SQLite and to inject faults into SQLite for testing 7778** purposes. ^The first parameter is an operation code that determines 7779** the number, meaning, and operation of all subsequent parameters. 7780** 7781** This interface is not for use by applications. It exists solely 7782** for verifying the correct operation of the SQLite library. Depending 7783** on how the SQLite library is compiled, this interface might not exist. 7784** 7785** The details of the operation codes, their meanings, the parameters 7786** they take, and what they do are all subject to change without notice. 7787** Unlike most of the SQLite API, this function is not guaranteed to 7788** operate consistently from one release to the next. 7789*/ 7790int sqlite3_test_control(int op, ...); 7791 7792/* 7793** CAPI3REF: Testing Interface Operation Codes 7794** 7795** These constants are the valid operation code parameters used 7796** as the first argument to [sqlite3_test_control()]. 7797** 7798** These parameters and their meanings are subject to change 7799** without notice. These values are for testing purposes only. 7800** Applications should not use any of these parameters or the 7801** [sqlite3_test_control()] interface. 7802*/ 7803#define SQLITE_TESTCTRL_FIRST 5 7804#define SQLITE_TESTCTRL_PRNG_SAVE 5 7805#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7806#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7807#define SQLITE_TESTCTRL_BITVEC_TEST 8 7808#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7809#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7810#define SQLITE_TESTCTRL_PENDING_BYTE 11 7811#define SQLITE_TESTCTRL_ASSERT 12 7812#define SQLITE_TESTCTRL_ALWAYS 13 7813#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 7814#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7815#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7816#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7817#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7818#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7819#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7820#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7821#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7822#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7823#define SQLITE_TESTCTRL_BYTEORDER 22 7824#define SQLITE_TESTCTRL_ISINIT 23 7825#define SQLITE_TESTCTRL_SORTER_MMAP 24 7826#define SQLITE_TESTCTRL_IMPOSTER 25 7827#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7828#define SQLITE_TESTCTRL_RESULT_INTREAL 27 7829#define SQLITE_TESTCTRL_PRNG_SEED 28 7830#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7831#define SQLITE_TESTCTRL_SEEK_COUNT 30 7832#define SQLITE_TESTCTRL_TRACEFLAGS 31 7833#define SQLITE_TESTCTRL_TUNE 32 7834#define SQLITE_TESTCTRL_LAST 32 /* Largest TESTCTRL */ 7835 7836/* 7837** CAPI3REF: SQL Keyword Checking 7838** 7839** These routines provide access to the set of SQL language keywords 7840** recognized by SQLite. Applications can uses these routines to determine 7841** whether or not a specific identifier needs to be escaped (for example, 7842** by enclosing in double-quotes) so as not to confuse the parser. 7843** 7844** The sqlite3_keyword_count() interface returns the number of distinct 7845** keywords understood by SQLite. 7846** 7847** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7848** makes *Z point to that keyword expressed as UTF8 and writes the number 7849** of bytes in the keyword into *L. The string that *Z points to is not 7850** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7851** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7852** or L are NULL or invalid pointers then calls to 7853** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7854** 7855** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7856** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7857** if it is and zero if not. 7858** 7859** The parser used by SQLite is forgiving. It is often possible to use 7860** a keyword as an identifier as long as such use does not result in a 7861** parsing ambiguity. For example, the statement 7862** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7863** creates a new table named "BEGIN" with three columns named 7864** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7865** using keywords as identifiers. Common techniques used to avoid keyword 7866** name collisions include: 7867** <ul> 7868** <li> Put all identifier names inside double-quotes. This is the official 7869** SQL way to escape identifier names. 7870** <li> Put identifier names inside [...]. This is not standard SQL, 7871** but it is what SQL Server does and so lots of programmers use this 7872** technique. 7873** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7874** with "Z". 7875** <li> Include a digit somewhere in every identifier name. 7876** </ul> 7877** 7878** Note that the number of keywords understood by SQLite can depend on 7879** compile-time options. For example, "VACUUM" is not a keyword if 7880** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7881** new keywords may be added to future releases of SQLite. 7882*/ 7883int sqlite3_keyword_count(void); 7884int sqlite3_keyword_name(int,const char**,int*); 7885int sqlite3_keyword_check(const char*,int); 7886 7887/* 7888** CAPI3REF: Dynamic String Object 7889** KEYWORDS: {dynamic string} 7890** 7891** An instance of the sqlite3_str object contains a dynamically-sized 7892** string under construction. 7893** 7894** The lifecycle of an sqlite3_str object is as follows: 7895** <ol> 7896** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7897** <li> ^Text is appended to the sqlite3_str object using various 7898** methods, such as [sqlite3_str_appendf()]. 7899** <li> ^The sqlite3_str object is destroyed and the string it created 7900** is returned using the [sqlite3_str_finish()] interface. 7901** </ol> 7902*/ 7903typedef struct sqlite3_str sqlite3_str; 7904 7905/* 7906** CAPI3REF: Create A New Dynamic String Object 7907** CONSTRUCTOR: sqlite3_str 7908** 7909** ^The [sqlite3_str_new(D)] interface allocates and initializes 7910** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7911** [sqlite3_str_new()] must be freed by a subsequent call to 7912** [sqlite3_str_finish(X)]. 7913** 7914** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7915** valid [sqlite3_str] object, though in the event of an out-of-memory 7916** error the returned object might be a special singleton that will 7917** silently reject new text, always return SQLITE_NOMEM from 7918** [sqlite3_str_errcode()], always return 0 for 7919** [sqlite3_str_length()], and always return NULL from 7920** [sqlite3_str_finish(X)]. It is always safe to use the value 7921** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7922** to any of the other [sqlite3_str] methods. 7923** 7924** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7925** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7926** length of the string contained in the [sqlite3_str] object will be 7927** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7928** of [SQLITE_MAX_LENGTH]. 7929*/ 7930sqlite3_str *sqlite3_str_new(sqlite3*); 7931 7932/* 7933** CAPI3REF: Finalize A Dynamic String 7934** DESTRUCTOR: sqlite3_str 7935** 7936** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7937** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7938** that contains the constructed string. The calling application should 7939** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7940** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7941** errors were encountered during construction of the string. ^The 7942** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7943** string in [sqlite3_str] object X is zero bytes long. 7944*/ 7945char *sqlite3_str_finish(sqlite3_str*); 7946 7947/* 7948** CAPI3REF: Add Content To A Dynamic String 7949** METHOD: sqlite3_str 7950** 7951** These interfaces add content to an sqlite3_str object previously obtained 7952** from [sqlite3_str_new()]. 7953** 7954** ^The [sqlite3_str_appendf(X,F,...)] and 7955** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7956** functionality of SQLite to append formatted text onto the end of 7957** [sqlite3_str] object X. 7958** 7959** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7960** onto the end of the [sqlite3_str] object X. N must be non-negative. 7961** S must contain at least N non-zero bytes of content. To append a 7962** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7963** method instead. 7964** 7965** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7966** zero-terminated string S onto the end of [sqlite3_str] object X. 7967** 7968** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7969** single-byte character C onto the end of [sqlite3_str] object X. 7970** ^This method can be used, for example, to add whitespace indentation. 7971** 7972** ^The [sqlite3_str_reset(X)] method resets the string under construction 7973** inside [sqlite3_str] object X back to zero bytes in length. 7974** 7975** These methods do not return a result code. ^If an error occurs, that fact 7976** is recorded in the [sqlite3_str] object and can be recovered by a 7977** subsequent call to [sqlite3_str_errcode(X)]. 7978*/ 7979void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7980void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7981void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7982void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7983void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7984void sqlite3_str_reset(sqlite3_str*); 7985 7986/* 7987** CAPI3REF: Status Of A Dynamic String 7988** METHOD: sqlite3_str 7989** 7990** These interfaces return the current status of an [sqlite3_str] object. 7991** 7992** ^If any prior errors have occurred while constructing the dynamic string 7993** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7994** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7995** [SQLITE_NOMEM] following any out-of-memory error, or 7996** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7997** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7998** 7999** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8000** of the dynamic string under construction in [sqlite3_str] object X. 8001** ^The length returned by [sqlite3_str_length(X)] does not include the 8002** zero-termination byte. 8003** 8004** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8005** content of the dynamic string under construction in X. The value 8006** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8007** and might be freed or altered by any subsequent method on the same 8008** [sqlite3_str] object. Applications must not used the pointer returned 8009** [sqlite3_str_value(X)] after any subsequent method call on the same 8010** object. ^Applications may change the content of the string returned 8011** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8012** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8013** write any byte after any subsequent sqlite3_str method call. 8014*/ 8015int sqlite3_str_errcode(sqlite3_str*); 8016int sqlite3_str_length(sqlite3_str*); 8017char *sqlite3_str_value(sqlite3_str*); 8018 8019/* 8020** CAPI3REF: SQLite Runtime Status 8021** 8022** ^These interfaces are used to retrieve runtime status information 8023** about the performance of SQLite, and optionally to reset various 8024** highwater marks. ^The first argument is an integer code for 8025** the specific parameter to measure. ^(Recognized integer codes 8026** are of the form [status parameters | SQLITE_STATUS_...].)^ 8027** ^The current value of the parameter is returned into *pCurrent. 8028** ^The highest recorded value is returned in *pHighwater. ^If the 8029** resetFlag is true, then the highest record value is reset after 8030** *pHighwater is written. ^(Some parameters do not record the highest 8031** value. For those parameters 8032** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8033** ^(Other parameters record only the highwater mark and not the current 8034** value. For these latter parameters nothing is written into *pCurrent.)^ 8035** 8036** ^The sqlite3_status() and sqlite3_status64() routines return 8037** SQLITE_OK on success and a non-zero [error code] on failure. 8038** 8039** If either the current value or the highwater mark is too large to 8040** be represented by a 32-bit integer, then the values returned by 8041** sqlite3_status() are undefined. 8042** 8043** See also: [sqlite3_db_status()] 8044*/ 8045int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8046int sqlite3_status64( 8047 int op, 8048 sqlite3_int64 *pCurrent, 8049 sqlite3_int64 *pHighwater, 8050 int resetFlag 8051); 8052 8053 8054/* 8055** CAPI3REF: Status Parameters 8056** KEYWORDS: {status parameters} 8057** 8058** These integer constants designate various run-time status parameters 8059** that can be returned by [sqlite3_status()]. 8060** 8061** <dl> 8062** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8063** <dd>This parameter is the current amount of memory checked out 8064** using [sqlite3_malloc()], either directly or indirectly. The 8065** figure includes calls made to [sqlite3_malloc()] by the application 8066** and internal memory usage by the SQLite library. Auxiliary page-cache 8067** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8068** this parameter. The amount returned is the sum of the allocation 8069** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8070** 8071** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8072** <dd>This parameter records the largest memory allocation request 8073** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8074** internal equivalents). Only the value returned in the 8075** *pHighwater parameter to [sqlite3_status()] is of interest. 8076** The value written into the *pCurrent parameter is undefined.</dd>)^ 8077** 8078** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8079** <dd>This parameter records the number of separate memory allocations 8080** currently checked out.</dd>)^ 8081** 8082** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8083** <dd>This parameter returns the number of pages used out of the 8084** [pagecache memory allocator] that was configured using 8085** [SQLITE_CONFIG_PAGECACHE]. The 8086** value returned is in pages, not in bytes.</dd>)^ 8087** 8088** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8089** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8090** <dd>This parameter returns the number of bytes of page cache 8091** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8092** buffer and where forced to overflow to [sqlite3_malloc()]. The 8093** returned value includes allocations that overflowed because they 8094** where too large (they were larger than the "sz" parameter to 8095** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8096** no space was left in the page cache.</dd>)^ 8097** 8098** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8099** <dd>This parameter records the largest memory allocation request 8100** handed to the [pagecache memory allocator]. Only the value returned in the 8101** *pHighwater parameter to [sqlite3_status()] is of interest. 8102** The value written into the *pCurrent parameter is undefined.</dd>)^ 8103** 8104** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8105** <dd>No longer used.</dd> 8106** 8107** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8108** <dd>No longer used.</dd> 8109** 8110** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8111** <dd>No longer used.</dd> 8112** 8113** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8114** <dd>The *pHighwater parameter records the deepest parser stack. 8115** The *pCurrent value is undefined. The *pHighwater value is only 8116** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8117** </dl> 8118** 8119** New status parameters may be added from time to time. 8120*/ 8121#define SQLITE_STATUS_MEMORY_USED 0 8122#define SQLITE_STATUS_PAGECACHE_USED 1 8123#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8124#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8125#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8126#define SQLITE_STATUS_MALLOC_SIZE 5 8127#define SQLITE_STATUS_PARSER_STACK 6 8128#define SQLITE_STATUS_PAGECACHE_SIZE 7 8129#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8130#define SQLITE_STATUS_MALLOC_COUNT 9 8131 8132/* 8133** CAPI3REF: Database Connection Status 8134** METHOD: sqlite3 8135** 8136** ^This interface is used to retrieve runtime status information 8137** about a single [database connection]. ^The first argument is the 8138** database connection object to be interrogated. ^The second argument 8139** is an integer constant, taken from the set of 8140** [SQLITE_DBSTATUS options], that 8141** determines the parameter to interrogate. The set of 8142** [SQLITE_DBSTATUS options] is likely 8143** to grow in future releases of SQLite. 8144** 8145** ^The current value of the requested parameter is written into *pCur 8146** and the highest instantaneous value is written into *pHiwtr. ^If 8147** the resetFlg is true, then the highest instantaneous value is 8148** reset back down to the current value. 8149** 8150** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8151** non-zero [error code] on failure. 8152** 8153** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8154*/ 8155int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8156 8157/* 8158** CAPI3REF: Status Parameters for database connections 8159** KEYWORDS: {SQLITE_DBSTATUS options} 8160** 8161** These constants are the available integer "verbs" that can be passed as 8162** the second argument to the [sqlite3_db_status()] interface. 8163** 8164** New verbs may be added in future releases of SQLite. Existing verbs 8165** might be discontinued. Applications should check the return code from 8166** [sqlite3_db_status()] to make sure that the call worked. 8167** The [sqlite3_db_status()] interface will return a non-zero error code 8168** if a discontinued or unsupported verb is invoked. 8169** 8170** <dl> 8171** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8172** <dd>This parameter returns the number of lookaside memory slots currently 8173** checked out.</dd>)^ 8174** 8175** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8176** <dd>This parameter returns the number of malloc attempts that were 8177** satisfied using lookaside memory. Only the high-water value is meaningful; 8178** the current value is always zero.)^ 8179** 8180** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8181** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8182** <dd>This parameter returns the number malloc attempts that might have 8183** been satisfied using lookaside memory but failed due to the amount of 8184** memory requested being larger than the lookaside slot size. 8185** Only the high-water value is meaningful; 8186** the current value is always zero.)^ 8187** 8188** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8189** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8190** <dd>This parameter returns the number malloc attempts that might have 8191** been satisfied using lookaside memory but failed due to all lookaside 8192** memory already being in use. 8193** Only the high-water value is meaningful; 8194** the current value is always zero.)^ 8195** 8196** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8197** <dd>This parameter returns the approximate number of bytes of heap 8198** memory used by all pager caches associated with the database connection.)^ 8199** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8200** 8201** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8202** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8203** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8204** pager cache is shared between two or more connections the bytes of heap 8205** memory used by that pager cache is divided evenly between the attached 8206** connections.)^ In other words, if none of the pager caches associated 8207** with the database connection are shared, this request returns the same 8208** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8209** shared, the value returned by this call will be smaller than that returned 8210** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8211** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8212** 8213** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8214** <dd>This parameter returns the approximate number of bytes of heap 8215** memory used to store the schema for all databases associated 8216** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8217** ^The full amount of memory used by the schemas is reported, even if the 8218** schema memory is shared with other database connections due to 8219** [shared cache mode] being enabled. 8220** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8221** 8222** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8223** <dd>This parameter returns the approximate number of bytes of heap 8224** and lookaside memory used by all prepared statements associated with 8225** the database connection.)^ 8226** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8227** </dd> 8228** 8229** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8230** <dd>This parameter returns the number of pager cache hits that have 8231** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8232** is always 0. 8233** </dd> 8234** 8235** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8236** <dd>This parameter returns the number of pager cache misses that have 8237** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8238** is always 0. 8239** </dd> 8240** 8241** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8242** <dd>This parameter returns the number of dirty cache entries that have 8243** been written to disk. Specifically, the number of pages written to the 8244** wal file in wal mode databases, or the number of pages written to the 8245** database file in rollback mode databases. Any pages written as part of 8246** transaction rollback or database recovery operations are not included. 8247** If an IO or other error occurs while writing a page to disk, the effect 8248** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8249** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8250** </dd> 8251** 8252** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8253** <dd>This parameter returns the number of dirty cache entries that have 8254** been written to disk in the middle of a transaction due to the page 8255** cache overflowing. Transactions are more efficient if they are written 8256** to disk all at once. When pages spill mid-transaction, that introduces 8257** additional overhead. This parameter can be used help identify 8258** inefficiencies that can be resolved by increasing the cache size. 8259** </dd> 8260** 8261** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8262** <dd>This parameter returns zero for the current value if and only if 8263** all foreign key constraints (deferred or immediate) have been 8264** resolved.)^ ^The highwater mark is always 0. 8265** </dd> 8266** </dl> 8267*/ 8268#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8269#define SQLITE_DBSTATUS_CACHE_USED 1 8270#define SQLITE_DBSTATUS_SCHEMA_USED 2 8271#define SQLITE_DBSTATUS_STMT_USED 3 8272#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8273#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8274#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8275#define SQLITE_DBSTATUS_CACHE_HIT 7 8276#define SQLITE_DBSTATUS_CACHE_MISS 8 8277#define SQLITE_DBSTATUS_CACHE_WRITE 9 8278#define SQLITE_DBSTATUS_DEFERRED_FKS 10 8279#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8280#define SQLITE_DBSTATUS_CACHE_SPILL 12 8281#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8282 8283 8284/* 8285** CAPI3REF: Prepared Statement Status 8286** METHOD: sqlite3_stmt 8287** 8288** ^(Each prepared statement maintains various 8289** [SQLITE_STMTSTATUS counters] that measure the number 8290** of times it has performed specific operations.)^ These counters can 8291** be used to monitor the performance characteristics of the prepared 8292** statements. For example, if the number of table steps greatly exceeds 8293** the number of table searches or result rows, that would tend to indicate 8294** that the prepared statement is using a full table scan rather than 8295** an index. 8296** 8297** ^(This interface is used to retrieve and reset counter values from 8298** a [prepared statement]. The first argument is the prepared statement 8299** object to be interrogated. The second argument 8300** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8301** to be interrogated.)^ 8302** ^The current value of the requested counter is returned. 8303** ^If the resetFlg is true, then the counter is reset to zero after this 8304** interface call returns. 8305** 8306** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8307*/ 8308int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8309 8310/* 8311** CAPI3REF: Status Parameters for prepared statements 8312** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8313** 8314** These preprocessor macros define integer codes that name counter 8315** values associated with the [sqlite3_stmt_status()] interface. 8316** The meanings of the various counters are as follows: 8317** 8318** <dl> 8319** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8320** <dd>^This is the number of times that SQLite has stepped forward in 8321** a table as part of a full table scan. Large numbers for this counter 8322** may indicate opportunities for performance improvement through 8323** careful use of indices.</dd> 8324** 8325** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8326** <dd>^This is the number of sort operations that have occurred. 8327** A non-zero value in this counter may indicate an opportunity to 8328** improvement performance through careful use of indices.</dd> 8329** 8330** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8331** <dd>^This is the number of rows inserted into transient indices that 8332** were created automatically in order to help joins run faster. 8333** A non-zero value in this counter may indicate an opportunity to 8334** improvement performance by adding permanent indices that do not 8335** need to be reinitialized each time the statement is run.</dd> 8336** 8337** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8338** <dd>^This is the number of virtual machine operations executed 8339** by the prepared statement if that number is less than or equal 8340** to 2147483647. The number of virtual machine operations can be 8341** used as a proxy for the total work done by the prepared statement. 8342** If the number of virtual machine operations exceeds 2147483647 8343** then the value returned by this statement status code is undefined. 8344** 8345** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8346** <dd>^This is the number of times that the prepare statement has been 8347** automatically regenerated due to schema changes or changes to 8348** [bound parameters] that might affect the query plan. 8349** 8350** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8351** <dd>^This is the number of times that the prepared statement has 8352** been run. A single "run" for the purposes of this counter is one 8353** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8354** The counter is incremented on the first [sqlite3_step()] call of each 8355** cycle. 8356** 8357** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8358** <dd>^This is the approximate number of bytes of heap memory 8359** used to store the prepared statement. ^This value is not actually 8360** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8361** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8362** </dd> 8363** </dl> 8364*/ 8365#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8366#define SQLITE_STMTSTATUS_SORT 2 8367#define SQLITE_STMTSTATUS_AUTOINDEX 3 8368#define SQLITE_STMTSTATUS_VM_STEP 4 8369#define SQLITE_STMTSTATUS_REPREPARE 5 8370#define SQLITE_STMTSTATUS_RUN 6 8371#define SQLITE_STMTSTATUS_MEMUSED 99 8372 8373/* 8374** CAPI3REF: Custom Page Cache Object 8375** 8376** The sqlite3_pcache type is opaque. It is implemented by 8377** the pluggable module. The SQLite core has no knowledge of 8378** its size or internal structure and never deals with the 8379** sqlite3_pcache object except by holding and passing pointers 8380** to the object. 8381** 8382** See [sqlite3_pcache_methods2] for additional information. 8383*/ 8384typedef struct sqlite3_pcache sqlite3_pcache; 8385 8386/* 8387** CAPI3REF: Custom Page Cache Object 8388** 8389** The sqlite3_pcache_page object represents a single page in the 8390** page cache. The page cache will allocate instances of this 8391** object. Various methods of the page cache use pointers to instances 8392** of this object as parameters or as their return value. 8393** 8394** See [sqlite3_pcache_methods2] for additional information. 8395*/ 8396typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8397struct sqlite3_pcache_page { 8398 void *pBuf; /* The content of the page */ 8399 void *pExtra; /* Extra information associated with the page */ 8400}; 8401 8402/* 8403** CAPI3REF: Application Defined Page Cache. 8404** KEYWORDS: {page cache} 8405** 8406** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8407** register an alternative page cache implementation by passing in an 8408** instance of the sqlite3_pcache_methods2 structure.)^ 8409** In many applications, most of the heap memory allocated by 8410** SQLite is used for the page cache. 8411** By implementing a 8412** custom page cache using this API, an application can better control 8413** the amount of memory consumed by SQLite, the way in which 8414** that memory is allocated and released, and the policies used to 8415** determine exactly which parts of a database file are cached and for 8416** how long. 8417** 8418** The alternative page cache mechanism is an 8419** extreme measure that is only needed by the most demanding applications. 8420** The built-in page cache is recommended for most uses. 8421** 8422** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8423** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8424** the application may discard the parameter after the call to 8425** [sqlite3_config()] returns.)^ 8426** 8427** [[the xInit() page cache method]] 8428** ^(The xInit() method is called once for each effective 8429** call to [sqlite3_initialize()])^ 8430** (usually only once during the lifetime of the process). ^(The xInit() 8431** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8432** The intent of the xInit() method is to set up global data structures 8433** required by the custom page cache implementation. 8434** ^(If the xInit() method is NULL, then the 8435** built-in default page cache is used instead of the application defined 8436** page cache.)^ 8437** 8438** [[the xShutdown() page cache method]] 8439** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8440** It can be used to clean up 8441** any outstanding resources before process shutdown, if required. 8442** ^The xShutdown() method may be NULL. 8443** 8444** ^SQLite automatically serializes calls to the xInit method, 8445** so the xInit method need not be threadsafe. ^The 8446** xShutdown method is only called from [sqlite3_shutdown()] so it does 8447** not need to be threadsafe either. All other methods must be threadsafe 8448** in multithreaded applications. 8449** 8450** ^SQLite will never invoke xInit() more than once without an intervening 8451** call to xShutdown(). 8452** 8453** [[the xCreate() page cache methods]] 8454** ^SQLite invokes the xCreate() method to construct a new cache instance. 8455** SQLite will typically create one cache instance for each open database file, 8456** though this is not guaranteed. ^The 8457** first parameter, szPage, is the size in bytes of the pages that must 8458** be allocated by the cache. ^szPage will always a power of two. ^The 8459** second parameter szExtra is a number of bytes of extra storage 8460** associated with each page cache entry. ^The szExtra parameter will 8461** a number less than 250. SQLite will use the 8462** extra szExtra bytes on each page to store metadata about the underlying 8463** database page on disk. The value passed into szExtra depends 8464** on the SQLite version, the target platform, and how SQLite was compiled. 8465** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8466** created will be used to cache database pages of a file stored on disk, or 8467** false if it is used for an in-memory database. The cache implementation 8468** does not have to do anything special based with the value of bPurgeable; 8469** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8470** never invoke xUnpin() except to deliberately delete a page. 8471** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8472** false will always have the "discard" flag set to true. 8473** ^Hence, a cache created with bPurgeable false will 8474** never contain any unpinned pages. 8475** 8476** [[the xCachesize() page cache method]] 8477** ^(The xCachesize() method may be called at any time by SQLite to set the 8478** suggested maximum cache-size (number of pages stored by) the cache 8479** instance passed as the first argument. This is the value configured using 8480** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8481** parameter, the implementation is not required to do anything with this 8482** value; it is advisory only. 8483** 8484** [[the xPagecount() page cache methods]] 8485** The xPagecount() method must return the number of pages currently 8486** stored in the cache, both pinned and unpinned. 8487** 8488** [[the xFetch() page cache methods]] 8489** The xFetch() method locates a page in the cache and returns a pointer to 8490** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8491** The pBuf element of the returned sqlite3_pcache_page object will be a 8492** pointer to a buffer of szPage bytes used to store the content of a 8493** single database page. The pExtra element of sqlite3_pcache_page will be 8494** a pointer to the szExtra bytes of extra storage that SQLite has requested 8495** for each entry in the page cache. 8496** 8497** The page to be fetched is determined by the key. ^The minimum key value 8498** is 1. After it has been retrieved using xFetch, the page is considered 8499** to be "pinned". 8500** 8501** If the requested page is already in the page cache, then the page cache 8502** implementation must return a pointer to the page buffer with its content 8503** intact. If the requested page is not already in the cache, then the 8504** cache implementation should use the value of the createFlag 8505** parameter to help it determined what action to take: 8506** 8507** <table border=1 width=85% align=center> 8508** <tr><th> createFlag <th> Behavior when page is not already in cache 8509** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8510** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8511** Otherwise return NULL. 8512** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8513** NULL if allocating a new page is effectively impossible. 8514** </table> 8515** 8516** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8517** will only use a createFlag of 2 after a prior call with a createFlag of 1 8518** failed.)^ In between the xFetch() calls, SQLite may 8519** attempt to unpin one or more cache pages by spilling the content of 8520** pinned pages to disk and synching the operating system disk cache. 8521** 8522** [[the xUnpin() page cache method]] 8523** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8524** as its second argument. If the third parameter, discard, is non-zero, 8525** then the page must be evicted from the cache. 8526** ^If the discard parameter is 8527** zero, then the page may be discarded or retained at the discretion of 8528** page cache implementation. ^The page cache implementation 8529** may choose to evict unpinned pages at any time. 8530** 8531** The cache must not perform any reference counting. A single 8532** call to xUnpin() unpins the page regardless of the number of prior calls 8533** to xFetch(). 8534** 8535** [[the xRekey() page cache methods]] 8536** The xRekey() method is used to change the key value associated with the 8537** page passed as the second argument. If the cache 8538** previously contains an entry associated with newKey, it must be 8539** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8540** to be pinned. 8541** 8542** When SQLite calls the xTruncate() method, the cache must discard all 8543** existing cache entries with page numbers (keys) greater than or equal 8544** to the value of the iLimit parameter passed to xTruncate(). If any 8545** of these pages are pinned, they are implicitly unpinned, meaning that 8546** they can be safely discarded. 8547** 8548** [[the xDestroy() page cache method]] 8549** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8550** All resources associated with the specified cache should be freed. ^After 8551** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8552** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8553** functions. 8554** 8555** [[the xShrink() page cache method]] 8556** ^SQLite invokes the xShrink() method when it wants the page cache to 8557** free up as much of heap memory as possible. The page cache implementation 8558** is not obligated to free any memory, but well-behaved implementations should 8559** do their best. 8560*/ 8561typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8562struct sqlite3_pcache_methods2 { 8563 int iVersion; 8564 void *pArg; 8565 int (*xInit)(void*); 8566 void (*xShutdown)(void*); 8567 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8568 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8569 int (*xPagecount)(sqlite3_pcache*); 8570 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8571 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8572 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8573 unsigned oldKey, unsigned newKey); 8574 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8575 void (*xDestroy)(sqlite3_pcache*); 8576 void (*xShrink)(sqlite3_pcache*); 8577}; 8578 8579/* 8580** This is the obsolete pcache_methods object that has now been replaced 8581** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8582** retained in the header file for backwards compatibility only. 8583*/ 8584typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8585struct sqlite3_pcache_methods { 8586 void *pArg; 8587 int (*xInit)(void*); 8588 void (*xShutdown)(void*); 8589 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8590 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8591 int (*xPagecount)(sqlite3_pcache*); 8592 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8593 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8594 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8595 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8596 void (*xDestroy)(sqlite3_pcache*); 8597}; 8598 8599 8600/* 8601** CAPI3REF: Online Backup Object 8602** 8603** The sqlite3_backup object records state information about an ongoing 8604** online backup operation. ^The sqlite3_backup object is created by 8605** a call to [sqlite3_backup_init()] and is destroyed by a call to 8606** [sqlite3_backup_finish()]. 8607** 8608** See Also: [Using the SQLite Online Backup API] 8609*/ 8610typedef struct sqlite3_backup sqlite3_backup; 8611 8612/* 8613** CAPI3REF: Online Backup API. 8614** 8615** The backup API copies the content of one database into another. 8616** It is useful either for creating backups of databases or 8617** for copying in-memory databases to or from persistent files. 8618** 8619** See Also: [Using the SQLite Online Backup API] 8620** 8621** ^SQLite holds a write transaction open on the destination database file 8622** for the duration of the backup operation. 8623** ^The source database is read-locked only while it is being read; 8624** it is not locked continuously for the entire backup operation. 8625** ^Thus, the backup may be performed on a live source database without 8626** preventing other database connections from 8627** reading or writing to the source database while the backup is underway. 8628** 8629** ^(To perform a backup operation: 8630** <ol> 8631** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8632** backup, 8633** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8634** the data between the two databases, and finally 8635** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8636** associated with the backup operation. 8637** </ol>)^ 8638** There should be exactly one call to sqlite3_backup_finish() for each 8639** successful call to sqlite3_backup_init(). 8640** 8641** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8642** 8643** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8644** [database connection] associated with the destination database 8645** and the database name, respectively. 8646** ^The database name is "main" for the main database, "temp" for the 8647** temporary database, or the name specified after the AS keyword in 8648** an [ATTACH] statement for an attached database. 8649** ^The S and M arguments passed to 8650** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8651** and database name of the source database, respectively. 8652** ^The source and destination [database connections] (parameters S and D) 8653** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8654** an error. 8655** 8656** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8657** there is already a read or read-write transaction open on the 8658** destination database. 8659** 8660** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8661** returned and an error code and error message are stored in the 8662** destination [database connection] D. 8663** ^The error code and message for the failed call to sqlite3_backup_init() 8664** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8665** [sqlite3_errmsg16()] functions. 8666** ^A successful call to sqlite3_backup_init() returns a pointer to an 8667** [sqlite3_backup] object. 8668** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8669** sqlite3_backup_finish() functions to perform the specified backup 8670** operation. 8671** 8672** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8673** 8674** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8675** the source and destination databases specified by [sqlite3_backup] object B. 8676** ^If N is negative, all remaining source pages are copied. 8677** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8678** are still more pages to be copied, then the function returns [SQLITE_OK]. 8679** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8680** from source to destination, then it returns [SQLITE_DONE]. 8681** ^If an error occurs while running sqlite3_backup_step(B,N), 8682** then an [error code] is returned. ^As well as [SQLITE_OK] and 8683** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8684** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8685** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8686** 8687** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8688** <ol> 8689** <li> the destination database was opened read-only, or 8690** <li> the destination database is using write-ahead-log journaling 8691** and the destination and source page sizes differ, or 8692** <li> the destination database is an in-memory database and the 8693** destination and source page sizes differ. 8694** </ol>)^ 8695** 8696** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8697** the [sqlite3_busy_handler | busy-handler function] 8698** is invoked (if one is specified). ^If the 8699** busy-handler returns non-zero before the lock is available, then 8700** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8701** sqlite3_backup_step() can be retried later. ^If the source 8702** [database connection] 8703** is being used to write to the source database when sqlite3_backup_step() 8704** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8705** case the call to sqlite3_backup_step() can be retried later on. ^(If 8706** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8707** [SQLITE_READONLY] is returned, then 8708** there is no point in retrying the call to sqlite3_backup_step(). These 8709** errors are considered fatal.)^ The application must accept 8710** that the backup operation has failed and pass the backup operation handle 8711** to the sqlite3_backup_finish() to release associated resources. 8712** 8713** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8714** on the destination file. ^The exclusive lock is not released until either 8715** sqlite3_backup_finish() is called or the backup operation is complete 8716** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8717** sqlite3_backup_step() obtains a [shared lock] on the source database that 8718** lasts for the duration of the sqlite3_backup_step() call. 8719** ^Because the source database is not locked between calls to 8720** sqlite3_backup_step(), the source database may be modified mid-way 8721** through the backup process. ^If the source database is modified by an 8722** external process or via a database connection other than the one being 8723** used by the backup operation, then the backup will be automatically 8724** restarted by the next call to sqlite3_backup_step(). ^If the source 8725** database is modified by the using the same database connection as is used 8726** by the backup operation, then the backup database is automatically 8727** updated at the same time. 8728** 8729** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8730** 8731** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8732** application wishes to abandon the backup operation, the application 8733** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8734** ^The sqlite3_backup_finish() interfaces releases all 8735** resources associated with the [sqlite3_backup] object. 8736** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8737** active write-transaction on the destination database is rolled back. 8738** The [sqlite3_backup] object is invalid 8739** and may not be used following a call to sqlite3_backup_finish(). 8740** 8741** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8742** sqlite3_backup_step() errors occurred, regardless or whether or not 8743** sqlite3_backup_step() completed. 8744** ^If an out-of-memory condition or IO error occurred during any prior 8745** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8746** sqlite3_backup_finish() returns the corresponding [error code]. 8747** 8748** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8749** is not a permanent error and does not affect the return value of 8750** sqlite3_backup_finish(). 8751** 8752** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8753** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8754** 8755** ^The sqlite3_backup_remaining() routine returns the number of pages still 8756** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8757** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8758** in the source database at the conclusion of the most recent 8759** sqlite3_backup_step(). 8760** ^(The values returned by these functions are only updated by 8761** sqlite3_backup_step(). If the source database is modified in a way that 8762** changes the size of the source database or the number of pages remaining, 8763** those changes are not reflected in the output of sqlite3_backup_pagecount() 8764** and sqlite3_backup_remaining() until after the next 8765** sqlite3_backup_step().)^ 8766** 8767** <b>Concurrent Usage of Database Handles</b> 8768** 8769** ^The source [database connection] may be used by the application for other 8770** purposes while a backup operation is underway or being initialized. 8771** ^If SQLite is compiled and configured to support threadsafe database 8772** connections, then the source database connection may be used concurrently 8773** from within other threads. 8774** 8775** However, the application must guarantee that the destination 8776** [database connection] is not passed to any other API (by any thread) after 8777** sqlite3_backup_init() is called and before the corresponding call to 8778** sqlite3_backup_finish(). SQLite does not currently check to see 8779** if the application incorrectly accesses the destination [database connection] 8780** and so no error code is reported, but the operations may malfunction 8781** nevertheless. Use of the destination database connection while a 8782** backup is in progress might also also cause a mutex deadlock. 8783** 8784** If running in [shared cache mode], the application must 8785** guarantee that the shared cache used by the destination database 8786** is not accessed while the backup is running. In practice this means 8787** that the application must guarantee that the disk file being 8788** backed up to is not accessed by any connection within the process, 8789** not just the specific connection that was passed to sqlite3_backup_init(). 8790** 8791** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8792** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8793** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8794** APIs are not strictly speaking threadsafe. If they are invoked at the 8795** same time as another thread is invoking sqlite3_backup_step() it is 8796** possible that they return invalid values. 8797*/ 8798sqlite3_backup *sqlite3_backup_init( 8799 sqlite3 *pDest, /* Destination database handle */ 8800 const char *zDestName, /* Destination database name */ 8801 sqlite3 *pSource, /* Source database handle */ 8802 const char *zSourceName /* Source database name */ 8803); 8804int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8805int sqlite3_backup_finish(sqlite3_backup *p); 8806int sqlite3_backup_remaining(sqlite3_backup *p); 8807int sqlite3_backup_pagecount(sqlite3_backup *p); 8808 8809/* 8810** CAPI3REF: Unlock Notification 8811** METHOD: sqlite3 8812** 8813** ^When running in shared-cache mode, a database operation may fail with 8814** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8815** individual tables within the shared-cache cannot be obtained. See 8816** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8817** ^This API may be used to register a callback that SQLite will invoke 8818** when the connection currently holding the required lock relinquishes it. 8819** ^This API is only available if the library was compiled with the 8820** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8821** 8822** See Also: [Using the SQLite Unlock Notification Feature]. 8823** 8824** ^Shared-cache locks are released when a database connection concludes 8825** its current transaction, either by committing it or rolling it back. 8826** 8827** ^When a connection (known as the blocked connection) fails to obtain a 8828** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8829** identity of the database connection (the blocking connection) that 8830** has locked the required resource is stored internally. ^After an 8831** application receives an SQLITE_LOCKED error, it may call the 8832** sqlite3_unlock_notify() method with the blocked connection handle as 8833** the first argument to register for a callback that will be invoked 8834** when the blocking connections current transaction is concluded. ^The 8835** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8836** call that concludes the blocking connection's transaction. 8837** 8838** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8839** there is a chance that the blocking connection will have already 8840** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8841** If this happens, then the specified callback is invoked immediately, 8842** from within the call to sqlite3_unlock_notify().)^ 8843** 8844** ^If the blocked connection is attempting to obtain a write-lock on a 8845** shared-cache table, and more than one other connection currently holds 8846** a read-lock on the same table, then SQLite arbitrarily selects one of 8847** the other connections to use as the blocking connection. 8848** 8849** ^(There may be at most one unlock-notify callback registered by a 8850** blocked connection. If sqlite3_unlock_notify() is called when the 8851** blocked connection already has a registered unlock-notify callback, 8852** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8853** called with a NULL pointer as its second argument, then any existing 8854** unlock-notify callback is canceled. ^The blocked connections 8855** unlock-notify callback may also be canceled by closing the blocked 8856** connection using [sqlite3_close()]. 8857** 8858** The unlock-notify callback is not reentrant. If an application invokes 8859** any sqlite3_xxx API functions from within an unlock-notify callback, a 8860** crash or deadlock may be the result. 8861** 8862** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8863** returns SQLITE_OK. 8864** 8865** <b>Callback Invocation Details</b> 8866** 8867** When an unlock-notify callback is registered, the application provides a 8868** single void* pointer that is passed to the callback when it is invoked. 8869** However, the signature of the callback function allows SQLite to pass 8870** it an array of void* context pointers. The first argument passed to 8871** an unlock-notify callback is a pointer to an array of void* pointers, 8872** and the second is the number of entries in the array. 8873** 8874** When a blocking connection's transaction is concluded, there may be 8875** more than one blocked connection that has registered for an unlock-notify 8876** callback. ^If two or more such blocked connections have specified the 8877** same callback function, then instead of invoking the callback function 8878** multiple times, it is invoked once with the set of void* context pointers 8879** specified by the blocked connections bundled together into an array. 8880** This gives the application an opportunity to prioritize any actions 8881** related to the set of unblocked database connections. 8882** 8883** <b>Deadlock Detection</b> 8884** 8885** Assuming that after registering for an unlock-notify callback a 8886** database waits for the callback to be issued before taking any further 8887** action (a reasonable assumption), then using this API may cause the 8888** application to deadlock. For example, if connection X is waiting for 8889** connection Y's transaction to be concluded, and similarly connection 8890** Y is waiting on connection X's transaction, then neither connection 8891** will proceed and the system may remain deadlocked indefinitely. 8892** 8893** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8894** detection. ^If a given call to sqlite3_unlock_notify() would put the 8895** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8896** unlock-notify callback is registered. The system is said to be in 8897** a deadlocked state if connection A has registered for an unlock-notify 8898** callback on the conclusion of connection B's transaction, and connection 8899** B has itself registered for an unlock-notify callback when connection 8900** A's transaction is concluded. ^Indirect deadlock is also detected, so 8901** the system is also considered to be deadlocked if connection B has 8902** registered for an unlock-notify callback on the conclusion of connection 8903** C's transaction, where connection C is waiting on connection A. ^Any 8904** number of levels of indirection are allowed. 8905** 8906** <b>The "DROP TABLE" Exception</b> 8907** 8908** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8909** always appropriate to call sqlite3_unlock_notify(). There is however, 8910** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8911** SQLite checks if there are any currently executing SELECT statements 8912** that belong to the same connection. If there are, SQLITE_LOCKED is 8913** returned. In this case there is no "blocking connection", so invoking 8914** sqlite3_unlock_notify() results in the unlock-notify callback being 8915** invoked immediately. If the application then re-attempts the "DROP TABLE" 8916** or "DROP INDEX" query, an infinite loop might be the result. 8917** 8918** One way around this problem is to check the extended error code returned 8919** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8920** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8921** the special "DROP TABLE/INDEX" case, the extended error code is just 8922** SQLITE_LOCKED.)^ 8923*/ 8924int sqlite3_unlock_notify( 8925 sqlite3 *pBlocked, /* Waiting connection */ 8926 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8927 void *pNotifyArg /* Argument to pass to xNotify */ 8928); 8929 8930 8931/* 8932** CAPI3REF: String Comparison 8933** 8934** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8935** and extensions to compare the contents of two buffers containing UTF-8 8936** strings in a case-independent fashion, using the same definition of "case 8937** independence" that SQLite uses internally when comparing identifiers. 8938*/ 8939int sqlite3_stricmp(const char *, const char *); 8940int sqlite3_strnicmp(const char *, const char *, int); 8941 8942/* 8943** CAPI3REF: String Globbing 8944* 8945** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8946** string X matches the [GLOB] pattern P. 8947** ^The definition of [GLOB] pattern matching used in 8948** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8949** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8950** is case sensitive. 8951** 8952** Note that this routine returns zero on a match and non-zero if the strings 8953** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8954** 8955** See also: [sqlite3_strlike()]. 8956*/ 8957int sqlite3_strglob(const char *zGlob, const char *zStr); 8958 8959/* 8960** CAPI3REF: String LIKE Matching 8961* 8962** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8963** string X matches the [LIKE] pattern P with escape character E. 8964** ^The definition of [LIKE] pattern matching used in 8965** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8966** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8967** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8968** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8969** insensitive - equivalent upper and lower case ASCII characters match 8970** one another. 8971** 8972** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8973** only ASCII characters are case folded. 8974** 8975** Note that this routine returns zero on a match and non-zero if the strings 8976** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8977** 8978** See also: [sqlite3_strglob()]. 8979*/ 8980int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8981 8982/* 8983** CAPI3REF: Error Logging Interface 8984** 8985** ^The [sqlite3_log()] interface writes a message into the [error log] 8986** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8987** ^If logging is enabled, the zFormat string and subsequent arguments are 8988** used with [sqlite3_snprintf()] to generate the final output string. 8989** 8990** The sqlite3_log() interface is intended for use by extensions such as 8991** virtual tables, collating functions, and SQL functions. While there is 8992** nothing to prevent an application from calling sqlite3_log(), doing so 8993** is considered bad form. 8994** 8995** The zFormat string must not be NULL. 8996** 8997** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8998** will not use dynamically allocated memory. The log message is stored in 8999** a fixed-length buffer on the stack. If the log message is longer than 9000** a few hundred characters, it will be truncated to the length of the 9001** buffer. 9002*/ 9003void sqlite3_log(int iErrCode, const char *zFormat, ...); 9004 9005/* 9006** CAPI3REF: Write-Ahead Log Commit Hook 9007** METHOD: sqlite3 9008** 9009** ^The [sqlite3_wal_hook()] function is used to register a callback that 9010** is invoked each time data is committed to a database in wal mode. 9011** 9012** ^(The callback is invoked by SQLite after the commit has taken place and 9013** the associated write-lock on the database released)^, so the implementation 9014** may read, write or [checkpoint] the database as required. 9015** 9016** ^The first parameter passed to the callback function when it is invoked 9017** is a copy of the third parameter passed to sqlite3_wal_hook() when 9018** registering the callback. ^The second is a copy of the database handle. 9019** ^The third parameter is the name of the database that was written to - 9020** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9021** is the number of pages currently in the write-ahead log file, 9022** including those that were just committed. 9023** 9024** The callback function should normally return [SQLITE_OK]. ^If an error 9025** code is returned, that error will propagate back up through the 9026** SQLite code base to cause the statement that provoked the callback 9027** to report an error, though the commit will have still occurred. If the 9028** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9029** that does not correspond to any valid SQLite error code, the results 9030** are undefined. 9031** 9032** A single database handle may have at most a single write-ahead log callback 9033** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9034** previously registered write-ahead log callback. ^The return value is 9035** a copy of the third parameter from the previous call, if any, or 0. 9036** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9037** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9038** overwrite any prior [sqlite3_wal_hook()] settings. 9039*/ 9040void *sqlite3_wal_hook( 9041 sqlite3*, 9042 int(*)(void *,sqlite3*,const char*,int), 9043 void* 9044); 9045 9046/* 9047** CAPI3REF: Configure an auto-checkpoint 9048** METHOD: sqlite3 9049** 9050** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9051** [sqlite3_wal_hook()] that causes any database on [database connection] D 9052** to automatically [checkpoint] 9053** after committing a transaction if there are N or 9054** more frames in the [write-ahead log] file. ^Passing zero or 9055** a negative value as the nFrame parameter disables automatic 9056** checkpoints entirely. 9057** 9058** ^The callback registered by this function replaces any existing callback 9059** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9060** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9061** configured by this function. 9062** 9063** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9064** from SQL. 9065** 9066** ^Checkpoints initiated by this mechanism are 9067** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9068** 9069** ^Every new [database connection] defaults to having the auto-checkpoint 9070** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9071** pages. The use of this interface 9072** is only necessary if the default setting is found to be suboptimal 9073** for a particular application. 9074*/ 9075int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9076 9077/* 9078** CAPI3REF: Checkpoint a database 9079** METHOD: sqlite3 9080** 9081** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9082** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9083** 9084** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9085** [write-ahead log] for database X on [database connection] D to be 9086** transferred into the database file and for the write-ahead log to 9087** be reset. See the [checkpointing] documentation for addition 9088** information. 9089** 9090** This interface used to be the only way to cause a checkpoint to 9091** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9092** interface was added. This interface is retained for backwards 9093** compatibility and as a convenience for applications that need to manually 9094** start a callback but which do not need the full power (and corresponding 9095** complication) of [sqlite3_wal_checkpoint_v2()]. 9096*/ 9097int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9098 9099/* 9100** CAPI3REF: Checkpoint a database 9101** METHOD: sqlite3 9102** 9103** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9104** operation on database X of [database connection] D in mode M. Status 9105** information is written back into integers pointed to by L and C.)^ 9106** ^(The M parameter must be a valid [checkpoint mode]:)^ 9107** 9108** <dl> 9109** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9110** ^Checkpoint as many frames as possible without waiting for any database 9111** readers or writers to finish, then sync the database file if all frames 9112** in the log were checkpointed. ^The [busy-handler callback] 9113** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9114** ^On the other hand, passive mode might leave the checkpoint unfinished 9115** if there are concurrent readers or writers. 9116** 9117** <dt>SQLITE_CHECKPOINT_FULL<dd> 9118** ^This mode blocks (it invokes the 9119** [sqlite3_busy_handler|busy-handler callback]) until there is no 9120** database writer and all readers are reading from the most recent database 9121** snapshot. ^It then checkpoints all frames in the log file and syncs the 9122** database file. ^This mode blocks new database writers while it is pending, 9123** but new database readers are allowed to continue unimpeded. 9124** 9125** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9126** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9127** that after checkpointing the log file it blocks (calls the 9128** [busy-handler callback]) 9129** until all readers are reading from the database file only. ^This ensures 9130** that the next writer will restart the log file from the beginning. 9131** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9132** database writer attempts while it is pending, but does not impede readers. 9133** 9134** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9135** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9136** addition that it also truncates the log file to zero bytes just prior 9137** to a successful return. 9138** </dl> 9139** 9140** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9141** the log file or to -1 if the checkpoint could not run because 9142** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9143** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9144** log file (including any that were already checkpointed before the function 9145** was called) or to -1 if the checkpoint could not run due to an error or 9146** because the database is not in WAL mode. ^Note that upon successful 9147** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9148** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9149** 9150** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9151** any other process is running a checkpoint operation at the same time, the 9152** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9153** busy-handler configured, it will not be invoked in this case. 9154** 9155** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9156** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9157** obtained immediately, and a busy-handler is configured, it is invoked and 9158** the writer lock retried until either the busy-handler returns 0 or the lock 9159** is successfully obtained. ^The busy-handler is also invoked while waiting for 9160** database readers as described above. ^If the busy-handler returns 0 before 9161** the writer lock is obtained or while waiting for database readers, the 9162** checkpoint operation proceeds from that point in the same way as 9163** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9164** without blocking any further. ^SQLITE_BUSY is returned in this case. 9165** 9166** ^If parameter zDb is NULL or points to a zero length string, then the 9167** specified operation is attempted on all WAL databases [attached] to 9168** [database connection] db. In this case the 9169** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9170** an SQLITE_BUSY error is encountered when processing one or more of the 9171** attached WAL databases, the operation is still attempted on any remaining 9172** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9173** error occurs while processing an attached database, processing is abandoned 9174** and the error code is returned to the caller immediately. ^If no error 9175** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9176** databases, SQLITE_OK is returned. 9177** 9178** ^If database zDb is the name of an attached database that is not in WAL 9179** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9180** zDb is not NULL (or a zero length string) and is not the name of any 9181** attached database, SQLITE_ERROR is returned to the caller. 9182** 9183** ^Unless it returns SQLITE_MISUSE, 9184** the sqlite3_wal_checkpoint_v2() interface 9185** sets the error information that is queried by 9186** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9187** 9188** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9189** from SQL. 9190*/ 9191int sqlite3_wal_checkpoint_v2( 9192 sqlite3 *db, /* Database handle */ 9193 const char *zDb, /* Name of attached database (or NULL) */ 9194 int eMode, /* SQLITE_CHECKPOINT_* value */ 9195 int *pnLog, /* OUT: Size of WAL log in frames */ 9196 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9197); 9198 9199/* 9200** CAPI3REF: Checkpoint Mode Values 9201** KEYWORDS: {checkpoint mode} 9202** 9203** These constants define all valid values for the "checkpoint mode" passed 9204** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9205** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9206** meaning of each of these checkpoint modes. 9207*/ 9208#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9209#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9210#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9211#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9212 9213/* 9214** CAPI3REF: Virtual Table Interface Configuration 9215** 9216** This function may be called by either the [xConnect] or [xCreate] method 9217** of a [virtual table] implementation to configure 9218** various facets of the virtual table interface. 9219** 9220** If this interface is invoked outside the context of an xConnect or 9221** xCreate virtual table method then the behavior is undefined. 9222** 9223** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9224** [database connection] in which the virtual table is being created and 9225** which is passed in as the first argument to the [xConnect] or [xCreate] 9226** method that is invoking sqlite3_vtab_config(). The C parameter is one 9227** of the [virtual table configuration options]. The presence and meaning 9228** of parameters after C depend on which [virtual table configuration option] 9229** is used. 9230*/ 9231int sqlite3_vtab_config(sqlite3*, int op, ...); 9232 9233/* 9234** CAPI3REF: Virtual Table Configuration Options 9235** KEYWORDS: {virtual table configuration options} 9236** KEYWORDS: {virtual table configuration option} 9237** 9238** These macros define the various options to the 9239** [sqlite3_vtab_config()] interface that [virtual table] implementations 9240** can use to customize and optimize their behavior. 9241** 9242** <dl> 9243** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9244** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9245** <dd>Calls of the form 9246** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9247** where X is an integer. If X is zero, then the [virtual table] whose 9248** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9249** support constraints. In this configuration (which is the default) if 9250** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9251** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9252** specified as part of the users SQL statement, regardless of the actual 9253** ON CONFLICT mode specified. 9254** 9255** If X is non-zero, then the virtual table implementation guarantees 9256** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9257** any modifications to internal or persistent data structures have been made. 9258** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9259** is able to roll back a statement or database transaction, and abandon 9260** or continue processing the current SQL statement as appropriate. 9261** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9262** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9263** had been ABORT. 9264** 9265** Virtual table implementations that are required to handle OR REPLACE 9266** must do so within the [xUpdate] method. If a call to the 9267** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9268** CONFLICT policy is REPLACE, the virtual table implementation should 9269** silently replace the appropriate rows within the xUpdate callback and 9270** return SQLITE_OK. Or, if this is not possible, it may return 9271** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9272** constraint handling. 9273** </dd> 9274** 9275** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9276** <dd>Calls of the form 9277** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9278** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9279** prohibits that virtual table from being used from within triggers and 9280** views. 9281** </dd> 9282** 9283** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9284** <dd>Calls of the form 9285** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9286** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9287** identify that virtual table as being safe to use from within triggers 9288** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9289** virtual table can do no serious harm even if it is controlled by a 9290** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9291** flag unless absolutely necessary. 9292** </dd> 9293** </dl> 9294*/ 9295#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9296#define SQLITE_VTAB_INNOCUOUS 2 9297#define SQLITE_VTAB_DIRECTONLY 3 9298 9299/* 9300** CAPI3REF: Determine The Virtual Table Conflict Policy 9301** 9302** This function may only be called from within a call to the [xUpdate] method 9303** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9304** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9305** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9306** of the SQL statement that triggered the call to the [xUpdate] method of the 9307** [virtual table]. 9308*/ 9309int sqlite3_vtab_on_conflict(sqlite3 *); 9310 9311/* 9312** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9313** 9314** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9315** method of a [virtual table], then it might return true if the 9316** column is being fetched as part of an UPDATE operation during which the 9317** column value will not change. The virtual table implementation can use 9318** this hint as permission to substitute a return value that is less 9319** expensive to compute and that the corresponding 9320** [xUpdate] method understands as a "no-change" value. 9321** 9322** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9323** the column is not changed by the UPDATE statement, then the xColumn 9324** method can optionally return without setting a result, without calling 9325** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9326** In that case, [sqlite3_value_nochange(X)] will return true for the 9327** same column in the [xUpdate] method. 9328** 9329** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9330** implementations should continue to give a correct answer even if the 9331** sqlite3_vtab_nochange() interface were to always return false. In the 9332** current implementation, the sqlite3_vtab_nochange() interface does always 9333** returns false for the enhanced [UPDATE FROM] statement. 9334*/ 9335int sqlite3_vtab_nochange(sqlite3_context*); 9336 9337/* 9338** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9339** 9340** This function may only be called from within a call to the [xBestIndex] 9341** method of a [virtual table]. 9342** 9343** The first argument must be the sqlite3_index_info object that is the 9344** first parameter to the xBestIndex() method. The second argument must be 9345** an index into the aConstraint[] array belonging to the sqlite3_index_info 9346** structure passed to xBestIndex. This function returns a pointer to a buffer 9347** containing the name of the collation sequence for the corresponding 9348** constraint. 9349*/ 9350SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9351 9352/* 9353** CAPI3REF: Conflict resolution modes 9354** KEYWORDS: {conflict resolution mode} 9355** 9356** These constants are returned by [sqlite3_vtab_on_conflict()] to 9357** inform a [virtual table] implementation what the [ON CONFLICT] mode 9358** is for the SQL statement being evaluated. 9359** 9360** Note that the [SQLITE_IGNORE] constant is also used as a potential 9361** return value from the [sqlite3_set_authorizer()] callback and that 9362** [SQLITE_ABORT] is also a [result code]. 9363*/ 9364#define SQLITE_ROLLBACK 1 9365/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9366#define SQLITE_FAIL 3 9367/* #define SQLITE_ABORT 4 // Also an error code */ 9368#define SQLITE_REPLACE 5 9369 9370/* 9371** CAPI3REF: Prepared Statement Scan Status Opcodes 9372** KEYWORDS: {scanstatus options} 9373** 9374** The following constants can be used for the T parameter to the 9375** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9376** different metric for sqlite3_stmt_scanstatus() to return. 9377** 9378** When the value returned to V is a string, space to hold that string is 9379** managed by the prepared statement S and will be automatically freed when 9380** S is finalized. 9381** 9382** <dl> 9383** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9384** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9385** set to the total number of times that the X-th loop has run.</dd> 9386** 9387** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9388** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9389** to the total number of rows examined by all iterations of the X-th loop.</dd> 9390** 9391** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9392** <dd>^The "double" variable pointed to by the V parameter will be set to the 9393** query planner's estimate for the average number of rows output from each 9394** iteration of the X-th loop. If the query planner's estimates was accurate, 9395** then this value will approximate the quotient NVISIT/NLOOP and the 9396** product of this value for all prior loops with the same SELECTID will 9397** be the NLOOP value for the current loop. 9398** 9399** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9400** <dd>^The "const char *" variable pointed to by the V parameter will be set 9401** to a zero-terminated UTF-8 string containing the name of the index or table 9402** used for the X-th loop. 9403** 9404** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9405** <dd>^The "const char *" variable pointed to by the V parameter will be set 9406** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9407** description for the X-th loop. 9408** 9409** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9410** <dd>^The "int" variable pointed to by the V parameter will be set to the 9411** "select-id" for the X-th loop. The select-id identifies which query or 9412** subquery the loop is part of. The main query has a select-id of zero. 9413** The select-id is the same value as is output in the first column 9414** of an [EXPLAIN QUERY PLAN] query. 9415** </dl> 9416*/ 9417#define SQLITE_SCANSTAT_NLOOP 0 9418#define SQLITE_SCANSTAT_NVISIT 1 9419#define SQLITE_SCANSTAT_EST 2 9420#define SQLITE_SCANSTAT_NAME 3 9421#define SQLITE_SCANSTAT_EXPLAIN 4 9422#define SQLITE_SCANSTAT_SELECTID 5 9423 9424/* 9425** CAPI3REF: Prepared Statement Scan Status 9426** METHOD: sqlite3_stmt 9427** 9428** This interface returns information about the predicted and measured 9429** performance for pStmt. Advanced applications can use this 9430** interface to compare the predicted and the measured performance and 9431** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9432** 9433** Since this interface is expected to be rarely used, it is only 9434** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9435** compile-time option. 9436** 9437** The "iScanStatusOp" parameter determines which status information to return. 9438** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9439** of this interface is undefined. 9440** ^The requested measurement is written into a variable pointed to by 9441** the "pOut" parameter. 9442** Parameter "idx" identifies the specific loop to retrieve statistics for. 9443** Loops are numbered starting from zero. ^If idx is out of range - less than 9444** zero or greater than or equal to the total number of loops used to implement 9445** the statement - a non-zero value is returned and the variable that pOut 9446** points to is unchanged. 9447** 9448** ^Statistics might not be available for all loops in all statements. ^In cases 9449** where there exist loops with no available statistics, this function behaves 9450** as if the loop did not exist - it returns non-zero and leave the variable 9451** that pOut points to unchanged. 9452** 9453** See also: [sqlite3_stmt_scanstatus_reset()] 9454*/ 9455int sqlite3_stmt_scanstatus( 9456 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9457 int idx, /* Index of loop to report on */ 9458 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9459 void *pOut /* Result written here */ 9460); 9461 9462/* 9463** CAPI3REF: Zero Scan-Status Counters 9464** METHOD: sqlite3_stmt 9465** 9466** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9467** 9468** This API is only available if the library is built with pre-processor 9469** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9470*/ 9471void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9472 9473/* 9474** CAPI3REF: Flush caches to disk mid-transaction 9475** METHOD: sqlite3 9476** 9477** ^If a write-transaction is open on [database connection] D when the 9478** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9479** pages in the pager-cache that are not currently in use are written out 9480** to disk. A dirty page may be in use if a database cursor created by an 9481** active SQL statement is reading from it, or if it is page 1 of a database 9482** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9483** interface flushes caches for all schemas - "main", "temp", and 9484** any [attached] databases. 9485** 9486** ^If this function needs to obtain extra database locks before dirty pages 9487** can be flushed to disk, it does so. ^If those locks cannot be obtained 9488** immediately and there is a busy-handler callback configured, it is invoked 9489** in the usual manner. ^If the required lock still cannot be obtained, then 9490** the database is skipped and an attempt made to flush any dirty pages 9491** belonging to the next (if any) database. ^If any databases are skipped 9492** because locks cannot be obtained, but no other error occurs, this 9493** function returns SQLITE_BUSY. 9494** 9495** ^If any other error occurs while flushing dirty pages to disk (for 9496** example an IO error or out-of-memory condition), then processing is 9497** abandoned and an SQLite [error code] is returned to the caller immediately. 9498** 9499** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9500** 9501** ^This function does not set the database handle error code or message 9502** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9503*/ 9504int sqlite3_db_cacheflush(sqlite3*); 9505 9506/* 9507** CAPI3REF: The pre-update hook. 9508** METHOD: sqlite3 9509** 9510** ^These interfaces are only available if SQLite is compiled using the 9511** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9512** 9513** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9514** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9515** on a database table. 9516** ^At most one preupdate hook may be registered at a time on a single 9517** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9518** the previous setting. 9519** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9520** with a NULL pointer as the second parameter. 9521** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9522** the first parameter to callbacks. 9523** 9524** ^The preupdate hook only fires for changes to real database tables; the 9525** preupdate hook is not invoked for changes to [virtual tables] or to 9526** system tables like sqlite_sequence or sqlite_stat1. 9527** 9528** ^The second parameter to the preupdate callback is a pointer to 9529** the [database connection] that registered the preupdate hook. 9530** ^The third parameter to the preupdate callback is one of the constants 9531** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9532** kind of update operation that is about to occur. 9533** ^(The fourth parameter to the preupdate callback is the name of the 9534** database within the database connection that is being modified. This 9535** will be "main" for the main database or "temp" for TEMP tables or 9536** the name given after the AS keyword in the [ATTACH] statement for attached 9537** databases.)^ 9538** ^The fifth parameter to the preupdate callback is the name of the 9539** table that is being modified. 9540** 9541** For an UPDATE or DELETE operation on a [rowid table], the sixth 9542** parameter passed to the preupdate callback is the initial [rowid] of the 9543** row being modified or deleted. For an INSERT operation on a rowid table, 9544** or any operation on a WITHOUT ROWID table, the value of the sixth 9545** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9546** seventh parameter is the final rowid value of the row being inserted 9547** or updated. The value of the seventh parameter passed to the callback 9548** function is not defined for operations on WITHOUT ROWID tables, or for 9549** DELETE operations on rowid tables. 9550** 9551** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9552** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9553** provide additional information about a preupdate event. These routines 9554** may only be called from within a preupdate callback. Invoking any of 9555** these routines from outside of a preupdate callback or with a 9556** [database connection] pointer that is different from the one supplied 9557** to the preupdate callback results in undefined and probably undesirable 9558** behavior. 9559** 9560** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9561** in the row that is being inserted, updated, or deleted. 9562** 9563** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9564** a [protected sqlite3_value] that contains the value of the Nth column of 9565** the table row before it is updated. The N parameter must be between 0 9566** and one less than the number of columns or the behavior will be 9567** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9568** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9569** behavior is undefined. The [sqlite3_value] that P points to 9570** will be destroyed when the preupdate callback returns. 9571** 9572** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9573** a [protected sqlite3_value] that contains the value of the Nth column of 9574** the table row after it is updated. The N parameter must be between 0 9575** and one less than the number of columns or the behavior will be 9576** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9577** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9578** behavior is undefined. The [sqlite3_value] that P points to 9579** will be destroyed when the preupdate callback returns. 9580** 9581** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9582** callback was invoked as a result of a direct insert, update, or delete 9583** operation; or 1 for inserts, updates, or deletes invoked by top-level 9584** triggers; or 2 for changes resulting from triggers called by top-level 9585** triggers; and so forth. 9586** 9587** When the [sqlite3_blob_write()] API is used to update a blob column, 9588** the pre-update hook is invoked with SQLITE_DELETE. This is because the 9589** in this case the new values are not available. In this case, when a 9590** callback made with op==SQLITE_DELETE is actuall a write using the 9591** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 9592** the index of the column being written. In other cases, where the 9593** pre-update hook is being invoked for some other reason, including a 9594** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 9595** 9596** See also: [sqlite3_update_hook()] 9597*/ 9598#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9599void *sqlite3_preupdate_hook( 9600 sqlite3 *db, 9601 void(*xPreUpdate)( 9602 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9603 sqlite3 *db, /* Database handle */ 9604 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9605 char const *zDb, /* Database name */ 9606 char const *zName, /* Table name */ 9607 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9608 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9609 ), 9610 void* 9611); 9612int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9613int sqlite3_preupdate_count(sqlite3 *); 9614int sqlite3_preupdate_depth(sqlite3 *); 9615int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9616int sqlite3_preupdate_blobwrite(sqlite3 *); 9617#endif 9618 9619/* 9620** CAPI3REF: Low-level system error code 9621** METHOD: sqlite3 9622** 9623** ^Attempt to return the underlying operating system error code or error 9624** number that caused the most recent I/O error or failure to open a file. 9625** The return value is OS-dependent. For example, on unix systems, after 9626** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9627** called to get back the underlying "errno" that caused the problem, such 9628** as ENOSPC, EAUTH, EISDIR, and so forth. 9629*/ 9630int sqlite3_system_errno(sqlite3*); 9631 9632/* 9633** CAPI3REF: Database Snapshot 9634** KEYWORDS: {snapshot} {sqlite3_snapshot} 9635** 9636** An instance of the snapshot object records the state of a [WAL mode] 9637** database for some specific point in history. 9638** 9639** In [WAL mode], multiple [database connections] that are open on the 9640** same database file can each be reading a different historical version 9641** of the database file. When a [database connection] begins a read 9642** transaction, that connection sees an unchanging copy of the database 9643** as it existed for the point in time when the transaction first started. 9644** Subsequent changes to the database from other connections are not seen 9645** by the reader until a new read transaction is started. 9646** 9647** The sqlite3_snapshot object records state information about an historical 9648** version of the database file so that it is possible to later open a new read 9649** transaction that sees that historical version of the database rather than 9650** the most recent version. 9651*/ 9652typedef struct sqlite3_snapshot { 9653 unsigned char hidden[48]; 9654} sqlite3_snapshot; 9655 9656/* 9657** CAPI3REF: Record A Database Snapshot 9658** CONSTRUCTOR: sqlite3_snapshot 9659** 9660** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9661** new [sqlite3_snapshot] object that records the current state of 9662** schema S in database connection D. ^On success, the 9663** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9664** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9665** If there is not already a read-transaction open on schema S when 9666** this function is called, one is opened automatically. 9667** 9668** The following must be true for this function to succeed. If any of 9669** the following statements are false when sqlite3_snapshot_get() is 9670** called, SQLITE_ERROR is returned. The final value of *P is undefined 9671** in this case. 9672** 9673** <ul> 9674** <li> The database handle must not be in [autocommit mode]. 9675** 9676** <li> Schema S of [database connection] D must be a [WAL mode] database. 9677** 9678** <li> There must not be a write transaction open on schema S of database 9679** connection D. 9680** 9681** <li> One or more transactions must have been written to the current wal 9682** file since it was created on disk (by any connection). This means 9683** that a snapshot cannot be taken on a wal mode database with no wal 9684** file immediately after it is first opened. At least one transaction 9685** must be written to it first. 9686** </ul> 9687** 9688** This function may also return SQLITE_NOMEM. If it is called with the 9689** database handle in autocommit mode but fails for some other reason, 9690** whether or not a read transaction is opened on schema S is undefined. 9691** 9692** The [sqlite3_snapshot] object returned from a successful call to 9693** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9694** to avoid a memory leak. 9695** 9696** The [sqlite3_snapshot_get()] interface is only available when the 9697** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9698*/ 9699SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9700 sqlite3 *db, 9701 const char *zSchema, 9702 sqlite3_snapshot **ppSnapshot 9703); 9704 9705/* 9706** CAPI3REF: Start a read transaction on an historical snapshot 9707** METHOD: sqlite3_snapshot 9708** 9709** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9710** transaction or upgrades an existing one for schema S of 9711** [database connection] D such that the read transaction refers to 9712** historical [snapshot] P, rather than the most recent change to the 9713** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9714** on success or an appropriate [error code] if it fails. 9715** 9716** ^In order to succeed, the database connection must not be in 9717** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9718** is already a read transaction open on schema S, then the database handle 9719** must have no active statements (SELECT statements that have been passed 9720** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9721** SQLITE_ERROR is returned if either of these conditions is violated, or 9722** if schema S does not exist, or if the snapshot object is invalid. 9723** 9724** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9725** snapshot has been overwritten by a [checkpoint]. In this case 9726** SQLITE_ERROR_SNAPSHOT is returned. 9727** 9728** If there is already a read transaction open when this function is 9729** invoked, then the same read transaction remains open (on the same 9730** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9731** is returned. If another error code - for example SQLITE_PROTOCOL or an 9732** SQLITE_IOERR error code - is returned, then the final state of the 9733** read transaction is undefined. If SQLITE_OK is returned, then the 9734** read transaction is now open on database snapshot P. 9735** 9736** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9737** database connection D does not know that the database file for 9738** schema S is in [WAL mode]. A database connection might not know 9739** that the database file is in [WAL mode] if there has been no prior 9740** I/O on that database connection, or if the database entered [WAL mode] 9741** after the most recent I/O on the database connection.)^ 9742** (Hint: Run "[PRAGMA application_id]" against a newly opened 9743** database connection in order to make it ready to use snapshots.) 9744** 9745** The [sqlite3_snapshot_open()] interface is only available when the 9746** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9747*/ 9748SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9749 sqlite3 *db, 9750 const char *zSchema, 9751 sqlite3_snapshot *pSnapshot 9752); 9753 9754/* 9755** CAPI3REF: Destroy a snapshot 9756** DESTRUCTOR: sqlite3_snapshot 9757** 9758** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9759** The application must eventually free every [sqlite3_snapshot] object 9760** using this routine to avoid a memory leak. 9761** 9762** The [sqlite3_snapshot_free()] interface is only available when the 9763** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9764*/ 9765SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9766 9767/* 9768** CAPI3REF: Compare the ages of two snapshot handles. 9769** METHOD: sqlite3_snapshot 9770** 9771** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9772** of two valid snapshot handles. 9773** 9774** If the two snapshot handles are not associated with the same database 9775** file, the result of the comparison is undefined. 9776** 9777** Additionally, the result of the comparison is only valid if both of the 9778** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9779** last time the wal file was deleted. The wal file is deleted when the 9780** database is changed back to rollback mode or when the number of database 9781** clients drops to zero. If either snapshot handle was obtained before the 9782** wal file was last deleted, the value returned by this function 9783** is undefined. 9784** 9785** Otherwise, this API returns a negative value if P1 refers to an older 9786** snapshot than P2, zero if the two handles refer to the same database 9787** snapshot, and a positive value if P1 is a newer snapshot than P2. 9788** 9789** This interface is only available if SQLite is compiled with the 9790** [SQLITE_ENABLE_SNAPSHOT] option. 9791*/ 9792SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9793 sqlite3_snapshot *p1, 9794 sqlite3_snapshot *p2 9795); 9796 9797/* 9798** CAPI3REF: Recover snapshots from a wal file 9799** METHOD: sqlite3_snapshot 9800** 9801** If a [WAL file] remains on disk after all database connections close 9802** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9803** or because the last process to have the database opened exited without 9804** calling [sqlite3_close()]) and a new connection is subsequently opened 9805** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9806** will only be able to open the last transaction added to the WAL file 9807** even though the WAL file contains other valid transactions. 9808** 9809** This function attempts to scan the WAL file associated with database zDb 9810** of database handle db and make all valid snapshots available to 9811** sqlite3_snapshot_open(). It is an error if there is already a read 9812** transaction open on the database, or if the database is not a WAL mode 9813** database. 9814** 9815** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9816** 9817** This interface is only available if SQLite is compiled with the 9818** [SQLITE_ENABLE_SNAPSHOT] option. 9819*/ 9820SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9821 9822/* 9823** CAPI3REF: Serialize a database 9824** 9825** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9826** that is a serialization of the S database on [database connection] D. 9827** If P is not a NULL pointer, then the size of the database in bytes 9828** is written into *P. 9829** 9830** For an ordinary on-disk database file, the serialization is just a 9831** copy of the disk file. For an in-memory database or a "TEMP" database, 9832** the serialization is the same sequence of bytes which would be written 9833** to disk if that database where backed up to disk. 9834** 9835** The usual case is that sqlite3_serialize() copies the serialization of 9836** the database into memory obtained from [sqlite3_malloc64()] and returns 9837** a pointer to that memory. The caller is responsible for freeing the 9838** returned value to avoid a memory leak. However, if the F argument 9839** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9840** are made, and the sqlite3_serialize() function will return a pointer 9841** to the contiguous memory representation of the database that SQLite 9842** is currently using for that database, or NULL if the no such contiguous 9843** memory representation of the database exists. A contiguous memory 9844** representation of the database will usually only exist if there has 9845** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9846** values of D and S. 9847** The size of the database is written into *P even if the 9848** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9849** of the database exists. 9850** 9851** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9852** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9853** allocation error occurs. 9854** 9855** This interface is omitted if SQLite is compiled with the 9856** [SQLITE_OMIT_DESERIALIZE] option. 9857*/ 9858unsigned char *sqlite3_serialize( 9859 sqlite3 *db, /* The database connection */ 9860 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9861 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9862 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9863); 9864 9865/* 9866** CAPI3REF: Flags for sqlite3_serialize 9867** 9868** Zero or more of the following constants can be OR-ed together for 9869** the F argument to [sqlite3_serialize(D,S,P,F)]. 9870** 9871** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9872** a pointer to contiguous in-memory database that it is currently using, 9873** without making a copy of the database. If SQLite is not currently using 9874** a contiguous in-memory database, then this option causes 9875** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9876** using a contiguous in-memory database if it has been initialized by a 9877** prior call to [sqlite3_deserialize()]. 9878*/ 9879#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9880 9881/* 9882** CAPI3REF: Deserialize a database 9883** 9884** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9885** [database connection] D to disconnect from database S and then 9886** reopen S as an in-memory database based on the serialization contained 9887** in P. The serialized database P is N bytes in size. M is the size of 9888** the buffer P, which might be larger than N. If M is larger than N, and 9889** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9890** permitted to add content to the in-memory database as long as the total 9891** size does not exceed M bytes. 9892** 9893** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9894** invoke sqlite3_free() on the serialization buffer when the database 9895** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9896** SQLite will try to increase the buffer size using sqlite3_realloc64() 9897** if writes on the database cause it to grow larger than M bytes. 9898** 9899** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9900** database is currently in a read transaction or is involved in a backup 9901** operation. 9902** 9903** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9904** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9905** [sqlite3_free()] is invoked on argument P prior to returning. 9906** 9907** This interface is omitted if SQLite is compiled with the 9908** [SQLITE_OMIT_DESERIALIZE] option. 9909*/ 9910int sqlite3_deserialize( 9911 sqlite3 *db, /* The database connection */ 9912 const char *zSchema, /* Which DB to reopen with the deserialization */ 9913 unsigned char *pData, /* The serialized database content */ 9914 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9915 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9916 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9917); 9918 9919/* 9920** CAPI3REF: Flags for sqlite3_deserialize() 9921** 9922** The following are allowed values for 6th argument (the F argument) to 9923** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9924** 9925** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9926** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9927** and that SQLite should take ownership of this memory and automatically 9928** free it when it has finished using it. Without this flag, the caller 9929** is responsible for freeing any dynamically allocated memory. 9930** 9931** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9932** grow the size of the database using calls to [sqlite3_realloc64()]. This 9933** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9934** Without this flag, the deserialized database cannot increase in size beyond 9935** the number of bytes specified by the M parameter. 9936** 9937** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9938** should be treated as read-only. 9939*/ 9940#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9941#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9942#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9943 9944/* 9945** Undo the hack that converts floating point types to integer for 9946** builds on processors without floating point support. 9947*/ 9948#ifdef SQLITE_OMIT_FLOATING_POINT 9949# undef double 9950#endif 9951 9952#ifdef __cplusplus 9953} /* End of the 'extern "C"' block */ 9954#endif 9955#endif /* SQLITE3_H */ 9956