1/* 2** 2001 September 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 suppose 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** Add the ability to override 'extern' 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51 52/* 53** Add the ability to override 'cdecl' 54*/ 55#ifndef SQLITE_CDECL 56# define SQLITE_CDECL 57#endif 58 59/* 60** These no-op macros are used in front of interfaces to mark those 61** interfaces as either deprecated or experimental. New applications 62** should not use deprecated interfaces - they are supported for backwards 63** compatibility only. Application writers should be aware that 64** experimental interfaces are subject to change in point releases. 65** 66** These macros used to resolve to various kinds of compiler magic that 67** would generate warning messages when they were used. But that 68** compiler magic ended up generating such a flurry of bug reports 69** that we have taken it all out and gone back to using simple 70** noop macros. 71*/ 72#define SQLITE_DEPRECATED 73#define SQLITE_EXPERIMENTAL 74 75/* 76** Ensure these symbols were not defined by some previous header file. 77*/ 78#ifdef SQLITE_VERSION 79# undef SQLITE_VERSION 80#endif 81#ifdef SQLITE_VERSION_NUMBER 82# undef SQLITE_VERSION_NUMBER 83#endif 84 85/* 86** CAPI3REF: Compile-Time Library Version Numbers 87** 88** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 89** evaluates to a string literal that is the SQLite version in the 90** format "X.Y.Z" where X is the major version number (always 3 for 91** SQLite3) and Y is the minor version number and Z is the release number.)^ 92** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 93** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 94** numbers used in [SQLITE_VERSION].)^ 95** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 96** be larger than the release from which it is derived. Either Y will 97** be held constant and Z will be incremented or else Y will be incremented 98** and Z will be reset to zero. 99** 100** Since version 3.6.18, SQLite source code has been stored in the 101** <a href="http://www.fossil-scm.org/">Fossil configuration management 102** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 103** a string which identifies a particular check-in of SQLite 104** within its configuration management system. ^The SQLITE_SOURCE_ID 105** string contains the date and time of the check-in (UTC) and an SHA1 106** hash of the entire source tree. 107** 108** See also: [sqlite3_libversion()], 109** [sqlite3_libversion_number()], [sqlite3_sourceid()], 110** [sqlite_version()] and [sqlite_source_id()]. 111*/ 112#define SQLITE_VERSION "--VERS--" 113#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 114#define SQLITE_SOURCE_ID "--SOURCE-ID--" 115 116/* 117** CAPI3REF: Run-Time Library Version Numbers 118** KEYWORDS: sqlite3_version, sqlite3_sourceid 119** 120** These interfaces provide the same information as the [SQLITE_VERSION], 121** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 122** but are associated with the library instead of the header file. ^(Cautious 123** programmers might include assert() statements in their application to 124** verify that values returned by these interfaces match the macros in 125** the header, and thus insure that the application is 126** compiled with matching library and header files. 127** 128** <blockquote><pre> 129** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 130** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 131** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 132** </pre></blockquote>)^ 133** 134** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 135** macro. ^The sqlite3_libversion() function returns a pointer to the 136** to the sqlite3_version[] string constant. The sqlite3_libversion() 137** function is provided for use in DLLs since DLL users usually do not have 138** direct access to string constants within the DLL. ^The 139** sqlite3_libversion_number() function returns an integer equal to 140** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 141** a pointer to a string constant whose value is the same as the 142** [SQLITE_SOURCE_ID] C preprocessor macro. 143** 144** See also: [sqlite_version()] and [sqlite_source_id()]. 145*/ 146SQLITE_EXTERN const char sqlite3_version[]; 147const char *sqlite3_libversion(void); 148const char *sqlite3_sourceid(void); 149int sqlite3_libversion_number(void); 150 151/* 152** CAPI3REF: Run-Time Library Compilation Options Diagnostics 153** 154** ^The sqlite3_compileoption_used() function returns 0 or 1 155** indicating whether the specified option was defined at 156** compile time. ^The SQLITE_ prefix may be omitted from the 157** option name passed to sqlite3_compileoption_used(). 158** 159** ^The sqlite3_compileoption_get() function allows iterating 160** over the list of options that were defined at compile time by 161** returning the N-th compile time option string. ^If N is out of range, 162** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 163** prefix is omitted from any strings returned by 164** sqlite3_compileoption_get(). 165** 166** ^Support for the diagnostic functions sqlite3_compileoption_used() 167** and sqlite3_compileoption_get() may be omitted by specifying the 168** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 169** 170** See also: SQL functions [sqlite_compileoption_used()] and 171** [sqlite_compileoption_get()] and the [compile_options pragma]. 172*/ 173#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 174int sqlite3_compileoption_used(const char *zOptName); 175const char *sqlite3_compileoption_get(int N); 176#endif 177 178/* 179** CAPI3REF: Test To See If The Library Is Threadsafe 180** 181** ^The sqlite3_threadsafe() function returns zero if and only if 182** SQLite was compiled with mutexing code omitted due to the 183** [SQLITE_THREADSAFE] compile-time option being set to 0. 184** 185** SQLite can be compiled with or without mutexes. When 186** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 187** are enabled and SQLite is threadsafe. When the 188** [SQLITE_THREADSAFE] macro is 0, 189** the mutexes are omitted. Without the mutexes, it is not safe 190** to use SQLite concurrently from more than one thread. 191** 192** Enabling mutexes incurs a measurable performance penalty. 193** So if speed is of utmost importance, it makes sense to disable 194** the mutexes. But for maximum safety, mutexes should be enabled. 195** ^The default behavior is for mutexes to be enabled. 196** 197** This interface can be used by an application to make sure that the 198** version of SQLite that it is linking against was compiled with 199** the desired setting of the [SQLITE_THREADSAFE] macro. 200** 201** This interface only reports on the compile-time mutex setting 202** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 203** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 204** can be fully or partially disabled using a call to [sqlite3_config()] 205** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 206** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 207** sqlite3_threadsafe() function shows only the compile-time setting of 208** thread safety, not any run-time changes to that setting made by 209** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 210** is unchanged by calls to sqlite3_config().)^ 211** 212** See the [threading mode] documentation for additional information. 213*/ 214int sqlite3_threadsafe(void); 215 216/* 217** CAPI3REF: Database Connection Handle 218** KEYWORDS: {database connection} {database connections} 219** 220** Each open SQLite database is represented by a pointer to an instance of 221** the opaque structure named "sqlite3". It is useful to think of an sqlite3 222** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 223** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 224** and [sqlite3_close_v2()] are its destructors. There are many other 225** interfaces (such as 226** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 227** [sqlite3_busy_timeout()] to name but three) that are methods on an 228** sqlite3 object. 229*/ 230typedef struct sqlite3 sqlite3; 231 232/* 233** CAPI3REF: 64-Bit Integer Types 234** KEYWORDS: sqlite_int64 sqlite_uint64 235** 236** Because there is no cross-platform way to specify 64-bit integer types 237** SQLite includes typedefs for 64-bit signed and unsigned integers. 238** 239** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 240** The sqlite_int64 and sqlite_uint64 types are supported for backwards 241** compatibility only. 242** 243** ^The sqlite3_int64 and sqlite_int64 types can store integer values 244** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 245** sqlite3_uint64 and sqlite_uint64 types can store integer values 246** between 0 and +18446744073709551615 inclusive. 247*/ 248#ifdef SQLITE_INT64_TYPE 249 typedef SQLITE_INT64_TYPE sqlite_int64; 250 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 251#elif defined(_MSC_VER) || defined(__BORLANDC__) 252 typedef __int64 sqlite_int64; 253 typedef unsigned __int64 sqlite_uint64; 254#else 255 typedef long long int sqlite_int64; 256 typedef unsigned long long int sqlite_uint64; 257#endif 258typedef sqlite_int64 sqlite3_int64; 259typedef sqlite_uint64 sqlite3_uint64; 260 261/* 262** If compiling for a processor that lacks floating point support, 263** substitute integer for floating-point. 264*/ 265#ifdef SQLITE_OMIT_FLOATING_POINT 266# define double sqlite3_int64 267#endif 268 269/* 270** CAPI3REF: Closing A Database Connection 271** 272** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 273** for the [sqlite3] object. 274** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 275** the [sqlite3] object is successfully destroyed and all associated 276** resources are deallocated. 277** 278** ^If the database connection is associated with unfinalized prepared 279** statements or unfinished sqlite3_backup objects then sqlite3_close() 280** will leave the database connection open and return [SQLITE_BUSY]. 281** ^If sqlite3_close_v2() is called with unfinalized prepared statements 282** and/or unfinished sqlite3_backups, then the database connection becomes 283** an unusable "zombie" which will automatically be deallocated when the 284** last prepared statement is finalized or the last sqlite3_backup is 285** finished. The sqlite3_close_v2() interface is intended for use with 286** host languages that are garbage collected, and where the order in which 287** destructors are called is arbitrary. 288** 289** Applications should [sqlite3_finalize | finalize] all [prepared statements], 290** [sqlite3_blob_close | close] all [BLOB handles], and 291** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 292** with the [sqlite3] object prior to attempting to close the object. ^If 293** sqlite3_close_v2() is called on a [database connection] that still has 294** outstanding [prepared statements], [BLOB handles], and/or 295** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 296** of resources is deferred until all [prepared statements], [BLOB handles], 297** and [sqlite3_backup] objects are also destroyed. 298** 299** ^If an [sqlite3] object is destroyed while a transaction is open, 300** the transaction is automatically rolled back. 301** 302** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 303** must be either a NULL 304** pointer or an [sqlite3] object pointer obtained 305** from [sqlite3_open()], [sqlite3_open16()], or 306** [sqlite3_open_v2()], and not previously closed. 307** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 308** argument is a harmless no-op. 309*/ 310int sqlite3_close(sqlite3*); 311int sqlite3_close_v2(sqlite3*); 312 313/* 314** The type for a callback function. 315** This is legacy and deprecated. It is included for historical 316** compatibility and is not documented. 317*/ 318typedef int (*sqlite3_callback)(void*,int,char**, char**); 319 320/* 321** CAPI3REF: One-Step Query Execution Interface 322** 323** The sqlite3_exec() interface is a convenience wrapper around 324** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 325** that allows an application to run multiple statements of SQL 326** without having to use a lot of C code. 327** 328** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 329** semicolon-separate SQL statements passed into its 2nd argument, 330** in the context of the [database connection] passed in as its 1st 331** argument. ^If the callback function of the 3rd argument to 332** sqlite3_exec() is not NULL, then it is invoked for each result row 333** coming out of the evaluated SQL statements. ^The 4th argument to 334** sqlite3_exec() is relayed through to the 1st argument of each 335** callback invocation. ^If the callback pointer to sqlite3_exec() 336** is NULL, then no callback is ever invoked and result rows are 337** ignored. 338** 339** ^If an error occurs while evaluating the SQL statements passed into 340** sqlite3_exec(), then execution of the current statement stops and 341** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 342** is not NULL then any error message is written into memory obtained 343** from [sqlite3_malloc()] and passed back through the 5th parameter. 344** To avoid memory leaks, the application should invoke [sqlite3_free()] 345** on error message strings returned through the 5th parameter of 346** of sqlite3_exec() after the error message string is no longer needed. 347** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 348** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 349** NULL before returning. 350** 351** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 352** routine returns SQLITE_ABORT without invoking the callback again and 353** without running any subsequent SQL statements. 354** 355** ^The 2nd argument to the sqlite3_exec() callback function is the 356** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 357** callback is an array of pointers to strings obtained as if from 358** [sqlite3_column_text()], one for each column. ^If an element of a 359** result row is NULL then the corresponding string pointer for the 360** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 361** sqlite3_exec() callback is an array of pointers to strings where each 362** entry represents the name of corresponding result column as obtained 363** from [sqlite3_column_name()]. 364** 365** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 366** to an empty string, or a pointer that contains only whitespace and/or 367** SQL comments, then no SQL statements are evaluated and the database 368** is not changed. 369** 370** Restrictions: 371** 372** <ul> 373** <li> The application must insure that the 1st parameter to sqlite3_exec() 374** is a valid and open [database connection]. 375** <li> The application must not close the [database connection] specified by 376** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 377** <li> The application must not modify the SQL statement text passed into 378** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 379** </ul> 380*/ 381int sqlite3_exec( 382 sqlite3*, /* An open database */ 383 const char *sql, /* SQL to be evaluated */ 384 int (*callback)(void*,int,char**,char**), /* Callback function */ 385 void *, /* 1st argument to callback */ 386 char **errmsg /* Error msg written here */ 387); 388 389/* 390** CAPI3REF: Result Codes 391** KEYWORDS: {result code definitions} 392** 393** Many SQLite functions return an integer result code from the set shown 394** here in order to indicate success or failure. 395** 396** New error codes may be added in future versions of SQLite. 397** 398** See also: [extended result code definitions] 399*/ 400#define SQLITE_OK 0 /* Successful result */ 401/* beginning-of-error-codes */ 402#define SQLITE_ERROR 1 /* SQL error or missing database */ 403#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 404#define SQLITE_PERM 3 /* Access permission denied */ 405#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 406#define SQLITE_BUSY 5 /* The database file is locked */ 407#define SQLITE_LOCKED 6 /* A table in the database is locked */ 408#define SQLITE_NOMEM 7 /* A malloc() failed */ 409#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 410#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 411#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 412#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 413#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 414#define SQLITE_FULL 13 /* Insertion failed because database is full */ 415#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 416#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 417#define SQLITE_EMPTY 16 /* Database is empty */ 418#define SQLITE_SCHEMA 17 /* The database schema changed */ 419#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 420#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 421#define SQLITE_MISMATCH 20 /* Data type mismatch */ 422#define SQLITE_MISUSE 21 /* Library used incorrectly */ 423#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 424#define SQLITE_AUTH 23 /* Authorization denied */ 425#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 426#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 427#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 428#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 429#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 430#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 431#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 432/* end-of-error-codes */ 433 434/* 435** CAPI3REF: Extended Result Codes 436** KEYWORDS: {extended result code definitions} 437** 438** In its default configuration, SQLite API routines return one of 30 integer 439** [result codes]. However, experience has shown that many of 440** these result codes are too coarse-grained. They do not provide as 441** much information about problems as programmers might like. In an effort to 442** address this, newer versions of SQLite (version 3.3.8 and later) include 443** support for additional result codes that provide more detailed information 444** about errors. These [extended result codes] are enabled or disabled 445** on a per database connection basis using the 446** [sqlite3_extended_result_codes()] API. Or, the extended code for 447** the most recent error can be obtained using 448** [sqlite3_extended_errcode()]. 449*/ 450#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 451#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 452#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 453#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 454#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 455#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 456#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 457#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 458#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 459#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 460#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 461#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 462#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 463#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 464#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 465#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 466#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 467#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 468#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 469#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 470#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 471#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 472#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 473#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 474#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 475#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 476#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 477#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 478#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 479#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 480#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 481#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 482#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 483#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 484#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 485#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 486#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 487#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 488#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 489#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 490#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 491#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 492#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 493#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 494#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 495#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 496#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 497#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 498#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 499#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 500#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 501#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 502#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 503 504/* 505** CAPI3REF: Flags For File Open Operations 506** 507** These bit values are intended for use in the 508** 3rd parameter to the [sqlite3_open_v2()] interface and 509** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 510*/ 511#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 512#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 513#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 514#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 515#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 516#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 517#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 518#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 519#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 520#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 521#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 522#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 523#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 524#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 525#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 526#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 527#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 528#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 529#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 530#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 531 532/* Reserved: 0x00F00000 */ 533 534/* 535** CAPI3REF: Device Characteristics 536** 537** The xDeviceCharacteristics method of the [sqlite3_io_methods] 538** object returns an integer which is a vector of these 539** bit values expressing I/O characteristics of the mass storage 540** device that holds the file that the [sqlite3_io_methods] 541** refers to. 542** 543** The SQLITE_IOCAP_ATOMIC property means that all writes of 544** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 545** mean that writes of blocks that are nnn bytes in size and 546** are aligned to an address which is an integer multiple of 547** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 548** that when data is appended to a file, the data is appended 549** first then the size of the file is extended, never the other 550** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 551** information is written to disk in the same order as calls 552** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 553** after reboot following a crash or power loss, the only bytes in a 554** file that were written at the application level might have changed 555** and that adjacent bytes, even bytes within the same sector are 556** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 557** flag indicate that a file cannot be deleted when open. The 558** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 559** read-only media and cannot be changed even by processes with 560** elevated privileges. 561*/ 562#define SQLITE_IOCAP_ATOMIC 0x00000001 563#define SQLITE_IOCAP_ATOMIC512 0x00000002 564#define SQLITE_IOCAP_ATOMIC1K 0x00000004 565#define SQLITE_IOCAP_ATOMIC2K 0x00000008 566#define SQLITE_IOCAP_ATOMIC4K 0x00000010 567#define SQLITE_IOCAP_ATOMIC8K 0x00000020 568#define SQLITE_IOCAP_ATOMIC16K 0x00000040 569#define SQLITE_IOCAP_ATOMIC32K 0x00000080 570#define SQLITE_IOCAP_ATOMIC64K 0x00000100 571#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 572#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 573#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 574#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 575#define SQLITE_IOCAP_IMMUTABLE 0x00002000 576 577/* 578** CAPI3REF: File Locking Levels 579** 580** SQLite uses one of these integer values as the second 581** argument to calls it makes to the xLock() and xUnlock() methods 582** of an [sqlite3_io_methods] object. 583*/ 584#define SQLITE_LOCK_NONE 0 585#define SQLITE_LOCK_SHARED 1 586#define SQLITE_LOCK_RESERVED 2 587#define SQLITE_LOCK_PENDING 3 588#define SQLITE_LOCK_EXCLUSIVE 4 589 590/* 591** CAPI3REF: Synchronization Type Flags 592** 593** When SQLite invokes the xSync() method of an 594** [sqlite3_io_methods] object it uses a combination of 595** these integer values as the second argument. 596** 597** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 598** sync operation only needs to flush data to mass storage. Inode 599** information need not be flushed. If the lower four bits of the flag 600** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 601** If the lower four bits equal SQLITE_SYNC_FULL, that means 602** to use Mac OS X style fullsync instead of fsync(). 603** 604** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 605** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 606** settings. The [synchronous pragma] determines when calls to the 607** xSync VFS method occur and applies uniformly across all platforms. 608** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 609** energetic or rigorous or forceful the sync operations are and 610** only make a difference on Mac OSX for the default SQLite code. 611** (Third-party VFS implementations might also make the distinction 612** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 613** operating systems natively supported by SQLite, only Mac OSX 614** cares about the difference.) 615*/ 616#define SQLITE_SYNC_NORMAL 0x00002 617#define SQLITE_SYNC_FULL 0x00003 618#define SQLITE_SYNC_DATAONLY 0x00010 619 620/* 621** CAPI3REF: OS Interface Open File Handle 622** 623** An [sqlite3_file] object represents an open file in the 624** [sqlite3_vfs | OS interface layer]. Individual OS interface 625** implementations will 626** want to subclass this object by appending additional fields 627** for their own use. The pMethods entry is a pointer to an 628** [sqlite3_io_methods] object that defines methods for performing 629** I/O operations on the open file. 630*/ 631typedef struct sqlite3_file sqlite3_file; 632struct sqlite3_file { 633 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 634}; 635 636/* 637** CAPI3REF: OS Interface File Virtual Methods Object 638** 639** Every file opened by the [sqlite3_vfs.xOpen] method populates an 640** [sqlite3_file] object (or, more commonly, a subclass of the 641** [sqlite3_file] object) with a pointer to an instance of this object. 642** This object defines the methods used to perform various operations 643** against the open file represented by the [sqlite3_file] object. 644** 645** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 646** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 647** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 648** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 649** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 650** to NULL. 651** 652** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 653** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 654** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 655** flag may be ORed in to indicate that only the data of the file 656** and not its inode needs to be synced. 657** 658** The integer values to xLock() and xUnlock() are one of 659** <ul> 660** <li> [SQLITE_LOCK_NONE], 661** <li> [SQLITE_LOCK_SHARED], 662** <li> [SQLITE_LOCK_RESERVED], 663** <li> [SQLITE_LOCK_PENDING], or 664** <li> [SQLITE_LOCK_EXCLUSIVE]. 665** </ul> 666** xLock() increases the lock. xUnlock() decreases the lock. 667** The xCheckReservedLock() method checks whether any database connection, 668** either in this process or in some other process, is holding a RESERVED, 669** PENDING, or EXCLUSIVE lock on the file. It returns true 670** if such a lock exists and false otherwise. 671** 672** The xFileControl() method is a generic interface that allows custom 673** VFS implementations to directly control an open file using the 674** [sqlite3_file_control()] interface. The second "op" argument is an 675** integer opcode. The third argument is a generic pointer intended to 676** point to a structure that may contain arguments or space in which to 677** write return values. Potential uses for xFileControl() might be 678** functions to enable blocking locks with timeouts, to change the 679** locking strategy (for example to use dot-file locks), to inquire 680** about the status of a lock, or to break stale locks. The SQLite 681** core reserves all opcodes less than 100 for its own use. 682** A [file control opcodes | list of opcodes] less than 100 is available. 683** Applications that define a custom xFileControl method should use opcodes 684** greater than 100 to avoid conflicts. VFS implementations should 685** return [SQLITE_NOTFOUND] for file control opcodes that they do not 686** recognize. 687** 688** The xSectorSize() method returns the sector size of the 689** device that underlies the file. The sector size is the 690** minimum write that can be performed without disturbing 691** other bytes in the file. The xDeviceCharacteristics() 692** method returns a bit vector describing behaviors of the 693** underlying device: 694** 695** <ul> 696** <li> [SQLITE_IOCAP_ATOMIC] 697** <li> [SQLITE_IOCAP_ATOMIC512] 698** <li> [SQLITE_IOCAP_ATOMIC1K] 699** <li> [SQLITE_IOCAP_ATOMIC2K] 700** <li> [SQLITE_IOCAP_ATOMIC4K] 701** <li> [SQLITE_IOCAP_ATOMIC8K] 702** <li> [SQLITE_IOCAP_ATOMIC16K] 703** <li> [SQLITE_IOCAP_ATOMIC32K] 704** <li> [SQLITE_IOCAP_ATOMIC64K] 705** <li> [SQLITE_IOCAP_SAFE_APPEND] 706** <li> [SQLITE_IOCAP_SEQUENTIAL] 707** </ul> 708** 709** The SQLITE_IOCAP_ATOMIC property means that all writes of 710** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 711** mean that writes of blocks that are nnn bytes in size and 712** are aligned to an address which is an integer multiple of 713** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 714** that when data is appended to a file, the data is appended 715** first then the size of the file is extended, never the other 716** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 717** information is written to disk in the same order as calls 718** to xWrite(). 719** 720** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 721** in the unread portions of the buffer with zeros. A VFS that 722** fails to zero-fill short reads might seem to work. However, 723** failure to zero-fill short reads will eventually lead to 724** database corruption. 725*/ 726typedef struct sqlite3_io_methods sqlite3_io_methods; 727struct sqlite3_io_methods { 728 int iVersion; 729 int (*xClose)(sqlite3_file*); 730 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 731 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 732 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 733 int (*xSync)(sqlite3_file*, int flags); 734 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 735 int (*xLock)(sqlite3_file*, int); 736 int (*xUnlock)(sqlite3_file*, int); 737 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 738 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 739 int (*xSectorSize)(sqlite3_file*); 740 int (*xDeviceCharacteristics)(sqlite3_file*); 741 /* Methods above are valid for version 1 */ 742 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 743 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 744 void (*xShmBarrier)(sqlite3_file*); 745 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 746 /* Methods above are valid for version 2 */ 747 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 748 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 749 /* Methods above are valid for version 3 */ 750 /* Additional methods may be added in future releases */ 751}; 752 753/* 754** CAPI3REF: Standard File Control Opcodes 755** KEYWORDS: {file control opcodes} {file control opcode} 756** 757** These integer constants are opcodes for the xFileControl method 758** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 759** interface. 760** 761** <ul> 762** <li>[[SQLITE_FCNTL_LOCKSTATE]] 763** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 764** opcode causes the xFileControl method to write the current state of 765** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 766** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 767** into an integer that the pArg argument points to. This capability 768** is used during testing and is only available when the SQLITE_TEST 769** compile-time option is used. 770** 771** <li>[[SQLITE_FCNTL_SIZE_HINT]] 772** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 773** layer a hint of how large the database file will grow to be during the 774** current transaction. This hint is not guaranteed to be accurate but it 775** is often close. The underlying VFS might choose to preallocate database 776** file space based on this hint in order to help writes to the database 777** file run faster. 778** 779** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 780** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 781** extends and truncates the database file in chunks of a size specified 782** by the user. The fourth argument to [sqlite3_file_control()] should 783** point to an integer (type int) containing the new chunk-size to use 784** for the nominated database. Allocating database file space in large 785** chunks (say 1MB at a time), may reduce file-system fragmentation and 786** improve performance on some systems. 787** 788** <li>[[SQLITE_FCNTL_FILE_POINTER]] 789** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 790** to the [sqlite3_file] object associated with a particular database 791** connection. See the [sqlite3_file_control()] documentation for 792** additional information. 793** 794** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 795** No longer in use. 796** 797** <li>[[SQLITE_FCNTL_SYNC]] 798** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 799** sent to the VFS immediately before the xSync method is invoked on a 800** database file descriptor. Or, if the xSync method is not invoked 801** because the user has configured SQLite with 802** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 803** of the xSync method. In most cases, the pointer argument passed with 804** this file-control is NULL. However, if the database file is being synced 805** as part of a multi-database commit, the argument points to a nul-terminated 806** string containing the transactions master-journal file name. VFSes that 807** do not need this signal should silently ignore this opcode. Applications 808** should not call [sqlite3_file_control()] with this opcode as doing so may 809** disrupt the operation of the specialized VFSes that do require it. 810** 811** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 812** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 813** and sent to the VFS after a transaction has been committed immediately 814** but before the database is unlocked. VFSes that do not need this signal 815** should silently ignore this opcode. Applications should not call 816** [sqlite3_file_control()] with this opcode as doing so may disrupt the 817** operation of the specialized VFSes that do require it. 818** 819** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 820** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 821** retry counts and intervals for certain disk I/O operations for the 822** windows [VFS] in order to provide robustness in the presence of 823** anti-virus programs. By default, the windows VFS will retry file read, 824** file write, and file delete operations up to 10 times, with a delay 825** of 25 milliseconds before the first retry and with the delay increasing 826** by an additional 25 milliseconds with each subsequent retry. This 827** opcode allows these two values (10 retries and 25 milliseconds of delay) 828** to be adjusted. The values are changed for all database connections 829** within the same process. The argument is a pointer to an array of two 830** integers where the first integer i the new retry count and the second 831** integer is the delay. If either integer is negative, then the setting 832** is not changed but instead the prior value of that setting is written 833** into the array entry, allowing the current retry settings to be 834** interrogated. The zDbName parameter is ignored. 835** 836** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 837** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 838** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 839** write ahead log and shared memory files used for transaction control 840** are automatically deleted when the latest connection to the database 841** closes. Setting persistent WAL mode causes those files to persist after 842** close. Persisting the files is useful when other processes that do not 843** have write permission on the directory containing the database file want 844** to read the database file, as the WAL and shared memory files must exist 845** in order for the database to be readable. The fourth parameter to 846** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 847** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 848** WAL mode. If the integer is -1, then it is overwritten with the current 849** WAL persistence setting. 850** 851** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 852** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 853** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 854** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 855** xDeviceCharacteristics methods. The fourth parameter to 856** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 857** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 858** mode. If the integer is -1, then it is overwritten with the current 859** zero-damage mode setting. 860** 861** <li>[[SQLITE_FCNTL_OVERWRITE]] 862** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 863** a write transaction to indicate that, unless it is rolled back for some 864** reason, the entire database file will be overwritten by the current 865** transaction. This is used by VACUUM operations. 866** 867** <li>[[SQLITE_FCNTL_VFSNAME]] 868** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 869** all [VFSes] in the VFS stack. The names are of all VFS shims and the 870** final bottom-level VFS are written into memory obtained from 871** [sqlite3_malloc()] and the result is stored in the char* variable 872** that the fourth parameter of [sqlite3_file_control()] points to. 873** The caller is responsible for freeing the memory when done. As with 874** all file-control actions, there is no guarantee that this will actually 875** do anything. Callers should initialize the char* variable to a NULL 876** pointer in case this file-control is not implemented. This file-control 877** is intended for diagnostic use only. 878** 879** <li>[[SQLITE_FCNTL_PRAGMA]] 880** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 881** file control is sent to the open [sqlite3_file] object corresponding 882** to the database file to which the pragma statement refers. ^The argument 883** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 884** pointers to strings (char**) in which the second element of the array 885** is the name of the pragma and the third element is the argument to the 886** pragma or NULL if the pragma has no argument. ^The handler for an 887** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 888** of the char** argument point to a string obtained from [sqlite3_mprintf()] 889** or the equivalent and that string will become the result of the pragma or 890** the error message if the pragma fails. ^If the 891** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 892** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 893** file control returns [SQLITE_OK], then the parser assumes that the 894** VFS has handled the PRAGMA itself and the parser generates a no-op 895** prepared statement if result string is NULL, or that returns a copy 896** of the result string if the string is non-NULL. 897** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 898** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 899** that the VFS encountered an error while handling the [PRAGMA] and the 900** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 901** file control occurs at the beginning of pragma statement analysis and so 902** it is able to override built-in [PRAGMA] statements. 903** 904** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 905** ^The [SQLITE_FCNTL_BUSYHANDLER] 906** file-control may be invoked by SQLite on the database file handle 907** shortly after it is opened in order to provide a custom VFS with access 908** to the connections busy-handler callback. The argument is of type (void **) 909** - an array of two (void *) values. The first (void *) actually points 910** to a function of type (int (*)(void *)). In order to invoke the connections 911** busy-handler, this function should be invoked with the second (void *) in 912** the array as the only argument. If it returns non-zero, then the operation 913** should be retried. If it returns zero, the custom VFS should abandon the 914** current operation. 915** 916** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 917** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 918** to have SQLite generate a 919** temporary filename using the same algorithm that is followed to generate 920** temporary filenames for TEMP tables and other internal uses. The 921** argument should be a char** which will be filled with the filename 922** written into memory obtained from [sqlite3_malloc()]. The caller should 923** invoke [sqlite3_free()] on the result to avoid a memory leak. 924** 925** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 926** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 927** maximum number of bytes that will be used for memory-mapped I/O. 928** The argument is a pointer to a value of type sqlite3_int64 that 929** is an advisory maximum number of bytes in the file to memory map. The 930** pointer is overwritten with the old value. The limit is not changed if 931** the value originally pointed to is negative, and so the current limit 932** can be queried by passing in a pointer to a negative number. This 933** file-control is used internally to implement [PRAGMA mmap_size]. 934** 935** <li>[[SQLITE_FCNTL_TRACE]] 936** The [SQLITE_FCNTL_TRACE] file control provides advisory information 937** to the VFS about what the higher layers of the SQLite stack are doing. 938** This file control is used by some VFS activity tracing [shims]. 939** The argument is a zero-terminated string. Higher layers in the 940** SQLite stack may generate instances of this file control if 941** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 942** 943** <li>[[SQLITE_FCNTL_HAS_MOVED]] 944** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 945** pointer to an integer and it writes a boolean into that integer depending 946** on whether or not the file has been renamed, moved, or deleted since it 947** was first opened. 948** 949** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 950** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 951** opcode causes the xFileControl method to swap the file handle with the one 952** pointed to by the pArg argument. This capability is used during testing 953** and only needs to be supported when SQLITE_TEST is defined. 954** 955** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 956** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 957** be advantageous to block on the next WAL lock if the lock is not immediately 958** available. The WAL subsystem issues this signal during rare 959** circumstances in order to fix a problem with priority inversion. 960** Applications should <em>not</em> use this file-control. 961** 962** </ul> 963*/ 964#define SQLITE_FCNTL_LOCKSTATE 1 965#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 966#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 967#define SQLITE_FCNTL_LAST_ERRNO 4 968#define SQLITE_FCNTL_SIZE_HINT 5 969#define SQLITE_FCNTL_CHUNK_SIZE 6 970#define SQLITE_FCNTL_FILE_POINTER 7 971#define SQLITE_FCNTL_SYNC_OMITTED 8 972#define SQLITE_FCNTL_WIN32_AV_RETRY 9 973#define SQLITE_FCNTL_PERSIST_WAL 10 974#define SQLITE_FCNTL_OVERWRITE 11 975#define SQLITE_FCNTL_VFSNAME 12 976#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 977#define SQLITE_FCNTL_PRAGMA 14 978#define SQLITE_FCNTL_BUSYHANDLER 15 979#define SQLITE_FCNTL_TEMPFILENAME 16 980#define SQLITE_FCNTL_MMAP_SIZE 18 981#define SQLITE_FCNTL_TRACE 19 982#define SQLITE_FCNTL_HAS_MOVED 20 983#define SQLITE_FCNTL_SYNC 21 984#define SQLITE_FCNTL_COMMIT_PHASETWO 22 985#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 986#define SQLITE_FCNTL_WAL_BLOCK 24 987 988/* deprecated names */ 989#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 990#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 991#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 992 993 994/* 995** CAPI3REF: Mutex Handle 996** 997** The mutex module within SQLite defines [sqlite3_mutex] to be an 998** abstract type for a mutex object. The SQLite core never looks 999** at the internal representation of an [sqlite3_mutex]. It only 1000** deals with pointers to the [sqlite3_mutex] object. 1001** 1002** Mutexes are created using [sqlite3_mutex_alloc()]. 1003*/ 1004typedef struct sqlite3_mutex sqlite3_mutex; 1005 1006/* 1007** CAPI3REF: OS Interface Object 1008** 1009** An instance of the sqlite3_vfs object defines the interface between 1010** the SQLite core and the underlying operating system. The "vfs" 1011** in the name of the object stands for "virtual file system". See 1012** the [VFS | VFS documentation] for further information. 1013** 1014** The value of the iVersion field is initially 1 but may be larger in 1015** future versions of SQLite. Additional fields may be appended to this 1016** object when the iVersion value is increased. Note that the structure 1017** of the sqlite3_vfs object changes in the transaction between 1018** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1019** modified. 1020** 1021** The szOsFile field is the size of the subclassed [sqlite3_file] 1022** structure used by this VFS. mxPathname is the maximum length of 1023** a pathname in this VFS. 1024** 1025** Registered sqlite3_vfs objects are kept on a linked list formed by 1026** the pNext pointer. The [sqlite3_vfs_register()] 1027** and [sqlite3_vfs_unregister()] interfaces manage this list 1028** in a thread-safe way. The [sqlite3_vfs_find()] interface 1029** searches the list. Neither the application code nor the VFS 1030** implementation should use the pNext pointer. 1031** 1032** The pNext field is the only field in the sqlite3_vfs 1033** structure that SQLite will ever modify. SQLite will only access 1034** or modify this field while holding a particular static mutex. 1035** The application should never modify anything within the sqlite3_vfs 1036** object once the object has been registered. 1037** 1038** The zName field holds the name of the VFS module. The name must 1039** be unique across all VFS modules. 1040** 1041** [[sqlite3_vfs.xOpen]] 1042** ^SQLite guarantees that the zFilename parameter to xOpen 1043** is either a NULL pointer or string obtained 1044** from xFullPathname() with an optional suffix added. 1045** ^If a suffix is added to the zFilename parameter, it will 1046** consist of a single "-" character followed by no more than 1047** 11 alphanumeric and/or "-" characters. 1048** ^SQLite further guarantees that 1049** the string will be valid and unchanged until xClose() is 1050** called. Because of the previous sentence, 1051** the [sqlite3_file] can safely store a pointer to the 1052** filename if it needs to remember the filename for some reason. 1053** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1054** must invent its own temporary name for the file. ^Whenever the 1055** xFilename parameter is NULL it will also be the case that the 1056** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1057** 1058** The flags argument to xOpen() includes all bits set in 1059** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1060** or [sqlite3_open16()] is used, then flags includes at least 1061** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1062** If xOpen() opens a file read-only then it sets *pOutFlags to 1063** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1064** 1065** ^(SQLite will also add one of the following flags to the xOpen() 1066** call, depending on the object being opened: 1067** 1068** <ul> 1069** <li> [SQLITE_OPEN_MAIN_DB] 1070** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1071** <li> [SQLITE_OPEN_TEMP_DB] 1072** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1073** <li> [SQLITE_OPEN_TRANSIENT_DB] 1074** <li> [SQLITE_OPEN_SUBJOURNAL] 1075** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1076** <li> [SQLITE_OPEN_WAL] 1077** </ul>)^ 1078** 1079** The file I/O implementation can use the object type flags to 1080** change the way it deals with files. For example, an application 1081** that does not care about crash recovery or rollback might make 1082** the open of a journal file a no-op. Writes to this journal would 1083** also be no-ops, and any attempt to read the journal would return 1084** SQLITE_IOERR. Or the implementation might recognize that a database 1085** file will be doing page-aligned sector reads and writes in a random 1086** order and set up its I/O subsystem accordingly. 1087** 1088** SQLite might also add one of the following flags to the xOpen method: 1089** 1090** <ul> 1091** <li> [SQLITE_OPEN_DELETEONCLOSE] 1092** <li> [SQLITE_OPEN_EXCLUSIVE] 1093** </ul> 1094** 1095** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1096** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1097** will be set for TEMP databases and their journals, transient 1098** databases, and subjournals. 1099** 1100** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1101** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1102** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1103** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1104** SQLITE_OPEN_CREATE, is used to indicate that file should always 1105** be created, and that it is an error if it already exists. 1106** It is <i>not</i> used to indicate the file should be opened 1107** for exclusive access. 1108** 1109** ^At least szOsFile bytes of memory are allocated by SQLite 1110** to hold the [sqlite3_file] structure passed as the third 1111** argument to xOpen. The xOpen method does not have to 1112** allocate the structure; it should just fill it in. Note that 1113** the xOpen method must set the sqlite3_file.pMethods to either 1114** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1115** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1116** element will be valid after xOpen returns regardless of the success 1117** or failure of the xOpen call. 1118** 1119** [[sqlite3_vfs.xAccess]] 1120** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1121** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1122** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1123** to test whether a file is at least readable. The file can be a 1124** directory. 1125** 1126** ^SQLite will always allocate at least mxPathname+1 bytes for the 1127** output buffer xFullPathname. The exact size of the output buffer 1128** is also passed as a parameter to both methods. If the output buffer 1129** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1130** handled as a fatal error by SQLite, vfs implementations should endeavor 1131** to prevent this by setting mxPathname to a sufficiently large value. 1132** 1133** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1134** interfaces are not strictly a part of the filesystem, but they are 1135** included in the VFS structure for completeness. 1136** The xRandomness() function attempts to return nBytes bytes 1137** of good-quality randomness into zOut. The return value is 1138** the actual number of bytes of randomness obtained. 1139** The xSleep() method causes the calling thread to sleep for at 1140** least the number of microseconds given. ^The xCurrentTime() 1141** method returns a Julian Day Number for the current date and time as 1142** a floating point value. 1143** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1144** Day Number multiplied by 86400000 (the number of milliseconds in 1145** a 24-hour day). 1146** ^SQLite will use the xCurrentTimeInt64() method to get the current 1147** date and time if that method is available (if iVersion is 2 or 1148** greater and the function pointer is not NULL) and will fall back 1149** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1150** 1151** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1152** are not used by the SQLite core. These optional interfaces are provided 1153** by some VFSes to facilitate testing of the VFS code. By overriding 1154** system calls with functions under its control, a test program can 1155** simulate faults and error conditions that would otherwise be difficult 1156** or impossible to induce. The set of system calls that can be overridden 1157** varies from one VFS to another, and from one version of the same VFS to the 1158** next. Applications that use these interfaces must be prepared for any 1159** or all of these interfaces to be NULL or for their behavior to change 1160** from one release to the next. Applications must not attempt to access 1161** any of these methods if the iVersion of the VFS is less than 3. 1162*/ 1163typedef struct sqlite3_vfs sqlite3_vfs; 1164typedef void (*sqlite3_syscall_ptr)(void); 1165struct sqlite3_vfs { 1166 int iVersion; /* Structure version number (currently 3) */ 1167 int szOsFile; /* Size of subclassed sqlite3_file */ 1168 int mxPathname; /* Maximum file pathname length */ 1169 sqlite3_vfs *pNext; /* Next registered VFS */ 1170 const char *zName; /* Name of this virtual file system */ 1171 void *pAppData; /* Pointer to application-specific data */ 1172 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1173 int flags, int *pOutFlags); 1174 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1175 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1176 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1177 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1178 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1179 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1180 void (*xDlClose)(sqlite3_vfs*, void*); 1181 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1182 int (*xSleep)(sqlite3_vfs*, int microseconds); 1183 int (*xCurrentTime)(sqlite3_vfs*, double*); 1184 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1185 /* 1186 ** The methods above are in version 1 of the sqlite_vfs object 1187 ** definition. Those that follow are added in version 2 or later 1188 */ 1189 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1190 /* 1191 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1192 ** Those below are for version 3 and greater. 1193 */ 1194 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1195 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1196 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1197 /* 1198 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1199 ** New fields may be appended in figure versions. The iVersion 1200 ** value will increment whenever this happens. 1201 */ 1202}; 1203 1204/* 1205** CAPI3REF: Flags for the xAccess VFS method 1206** 1207** These integer constants can be used as the third parameter to 1208** the xAccess method of an [sqlite3_vfs] object. They determine 1209** what kind of permissions the xAccess method is looking for. 1210** With SQLITE_ACCESS_EXISTS, the xAccess method 1211** simply checks whether the file exists. 1212** With SQLITE_ACCESS_READWRITE, the xAccess method 1213** checks whether the named directory is both readable and writable 1214** (in other words, if files can be added, removed, and renamed within 1215** the directory). 1216** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1217** [temp_store_directory pragma], though this could change in a future 1218** release of SQLite. 1219** With SQLITE_ACCESS_READ, the xAccess method 1220** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1221** currently unused, though it might be used in a future release of 1222** SQLite. 1223*/ 1224#define SQLITE_ACCESS_EXISTS 0 1225#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1226#define SQLITE_ACCESS_READ 2 /* Unused */ 1227 1228/* 1229** CAPI3REF: Flags for the xShmLock VFS method 1230** 1231** These integer constants define the various locking operations 1232** allowed by the xShmLock method of [sqlite3_io_methods]. The 1233** following are the only legal combinations of flags to the 1234** xShmLock method: 1235** 1236** <ul> 1237** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1238** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1239** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1240** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1241** </ul> 1242** 1243** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1244** was given on the corresponding lock. 1245** 1246** The xShmLock method can transition between unlocked and SHARED or 1247** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1248** and EXCLUSIVE. 1249*/ 1250#define SQLITE_SHM_UNLOCK 1 1251#define SQLITE_SHM_LOCK 2 1252#define SQLITE_SHM_SHARED 4 1253#define SQLITE_SHM_EXCLUSIVE 8 1254 1255/* 1256** CAPI3REF: Maximum xShmLock index 1257** 1258** The xShmLock method on [sqlite3_io_methods] may use values 1259** between 0 and this upper bound as its "offset" argument. 1260** The SQLite core will never attempt to acquire or release a 1261** lock outside of this range 1262*/ 1263#define SQLITE_SHM_NLOCK 8 1264 1265 1266/* 1267** CAPI3REF: Initialize The SQLite Library 1268** 1269** ^The sqlite3_initialize() routine initializes the 1270** SQLite library. ^The sqlite3_shutdown() routine 1271** deallocates any resources that were allocated by sqlite3_initialize(). 1272** These routines are designed to aid in process initialization and 1273** shutdown on embedded systems. Workstation applications using 1274** SQLite normally do not need to invoke either of these routines. 1275** 1276** A call to sqlite3_initialize() is an "effective" call if it is 1277** the first time sqlite3_initialize() is invoked during the lifetime of 1278** the process, or if it is the first time sqlite3_initialize() is invoked 1279** following a call to sqlite3_shutdown(). ^(Only an effective call 1280** of sqlite3_initialize() does any initialization. All other calls 1281** are harmless no-ops.)^ 1282** 1283** A call to sqlite3_shutdown() is an "effective" call if it is the first 1284** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1285** an effective call to sqlite3_shutdown() does any deinitialization. 1286** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1287** 1288** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1289** is not. The sqlite3_shutdown() interface must only be called from a 1290** single thread. All open [database connections] must be closed and all 1291** other SQLite resources must be deallocated prior to invoking 1292** sqlite3_shutdown(). 1293** 1294** Among other things, ^sqlite3_initialize() will invoke 1295** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1296** will invoke sqlite3_os_end(). 1297** 1298** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1299** ^If for some reason, sqlite3_initialize() is unable to initialize 1300** the library (perhaps it is unable to allocate a needed resource such 1301** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1302** 1303** ^The sqlite3_initialize() routine is called internally by many other 1304** SQLite interfaces so that an application usually does not need to 1305** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1306** calls sqlite3_initialize() so the SQLite library will be automatically 1307** initialized when [sqlite3_open()] is called if it has not be initialized 1308** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1309** compile-time option, then the automatic calls to sqlite3_initialize() 1310** are omitted and the application must call sqlite3_initialize() directly 1311** prior to using any other SQLite interface. For maximum portability, 1312** it is recommended that applications always invoke sqlite3_initialize() 1313** directly prior to using any other SQLite interface. Future releases 1314** of SQLite may require this. In other words, the behavior exhibited 1315** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1316** default behavior in some future release of SQLite. 1317** 1318** The sqlite3_os_init() routine does operating-system specific 1319** initialization of the SQLite library. The sqlite3_os_end() 1320** routine undoes the effect of sqlite3_os_init(). Typical tasks 1321** performed by these routines include allocation or deallocation 1322** of static resources, initialization of global variables, 1323** setting up a default [sqlite3_vfs] module, or setting up 1324** a default configuration using [sqlite3_config()]. 1325** 1326** The application should never invoke either sqlite3_os_init() 1327** or sqlite3_os_end() directly. The application should only invoke 1328** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1329** interface is called automatically by sqlite3_initialize() and 1330** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1331** implementations for sqlite3_os_init() and sqlite3_os_end() 1332** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1333** When [custom builds | built for other platforms] 1334** (using the [SQLITE_OS_OTHER=1] compile-time 1335** option) the application must supply a suitable implementation for 1336** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1337** implementation of sqlite3_os_init() or sqlite3_os_end() 1338** must return [SQLITE_OK] on success and some other [error code] upon 1339** failure. 1340*/ 1341int sqlite3_initialize(void); 1342int sqlite3_shutdown(void); 1343int sqlite3_os_init(void); 1344int sqlite3_os_end(void); 1345 1346/* 1347** CAPI3REF: Configuring The SQLite Library 1348** 1349** The sqlite3_config() interface is used to make global configuration 1350** changes to SQLite in order to tune SQLite to the specific needs of 1351** the application. The default configuration is recommended for most 1352** applications and so this routine is usually not necessary. It is 1353** provided to support rare applications with unusual needs. 1354** 1355** The sqlite3_config() interface is not threadsafe. The application 1356** must insure that no other SQLite interfaces are invoked by other 1357** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1358** may only be invoked prior to library initialization using 1359** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1360** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1361** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1362** Note, however, that ^sqlite3_config() can be called as part of the 1363** implementation of an application-defined [sqlite3_os_init()]. 1364** 1365** The first argument to sqlite3_config() is an integer 1366** [configuration option] that determines 1367** what property of SQLite is to be configured. Subsequent arguments 1368** vary depending on the [configuration option] 1369** in the first argument. 1370** 1371** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1372** ^If the option is unknown or SQLite is unable to set the option 1373** then this routine returns a non-zero [error code]. 1374*/ 1375int sqlite3_config(int, ...); 1376 1377/* 1378** CAPI3REF: Configure database connections 1379** 1380** The sqlite3_db_config() interface is used to make configuration 1381** changes to a [database connection]. The interface is similar to 1382** [sqlite3_config()] except that the changes apply to a single 1383** [database connection] (specified in the first argument). 1384** 1385** The second argument to sqlite3_db_config(D,V,...) is the 1386** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1387** that indicates what aspect of the [database connection] is being configured. 1388** Subsequent arguments vary depending on the configuration verb. 1389** 1390** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1391** the call is considered successful. 1392*/ 1393int sqlite3_db_config(sqlite3*, int op, ...); 1394 1395/* 1396** CAPI3REF: Memory Allocation Routines 1397** 1398** An instance of this object defines the interface between SQLite 1399** and low-level memory allocation routines. 1400** 1401** This object is used in only one place in the SQLite interface. 1402** A pointer to an instance of this object is the argument to 1403** [sqlite3_config()] when the configuration option is 1404** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1405** By creating an instance of this object 1406** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1407** during configuration, an application can specify an alternative 1408** memory allocation subsystem for SQLite to use for all of its 1409** dynamic memory needs. 1410** 1411** Note that SQLite comes with several [built-in memory allocators] 1412** that are perfectly adequate for the overwhelming majority of applications 1413** and that this object is only useful to a tiny minority of applications 1414** with specialized memory allocation requirements. This object is 1415** also used during testing of SQLite in order to specify an alternative 1416** memory allocator that simulates memory out-of-memory conditions in 1417** order to verify that SQLite recovers gracefully from such 1418** conditions. 1419** 1420** The xMalloc, xRealloc, and xFree methods must work like the 1421** malloc(), realloc() and free() functions from the standard C library. 1422** ^SQLite guarantees that the second argument to 1423** xRealloc is always a value returned by a prior call to xRoundup. 1424** 1425** xSize should return the allocated size of a memory allocation 1426** previously obtained from xMalloc or xRealloc. The allocated size 1427** is always at least as big as the requested size but may be larger. 1428** 1429** The xRoundup method returns what would be the allocated size of 1430** a memory allocation given a particular requested size. Most memory 1431** allocators round up memory allocations at least to the next multiple 1432** of 8. Some allocators round up to a larger multiple or to a power of 2. 1433** Every memory allocation request coming in through [sqlite3_malloc()] 1434** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1435** that causes the corresponding memory allocation to fail. 1436** 1437** The xInit method initializes the memory allocator. For example, 1438** it might allocate any require mutexes or initialize internal data 1439** structures. The xShutdown method is invoked (indirectly) by 1440** [sqlite3_shutdown()] and should deallocate any resources acquired 1441** by xInit. The pAppData pointer is used as the only parameter to 1442** xInit and xShutdown. 1443** 1444** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1445** the xInit method, so the xInit method need not be threadsafe. The 1446** xShutdown method is only called from [sqlite3_shutdown()] so it does 1447** not need to be threadsafe either. For all other methods, SQLite 1448** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1449** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1450** it is by default) and so the methods are automatically serialized. 1451** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1452** methods must be threadsafe or else make their own arrangements for 1453** serialization. 1454** 1455** SQLite will never invoke xInit() more than once without an intervening 1456** call to xShutdown(). 1457*/ 1458typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1459struct sqlite3_mem_methods { 1460 void *(*xMalloc)(int); /* Memory allocation function */ 1461 void (*xFree)(void*); /* Free a prior allocation */ 1462 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1463 int (*xSize)(void*); /* Return the size of an allocation */ 1464 int (*xRoundup)(int); /* Round up request size to allocation size */ 1465 int (*xInit)(void*); /* Initialize the memory allocator */ 1466 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1467 void *pAppData; /* Argument to xInit() and xShutdown() */ 1468}; 1469 1470/* 1471** CAPI3REF: Configuration Options 1472** KEYWORDS: {configuration option} 1473** 1474** These constants are the available integer configuration options that 1475** can be passed as the first argument to the [sqlite3_config()] interface. 1476** 1477** New configuration options may be added in future releases of SQLite. 1478** Existing configuration options might be discontinued. Applications 1479** should check the return code from [sqlite3_config()] to make sure that 1480** the call worked. The [sqlite3_config()] interface will return a 1481** non-zero [error code] if a discontinued or unsupported configuration option 1482** is invoked. 1483** 1484** <dl> 1485** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1486** <dd>There are no arguments to this option. ^This option sets the 1487** [threading mode] to Single-thread. In other words, it disables 1488** all mutexing and puts SQLite into a mode where it can only be used 1489** by a single thread. ^If SQLite is compiled with 1490** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1491** it is not possible to change the [threading mode] from its default 1492** value of Single-thread and so [sqlite3_config()] will return 1493** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1494** configuration option.</dd> 1495** 1496** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1497** <dd>There are no arguments to this option. ^This option sets the 1498** [threading mode] to Multi-thread. In other words, it disables 1499** mutexing on [database connection] and [prepared statement] objects. 1500** The application is responsible for serializing access to 1501** [database connections] and [prepared statements]. But other mutexes 1502** are enabled so that SQLite will be safe to use in a multi-threaded 1503** environment as long as no two threads attempt to use the same 1504** [database connection] at the same time. ^If SQLite is compiled with 1505** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1506** it is not possible to set the Multi-thread [threading mode] and 1507** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1508** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1509** 1510** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1511** <dd>There are no arguments to this option. ^This option sets the 1512** [threading mode] to Serialized. In other words, this option enables 1513** all mutexes including the recursive 1514** mutexes on [database connection] and [prepared statement] objects. 1515** In this mode (which is the default when SQLite is compiled with 1516** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1517** to [database connections] and [prepared statements] so that the 1518** application is free to use the same [database connection] or the 1519** same [prepared statement] in different threads at the same time. 1520** ^If SQLite is compiled with 1521** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1522** it is not possible to set the Serialized [threading mode] and 1523** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1524** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1525** 1526** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1527** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1528** a pointer to an instance of the [sqlite3_mem_methods] structure. 1529** The argument specifies 1530** alternative low-level memory allocation routines to be used in place of 1531** the memory allocation routines built into SQLite.)^ ^SQLite makes 1532** its own private copy of the content of the [sqlite3_mem_methods] structure 1533** before the [sqlite3_config()] call returns.</dd> 1534** 1535** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1536** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1537** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1538** The [sqlite3_mem_methods] 1539** structure is filled with the currently defined memory allocation routines.)^ 1540** This option can be used to overload the default memory allocation 1541** routines with a wrapper that simulations memory allocation failure or 1542** tracks memory usage, for example. </dd> 1543** 1544** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1545** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1546** interpreted as a boolean, which enables or disables the collection of 1547** memory allocation statistics. ^(When memory allocation statistics are 1548** disabled, the following SQLite interfaces become non-operational: 1549** <ul> 1550** <li> [sqlite3_memory_used()] 1551** <li> [sqlite3_memory_highwater()] 1552** <li> [sqlite3_soft_heap_limit64()] 1553** <li> [sqlite3_status()] 1554** </ul>)^ 1555** ^Memory allocation statistics are enabled by default unless SQLite is 1556** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1557** allocation statistics are disabled by default. 1558** </dd> 1559** 1560** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1561** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1562** that SQLite can use for scratch memory. ^(There are three arguments 1563** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1564** aligned memory buffer from which the scratch allocations will be 1565** drawn, the size of each scratch allocation (sz), 1566** and the maximum number of scratch allocations (N).)^ 1567** The first argument must be a pointer to an 8-byte aligned buffer 1568** of at least sz*N bytes of memory. 1569** ^SQLite will not use more than one scratch buffers per thread. 1570** ^SQLite will never request a scratch buffer that is more than 6 1571** times the database page size. 1572** ^If SQLite needs needs additional 1573** scratch memory beyond what is provided by this configuration option, then 1574** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1575** ^When the application provides any amount of scratch memory using 1576** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1577** [sqlite3_malloc|heap allocations]. 1578** This can help [Robson proof|prevent memory allocation failures] due to heap 1579** fragmentation in low-memory embedded systems. 1580** </dd> 1581** 1582** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1583** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer 1584** that SQLite can use for the database page cache with the default page 1585** cache implementation. 1586** This configuration should not be used if an application-define page 1587** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2] 1588** configuration option. 1589** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1590** 8-byte aligned 1591** memory, the size of each page buffer (sz), and the number of pages (N). 1592** The sz argument should be the size of the largest database page 1593** (a power of two between 512 and 65536) plus some extra bytes for each 1594** page header. ^The number of extra bytes needed by the page header 1595** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option 1596** to [sqlite3_config()]. 1597** ^It is harmless, apart from the wasted memory, 1598** for the sz parameter to be larger than necessary. The first 1599** argument should pointer to an 8-byte aligned block of memory that 1600** is at least sz*N bytes of memory, otherwise subsequent behavior is 1601** undefined. 1602** ^SQLite will use the memory provided by the first argument to satisfy its 1603** memory needs for the first N pages that it adds to cache. ^If additional 1604** page cache memory is needed beyond what is provided by this option, then 1605** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd> 1606** 1607** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1608** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1609** that SQLite will use for all of its dynamic memory allocation needs 1610** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1611** [SQLITE_CONFIG_PAGECACHE]. 1612** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1613** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1614** [SQLITE_ERROR] if invoked otherwise. 1615** ^There are three arguments to SQLITE_CONFIG_HEAP: 1616** An 8-byte aligned pointer to the memory, 1617** the number of bytes in the memory buffer, and the minimum allocation size. 1618** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1619** to using its default memory allocator (the system malloc() implementation), 1620** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1621** memory pointer is not NULL then the alternative memory 1622** allocator is engaged to handle all of SQLites memory allocation needs. 1623** The first pointer (the memory pointer) must be aligned to an 8-byte 1624** boundary or subsequent behavior of SQLite will be undefined. 1625** The minimum allocation size is capped at 2**12. Reasonable values 1626** for the minimum allocation size are 2**5 through 2**8.</dd> 1627** 1628** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1629** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1630** pointer to an instance of the [sqlite3_mutex_methods] structure. 1631** The argument specifies alternative low-level mutex routines to be used 1632** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1633** the content of the [sqlite3_mutex_methods] structure before the call to 1634** [sqlite3_config()] returns. ^If SQLite is compiled with 1635** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1636** the entire mutexing subsystem is omitted from the build and hence calls to 1637** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1638** return [SQLITE_ERROR].</dd> 1639** 1640** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1641** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1642** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1643** [sqlite3_mutex_methods] 1644** structure is filled with the currently defined mutex routines.)^ 1645** This option can be used to overload the default mutex allocation 1646** routines with a wrapper used to track mutex usage for performance 1647** profiling or testing, for example. ^If SQLite is compiled with 1648** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1649** the entire mutexing subsystem is omitted from the build and hence calls to 1650** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1651** return [SQLITE_ERROR].</dd> 1652** 1653** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1654** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1655** the default size of lookaside memory on each [database connection]. 1656** The first argument is the 1657** size of each lookaside buffer slot and the second is the number of 1658** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1659** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1660** option to [sqlite3_db_config()] can be used to change the lookaside 1661** configuration on individual connections.)^ </dd> 1662** 1663** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1664** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1665** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1666** the interface to a custom page cache implementation.)^ 1667** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1668** 1669** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1670** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1671** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1672** the current page cache implementation into that object.)^ </dd> 1673** 1674** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1675** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1676** global [error log]. 1677** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1678** function with a call signature of void(*)(void*,int,const char*), 1679** and a pointer to void. ^If the function pointer is not NULL, it is 1680** invoked by [sqlite3_log()] to process each logging event. ^If the 1681** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1682** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1683** passed through as the first parameter to the application-defined logger 1684** function whenever that function is invoked. ^The second parameter to 1685** the logger function is a copy of the first parameter to the corresponding 1686** [sqlite3_log()] call and is intended to be a [result code] or an 1687** [extended result code]. ^The third parameter passed to the logger is 1688** log message after formatting via [sqlite3_snprintf()]. 1689** The SQLite logging interface is not reentrant; the logger function 1690** supplied by the application must not invoke any SQLite interface. 1691** In a multi-threaded application, the application-defined logger 1692** function must be threadsafe. </dd> 1693** 1694** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1695** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1696** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1697** then URI handling is globally disabled.)^ ^If URI handling is globally 1698** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1699** [sqlite3_open16()] or 1700** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1701** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1702** connection is opened. ^If it is globally disabled, filenames are 1703** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1704** database connection is opened. ^(By default, URI handling is globally 1705** disabled. The default value may be changed by compiling with the 1706** [SQLITE_USE_URI] symbol defined.)^ 1707** 1708** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1709** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1710** argument which is interpreted as a boolean in order to enable or disable 1711** the use of covering indices for full table scans in the query optimizer. 1712** ^The default setting is determined 1713** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1714** if that compile-time option is omitted. 1715** The ability to disable the use of covering indices for full table scans 1716** is because some incorrectly coded legacy applications might malfunction 1717** when the optimization is enabled. Providing the ability to 1718** disable the optimization allows the older, buggy application code to work 1719** without change even with newer versions of SQLite. 1720** 1721** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1722** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1723** <dd> These options are obsolete and should not be used by new code. 1724** They are retained for backwards compatibility but are now no-ops. 1725** </dd> 1726** 1727** [[SQLITE_CONFIG_SQLLOG]] 1728** <dt>SQLITE_CONFIG_SQLLOG 1729** <dd>This option is only available if sqlite is compiled with the 1730** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1731** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1732** The second should be of type (void*). The callback is invoked by the library 1733** in three separate circumstances, identified by the value passed as the 1734** fourth parameter. If the fourth parameter is 0, then the database connection 1735** passed as the second argument has just been opened. The third argument 1736** points to a buffer containing the name of the main database file. If the 1737** fourth parameter is 1, then the SQL statement that the third parameter 1738** points to has just been executed. Or, if the fourth parameter is 2, then 1739** the connection being passed as the second parameter is being closed. The 1740** third parameter is passed NULL In this case. An example of using this 1741** configuration option can be seen in the "test_sqllog.c" source file in 1742** the canonical SQLite source tree.</dd> 1743** 1744** [[SQLITE_CONFIG_MMAP_SIZE]] 1745** <dt>SQLITE_CONFIG_MMAP_SIZE 1746** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1747** that are the default mmap size limit (the default setting for 1748** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1749** ^The default setting can be overridden by each database connection using 1750** either the [PRAGMA mmap_size] command, or by using the 1751** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1752** will be silently truncated if necessary so that it does not exceed the 1753** compile-time maximum mmap size set by the 1754** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1755** ^If either argument to this option is negative, then that argument is 1756** changed to its compile-time default. 1757** 1758** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1759** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1760** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1761** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1762** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1763** that specifies the maximum size of the created heap. 1764** 1765** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1766** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1767** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1768** is a pointer to an integer and writes into that integer the number of extra 1769** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1770** The amount of extra space required can change depending on the compiler, 1771** target platform, and SQLite version. 1772** 1773** [[SQLITE_CONFIG_PMASZ]] 1774** <dt>SQLITE_CONFIG_PMASZ 1775** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1776** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1777** sorter to that integer. The default minimum PMA Size is set by the 1778** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1779** to help with sort operations when multithreaded sorting 1780** is enabled (using the [PRAGMA threads] command) and the amount of content 1781** to be sorted exceeds the page size times the minimum of the 1782** [PRAGMA cache_size] setting and this value. 1783** </dl> 1784*/ 1785#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1786#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1787#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1788#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1789#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1790#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1791#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1792#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1793#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1794#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1795#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1796/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1797#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1798#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1799#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1800#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1801#define SQLITE_CONFIG_URI 17 /* int */ 1802#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1803#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1804#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1805#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1806#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1807#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1808#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1809#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1810 1811/* 1812** CAPI3REF: Database Connection Configuration Options 1813** 1814** These constants are the available integer configuration options that 1815** can be passed as the second argument to the [sqlite3_db_config()] interface. 1816** 1817** New configuration options may be added in future releases of SQLite. 1818** Existing configuration options might be discontinued. Applications 1819** should check the return code from [sqlite3_db_config()] to make sure that 1820** the call worked. ^The [sqlite3_db_config()] interface will return a 1821** non-zero [error code] if a discontinued or unsupported configuration option 1822** is invoked. 1823** 1824** <dl> 1825** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1826** <dd> ^This option takes three additional arguments that determine the 1827** [lookaside memory allocator] configuration for the [database connection]. 1828** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1829** pointer to a memory buffer to use for lookaside memory. 1830** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1831** may be NULL in which case SQLite will allocate the 1832** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1833** size of each lookaside buffer slot. ^The third argument is the number of 1834** slots. The size of the buffer in the first argument must be greater than 1835** or equal to the product of the second and third arguments. The buffer 1836** must be aligned to an 8-byte boundary. ^If the second argument to 1837** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1838** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1839** configuration for a database connection can only be changed when that 1840** connection is not currently using lookaside memory, or in other words 1841** when the "current value" returned by 1842** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1843** Any attempt to change the lookaside memory configuration when lookaside 1844** memory is in use leaves the configuration unchanged and returns 1845** [SQLITE_BUSY].)^</dd> 1846** 1847** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1848** <dd> ^This option is used to enable or disable the enforcement of 1849** [foreign key constraints]. There should be two additional arguments. 1850** The first argument is an integer which is 0 to disable FK enforcement, 1851** positive to enable FK enforcement or negative to leave FK enforcement 1852** unchanged. The second parameter is a pointer to an integer into which 1853** is written 0 or 1 to indicate whether FK enforcement is off or on 1854** following this call. The second parameter may be a NULL pointer, in 1855** which case the FK enforcement setting is not reported back. </dd> 1856** 1857** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1858** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1859** There should be two additional arguments. 1860** The first argument is an integer which is 0 to disable triggers, 1861** positive to enable triggers or negative to leave the setting unchanged. 1862** The second parameter is a pointer to an integer into which 1863** is written 0 or 1 to indicate whether triggers are disabled or enabled 1864** following this call. The second parameter may be a NULL pointer, in 1865** which case the trigger setting is not reported back. </dd> 1866** 1867** </dl> 1868*/ 1869#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1870#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1871#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1872 1873 1874/* 1875** CAPI3REF: Enable Or Disable Extended Result Codes 1876** 1877** ^The sqlite3_extended_result_codes() routine enables or disables the 1878** [extended result codes] feature of SQLite. ^The extended result 1879** codes are disabled by default for historical compatibility. 1880*/ 1881int sqlite3_extended_result_codes(sqlite3*, int onoff); 1882 1883/* 1884** CAPI3REF: Last Insert Rowid 1885** 1886** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1887** has a unique 64-bit signed 1888** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1889** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1890** names are not also used by explicitly declared columns. ^If 1891** the table has a column of type [INTEGER PRIMARY KEY] then that column 1892** is another alias for the rowid. 1893** 1894** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1895** most recent successful [INSERT] into a rowid table or [virtual table] 1896** on database connection D. 1897** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1898** ^If no successful [INSERT]s into rowid tables 1899** have ever occurred on the database connection D, 1900** then sqlite3_last_insert_rowid(D) returns zero. 1901** 1902** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1903** method, then this routine will return the [rowid] of the inserted 1904** row as long as the trigger or virtual table method is running. 1905** But once the trigger or virtual table method ends, the value returned 1906** by this routine reverts to what it was before the trigger or virtual 1907** table method began.)^ 1908** 1909** ^An [INSERT] that fails due to a constraint violation is not a 1910** successful [INSERT] and does not change the value returned by this 1911** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1912** and INSERT OR ABORT make no changes to the return value of this 1913** routine when their insertion fails. ^(When INSERT OR REPLACE 1914** encounters a constraint violation, it does not fail. The 1915** INSERT continues to completion after deleting rows that caused 1916** the constraint problem so INSERT OR REPLACE will always change 1917** the return value of this interface.)^ 1918** 1919** ^For the purposes of this routine, an [INSERT] is considered to 1920** be successful even if it is subsequently rolled back. 1921** 1922** This function is accessible to SQL statements via the 1923** [last_insert_rowid() SQL function]. 1924** 1925** If a separate thread performs a new [INSERT] on the same 1926** database connection while the [sqlite3_last_insert_rowid()] 1927** function is running and thus changes the last insert [rowid], 1928** then the value returned by [sqlite3_last_insert_rowid()] is 1929** unpredictable and might not equal either the old or the new 1930** last insert [rowid]. 1931*/ 1932sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1933 1934/* 1935** CAPI3REF: Count The Number Of Rows Modified 1936** 1937** ^This function returns the number of rows modified, inserted or 1938** deleted by the most recently completed INSERT, UPDATE or DELETE 1939** statement on the database connection specified by the only parameter. 1940** ^Executing any other type of SQL statement does not modify the value 1941** returned by this function. 1942** 1943** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 1944** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 1945** [foreign key actions] or [REPLACE] constraint resolution are not counted. 1946** 1947** Changes to a view that are intercepted by 1948** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 1949** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 1950** DELETE statement run on a view is always zero. Only changes made to real 1951** tables are counted. 1952** 1953** Things are more complicated if the sqlite3_changes() function is 1954** executed while a trigger program is running. This may happen if the 1955** program uses the [changes() SQL function], or if some other callback 1956** function invokes sqlite3_changes() directly. Essentially: 1957** 1958** <ul> 1959** <li> ^(Before entering a trigger program the value returned by 1960** sqlite3_changes() function is saved. After the trigger program 1961** has finished, the original value is restored.)^ 1962** 1963** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 1964** statement sets the value returned by sqlite3_changes() 1965** upon completion as normal. Of course, this value will not include 1966** any changes performed by sub-triggers, as the sqlite3_changes() 1967** value will be saved and restored after each sub-trigger has run.)^ 1968** </ul> 1969** 1970** ^This means that if the changes() SQL function (or similar) is used 1971** by the first INSERT, UPDATE or DELETE statement within a trigger, it 1972** returns the value as set when the calling statement began executing. 1973** ^If it is used by the second or subsequent such statement within a trigger 1974** program, the value returned reflects the number of rows modified by the 1975** previous INSERT, UPDATE or DELETE statement within the same trigger. 1976** 1977** See also the [sqlite3_total_changes()] interface, the 1978** [count_changes pragma], and the [changes() SQL function]. 1979** 1980** If a separate thread makes changes on the same database connection 1981** while [sqlite3_changes()] is running then the value returned 1982** is unpredictable and not meaningful. 1983*/ 1984int sqlite3_changes(sqlite3*); 1985 1986/* 1987** CAPI3REF: Total Number Of Rows Modified 1988** 1989** ^This function returns the total number of rows inserted, modified or 1990** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 1991** since the database connection was opened, including those executed as 1992** part of trigger programs. ^Executing any other type of SQL statement 1993** does not affect the value returned by sqlite3_total_changes(). 1994** 1995** ^Changes made as part of [foreign key actions] are included in the 1996** count, but those made as part of REPLACE constraint resolution are 1997** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 1998** are not counted. 1999** 2000** See also the [sqlite3_changes()] interface, the 2001** [count_changes pragma], and the [total_changes() SQL function]. 2002** 2003** If a separate thread makes changes on the same database connection 2004** while [sqlite3_total_changes()] is running then the value 2005** returned is unpredictable and not meaningful. 2006*/ 2007int sqlite3_total_changes(sqlite3*); 2008 2009/* 2010** CAPI3REF: Interrupt A Long-Running Query 2011** 2012** ^This function causes any pending database operation to abort and 2013** return at its earliest opportunity. This routine is typically 2014** called in response to a user action such as pressing "Cancel" 2015** or Ctrl-C where the user wants a long query operation to halt 2016** immediately. 2017** 2018** ^It is safe to call this routine from a thread different from the 2019** thread that is currently running the database operation. But it 2020** is not safe to call this routine with a [database connection] that 2021** is closed or might close before sqlite3_interrupt() returns. 2022** 2023** ^If an SQL operation is very nearly finished at the time when 2024** sqlite3_interrupt() is called, then it might not have an opportunity 2025** to be interrupted and might continue to completion. 2026** 2027** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2028** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2029** that is inside an explicit transaction, then the entire transaction 2030** will be rolled back automatically. 2031** 2032** ^The sqlite3_interrupt(D) call is in effect until all currently running 2033** SQL statements on [database connection] D complete. ^Any new SQL statements 2034** that are started after the sqlite3_interrupt() call and before the 2035** running statements reaches zero are interrupted as if they had been 2036** running prior to the sqlite3_interrupt() call. ^New SQL statements 2037** that are started after the running statement count reaches zero are 2038** not effected by the sqlite3_interrupt(). 2039** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2040** SQL statements is a no-op and has no effect on SQL statements 2041** that are started after the sqlite3_interrupt() call returns. 2042** 2043** If the database connection closes while [sqlite3_interrupt()] 2044** is running then bad things will likely happen. 2045*/ 2046void sqlite3_interrupt(sqlite3*); 2047 2048/* 2049** CAPI3REF: Determine If An SQL Statement Is Complete 2050** 2051** These routines are useful during command-line input to determine if the 2052** currently entered text seems to form a complete SQL statement or 2053** if additional input is needed before sending the text into 2054** SQLite for parsing. ^These routines return 1 if the input string 2055** appears to be a complete SQL statement. ^A statement is judged to be 2056** complete if it ends with a semicolon token and is not a prefix of a 2057** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2058** string literals or quoted identifier names or comments are not 2059** independent tokens (they are part of the token in which they are 2060** embedded) and thus do not count as a statement terminator. ^Whitespace 2061** and comments that follow the final semicolon are ignored. 2062** 2063** ^These routines return 0 if the statement is incomplete. ^If a 2064** memory allocation fails, then SQLITE_NOMEM is returned. 2065** 2066** ^These routines do not parse the SQL statements thus 2067** will not detect syntactically incorrect SQL. 2068** 2069** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2070** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2071** automatically by sqlite3_complete16(). If that initialization fails, 2072** then the return value from sqlite3_complete16() will be non-zero 2073** regardless of whether or not the input SQL is complete.)^ 2074** 2075** The input to [sqlite3_complete()] must be a zero-terminated 2076** UTF-8 string. 2077** 2078** The input to [sqlite3_complete16()] must be a zero-terminated 2079** UTF-16 string in native byte order. 2080*/ 2081int sqlite3_complete(const char *sql); 2082int sqlite3_complete16(const void *sql); 2083 2084/* 2085** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2086** KEYWORDS: {busy-handler callback} {busy handler} 2087** 2088** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2089** that might be invoked with argument P whenever 2090** an attempt is made to access a database table associated with 2091** [database connection] D when another thread 2092** or process has the table locked. 2093** The sqlite3_busy_handler() interface is used to implement 2094** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2095** 2096** ^If the busy callback is NULL, then [SQLITE_BUSY] 2097** is returned immediately upon encountering the lock. ^If the busy callback 2098** is not NULL, then the callback might be invoked with two arguments. 2099** 2100** ^The first argument to the busy handler is a copy of the void* pointer which 2101** is the third argument to sqlite3_busy_handler(). ^The second argument to 2102** the busy handler callback is the number of times that the busy handler has 2103** been invoked previously for the same locking event. ^If the 2104** busy callback returns 0, then no additional attempts are made to 2105** access the database and [SQLITE_BUSY] is returned 2106** to the application. 2107** ^If the callback returns non-zero, then another attempt 2108** is made to access the database and the cycle repeats. 2109** 2110** The presence of a busy handler does not guarantee that it will be invoked 2111** when there is lock contention. ^If SQLite determines that invoking the busy 2112** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2113** to the application instead of invoking the 2114** busy handler. 2115** Consider a scenario where one process is holding a read lock that 2116** it is trying to promote to a reserved lock and 2117** a second process is holding a reserved lock that it is trying 2118** to promote to an exclusive lock. The first process cannot proceed 2119** because it is blocked by the second and the second process cannot 2120** proceed because it is blocked by the first. If both processes 2121** invoke the busy handlers, neither will make any progress. Therefore, 2122** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2123** will induce the first process to release its read lock and allow 2124** the second process to proceed. 2125** 2126** ^The default busy callback is NULL. 2127** 2128** ^(There can only be a single busy handler defined for each 2129** [database connection]. Setting a new busy handler clears any 2130** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2131** or evaluating [PRAGMA busy_timeout=N] will change the 2132** busy handler and thus clear any previously set busy handler. 2133** 2134** The busy callback should not take any actions which modify the 2135** database connection that invoked the busy handler. In other words, 2136** the busy handler is not reentrant. Any such actions 2137** result in undefined behavior. 2138** 2139** A busy handler must not close the database connection 2140** or [prepared statement] that invoked the busy handler. 2141*/ 2142int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2143 2144/* 2145** CAPI3REF: Set A Busy Timeout 2146** 2147** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2148** for a specified amount of time when a table is locked. ^The handler 2149** will sleep multiple times until at least "ms" milliseconds of sleeping 2150** have accumulated. ^After at least "ms" milliseconds of sleeping, 2151** the handler returns 0 which causes [sqlite3_step()] to return 2152** [SQLITE_BUSY]. 2153** 2154** ^Calling this routine with an argument less than or equal to zero 2155** turns off all busy handlers. 2156** 2157** ^(There can only be a single busy handler for a particular 2158** [database connection] at any given moment. If another busy handler 2159** was defined (using [sqlite3_busy_handler()]) prior to calling 2160** this routine, that other busy handler is cleared.)^ 2161** 2162** See also: [PRAGMA busy_timeout] 2163*/ 2164int sqlite3_busy_timeout(sqlite3*, int ms); 2165 2166/* 2167** CAPI3REF: Convenience Routines For Running Queries 2168** 2169** This is a legacy interface that is preserved for backwards compatibility. 2170** Use of this interface is not recommended. 2171** 2172** Definition: A <b>result table</b> is memory data structure created by the 2173** [sqlite3_get_table()] interface. A result table records the 2174** complete query results from one or more queries. 2175** 2176** The table conceptually has a number of rows and columns. But 2177** these numbers are not part of the result table itself. These 2178** numbers are obtained separately. Let N be the number of rows 2179** and M be the number of columns. 2180** 2181** A result table is an array of pointers to zero-terminated UTF-8 strings. 2182** There are (N+1)*M elements in the array. The first M pointers point 2183** to zero-terminated strings that contain the names of the columns. 2184** The remaining entries all point to query results. NULL values result 2185** in NULL pointers. All other values are in their UTF-8 zero-terminated 2186** string representation as returned by [sqlite3_column_text()]. 2187** 2188** A result table might consist of one or more memory allocations. 2189** It is not safe to pass a result table directly to [sqlite3_free()]. 2190** A result table should be deallocated using [sqlite3_free_table()]. 2191** 2192** ^(As an example of the result table format, suppose a query result 2193** is as follows: 2194** 2195** <blockquote><pre> 2196** Name | Age 2197** ----------------------- 2198** Alice | 43 2199** Bob | 28 2200** Cindy | 21 2201** </pre></blockquote> 2202** 2203** There are two column (M==2) and three rows (N==3). Thus the 2204** result table has 8 entries. Suppose the result table is stored 2205** in an array names azResult. Then azResult holds this content: 2206** 2207** <blockquote><pre> 2208** azResult[0] = "Name"; 2209** azResult[1] = "Age"; 2210** azResult[2] = "Alice"; 2211** azResult[3] = "43"; 2212** azResult[4] = "Bob"; 2213** azResult[5] = "28"; 2214** azResult[6] = "Cindy"; 2215** azResult[7] = "21"; 2216** </pre></blockquote>)^ 2217** 2218** ^The sqlite3_get_table() function evaluates one or more 2219** semicolon-separated SQL statements in the zero-terminated UTF-8 2220** string of its 2nd parameter and returns a result table to the 2221** pointer given in its 3rd parameter. 2222** 2223** After the application has finished with the result from sqlite3_get_table(), 2224** it must pass the result table pointer to sqlite3_free_table() in order to 2225** release the memory that was malloced. Because of the way the 2226** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2227** function must not try to call [sqlite3_free()] directly. Only 2228** [sqlite3_free_table()] is able to release the memory properly and safely. 2229** 2230** The sqlite3_get_table() interface is implemented as a wrapper around 2231** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2232** to any internal data structures of SQLite. It uses only the public 2233** interface defined here. As a consequence, errors that occur in the 2234** wrapper layer outside of the internal [sqlite3_exec()] call are not 2235** reflected in subsequent calls to [sqlite3_errcode()] or 2236** [sqlite3_errmsg()]. 2237*/ 2238int sqlite3_get_table( 2239 sqlite3 *db, /* An open database */ 2240 const char *zSql, /* SQL to be evaluated */ 2241 char ***pazResult, /* Results of the query */ 2242 int *pnRow, /* Number of result rows written here */ 2243 int *pnColumn, /* Number of result columns written here */ 2244 char **pzErrmsg /* Error msg written here */ 2245); 2246void sqlite3_free_table(char **result); 2247 2248/* 2249** CAPI3REF: Formatted String Printing Functions 2250** 2251** These routines are work-alikes of the "printf()" family of functions 2252** from the standard C library. 2253** These routines understand most of the common K&R formatting options, 2254** plus some additional non-standard formats, detailed below. 2255** Note that some of the more obscure formatting options from recent 2256** C-library standards are omitted from this implementation. 2257** 2258** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2259** results into memory obtained from [sqlite3_malloc()]. 2260** The strings returned by these two routines should be 2261** released by [sqlite3_free()]. ^Both routines return a 2262** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2263** memory to hold the resulting string. 2264** 2265** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2266** the standard C library. The result is written into the 2267** buffer supplied as the second parameter whose size is given by 2268** the first parameter. Note that the order of the 2269** first two parameters is reversed from snprintf().)^ This is an 2270** historical accident that cannot be fixed without breaking 2271** backwards compatibility. ^(Note also that sqlite3_snprintf() 2272** returns a pointer to its buffer instead of the number of 2273** characters actually written into the buffer.)^ We admit that 2274** the number of characters written would be a more useful return 2275** value but we cannot change the implementation of sqlite3_snprintf() 2276** now without breaking compatibility. 2277** 2278** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2279** guarantees that the buffer is always zero-terminated. ^The first 2280** parameter "n" is the total size of the buffer, including space for 2281** the zero terminator. So the longest string that can be completely 2282** written will be n-1 characters. 2283** 2284** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2285** 2286** These routines all implement some additional formatting 2287** options that are useful for constructing SQL statements. 2288** All of the usual printf() formatting options apply. In addition, there 2289** is are "%q", "%Q", "%w" and "%z" options. 2290** 2291** ^(The %q option works like %s in that it substitutes a nul-terminated 2292** string from the argument list. But %q also doubles every '\'' character. 2293** %q is designed for use inside a string literal.)^ By doubling each '\'' 2294** character it escapes that character and allows it to be inserted into 2295** the string. 2296** 2297** For example, assume the string variable zText contains text as follows: 2298** 2299** <blockquote><pre> 2300** char *zText = "It's a happy day!"; 2301** </pre></blockquote> 2302** 2303** One can use this text in an SQL statement as follows: 2304** 2305** <blockquote><pre> 2306** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2307** sqlite3_exec(db, zSQL, 0, 0, 0); 2308** sqlite3_free(zSQL); 2309** </pre></blockquote> 2310** 2311** Because the %q format string is used, the '\'' character in zText 2312** is escaped and the SQL generated is as follows: 2313** 2314** <blockquote><pre> 2315** INSERT INTO table1 VALUES('It''s a happy day!') 2316** </pre></blockquote> 2317** 2318** This is correct. Had we used %s instead of %q, the generated SQL 2319** would have looked like this: 2320** 2321** <blockquote><pre> 2322** INSERT INTO table1 VALUES('It's a happy day!'); 2323** </pre></blockquote> 2324** 2325** This second example is an SQL syntax error. As a general rule you should 2326** always use %q instead of %s when inserting text into a string literal. 2327** 2328** ^(The %Q option works like %q except it also adds single quotes around 2329** the outside of the total string. Additionally, if the parameter in the 2330** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2331** single quotes).)^ So, for example, one could say: 2332** 2333** <blockquote><pre> 2334** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2335** sqlite3_exec(db, zSQL, 0, 0, 0); 2336** sqlite3_free(zSQL); 2337** </pre></blockquote> 2338** 2339** The code above will render a correct SQL statement in the zSQL 2340** variable even if the zText variable is a NULL pointer. 2341** 2342** ^(The "%w" formatting option is like "%q" except that it expects to 2343** be contained within double-quotes instead of single quotes, and it 2344** escapes the double-quote character instead of the single-quote 2345** character.)^ The "%w" formatting option is intended for safely inserting 2346** table and column names into a constructed SQL statement. 2347** 2348** ^(The "%z" formatting option works like "%s" but with the 2349** addition that after the string has been read and copied into 2350** the result, [sqlite3_free()] is called on the input string.)^ 2351*/ 2352char *sqlite3_mprintf(const char*,...); 2353char *sqlite3_vmprintf(const char*, va_list); 2354char *sqlite3_snprintf(int,char*,const char*, ...); 2355char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2356 2357/* 2358** CAPI3REF: Memory Allocation Subsystem 2359** 2360** The SQLite core uses these three routines for all of its own 2361** internal memory allocation needs. "Core" in the previous sentence 2362** does not include operating-system specific VFS implementation. The 2363** Windows VFS uses native malloc() and free() for some operations. 2364** 2365** ^The sqlite3_malloc() routine returns a pointer to a block 2366** of memory at least N bytes in length, where N is the parameter. 2367** ^If sqlite3_malloc() is unable to obtain sufficient free 2368** memory, it returns a NULL pointer. ^If the parameter N to 2369** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2370** a NULL pointer. 2371** 2372** ^The sqlite3_malloc64(N) routine works just like 2373** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2374** of a signed 32-bit integer. 2375** 2376** ^Calling sqlite3_free() with a pointer previously returned 2377** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2378** that it might be reused. ^The sqlite3_free() routine is 2379** a no-op if is called with a NULL pointer. Passing a NULL pointer 2380** to sqlite3_free() is harmless. After being freed, memory 2381** should neither be read nor written. Even reading previously freed 2382** memory might result in a segmentation fault or other severe error. 2383** Memory corruption, a segmentation fault, or other severe error 2384** might result if sqlite3_free() is called with a non-NULL pointer that 2385** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2386** 2387** ^The sqlite3_realloc(X,N) interface attempts to resize a 2388** prior memory allocation X to be at least N bytes. 2389** ^If the X parameter to sqlite3_realloc(X,N) 2390** is a NULL pointer then its behavior is identical to calling 2391** sqlite3_malloc(N). 2392** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2393** negative then the behavior is exactly the same as calling 2394** sqlite3_free(X). 2395** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2396** of at least N bytes in size or NULL if insufficient memory is available. 2397** ^If M is the size of the prior allocation, then min(N,M) bytes 2398** of the prior allocation are copied into the beginning of buffer returned 2399** by sqlite3_realloc(X,N) and the prior allocation is freed. 2400** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2401** prior allocation is not freed. 2402** 2403** ^The sqlite3_realloc64(X,N) interfaces works the same as 2404** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2405** of a 32-bit signed integer. 2406** 2407** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2408** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2409** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2410** ^The value returned by sqlite3_msize(X) might be larger than the number 2411** of bytes requested when X was allocated. ^If X is a NULL pointer then 2412** sqlite3_msize(X) returns zero. If X points to something that is not 2413** the beginning of memory allocation, or if it points to a formerly 2414** valid memory allocation that has now been freed, then the behavior 2415** of sqlite3_msize(X) is undefined and possibly harmful. 2416** 2417** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2418** sqlite3_malloc64(), and sqlite3_realloc64() 2419** is always aligned to at least an 8 byte boundary, or to a 2420** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2421** option is used. 2422** 2423** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2424** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2425** implementation of these routines to be omitted. That capability 2426** is no longer provided. Only built-in memory allocators can be used. 2427** 2428** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2429** the system malloc() and free() directly when converting 2430** filenames between the UTF-8 encoding used by SQLite 2431** and whatever filename encoding is used by the particular Windows 2432** installation. Memory allocation errors were detected, but 2433** they were reported back as [SQLITE_CANTOPEN] or 2434** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2435** 2436** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2437** must be either NULL or else pointers obtained from a prior 2438** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2439** not yet been released. 2440** 2441** The application must not read or write any part of 2442** a block of memory after it has been released using 2443** [sqlite3_free()] or [sqlite3_realloc()]. 2444*/ 2445void *sqlite3_malloc(int); 2446void *sqlite3_malloc64(sqlite3_uint64); 2447void *sqlite3_realloc(void*, int); 2448void *sqlite3_realloc64(void*, sqlite3_uint64); 2449void sqlite3_free(void*); 2450sqlite3_uint64 sqlite3_msize(void*); 2451 2452/* 2453** CAPI3REF: Memory Allocator Statistics 2454** 2455** SQLite provides these two interfaces for reporting on the status 2456** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2457** routines, which form the built-in memory allocation subsystem. 2458** 2459** ^The [sqlite3_memory_used()] routine returns the number of bytes 2460** of memory currently outstanding (malloced but not freed). 2461** ^The [sqlite3_memory_highwater()] routine returns the maximum 2462** value of [sqlite3_memory_used()] since the high-water mark 2463** was last reset. ^The values returned by [sqlite3_memory_used()] and 2464** [sqlite3_memory_highwater()] include any overhead 2465** added by SQLite in its implementation of [sqlite3_malloc()], 2466** but not overhead added by the any underlying system library 2467** routines that [sqlite3_malloc()] may call. 2468** 2469** ^The memory high-water mark is reset to the current value of 2470** [sqlite3_memory_used()] if and only if the parameter to 2471** [sqlite3_memory_highwater()] is true. ^The value returned 2472** by [sqlite3_memory_highwater(1)] is the high-water mark 2473** prior to the reset. 2474*/ 2475sqlite3_int64 sqlite3_memory_used(void); 2476sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2477 2478/* 2479** CAPI3REF: Pseudo-Random Number Generator 2480** 2481** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2482** select random [ROWID | ROWIDs] when inserting new records into a table that 2483** already uses the largest possible [ROWID]. The PRNG is also used for 2484** the build-in random() and randomblob() SQL functions. This interface allows 2485** applications to access the same PRNG for other purposes. 2486** 2487** ^A call to this routine stores N bytes of randomness into buffer P. 2488** ^The P parameter can be a NULL pointer. 2489** 2490** ^If this routine has not been previously called or if the previous 2491** call had N less than one or a NULL pointer for P, then the PRNG is 2492** seeded using randomness obtained from the xRandomness method of 2493** the default [sqlite3_vfs] object. 2494** ^If the previous call to this routine had an N of 1 or more and a 2495** non-NULL P then the pseudo-randomness is generated 2496** internally and without recourse to the [sqlite3_vfs] xRandomness 2497** method. 2498*/ 2499void sqlite3_randomness(int N, void *P); 2500 2501/* 2502** CAPI3REF: Compile-Time Authorization Callbacks 2503** 2504** ^This routine registers an authorizer callback with a particular 2505** [database connection], supplied in the first argument. 2506** ^The authorizer callback is invoked as SQL statements are being compiled 2507** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2508** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2509** points during the compilation process, as logic is being created 2510** to perform various actions, the authorizer callback is invoked to 2511** see if those actions are allowed. ^The authorizer callback should 2512** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2513** specific action but allow the SQL statement to continue to be 2514** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2515** rejected with an error. ^If the authorizer callback returns 2516** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2517** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2518** the authorizer will fail with an error message. 2519** 2520** When the callback returns [SQLITE_OK], that means the operation 2521** requested is ok. ^When the callback returns [SQLITE_DENY], the 2522** [sqlite3_prepare_v2()] or equivalent call that triggered the 2523** authorizer will fail with an error message explaining that 2524** access is denied. 2525** 2526** ^The first parameter to the authorizer callback is a copy of the third 2527** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2528** to the callback is an integer [SQLITE_COPY | action code] that specifies 2529** the particular action to be authorized. ^The third through sixth parameters 2530** to the callback are zero-terminated strings that contain additional 2531** details about the action to be authorized. 2532** 2533** ^If the action code is [SQLITE_READ] 2534** and the callback returns [SQLITE_IGNORE] then the 2535** [prepared statement] statement is constructed to substitute 2536** a NULL value in place of the table column that would have 2537** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2538** return can be used to deny an untrusted user access to individual 2539** columns of a table. 2540** ^If the action code is [SQLITE_DELETE] and the callback returns 2541** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2542** [truncate optimization] is disabled and all rows are deleted individually. 2543** 2544** An authorizer is used when [sqlite3_prepare | preparing] 2545** SQL statements from an untrusted source, to ensure that the SQL statements 2546** do not try to access data they are not allowed to see, or that they do not 2547** try to execute malicious statements that damage the database. For 2548** example, an application may allow a user to enter arbitrary 2549** SQL queries for evaluation by a database. But the application does 2550** not want the user to be able to make arbitrary changes to the 2551** database. An authorizer could then be put in place while the 2552** user-entered SQL is being [sqlite3_prepare | prepared] that 2553** disallows everything except [SELECT] statements. 2554** 2555** Applications that need to process SQL from untrusted sources 2556** might also consider lowering resource limits using [sqlite3_limit()] 2557** and limiting database size using the [max_page_count] [PRAGMA] 2558** in addition to using an authorizer. 2559** 2560** ^(Only a single authorizer can be in place on a database connection 2561** at a time. Each call to sqlite3_set_authorizer overrides the 2562** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2563** The authorizer is disabled by default. 2564** 2565** The authorizer callback must not do anything that will modify 2566** the database connection that invoked the authorizer callback. 2567** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2568** database connections for the meaning of "modify" in this paragraph. 2569** 2570** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2571** statement might be re-prepared during [sqlite3_step()] due to a 2572** schema change. Hence, the application should ensure that the 2573** correct authorizer callback remains in place during the [sqlite3_step()]. 2574** 2575** ^Note that the authorizer callback is invoked only during 2576** [sqlite3_prepare()] or its variants. Authorization is not 2577** performed during statement evaluation in [sqlite3_step()], unless 2578** as stated in the previous paragraph, sqlite3_step() invokes 2579** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2580*/ 2581int sqlite3_set_authorizer( 2582 sqlite3*, 2583 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2584 void *pUserData 2585); 2586 2587/* 2588** CAPI3REF: Authorizer Return Codes 2589** 2590** The [sqlite3_set_authorizer | authorizer callback function] must 2591** return either [SQLITE_OK] or one of these two constants in order 2592** to signal SQLite whether or not the action is permitted. See the 2593** [sqlite3_set_authorizer | authorizer documentation] for additional 2594** information. 2595** 2596** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2597** returned from the [sqlite3_vtab_on_conflict()] interface. 2598*/ 2599#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2600#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2601 2602/* 2603** CAPI3REF: Authorizer Action Codes 2604** 2605** The [sqlite3_set_authorizer()] interface registers a callback function 2606** that is invoked to authorize certain SQL statement actions. The 2607** second parameter to the callback is an integer code that specifies 2608** what action is being authorized. These are the integer action codes that 2609** the authorizer callback may be passed. 2610** 2611** These action code values signify what kind of operation is to be 2612** authorized. The 3rd and 4th parameters to the authorization 2613** callback function will be parameters or NULL depending on which of these 2614** codes is used as the second parameter. ^(The 5th parameter to the 2615** authorizer callback is the name of the database ("main", "temp", 2616** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2617** is the name of the inner-most trigger or view that is responsible for 2618** the access attempt or NULL if this access attempt is directly from 2619** top-level SQL code. 2620*/ 2621/******************************************* 3rd ************ 4th ***********/ 2622#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2623#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2624#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2625#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2626#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2627#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2628#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2629#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2630#define SQLITE_DELETE 9 /* Table Name NULL */ 2631#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2632#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2633#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2634#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2635#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2636#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2637#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2638#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2639#define SQLITE_INSERT 18 /* Table Name NULL */ 2640#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2641#define SQLITE_READ 20 /* Table Name Column Name */ 2642#define SQLITE_SELECT 21 /* NULL NULL */ 2643#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2644#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2645#define SQLITE_ATTACH 24 /* Filename NULL */ 2646#define SQLITE_DETACH 25 /* Database Name NULL */ 2647#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2648#define SQLITE_REINDEX 27 /* Index Name NULL */ 2649#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2650#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2651#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2652#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2653#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2654#define SQLITE_COPY 0 /* No longer used */ 2655#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2656 2657/* 2658** CAPI3REF: Tracing And Profiling Functions 2659** 2660** These routines register callback functions that can be used for 2661** tracing and profiling the execution of SQL statements. 2662** 2663** ^The callback function registered by sqlite3_trace() is invoked at 2664** various times when an SQL statement is being run by [sqlite3_step()]. 2665** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2666** SQL statement text as the statement first begins executing. 2667** ^(Additional sqlite3_trace() callbacks might occur 2668** as each triggered subprogram is entered. The callbacks for triggers 2669** contain a UTF-8 SQL comment that identifies the trigger.)^ 2670** 2671** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2672** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2673** 2674** ^The callback function registered by sqlite3_profile() is invoked 2675** as each SQL statement finishes. ^The profile callback contains 2676** the original statement text and an estimate of wall-clock time 2677** of how long that statement took to run. ^The profile callback 2678** time is in units of nanoseconds, however the current implementation 2679** is only capable of millisecond resolution so the six least significant 2680** digits in the time are meaningless. Future versions of SQLite 2681** might provide greater resolution on the profiler callback. The 2682** sqlite3_profile() function is considered experimental and is 2683** subject to change in future versions of SQLite. 2684*/ 2685void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2686SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2687 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2688 2689/* 2690** CAPI3REF: Query Progress Callbacks 2691** 2692** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2693** function X to be invoked periodically during long running calls to 2694** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2695** database connection D. An example use for this 2696** interface is to keep a GUI updated during a large query. 2697** 2698** ^The parameter P is passed through as the only parameter to the 2699** callback function X. ^The parameter N is the approximate number of 2700** [virtual machine instructions] that are evaluated between successive 2701** invocations of the callback X. ^If N is less than one then the progress 2702** handler is disabled. 2703** 2704** ^Only a single progress handler may be defined at one time per 2705** [database connection]; setting a new progress handler cancels the 2706** old one. ^Setting parameter X to NULL disables the progress handler. 2707** ^The progress handler is also disabled by setting N to a value less 2708** than 1. 2709** 2710** ^If the progress callback returns non-zero, the operation is 2711** interrupted. This feature can be used to implement a 2712** "Cancel" button on a GUI progress dialog box. 2713** 2714** The progress handler callback must not do anything that will modify 2715** the database connection that invoked the progress handler. 2716** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2717** database connections for the meaning of "modify" in this paragraph. 2718** 2719*/ 2720void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2721 2722/* 2723** CAPI3REF: Opening A New Database Connection 2724** 2725** ^These routines open an SQLite database file as specified by the 2726** filename argument. ^The filename argument is interpreted as UTF-8 for 2727** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2728** order for sqlite3_open16(). ^(A [database connection] handle is usually 2729** returned in *ppDb, even if an error occurs. The only exception is that 2730** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2731** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2732** object.)^ ^(If the database is opened (and/or created) successfully, then 2733** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2734** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2735** an English language description of the error following a failure of any 2736** of the sqlite3_open() routines. 2737** 2738** ^The default encoding will be UTF-8 for databases created using 2739** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2740** created using sqlite3_open16() will be UTF-16 in the native byte order. 2741** 2742** Whether or not an error occurs when it is opened, resources 2743** associated with the [database connection] handle should be released by 2744** passing it to [sqlite3_close()] when it is no longer required. 2745** 2746** The sqlite3_open_v2() interface works like sqlite3_open() 2747** except that it accepts two additional parameters for additional control 2748** over the new database connection. ^(The flags parameter to 2749** sqlite3_open_v2() can take one of 2750** the following three values, optionally combined with the 2751** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2752** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2753** 2754** <dl> 2755** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2756** <dd>The database is opened in read-only mode. If the database does not 2757** already exist, an error is returned.</dd>)^ 2758** 2759** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2760** <dd>The database is opened for reading and writing if possible, or reading 2761** only if the file is write protected by the operating system. In either 2762** case the database must already exist, otherwise an error is returned.</dd>)^ 2763** 2764** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2765** <dd>The database is opened for reading and writing, and is created if 2766** it does not already exist. This is the behavior that is always used for 2767** sqlite3_open() and sqlite3_open16().</dd>)^ 2768** </dl> 2769** 2770** If the 3rd parameter to sqlite3_open_v2() is not one of the 2771** combinations shown above optionally combined with other 2772** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2773** then the behavior is undefined. 2774** 2775** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2776** opens in the multi-thread [threading mode] as long as the single-thread 2777** mode has not been set at compile-time or start-time. ^If the 2778** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2779** in the serialized [threading mode] unless single-thread was 2780** previously selected at compile-time or start-time. 2781** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2782** eligible to use [shared cache mode], regardless of whether or not shared 2783** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2784** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2785** participate in [shared cache mode] even if it is enabled. 2786** 2787** ^The fourth parameter to sqlite3_open_v2() is the name of the 2788** [sqlite3_vfs] object that defines the operating system interface that 2789** the new database connection should use. ^If the fourth parameter is 2790** a NULL pointer then the default [sqlite3_vfs] object is used. 2791** 2792** ^If the filename is ":memory:", then a private, temporary in-memory database 2793** is created for the connection. ^This in-memory database will vanish when 2794** the database connection is closed. Future versions of SQLite might 2795** make use of additional special filenames that begin with the ":" character. 2796** It is recommended that when a database filename actually does begin with 2797** a ":" character you should prefix the filename with a pathname such as 2798** "./" to avoid ambiguity. 2799** 2800** ^If the filename is an empty string, then a private, temporary 2801** on-disk database will be created. ^This private database will be 2802** automatically deleted as soon as the database connection is closed. 2803** 2804** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2805** 2806** ^If [URI filename] interpretation is enabled, and the filename argument 2807** begins with "file:", then the filename is interpreted as a URI. ^URI 2808** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2809** set in the fourth argument to sqlite3_open_v2(), or if it has 2810** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2811** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2812** As of SQLite version 3.7.7, URI filename interpretation is turned off 2813** by default, but future releases of SQLite might enable URI filename 2814** interpretation by default. See "[URI filenames]" for additional 2815** information. 2816** 2817** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2818** authority, then it must be either an empty string or the string 2819** "localhost". ^If the authority is not an empty string or "localhost", an 2820** error is returned to the caller. ^The fragment component of a URI, if 2821** present, is ignored. 2822** 2823** ^SQLite uses the path component of the URI as the name of the disk file 2824** which contains the database. ^If the path begins with a '/' character, 2825** then it is interpreted as an absolute path. ^If the path does not begin 2826** with a '/' (meaning that the authority section is omitted from the URI) 2827** then the path is interpreted as a relative path. 2828** ^(On windows, the first component of an absolute path 2829** is a drive specification (e.g. "C:").)^ 2830** 2831** [[core URI query parameters]] 2832** The query component of a URI may contain parameters that are interpreted 2833** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2834** SQLite and its built-in [VFSes] interpret the 2835** following query parameters: 2836** 2837** <ul> 2838** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2839** a VFS object that provides the operating system interface that should 2840** be used to access the database file on disk. ^If this option is set to 2841** an empty string the default VFS object is used. ^Specifying an unknown 2842** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2843** present, then the VFS specified by the option takes precedence over 2844** the value passed as the fourth parameter to sqlite3_open_v2(). 2845** 2846** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2847** "rwc", or "memory". Attempting to set it to any other value is 2848** an error)^. 2849** ^If "ro" is specified, then the database is opened for read-only 2850** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2851** third argument to sqlite3_open_v2(). ^If the mode option is set to 2852** "rw", then the database is opened for read-write (but not create) 2853** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2854** been set. ^Value "rwc" is equivalent to setting both 2855** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2856** set to "memory" then a pure [in-memory database] that never reads 2857** or writes from disk is used. ^It is an error to specify a value for 2858** the mode parameter that is less restrictive than that specified by 2859** the flags passed in the third parameter to sqlite3_open_v2(). 2860** 2861** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2862** "private". ^Setting it to "shared" is equivalent to setting the 2863** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2864** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2865** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2866** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2867** a URI filename, its value overrides any behavior requested by setting 2868** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2869** 2870** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 2871** [powersafe overwrite] property does or does not apply to the 2872** storage media on which the database file resides. 2873** 2874** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2875** which if set disables file locking in rollback journal modes. This 2876** is useful for accessing a database on a filesystem that does not 2877** support locking. Caution: Database corruption might result if two 2878** or more processes write to the same database and any one of those 2879** processes uses nolock=1. 2880** 2881** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2882** parameter that indicates that the database file is stored on 2883** read-only media. ^When immutable is set, SQLite assumes that the 2884** database file cannot be changed, even by a process with higher 2885** privilege, and so the database is opened read-only and all locking 2886** and change detection is disabled. Caution: Setting the immutable 2887** property on a database file that does in fact change can result 2888** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2889** See also: [SQLITE_IOCAP_IMMUTABLE]. 2890** 2891** </ul> 2892** 2893** ^Specifying an unknown parameter in the query component of a URI is not an 2894** error. Future versions of SQLite might understand additional query 2895** parameters. See "[query parameters with special meaning to SQLite]" for 2896** additional information. 2897** 2898** [[URI filename examples]] <h3>URI filename examples</h3> 2899** 2900** <table border="1" align=center cellpadding=5> 2901** <tr><th> URI filenames <th> Results 2902** <tr><td> file:data.db <td> 2903** Open the file "data.db" in the current directory. 2904** <tr><td> file:/home/fred/data.db<br> 2905** file:///home/fred/data.db <br> 2906** file://localhost/home/fred/data.db <br> <td> 2907** Open the database file "/home/fred/data.db". 2908** <tr><td> file://darkstar/home/fred/data.db <td> 2909** An error. "darkstar" is not a recognized authority. 2910** <tr><td style="white-space:nowrap"> 2911** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2912** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2913** C:. Note that the %20 escaping in this example is not strictly 2914** necessary - space characters can be used literally 2915** in URI filenames. 2916** <tr><td> file:data.db?mode=ro&cache=private <td> 2917** Open file "data.db" in the current directory for read-only access. 2918** Regardless of whether or not shared-cache mode is enabled by 2919** default, use a private cache. 2920** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 2921** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 2922** that uses dot-files in place of posix advisory locking. 2923** <tr><td> file:data.db?mode=readonly <td> 2924** An error. "readonly" is not a valid option for the "mode" parameter. 2925** </table> 2926** 2927** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2928** query components of a URI. A hexadecimal escape sequence consists of a 2929** percent sign - "%" - followed by exactly two hexadecimal digits 2930** specifying an octet value. ^Before the path or query components of a 2931** URI filename are interpreted, they are encoded using UTF-8 and all 2932** hexadecimal escape sequences replaced by a single byte containing the 2933** corresponding octet. If this process generates an invalid UTF-8 encoding, 2934** the results are undefined. 2935** 2936** <b>Note to Windows users:</b> The encoding used for the filename argument 2937** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2938** codepage is currently defined. Filenames containing international 2939** characters must be converted to UTF-8 prior to passing them into 2940** sqlite3_open() or sqlite3_open_v2(). 2941** 2942** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2943** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2944** features that require the use of temporary files may fail. 2945** 2946** See also: [sqlite3_temp_directory] 2947*/ 2948int sqlite3_open( 2949 const char *filename, /* Database filename (UTF-8) */ 2950 sqlite3 **ppDb /* OUT: SQLite db handle */ 2951); 2952int sqlite3_open16( 2953 const void *filename, /* Database filename (UTF-16) */ 2954 sqlite3 **ppDb /* OUT: SQLite db handle */ 2955); 2956int sqlite3_open_v2( 2957 const char *filename, /* Database filename (UTF-8) */ 2958 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2959 int flags, /* Flags */ 2960 const char *zVfs /* Name of VFS module to use */ 2961); 2962 2963/* 2964** CAPI3REF: Obtain Values For URI Parameters 2965** 2966** These are utility routines, useful to VFS implementations, that check 2967** to see if a database file was a URI that contained a specific query 2968** parameter, and if so obtains the value of that query parameter. 2969** 2970** If F is the database filename pointer passed into the xOpen() method of 2971** a VFS implementation when the flags parameter to xOpen() has one or 2972** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2973** P is the name of the query parameter, then 2974** sqlite3_uri_parameter(F,P) returns the value of the P 2975** parameter if it exists or a NULL pointer if P does not appear as a 2976** query parameter on F. If P is a query parameter of F 2977** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2978** a pointer to an empty string. 2979** 2980** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2981** parameter and returns true (1) or false (0) according to the value 2982** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 2983** value of query parameter P is one of "yes", "true", or "on" in any 2984** case or if the value begins with a non-zero number. The 2985** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 2986** query parameter P is one of "no", "false", or "off" in any case or 2987** if the value begins with a numeric zero. If P is not a query 2988** parameter on F or if the value of P is does not match any of the 2989** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2990** 2991** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2992** 64-bit signed integer and returns that integer, or D if P does not 2993** exist. If the value of P is something other than an integer, then 2994** zero is returned. 2995** 2996** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2997** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2998** is not a database file pathname pointer that SQLite passed into the xOpen 2999** VFS method, then the behavior of this routine is undefined and probably 3000** undesirable. 3001*/ 3002const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3003int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3004sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3005 3006 3007/* 3008** CAPI3REF: Error Codes And Messages 3009** 3010** ^If the most recent sqlite3_* API call associated with 3011** [database connection] D failed, then the sqlite3_errcode(D) interface 3012** returns the numeric [result code] or [extended result code] for that 3013** API call. 3014** If the most recent API call was successful, 3015** then the return value from sqlite3_errcode() is undefined. 3016** ^The sqlite3_extended_errcode() 3017** interface is the same except that it always returns the 3018** [extended result code] even when extended result codes are 3019** disabled. 3020** 3021** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3022** text that describes the error, as either UTF-8 or UTF-16 respectively. 3023** ^(Memory to hold the error message string is managed internally. 3024** The application does not need to worry about freeing the result. 3025** However, the error string might be overwritten or deallocated by 3026** subsequent calls to other SQLite interface functions.)^ 3027** 3028** ^The sqlite3_errstr() interface returns the English-language text 3029** that describes the [result code], as UTF-8. 3030** ^(Memory to hold the error message string is managed internally 3031** and must not be freed by the application)^. 3032** 3033** When the serialized [threading mode] is in use, it might be the 3034** case that a second error occurs on a separate thread in between 3035** the time of the first error and the call to these interfaces. 3036** When that happens, the second error will be reported since these 3037** interfaces always report the most recent result. To avoid 3038** this, each thread can obtain exclusive use of the [database connection] D 3039** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3040** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3041** all calls to the interfaces listed here are completed. 3042** 3043** If an interface fails with SQLITE_MISUSE, that means the interface 3044** was invoked incorrectly by the application. In that case, the 3045** error code and message may or may not be set. 3046*/ 3047int sqlite3_errcode(sqlite3 *db); 3048int sqlite3_extended_errcode(sqlite3 *db); 3049const char *sqlite3_errmsg(sqlite3*); 3050const void *sqlite3_errmsg16(sqlite3*); 3051const char *sqlite3_errstr(int); 3052 3053/* 3054** CAPI3REF: SQL Statement Object 3055** KEYWORDS: {prepared statement} {prepared statements} 3056** 3057** An instance of this object represents a single SQL statement. 3058** This object is variously known as a "prepared statement" or a 3059** "compiled SQL statement" or simply as a "statement". 3060** 3061** The life of a statement object goes something like this: 3062** 3063** <ol> 3064** <li> Create the object using [sqlite3_prepare_v2()] or a related 3065** function. 3066** <li> Bind values to [host parameters] using the sqlite3_bind_*() 3067** interfaces. 3068** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3069** <li> Reset the statement using [sqlite3_reset()] then go back 3070** to step 2. Do this zero or more times. 3071** <li> Destroy the object using [sqlite3_finalize()]. 3072** </ol> 3073** 3074** Refer to documentation on individual methods above for additional 3075** information. 3076*/ 3077typedef struct sqlite3_stmt sqlite3_stmt; 3078 3079/* 3080** CAPI3REF: Run-time Limits 3081** 3082** ^(This interface allows the size of various constructs to be limited 3083** on a connection by connection basis. The first parameter is the 3084** [database connection] whose limit is to be set or queried. The 3085** second parameter is one of the [limit categories] that define a 3086** class of constructs to be size limited. The third parameter is the 3087** new limit for that construct.)^ 3088** 3089** ^If the new limit is a negative number, the limit is unchanged. 3090** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3091** [limits | hard upper bound] 3092** set at compile-time by a C preprocessor macro called 3093** [limits | SQLITE_MAX_<i>NAME</i>]. 3094** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3095** ^Attempts to increase a limit above its hard upper bound are 3096** silently truncated to the hard upper bound. 3097** 3098** ^Regardless of whether or not the limit was changed, the 3099** [sqlite3_limit()] interface returns the prior value of the limit. 3100** ^Hence, to find the current value of a limit without changing it, 3101** simply invoke this interface with the third parameter set to -1. 3102** 3103** Run-time limits are intended for use in applications that manage 3104** both their own internal database and also databases that are controlled 3105** by untrusted external sources. An example application might be a 3106** web browser that has its own databases for storing history and 3107** separate databases controlled by JavaScript applications downloaded 3108** off the Internet. The internal databases can be given the 3109** large, default limits. Databases managed by external sources can 3110** be given much smaller limits designed to prevent a denial of service 3111** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3112** interface to further control untrusted SQL. The size of the database 3113** created by an untrusted script can be contained using the 3114** [max_page_count] [PRAGMA]. 3115** 3116** New run-time limit categories may be added in future releases. 3117*/ 3118int sqlite3_limit(sqlite3*, int id, int newVal); 3119 3120/* 3121** CAPI3REF: Run-Time Limit Categories 3122** KEYWORDS: {limit category} {*limit categories} 3123** 3124** These constants define various performance limits 3125** that can be lowered at run-time using [sqlite3_limit()]. 3126** The synopsis of the meanings of the various limits is shown below. 3127** Additional information is available at [limits | Limits in SQLite]. 3128** 3129** <dl> 3130** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3131** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3132** 3133** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3134** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3135** 3136** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3137** <dd>The maximum number of columns in a table definition or in the 3138** result set of a [SELECT] or the maximum number of columns in an index 3139** or in an ORDER BY or GROUP BY clause.</dd>)^ 3140** 3141** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3142** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3143** 3144** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3145** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3146** 3147** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3148** <dd>The maximum number of instructions in a virtual machine program 3149** used to implement an SQL statement. This limit is not currently 3150** enforced, though that might be added in some future release of 3151** SQLite.</dd>)^ 3152** 3153** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3154** <dd>The maximum number of arguments on a function.</dd>)^ 3155** 3156** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3157** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3158** 3159** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3160** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3161** <dd>The maximum length of the pattern argument to the [LIKE] or 3162** [GLOB] operators.</dd>)^ 3163** 3164** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3165** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3166** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3167** 3168** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3169** <dd>The maximum depth of recursion for triggers.</dd>)^ 3170** 3171** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3172** <dd>The maximum number of auxiliary worker threads that a single 3173** [prepared statement] may start.</dd>)^ 3174** </dl> 3175*/ 3176#define SQLITE_LIMIT_LENGTH 0 3177#define SQLITE_LIMIT_SQL_LENGTH 1 3178#define SQLITE_LIMIT_COLUMN 2 3179#define SQLITE_LIMIT_EXPR_DEPTH 3 3180#define SQLITE_LIMIT_COMPOUND_SELECT 4 3181#define SQLITE_LIMIT_VDBE_OP 5 3182#define SQLITE_LIMIT_FUNCTION_ARG 6 3183#define SQLITE_LIMIT_ATTACHED 7 3184#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3185#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3186#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3187#define SQLITE_LIMIT_WORKER_THREADS 11 3188 3189/* 3190** CAPI3REF: Compiling An SQL Statement 3191** KEYWORDS: {SQL statement compiler} 3192** 3193** To execute an SQL query, it must first be compiled into a byte-code 3194** program using one of these routines. 3195** 3196** The first argument, "db", is a [database connection] obtained from a 3197** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3198** [sqlite3_open16()]. The database connection must not have been closed. 3199** 3200** The second argument, "zSql", is the statement to be compiled, encoded 3201** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3202** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3203** use UTF-16. 3204** 3205** ^If the nByte argument is negative, then zSql is read up to the 3206** first zero terminator. ^If nByte is positive, then it is the 3207** number of bytes read from zSql. ^If nByte is zero, then no prepared 3208** statement is generated. 3209** If the caller knows that the supplied string is nul-terminated, then 3210** there is a small performance advantage to passing an nByte parameter that 3211** is the number of bytes in the input string <i>including</i> 3212** the nul-terminator. 3213** 3214** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3215** past the end of the first SQL statement in zSql. These routines only 3216** compile the first statement in zSql, so *pzTail is left pointing to 3217** what remains uncompiled. 3218** 3219** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3220** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3221** to NULL. ^If the input text contains no SQL (if the input is an empty 3222** string or a comment) then *ppStmt is set to NULL. 3223** The calling procedure is responsible for deleting the compiled 3224** SQL statement using [sqlite3_finalize()] after it has finished with it. 3225** ppStmt may not be NULL. 3226** 3227** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3228** otherwise an [error code] is returned. 3229** 3230** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3231** recommended for all new programs. The two older interfaces are retained 3232** for backwards compatibility, but their use is discouraged. 3233** ^In the "v2" interfaces, the prepared statement 3234** that is returned (the [sqlite3_stmt] object) contains a copy of the 3235** original SQL text. This causes the [sqlite3_step()] interface to 3236** behave differently in three ways: 3237** 3238** <ol> 3239** <li> 3240** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3241** always used to do, [sqlite3_step()] will automatically recompile the SQL 3242** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3243** retries will occur before sqlite3_step() gives up and returns an error. 3244** </li> 3245** 3246** <li> 3247** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3248** [error codes] or [extended error codes]. ^The legacy behavior was that 3249** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3250** and the application would have to make a second call to [sqlite3_reset()] 3251** in order to find the underlying cause of the problem. With the "v2" prepare 3252** interfaces, the underlying reason for the error is returned immediately. 3253** </li> 3254** 3255** <li> 3256** ^If the specific value bound to [parameter | host parameter] in the 3257** WHERE clause might influence the choice of query plan for a statement, 3258** then the statement will be automatically recompiled, as if there had been 3259** a schema change, on the first [sqlite3_step()] call following any change 3260** to the [sqlite3_bind_text | bindings] of that [parameter]. 3261** ^The specific value of WHERE-clause [parameter] might influence the 3262** choice of query plan if the parameter is the left-hand side of a [LIKE] 3263** or [GLOB] operator or if the parameter is compared to an indexed column 3264** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3265** </li> 3266** </ol> 3267*/ 3268int sqlite3_prepare( 3269 sqlite3 *db, /* Database handle */ 3270 const char *zSql, /* SQL statement, UTF-8 encoded */ 3271 int nByte, /* Maximum length of zSql in bytes. */ 3272 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3273 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3274); 3275int sqlite3_prepare_v2( 3276 sqlite3 *db, /* Database handle */ 3277 const char *zSql, /* SQL statement, UTF-8 encoded */ 3278 int nByte, /* Maximum length of zSql in bytes. */ 3279 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3280 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3281); 3282int sqlite3_prepare16( 3283 sqlite3 *db, /* Database handle */ 3284 const void *zSql, /* SQL statement, UTF-16 encoded */ 3285 int nByte, /* Maximum length of zSql in bytes. */ 3286 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3287 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3288); 3289int sqlite3_prepare16_v2( 3290 sqlite3 *db, /* Database handle */ 3291 const void *zSql, /* SQL statement, UTF-16 encoded */ 3292 int nByte, /* Maximum length of zSql in bytes. */ 3293 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3294 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3295); 3296 3297/* 3298** CAPI3REF: Retrieving Statement SQL 3299** 3300** ^This interface can be used to retrieve a saved copy of the original 3301** SQL text used to create a [prepared statement] if that statement was 3302** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3303*/ 3304const char *sqlite3_sql(sqlite3_stmt *pStmt); 3305 3306/* 3307** CAPI3REF: Determine If An SQL Statement Writes The Database 3308** 3309** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3310** and only if the [prepared statement] X makes no direct changes to 3311** the content of the database file. 3312** 3313** Note that [application-defined SQL functions] or 3314** [virtual tables] might change the database indirectly as a side effect. 3315** ^(For example, if an application defines a function "eval()" that 3316** calls [sqlite3_exec()], then the following SQL statement would 3317** change the database file through side-effects: 3318** 3319** <blockquote><pre> 3320** SELECT eval('DELETE FROM t1') FROM t2; 3321** </pre></blockquote> 3322** 3323** But because the [SELECT] statement does not change the database file 3324** directly, sqlite3_stmt_readonly() would still return true.)^ 3325** 3326** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3327** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3328** since the statements themselves do not actually modify the database but 3329** rather they control the timing of when other statements modify the 3330** database. ^The [ATTACH] and [DETACH] statements also cause 3331** sqlite3_stmt_readonly() to return true since, while those statements 3332** change the configuration of a database connection, they do not make 3333** changes to the content of the database files on disk. 3334*/ 3335int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3336 3337/* 3338** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3339** 3340** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3341** [prepared statement] S has been stepped at least once using 3342** [sqlite3_step(S)] but has not run to completion and/or has not 3343** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3344** interface returns false if S is a NULL pointer. If S is not a 3345** NULL pointer and is not a pointer to a valid [prepared statement] 3346** object, then the behavior is undefined and probably undesirable. 3347** 3348** This interface can be used in combination [sqlite3_next_stmt()] 3349** to locate all prepared statements associated with a database 3350** connection that are in need of being reset. This can be used, 3351** for example, in diagnostic routines to search for prepared 3352** statements that are holding a transaction open. 3353*/ 3354int sqlite3_stmt_busy(sqlite3_stmt*); 3355 3356/* 3357** CAPI3REF: Dynamically Typed Value Object 3358** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3359** 3360** SQLite uses the sqlite3_value object to represent all values 3361** that can be stored in a database table. SQLite uses dynamic typing 3362** for the values it stores. ^Values stored in sqlite3_value objects 3363** can be integers, floating point values, strings, BLOBs, or NULL. 3364** 3365** An sqlite3_value object may be either "protected" or "unprotected". 3366** Some interfaces require a protected sqlite3_value. Other interfaces 3367** will accept either a protected or an unprotected sqlite3_value. 3368** Every interface that accepts sqlite3_value arguments specifies 3369** whether or not it requires a protected sqlite3_value. 3370** 3371** The terms "protected" and "unprotected" refer to whether or not 3372** a mutex is held. An internal mutex is held for a protected 3373** sqlite3_value object but no mutex is held for an unprotected 3374** sqlite3_value object. If SQLite is compiled to be single-threaded 3375** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3376** or if SQLite is run in one of reduced mutex modes 3377** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3378** then there is no distinction between protected and unprotected 3379** sqlite3_value objects and they can be used interchangeably. However, 3380** for maximum code portability it is recommended that applications 3381** still make the distinction between protected and unprotected 3382** sqlite3_value objects even when not strictly required. 3383** 3384** ^The sqlite3_value objects that are passed as parameters into the 3385** implementation of [application-defined SQL functions] are protected. 3386** ^The sqlite3_value object returned by 3387** [sqlite3_column_value()] is unprotected. 3388** Unprotected sqlite3_value objects may only be used with 3389** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3390** The [sqlite3_value_blob | sqlite3_value_type()] family of 3391** interfaces require protected sqlite3_value objects. 3392*/ 3393typedef struct Mem sqlite3_value; 3394 3395/* 3396** CAPI3REF: SQL Function Context Object 3397** 3398** The context in which an SQL function executes is stored in an 3399** sqlite3_context object. ^A pointer to an sqlite3_context object 3400** is always first parameter to [application-defined SQL functions]. 3401** The application-defined SQL function implementation will pass this 3402** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3403** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3404** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3405** and/or [sqlite3_set_auxdata()]. 3406*/ 3407typedef struct sqlite3_context sqlite3_context; 3408 3409/* 3410** CAPI3REF: Binding Values To Prepared Statements 3411** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3412** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3413** 3414** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3415** literals may be replaced by a [parameter] that matches one of following 3416** templates: 3417** 3418** <ul> 3419** <li> ? 3420** <li> ?NNN 3421** <li> :VVV 3422** <li> @VVV 3423** <li> $VVV 3424** </ul> 3425** 3426** In the templates above, NNN represents an integer literal, 3427** and VVV represents an alphanumeric identifier.)^ ^The values of these 3428** parameters (also called "host parameter names" or "SQL parameters") 3429** can be set using the sqlite3_bind_*() routines defined here. 3430** 3431** ^The first argument to the sqlite3_bind_*() routines is always 3432** a pointer to the [sqlite3_stmt] object returned from 3433** [sqlite3_prepare_v2()] or its variants. 3434** 3435** ^The second argument is the index of the SQL parameter to be set. 3436** ^The leftmost SQL parameter has an index of 1. ^When the same named 3437** SQL parameter is used more than once, second and subsequent 3438** occurrences have the same index as the first occurrence. 3439** ^The index for named parameters can be looked up using the 3440** [sqlite3_bind_parameter_index()] API if desired. ^The index 3441** for "?NNN" parameters is the value of NNN. 3442** ^The NNN value must be between 1 and the [sqlite3_limit()] 3443** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3444** 3445** ^The third argument is the value to bind to the parameter. 3446** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3447** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3448** is ignored and the end result is the same as sqlite3_bind_null(). 3449** 3450** ^(In those routines that have a fourth argument, its value is the 3451** number of bytes in the parameter. To be clear: the value is the 3452** number of <u>bytes</u> in the value, not the number of characters.)^ 3453** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3454** is negative, then the length of the string is 3455** the number of bytes up to the first zero terminator. 3456** If the fourth parameter to sqlite3_bind_blob() is negative, then 3457** the behavior is undefined. 3458** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3459** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3460** that parameter must be the byte offset 3461** where the NUL terminator would occur assuming the string were NUL 3462** terminated. If any NUL characters occur at byte offsets less than 3463** the value of the fourth parameter then the resulting string value will 3464** contain embedded NULs. The result of expressions involving strings 3465** with embedded NULs is undefined. 3466** 3467** ^The fifth argument to the BLOB and string binding interfaces 3468** is a destructor used to dispose of the BLOB or 3469** string after SQLite has finished with it. ^The destructor is called 3470** to dispose of the BLOB or string even if the call to bind API fails. 3471** ^If the fifth argument is 3472** the special value [SQLITE_STATIC], then SQLite assumes that the 3473** information is in static, unmanaged space and does not need to be freed. 3474** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3475** SQLite makes its own private copy of the data immediately, before 3476** the sqlite3_bind_*() routine returns. 3477** 3478** ^The sixth argument to sqlite3_bind_text64() must be one of 3479** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3480** to specify the encoding of the text in the third parameter. If 3481** the sixth argument to sqlite3_bind_text64() is not one of the 3482** allowed values shown above, or if the text encoding is different 3483** from the encoding specified by the sixth parameter, then the behavior 3484** is undefined. 3485** 3486** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3487** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3488** (just an integer to hold its size) while it is being processed. 3489** Zeroblobs are intended to serve as placeholders for BLOBs whose 3490** content is later written using 3491** [sqlite3_blob_open | incremental BLOB I/O] routines. 3492** ^A negative value for the zeroblob results in a zero-length BLOB. 3493** 3494** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3495** for the [prepared statement] or with a prepared statement for which 3496** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3497** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3498** routine is passed a [prepared statement] that has been finalized, the 3499** result is undefined and probably harmful. 3500** 3501** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3502** ^Unbound parameters are interpreted as NULL. 3503** 3504** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3505** [error code] if anything goes wrong. 3506** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3507** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3508** [SQLITE_MAX_LENGTH]. 3509** ^[SQLITE_RANGE] is returned if the parameter 3510** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3511** 3512** See also: [sqlite3_bind_parameter_count()], 3513** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3514*/ 3515int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3516int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3517 void(*)(void*)); 3518int sqlite3_bind_double(sqlite3_stmt*, int, double); 3519int sqlite3_bind_int(sqlite3_stmt*, int, int); 3520int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3521int sqlite3_bind_null(sqlite3_stmt*, int); 3522int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3523int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3524int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3525 void(*)(void*), unsigned char encoding); 3526int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3527int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3528 3529/* 3530** CAPI3REF: Number Of SQL Parameters 3531** 3532** ^This routine can be used to find the number of [SQL parameters] 3533** in a [prepared statement]. SQL parameters are tokens of the 3534** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3535** placeholders for values that are [sqlite3_bind_blob | bound] 3536** to the parameters at a later time. 3537** 3538** ^(This routine actually returns the index of the largest (rightmost) 3539** parameter. For all forms except ?NNN, this will correspond to the 3540** number of unique parameters. If parameters of the ?NNN form are used, 3541** there may be gaps in the list.)^ 3542** 3543** See also: [sqlite3_bind_blob|sqlite3_bind()], 3544** [sqlite3_bind_parameter_name()], and 3545** [sqlite3_bind_parameter_index()]. 3546*/ 3547int sqlite3_bind_parameter_count(sqlite3_stmt*); 3548 3549/* 3550** CAPI3REF: Name Of A Host Parameter 3551** 3552** ^The sqlite3_bind_parameter_name(P,N) interface returns 3553** the name of the N-th [SQL parameter] in the [prepared statement] P. 3554** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3555** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3556** respectively. 3557** In other words, the initial ":" or "$" or "@" or "?" 3558** is included as part of the name.)^ 3559** ^Parameters of the form "?" without a following integer have no name 3560** and are referred to as "nameless" or "anonymous parameters". 3561** 3562** ^The first host parameter has an index of 1, not 0. 3563** 3564** ^If the value N is out of range or if the N-th parameter is 3565** nameless, then NULL is returned. ^The returned string is 3566** always in UTF-8 encoding even if the named parameter was 3567** originally specified as UTF-16 in [sqlite3_prepare16()] or 3568** [sqlite3_prepare16_v2()]. 3569** 3570** See also: [sqlite3_bind_blob|sqlite3_bind()], 3571** [sqlite3_bind_parameter_count()], and 3572** [sqlite3_bind_parameter_index()]. 3573*/ 3574const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3575 3576/* 3577** CAPI3REF: Index Of A Parameter With A Given Name 3578** 3579** ^Return the index of an SQL parameter given its name. ^The 3580** index value returned is suitable for use as the second 3581** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3582** is returned if no matching parameter is found. ^The parameter 3583** name must be given in UTF-8 even if the original statement 3584** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3585** 3586** See also: [sqlite3_bind_blob|sqlite3_bind()], 3587** [sqlite3_bind_parameter_count()], and 3588** [sqlite3_bind_parameter_index()]. 3589*/ 3590int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3591 3592/* 3593** CAPI3REF: Reset All Bindings On A Prepared Statement 3594** 3595** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3596** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3597** ^Use this routine to reset all host parameters to NULL. 3598*/ 3599int sqlite3_clear_bindings(sqlite3_stmt*); 3600 3601/* 3602** CAPI3REF: Number Of Columns In A Result Set 3603** 3604** ^Return the number of columns in the result set returned by the 3605** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3606** statement that does not return data (for example an [UPDATE]). 3607** 3608** See also: [sqlite3_data_count()] 3609*/ 3610int sqlite3_column_count(sqlite3_stmt *pStmt); 3611 3612/* 3613** CAPI3REF: Column Names In A Result Set 3614** 3615** ^These routines return the name assigned to a particular column 3616** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3617** interface returns a pointer to a zero-terminated UTF-8 string 3618** and sqlite3_column_name16() returns a pointer to a zero-terminated 3619** UTF-16 string. ^The first parameter is the [prepared statement] 3620** that implements the [SELECT] statement. ^The second parameter is the 3621** column number. ^The leftmost column is number 0. 3622** 3623** ^The returned string pointer is valid until either the [prepared statement] 3624** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3625** reprepared by the first call to [sqlite3_step()] for a particular run 3626** or until the next call to 3627** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3628** 3629** ^If sqlite3_malloc() fails during the processing of either routine 3630** (for example during a conversion from UTF-8 to UTF-16) then a 3631** NULL pointer is returned. 3632** 3633** ^The name of a result column is the value of the "AS" clause for 3634** that column, if there is an AS clause. If there is no AS clause 3635** then the name of the column is unspecified and may change from 3636** one release of SQLite to the next. 3637*/ 3638const char *sqlite3_column_name(sqlite3_stmt*, int N); 3639const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3640 3641/* 3642** CAPI3REF: Source Of Data In A Query Result 3643** 3644** ^These routines provide a means to determine the database, table, and 3645** table column that is the origin of a particular result column in 3646** [SELECT] statement. 3647** ^The name of the database or table or column can be returned as 3648** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3649** the database name, the _table_ routines return the table name, and 3650** the origin_ routines return the column name. 3651** ^The returned string is valid until the [prepared statement] is destroyed 3652** using [sqlite3_finalize()] or until the statement is automatically 3653** reprepared by the first call to [sqlite3_step()] for a particular run 3654** or until the same information is requested 3655** again in a different encoding. 3656** 3657** ^The names returned are the original un-aliased names of the 3658** database, table, and column. 3659** 3660** ^The first argument to these interfaces is a [prepared statement]. 3661** ^These functions return information about the Nth result column returned by 3662** the statement, where N is the second function argument. 3663** ^The left-most column is column 0 for these routines. 3664** 3665** ^If the Nth column returned by the statement is an expression or 3666** subquery and is not a column value, then all of these functions return 3667** NULL. ^These routine might also return NULL if a memory allocation error 3668** occurs. ^Otherwise, they return the name of the attached database, table, 3669** or column that query result column was extracted from. 3670** 3671** ^As with all other SQLite APIs, those whose names end with "16" return 3672** UTF-16 encoded strings and the other functions return UTF-8. 3673** 3674** ^These APIs are only available if the library was compiled with the 3675** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3676** 3677** If two or more threads call one or more of these routines against the same 3678** prepared statement and column at the same time then the results are 3679** undefined. 3680** 3681** If two or more threads call one or more 3682** [sqlite3_column_database_name | column metadata interfaces] 3683** for the same [prepared statement] and result column 3684** at the same time then the results are undefined. 3685*/ 3686const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3687const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3688const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3689const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3690const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3691const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3692 3693/* 3694** CAPI3REF: Declared Datatype Of A Query Result 3695** 3696** ^(The first parameter is a [prepared statement]. 3697** If this statement is a [SELECT] statement and the Nth column of the 3698** returned result set of that [SELECT] is a table column (not an 3699** expression or subquery) then the declared type of the table 3700** column is returned.)^ ^If the Nth column of the result set is an 3701** expression or subquery, then a NULL pointer is returned. 3702** ^The returned string is always UTF-8 encoded. 3703** 3704** ^(For example, given the database schema: 3705** 3706** CREATE TABLE t1(c1 VARIANT); 3707** 3708** and the following statement to be compiled: 3709** 3710** SELECT c1 + 1, c1 FROM t1; 3711** 3712** this routine would return the string "VARIANT" for the second result 3713** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3714** 3715** ^SQLite uses dynamic run-time typing. ^So just because a column 3716** is declared to contain a particular type does not mean that the 3717** data stored in that column is of the declared type. SQLite is 3718** strongly typed, but the typing is dynamic not static. ^Type 3719** is associated with individual values, not with the containers 3720** used to hold those values. 3721*/ 3722const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3723const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3724 3725/* 3726** CAPI3REF: Evaluate An SQL Statement 3727** 3728** After a [prepared statement] has been prepared using either 3729** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3730** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3731** must be called one or more times to evaluate the statement. 3732** 3733** The details of the behavior of the sqlite3_step() interface depend 3734** on whether the statement was prepared using the newer "v2" interface 3735** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3736** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3737** new "v2" interface is recommended for new applications but the legacy 3738** interface will continue to be supported. 3739** 3740** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3741** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3742** ^With the "v2" interface, any of the other [result codes] or 3743** [extended result codes] might be returned as well. 3744** 3745** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3746** database locks it needs to do its job. ^If the statement is a [COMMIT] 3747** or occurs outside of an explicit transaction, then you can retry the 3748** statement. If the statement is not a [COMMIT] and occurs within an 3749** explicit transaction then you should rollback the transaction before 3750** continuing. 3751** 3752** ^[SQLITE_DONE] means that the statement has finished executing 3753** successfully. sqlite3_step() should not be called again on this virtual 3754** machine without first calling [sqlite3_reset()] to reset the virtual 3755** machine back to its initial state. 3756** 3757** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3758** is returned each time a new row of data is ready for processing by the 3759** caller. The values may be accessed using the [column access functions]. 3760** sqlite3_step() is called again to retrieve the next row of data. 3761** 3762** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3763** violation) has occurred. sqlite3_step() should not be called again on 3764** the VM. More information may be found by calling [sqlite3_errmsg()]. 3765** ^With the legacy interface, a more specific error code (for example, 3766** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3767** can be obtained by calling [sqlite3_reset()] on the 3768** [prepared statement]. ^In the "v2" interface, 3769** the more specific error code is returned directly by sqlite3_step(). 3770** 3771** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3772** Perhaps it was called on a [prepared statement] that has 3773** already been [sqlite3_finalize | finalized] or on one that had 3774** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3775** be the case that the same database connection is being used by two or 3776** more threads at the same moment in time. 3777** 3778** For all versions of SQLite up to and including 3.6.23.1, a call to 3779** [sqlite3_reset()] was required after sqlite3_step() returned anything 3780** other than [SQLITE_ROW] before any subsequent invocation of 3781** sqlite3_step(). Failure to reset the prepared statement using 3782** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3783** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3784** calling [sqlite3_reset()] automatically in this circumstance rather 3785** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3786** break because any application that ever receives an SQLITE_MISUSE error 3787** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3788** can be used to restore the legacy behavior. 3789** 3790** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3791** API always returns a generic error code, [SQLITE_ERROR], following any 3792** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3793** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3794** specific [error codes] that better describes the error. 3795** We admit that this is a goofy design. The problem has been fixed 3796** with the "v2" interface. If you prepare all of your SQL statements 3797** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3798** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3799** then the more specific [error codes] are returned directly 3800** by sqlite3_step(). The use of the "v2" interface is recommended. 3801*/ 3802int sqlite3_step(sqlite3_stmt*); 3803 3804/* 3805** CAPI3REF: Number of columns in a result set 3806** 3807** ^The sqlite3_data_count(P) interface returns the number of columns in the 3808** current row of the result set of [prepared statement] P. 3809** ^If prepared statement P does not have results ready to return 3810** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3811** interfaces) then sqlite3_data_count(P) returns 0. 3812** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3813** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3814** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3815** will return non-zero if previous call to [sqlite3_step](P) returned 3816** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3817** where it always returns zero since each step of that multi-step 3818** pragma returns 0 columns of data. 3819** 3820** See also: [sqlite3_column_count()] 3821*/ 3822int sqlite3_data_count(sqlite3_stmt *pStmt); 3823 3824/* 3825** CAPI3REF: Fundamental Datatypes 3826** KEYWORDS: SQLITE_TEXT 3827** 3828** ^(Every value in SQLite has one of five fundamental datatypes: 3829** 3830** <ul> 3831** <li> 64-bit signed integer 3832** <li> 64-bit IEEE floating point number 3833** <li> string 3834** <li> BLOB 3835** <li> NULL 3836** </ul>)^ 3837** 3838** These constants are codes for each of those types. 3839** 3840** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3841** for a completely different meaning. Software that links against both 3842** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3843** SQLITE_TEXT. 3844*/ 3845#define SQLITE_INTEGER 1 3846#define SQLITE_FLOAT 2 3847#define SQLITE_BLOB 4 3848#define SQLITE_NULL 5 3849#ifdef SQLITE_TEXT 3850# undef SQLITE_TEXT 3851#else 3852# define SQLITE_TEXT 3 3853#endif 3854#define SQLITE3_TEXT 3 3855 3856/* 3857** CAPI3REF: Result Values From A Query 3858** KEYWORDS: {column access functions} 3859** 3860** These routines form the "result set" interface. 3861** 3862** ^These routines return information about a single column of the current 3863** result row of a query. ^In every case the first argument is a pointer 3864** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3865** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3866** and the second argument is the index of the column for which information 3867** should be returned. ^The leftmost column of the result set has the index 0. 3868** ^The number of columns in the result can be determined using 3869** [sqlite3_column_count()]. 3870** 3871** If the SQL statement does not currently point to a valid row, or if the 3872** column index is out of range, the result is undefined. 3873** These routines may only be called when the most recent call to 3874** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3875** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3876** If any of these routines are called after [sqlite3_reset()] or 3877** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3878** something other than [SQLITE_ROW], the results are undefined. 3879** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3880** are called from a different thread while any of these routines 3881** are pending, then the results are undefined. 3882** 3883** ^The sqlite3_column_type() routine returns the 3884** [SQLITE_INTEGER | datatype code] for the initial data type 3885** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3886** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3887** returned by sqlite3_column_type() is only meaningful if no type 3888** conversions have occurred as described below. After a type conversion, 3889** the value returned by sqlite3_column_type() is undefined. Future 3890** versions of SQLite may change the behavior of sqlite3_column_type() 3891** following a type conversion. 3892** 3893** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3894** routine returns the number of bytes in that BLOB or string. 3895** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3896** the string to UTF-8 and then returns the number of bytes. 3897** ^If the result is a numeric value then sqlite3_column_bytes() uses 3898** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3899** the number of bytes in that string. 3900** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3901** 3902** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3903** routine returns the number of bytes in that BLOB or string. 3904** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3905** the string to UTF-16 and then returns the number of bytes. 3906** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3907** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3908** the number of bytes in that string. 3909** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3910** 3911** ^The values returned by [sqlite3_column_bytes()] and 3912** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3913** of the string. ^For clarity: the values returned by 3914** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3915** bytes in the string, not the number of characters. 3916** 3917** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3918** even empty strings, are always zero-terminated. ^The return 3919** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3920** 3921** ^The object returned by [sqlite3_column_value()] is an 3922** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3923** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3924** If the [unprotected sqlite3_value] object returned by 3925** [sqlite3_column_value()] is used in any other way, including calls 3926** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3927** or [sqlite3_value_bytes()], then the behavior is undefined. 3928** 3929** These routines attempt to convert the value where appropriate. ^For 3930** example, if the internal representation is FLOAT and a text result 3931** is requested, [sqlite3_snprintf()] is used internally to perform the 3932** conversion automatically. ^(The following table details the conversions 3933** that are applied: 3934** 3935** <blockquote> 3936** <table border="1"> 3937** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3938** 3939** <tr><td> NULL <td> INTEGER <td> Result is 0 3940** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3941** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3942** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3943** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3944** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3945** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3946** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3947** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3948** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3949** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 3950** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 3951** <tr><td> TEXT <td> BLOB <td> No change 3952** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 3953** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 3954** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3955** </table> 3956** </blockquote>)^ 3957** 3958** The table above makes reference to standard C library functions atoi() 3959** and atof(). SQLite does not really use these functions. It has its 3960** own equivalent internal routines. The atoi() and atof() names are 3961** used in the table for brevity and because they are familiar to most 3962** C programmers. 3963** 3964** Note that when type conversions occur, pointers returned by prior 3965** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3966** sqlite3_column_text16() may be invalidated. 3967** Type conversions and pointer invalidations might occur 3968** in the following cases: 3969** 3970** <ul> 3971** <li> The initial content is a BLOB and sqlite3_column_text() or 3972** sqlite3_column_text16() is called. A zero-terminator might 3973** need to be added to the string.</li> 3974** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3975** sqlite3_column_text16() is called. The content must be converted 3976** to UTF-16.</li> 3977** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3978** sqlite3_column_text() is called. The content must be converted 3979** to UTF-8.</li> 3980** </ul> 3981** 3982** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3983** not invalidate a prior pointer, though of course the content of the buffer 3984** that the prior pointer references will have been modified. Other kinds 3985** of conversion are done in place when it is possible, but sometimes they 3986** are not possible and in those cases prior pointers are invalidated. 3987** 3988** The safest and easiest to remember policy is to invoke these routines 3989** in one of the following ways: 3990** 3991** <ul> 3992** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3993** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3994** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3995** </ul> 3996** 3997** In other words, you should call sqlite3_column_text(), 3998** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3999** into the desired format, then invoke sqlite3_column_bytes() or 4000** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4001** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4002** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4003** with calls to sqlite3_column_bytes(). 4004** 4005** ^The pointers returned are valid until a type conversion occurs as 4006** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4007** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4008** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 4009** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4010** [sqlite3_free()]. 4011** 4012** ^(If a memory allocation error occurs during the evaluation of any 4013** of these routines, a default value is returned. The default value 4014** is either the integer 0, the floating point number 0.0, or a NULL 4015** pointer. Subsequent calls to [sqlite3_errcode()] will return 4016** [SQLITE_NOMEM].)^ 4017*/ 4018const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4019int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4020int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4021double sqlite3_column_double(sqlite3_stmt*, int iCol); 4022int sqlite3_column_int(sqlite3_stmt*, int iCol); 4023sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4024const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4025const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4026int sqlite3_column_type(sqlite3_stmt*, int iCol); 4027sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4028 4029/* 4030** CAPI3REF: Destroy A Prepared Statement Object 4031** 4032** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4033** ^If the most recent evaluation of the statement encountered no errors 4034** or if the statement is never been evaluated, then sqlite3_finalize() returns 4035** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4036** sqlite3_finalize(S) returns the appropriate [error code] or 4037** [extended error code]. 4038** 4039** ^The sqlite3_finalize(S) routine can be called at any point during 4040** the life cycle of [prepared statement] S: 4041** before statement S is ever evaluated, after 4042** one or more calls to [sqlite3_reset()], or after any call 4043** to [sqlite3_step()] regardless of whether or not the statement has 4044** completed execution. 4045** 4046** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4047** 4048** The application must finalize every [prepared statement] in order to avoid 4049** resource leaks. It is a grievous error for the application to try to use 4050** a prepared statement after it has been finalized. Any use of a prepared 4051** statement after it has been finalized can result in undefined and 4052** undesirable behavior such as segfaults and heap corruption. 4053*/ 4054int sqlite3_finalize(sqlite3_stmt *pStmt); 4055 4056/* 4057** CAPI3REF: Reset A Prepared Statement Object 4058** 4059** The sqlite3_reset() function is called to reset a [prepared statement] 4060** object back to its initial state, ready to be re-executed. 4061** ^Any SQL statement variables that had values bound to them using 4062** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4063** Use [sqlite3_clear_bindings()] to reset the bindings. 4064** 4065** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4066** back to the beginning of its program. 4067** 4068** ^If the most recent call to [sqlite3_step(S)] for the 4069** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4070** or if [sqlite3_step(S)] has never before been called on S, 4071** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4072** 4073** ^If the most recent call to [sqlite3_step(S)] for the 4074** [prepared statement] S indicated an error, then 4075** [sqlite3_reset(S)] returns an appropriate [error code]. 4076** 4077** ^The [sqlite3_reset(S)] interface does not change the values 4078** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4079*/ 4080int sqlite3_reset(sqlite3_stmt *pStmt); 4081 4082/* 4083** CAPI3REF: Create Or Redefine SQL Functions 4084** KEYWORDS: {function creation routines} 4085** KEYWORDS: {application-defined SQL function} 4086** KEYWORDS: {application-defined SQL functions} 4087** 4088** ^These functions (collectively known as "function creation routines") 4089** are used to add SQL functions or aggregates or to redefine the behavior 4090** of existing SQL functions or aggregates. The only differences between 4091** these routines are the text encoding expected for 4092** the second parameter (the name of the function being created) 4093** and the presence or absence of a destructor callback for 4094** the application data pointer. 4095** 4096** ^The first parameter is the [database connection] to which the SQL 4097** function is to be added. ^If an application uses more than one database 4098** connection then application-defined SQL functions must be added 4099** to each database connection separately. 4100** 4101** ^The second parameter is the name of the SQL function to be created or 4102** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4103** representation, exclusive of the zero-terminator. ^Note that the name 4104** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4105** ^Any attempt to create a function with a longer name 4106** will result in [SQLITE_MISUSE] being returned. 4107** 4108** ^The third parameter (nArg) 4109** is the number of arguments that the SQL function or 4110** aggregate takes. ^If this parameter is -1, then the SQL function or 4111** aggregate may take any number of arguments between 0 and the limit 4112** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4113** parameter is less than -1 or greater than 127 then the behavior is 4114** undefined. 4115** 4116** ^The fourth parameter, eTextRep, specifies what 4117** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4118** its parameters. The application should set this parameter to 4119** [SQLITE_UTF16LE] if the function implementation invokes 4120** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4121** implementation invokes [sqlite3_value_text16be()] on an input, or 4122** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4123** otherwise. ^The same SQL function may be registered multiple times using 4124** different preferred text encodings, with different implementations for 4125** each encoding. 4126** ^When multiple implementations of the same function are available, SQLite 4127** will pick the one that involves the least amount of data conversion. 4128** 4129** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4130** to signal that the function will always return the same result given 4131** the same inputs within a single SQL statement. Most SQL functions are 4132** deterministic. The built-in [random()] SQL function is an example of a 4133** function that is not deterministic. The SQLite query planner is able to 4134** perform additional optimizations on deterministic functions, so use 4135** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4136** 4137** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4138** function can gain access to this pointer using [sqlite3_user_data()].)^ 4139** 4140** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4141** pointers to C-language functions that implement the SQL function or 4142** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4143** callback only; NULL pointers must be passed as the xStep and xFinal 4144** parameters. ^An aggregate SQL function requires an implementation of xStep 4145** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4146** SQL function or aggregate, pass NULL pointers for all three function 4147** callbacks. 4148** 4149** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4150** then it is destructor for the application data pointer. 4151** The destructor is invoked when the function is deleted, either by being 4152** overloaded or when the database connection closes.)^ 4153** ^The destructor is also invoked if the call to 4154** sqlite3_create_function_v2() fails. 4155** ^When the destructor callback of the tenth parameter is invoked, it 4156** is passed a single argument which is a copy of the application data 4157** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4158** 4159** ^It is permitted to register multiple implementations of the same 4160** functions with the same name but with either differing numbers of 4161** arguments or differing preferred text encodings. ^SQLite will use 4162** the implementation that most closely matches the way in which the 4163** SQL function is used. ^A function implementation with a non-negative 4164** nArg parameter is a better match than a function implementation with 4165** a negative nArg. ^A function where the preferred text encoding 4166** matches the database encoding is a better 4167** match than a function where the encoding is different. 4168** ^A function where the encoding difference is between UTF16le and UTF16be 4169** is a closer match than a function where the encoding difference is 4170** between UTF8 and UTF16. 4171** 4172** ^Built-in functions may be overloaded by new application-defined functions. 4173** 4174** ^An application-defined function is permitted to call other 4175** SQLite interfaces. However, such calls must not 4176** close the database connection nor finalize or reset the prepared 4177** statement in which the function is running. 4178*/ 4179int sqlite3_create_function( 4180 sqlite3 *db, 4181 const char *zFunctionName, 4182 int nArg, 4183 int eTextRep, 4184 void *pApp, 4185 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4186 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4187 void (*xFinal)(sqlite3_context*) 4188); 4189int sqlite3_create_function16( 4190 sqlite3 *db, 4191 const void *zFunctionName, 4192 int nArg, 4193 int eTextRep, 4194 void *pApp, 4195 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4196 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4197 void (*xFinal)(sqlite3_context*) 4198); 4199int sqlite3_create_function_v2( 4200 sqlite3 *db, 4201 const char *zFunctionName, 4202 int nArg, 4203 int eTextRep, 4204 void *pApp, 4205 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4206 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4207 void (*xFinal)(sqlite3_context*), 4208 void(*xDestroy)(void*) 4209); 4210 4211/* 4212** CAPI3REF: Text Encodings 4213** 4214** These constant define integer codes that represent the various 4215** text encodings supported by SQLite. 4216*/ 4217#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4218#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4219#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4220#define SQLITE_UTF16 4 /* Use native byte order */ 4221#define SQLITE_ANY 5 /* Deprecated */ 4222#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4223 4224/* 4225** CAPI3REF: Function Flags 4226** 4227** These constants may be ORed together with the 4228** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4229** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4230** [sqlite3_create_function_v2()]. 4231*/ 4232#define SQLITE_DETERMINISTIC 0x800 4233 4234/* 4235** CAPI3REF: Deprecated Functions 4236** DEPRECATED 4237** 4238** These functions are [deprecated]. In order to maintain 4239** backwards compatibility with older code, these functions continue 4240** to be supported. However, new applications should avoid 4241** the use of these functions. To encourage programmers to avoid 4242** these functions, we will not explain what they do. 4243*/ 4244#ifndef SQLITE_OMIT_DEPRECATED 4245SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4246SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4247SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4248SQLITE_DEPRECATED int sqlite3_global_recover(void); 4249SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4250SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4251 void*,sqlite3_int64); 4252#endif 4253 4254/* 4255** CAPI3REF: Obtaining SQL Function Parameter Values 4256** 4257** The C-language implementation of SQL functions and aggregates uses 4258** this set of interface routines to access the parameter values on 4259** the function or aggregate. 4260** 4261** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4262** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4263** define callbacks that implement the SQL functions and aggregates. 4264** The 3rd parameter to these callbacks is an array of pointers to 4265** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4266** each parameter to the SQL function. These routines are used to 4267** extract values from the [sqlite3_value] objects. 4268** 4269** These routines work only with [protected sqlite3_value] objects. 4270** Any attempt to use these routines on an [unprotected sqlite3_value] 4271** object results in undefined behavior. 4272** 4273** ^These routines work just like the corresponding [column access functions] 4274** except that these routines take a single [protected sqlite3_value] object 4275** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4276** 4277** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4278** in the native byte-order of the host machine. ^The 4279** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4280** extract UTF-16 strings as big-endian and little-endian respectively. 4281** 4282** ^(The sqlite3_value_numeric_type() interface attempts to apply 4283** numeric affinity to the value. This means that an attempt is 4284** made to convert the value to an integer or floating point. If 4285** such a conversion is possible without loss of information (in other 4286** words, if the value is a string that looks like a number) 4287** then the conversion is performed. Otherwise no conversion occurs. 4288** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4289** 4290** Please pay particular attention to the fact that the pointer returned 4291** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4292** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4293** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4294** or [sqlite3_value_text16()]. 4295** 4296** These routines must be called from the same thread as 4297** the SQL function that supplied the [sqlite3_value*] parameters. 4298*/ 4299const void *sqlite3_value_blob(sqlite3_value*); 4300int sqlite3_value_bytes(sqlite3_value*); 4301int sqlite3_value_bytes16(sqlite3_value*); 4302double sqlite3_value_double(sqlite3_value*); 4303int sqlite3_value_int(sqlite3_value*); 4304sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4305const unsigned char *sqlite3_value_text(sqlite3_value*); 4306const void *sqlite3_value_text16(sqlite3_value*); 4307const void *sqlite3_value_text16le(sqlite3_value*); 4308const void *sqlite3_value_text16be(sqlite3_value*); 4309int sqlite3_value_type(sqlite3_value*); 4310int sqlite3_value_numeric_type(sqlite3_value*); 4311 4312/* 4313** CAPI3REF: Obtain Aggregate Function Context 4314** 4315** Implementations of aggregate SQL functions use this 4316** routine to allocate memory for storing their state. 4317** 4318** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4319** for a particular aggregate function, SQLite 4320** allocates N of memory, zeroes out that memory, and returns a pointer 4321** to the new memory. ^On second and subsequent calls to 4322** sqlite3_aggregate_context() for the same aggregate function instance, 4323** the same buffer is returned. Sqlite3_aggregate_context() is normally 4324** called once for each invocation of the xStep callback and then one 4325** last time when the xFinal callback is invoked. ^(When no rows match 4326** an aggregate query, the xStep() callback of the aggregate function 4327** implementation is never called and xFinal() is called exactly once. 4328** In those cases, sqlite3_aggregate_context() might be called for the 4329** first time from within xFinal().)^ 4330** 4331** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4332** when first called if N is less than or equal to zero or if a memory 4333** allocate error occurs. 4334** 4335** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4336** determined by the N parameter on first successful call. Changing the 4337** value of N in subsequent call to sqlite3_aggregate_context() within 4338** the same aggregate function instance will not resize the memory 4339** allocation.)^ Within the xFinal callback, it is customary to set 4340** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4341** pointless memory allocations occur. 4342** 4343** ^SQLite automatically frees the memory allocated by 4344** sqlite3_aggregate_context() when the aggregate query concludes. 4345** 4346** The first parameter must be a copy of the 4347** [sqlite3_context | SQL function context] that is the first parameter 4348** to the xStep or xFinal callback routine that implements the aggregate 4349** function. 4350** 4351** This routine must be called from the same thread in which 4352** the aggregate SQL function is running. 4353*/ 4354void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4355 4356/* 4357** CAPI3REF: User Data For Functions 4358** 4359** ^The sqlite3_user_data() interface returns a copy of 4360** the pointer that was the pUserData parameter (the 5th parameter) 4361** of the [sqlite3_create_function()] 4362** and [sqlite3_create_function16()] routines that originally 4363** registered the application defined function. 4364** 4365** This routine must be called from the same thread in which 4366** the application-defined function is running. 4367*/ 4368void *sqlite3_user_data(sqlite3_context*); 4369 4370/* 4371** CAPI3REF: Database Connection For Functions 4372** 4373** ^The sqlite3_context_db_handle() interface returns a copy of 4374** the pointer to the [database connection] (the 1st parameter) 4375** of the [sqlite3_create_function()] 4376** and [sqlite3_create_function16()] routines that originally 4377** registered the application defined function. 4378*/ 4379sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4380 4381/* 4382** CAPI3REF: Function Auxiliary Data 4383** 4384** These functions may be used by (non-aggregate) SQL functions to 4385** associate metadata with argument values. If the same value is passed to 4386** multiple invocations of the same SQL function during query execution, under 4387** some circumstances the associated metadata may be preserved. An example 4388** of where this might be useful is in a regular-expression matching 4389** function. The compiled version of the regular expression can be stored as 4390** metadata associated with the pattern string. 4391** Then as long as the pattern string remains the same, 4392** the compiled regular expression can be reused on multiple 4393** invocations of the same function. 4394** 4395** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4396** associated by the sqlite3_set_auxdata() function with the Nth argument 4397** value to the application-defined function. ^If there is no metadata 4398** associated with the function argument, this sqlite3_get_auxdata() interface 4399** returns a NULL pointer. 4400** 4401** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4402** argument of the application-defined function. ^Subsequent 4403** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4404** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4405** NULL if the metadata has been discarded. 4406** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4407** SQLite will invoke the destructor function X with parameter P exactly 4408** once, when the metadata is discarded. 4409** SQLite is free to discard the metadata at any time, including: <ul> 4410** <li> when the corresponding function parameter changes, or 4411** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4412** SQL statement, or 4413** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4414** <li> during the original sqlite3_set_auxdata() call when a memory 4415** allocation error occurs. </ul>)^ 4416** 4417** Note the last bullet in particular. The destructor X in 4418** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4419** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4420** should be called near the end of the function implementation and the 4421** function implementation should not make any use of P after 4422** sqlite3_set_auxdata() has been called. 4423** 4424** ^(In practice, metadata is preserved between function calls for 4425** function parameters that are compile-time constants, including literal 4426** values and [parameters] and expressions composed from the same.)^ 4427** 4428** These routines must be called from the same thread in which 4429** the SQL function is running. 4430*/ 4431void *sqlite3_get_auxdata(sqlite3_context*, int N); 4432void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4433 4434 4435/* 4436** CAPI3REF: Constants Defining Special Destructor Behavior 4437** 4438** These are special values for the destructor that is passed in as the 4439** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4440** argument is SQLITE_STATIC, it means that the content pointer is constant 4441** and will never change. It does not need to be destroyed. ^The 4442** SQLITE_TRANSIENT value means that the content will likely change in 4443** the near future and that SQLite should make its own private copy of 4444** the content before returning. 4445** 4446** The typedef is necessary to work around problems in certain 4447** C++ compilers. 4448*/ 4449typedef void (*sqlite3_destructor_type)(void*); 4450#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4451#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4452 4453/* 4454** CAPI3REF: Setting The Result Of An SQL Function 4455** 4456** These routines are used by the xFunc or xFinal callbacks that 4457** implement SQL functions and aggregates. See 4458** [sqlite3_create_function()] and [sqlite3_create_function16()] 4459** for additional information. 4460** 4461** These functions work very much like the [parameter binding] family of 4462** functions used to bind values to host parameters in prepared statements. 4463** Refer to the [SQL parameter] documentation for additional information. 4464** 4465** ^The sqlite3_result_blob() interface sets the result from 4466** an application-defined function to be the BLOB whose content is pointed 4467** to by the second parameter and which is N bytes long where N is the 4468** third parameter. 4469** 4470** ^The sqlite3_result_zeroblob() interfaces set the result of 4471** the application-defined function to be a BLOB containing all zero 4472** bytes and N bytes in size, where N is the value of the 2nd parameter. 4473** 4474** ^The sqlite3_result_double() interface sets the result from 4475** an application-defined function to be a floating point value specified 4476** by its 2nd argument. 4477** 4478** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4479** cause the implemented SQL function to throw an exception. 4480** ^SQLite uses the string pointed to by the 4481** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4482** as the text of an error message. ^SQLite interprets the error 4483** message string from sqlite3_result_error() as UTF-8. ^SQLite 4484** interprets the string from sqlite3_result_error16() as UTF-16 in native 4485** byte order. ^If the third parameter to sqlite3_result_error() 4486** or sqlite3_result_error16() is negative then SQLite takes as the error 4487** message all text up through the first zero character. 4488** ^If the third parameter to sqlite3_result_error() or 4489** sqlite3_result_error16() is non-negative then SQLite takes that many 4490** bytes (not characters) from the 2nd parameter as the error message. 4491** ^The sqlite3_result_error() and sqlite3_result_error16() 4492** routines make a private copy of the error message text before 4493** they return. Hence, the calling function can deallocate or 4494** modify the text after they return without harm. 4495** ^The sqlite3_result_error_code() function changes the error code 4496** returned by SQLite as a result of an error in a function. ^By default, 4497** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4498** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4499** 4500** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4501** error indicating that a string or BLOB is too long to represent. 4502** 4503** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4504** error indicating that a memory allocation failed. 4505** 4506** ^The sqlite3_result_int() interface sets the return value 4507** of the application-defined function to be the 32-bit signed integer 4508** value given in the 2nd argument. 4509** ^The sqlite3_result_int64() interface sets the return value 4510** of the application-defined function to be the 64-bit signed integer 4511** value given in the 2nd argument. 4512** 4513** ^The sqlite3_result_null() interface sets the return value 4514** of the application-defined function to be NULL. 4515** 4516** ^The sqlite3_result_text(), sqlite3_result_text16(), 4517** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4518** set the return value of the application-defined function to be 4519** a text string which is represented as UTF-8, UTF-16 native byte order, 4520** UTF-16 little endian, or UTF-16 big endian, respectively. 4521** ^The sqlite3_result_text64() interface sets the return value of an 4522** application-defined function to be a text string in an encoding 4523** specified by the fifth (and last) parameter, which must be one 4524** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4525** ^SQLite takes the text result from the application from 4526** the 2nd parameter of the sqlite3_result_text* interfaces. 4527** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4528** is negative, then SQLite takes result text from the 2nd parameter 4529** through the first zero character. 4530** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4531** is non-negative, then as many bytes (not characters) of the text 4532** pointed to by the 2nd parameter are taken as the application-defined 4533** function result. If the 3rd parameter is non-negative, then it 4534** must be the byte offset into the string where the NUL terminator would 4535** appear if the string where NUL terminated. If any NUL characters occur 4536** in the string at a byte offset that is less than the value of the 3rd 4537** parameter, then the resulting string will contain embedded NULs and the 4538** result of expressions operating on strings with embedded NULs is undefined. 4539** ^If the 4th parameter to the sqlite3_result_text* interfaces 4540** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4541** function as the destructor on the text or BLOB result when it has 4542** finished using that result. 4543** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4544** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4545** assumes that the text or BLOB result is in constant space and does not 4546** copy the content of the parameter nor call a destructor on the content 4547** when it has finished using that result. 4548** ^If the 4th parameter to the sqlite3_result_text* interfaces 4549** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4550** then SQLite makes a copy of the result into space obtained from 4551** from [sqlite3_malloc()] before it returns. 4552** 4553** ^The sqlite3_result_value() interface sets the result of 4554** the application-defined function to be a copy the 4555** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4556** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4557** so that the [sqlite3_value] specified in the parameter may change or 4558** be deallocated after sqlite3_result_value() returns without harm. 4559** ^A [protected sqlite3_value] object may always be used where an 4560** [unprotected sqlite3_value] object is required, so either 4561** kind of [sqlite3_value] object can be used with this interface. 4562** 4563** If these routines are called from within the different thread 4564** than the one containing the application-defined function that received 4565** the [sqlite3_context] pointer, the results are undefined. 4566*/ 4567void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4568void sqlite3_result_blob64(sqlite3_context*,const void*, 4569 sqlite3_uint64,void(*)(void*)); 4570void sqlite3_result_double(sqlite3_context*, double); 4571void sqlite3_result_error(sqlite3_context*, const char*, int); 4572void sqlite3_result_error16(sqlite3_context*, const void*, int); 4573void sqlite3_result_error_toobig(sqlite3_context*); 4574void sqlite3_result_error_nomem(sqlite3_context*); 4575void sqlite3_result_error_code(sqlite3_context*, int); 4576void sqlite3_result_int(sqlite3_context*, int); 4577void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4578void sqlite3_result_null(sqlite3_context*); 4579void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4580void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4581 void(*)(void*), unsigned char encoding); 4582void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4583void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4584void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4585void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4586void sqlite3_result_zeroblob(sqlite3_context*, int n); 4587 4588/* 4589** CAPI3REF: Define New Collating Sequences 4590** 4591** ^These functions add, remove, or modify a [collation] associated 4592** with the [database connection] specified as the first argument. 4593** 4594** ^The name of the collation is a UTF-8 string 4595** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4596** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4597** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4598** considered to be the same name. 4599** 4600** ^(The third argument (eTextRep) must be one of the constants: 4601** <ul> 4602** <li> [SQLITE_UTF8], 4603** <li> [SQLITE_UTF16LE], 4604** <li> [SQLITE_UTF16BE], 4605** <li> [SQLITE_UTF16], or 4606** <li> [SQLITE_UTF16_ALIGNED]. 4607** </ul>)^ 4608** ^The eTextRep argument determines the encoding of strings passed 4609** to the collating function callback, xCallback. 4610** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4611** force strings to be UTF16 with native byte order. 4612** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4613** on an even byte address. 4614** 4615** ^The fourth argument, pArg, is an application data pointer that is passed 4616** through as the first argument to the collating function callback. 4617** 4618** ^The fifth argument, xCallback, is a pointer to the collating function. 4619** ^Multiple collating functions can be registered using the same name but 4620** with different eTextRep parameters and SQLite will use whichever 4621** function requires the least amount of data transformation. 4622** ^If the xCallback argument is NULL then the collating function is 4623** deleted. ^When all collating functions having the same name are deleted, 4624** that collation is no longer usable. 4625** 4626** ^The collating function callback is invoked with a copy of the pArg 4627** application data pointer and with two strings in the encoding specified 4628** by the eTextRep argument. The collating function must return an 4629** integer that is negative, zero, or positive 4630** if the first string is less than, equal to, or greater than the second, 4631** respectively. A collating function must always return the same answer 4632** given the same inputs. If two or more collating functions are registered 4633** to the same collation name (using different eTextRep values) then all 4634** must give an equivalent answer when invoked with equivalent strings. 4635** The collating function must obey the following properties for all 4636** strings A, B, and C: 4637** 4638** <ol> 4639** <li> If A==B then B==A. 4640** <li> If A==B and B==C then A==C. 4641** <li> If A<B THEN B>A. 4642** <li> If A<B and B<C then A<C. 4643** </ol> 4644** 4645** If a collating function fails any of the above constraints and that 4646** collating function is registered and used, then the behavior of SQLite 4647** is undefined. 4648** 4649** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4650** with the addition that the xDestroy callback is invoked on pArg when 4651** the collating function is deleted. 4652** ^Collating functions are deleted when they are overridden by later 4653** calls to the collation creation functions or when the 4654** [database connection] is closed using [sqlite3_close()]. 4655** 4656** ^The xDestroy callback is <u>not</u> called if the 4657** sqlite3_create_collation_v2() function fails. Applications that invoke 4658** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4659** check the return code and dispose of the application data pointer 4660** themselves rather than expecting SQLite to deal with it for them. 4661** This is different from every other SQLite interface. The inconsistency 4662** is unfortunate but cannot be changed without breaking backwards 4663** compatibility. 4664** 4665** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4666*/ 4667int sqlite3_create_collation( 4668 sqlite3*, 4669 const char *zName, 4670 int eTextRep, 4671 void *pArg, 4672 int(*xCompare)(void*,int,const void*,int,const void*) 4673); 4674int sqlite3_create_collation_v2( 4675 sqlite3*, 4676 const char *zName, 4677 int eTextRep, 4678 void *pArg, 4679 int(*xCompare)(void*,int,const void*,int,const void*), 4680 void(*xDestroy)(void*) 4681); 4682int sqlite3_create_collation16( 4683 sqlite3*, 4684 const void *zName, 4685 int eTextRep, 4686 void *pArg, 4687 int(*xCompare)(void*,int,const void*,int,const void*) 4688); 4689 4690/* 4691** CAPI3REF: Collation Needed Callbacks 4692** 4693** ^To avoid having to register all collation sequences before a database 4694** can be used, a single callback function may be registered with the 4695** [database connection] to be invoked whenever an undefined collation 4696** sequence is required. 4697** 4698** ^If the function is registered using the sqlite3_collation_needed() API, 4699** then it is passed the names of undefined collation sequences as strings 4700** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4701** the names are passed as UTF-16 in machine native byte order. 4702** ^A call to either function replaces the existing collation-needed callback. 4703** 4704** ^(When the callback is invoked, the first argument passed is a copy 4705** of the second argument to sqlite3_collation_needed() or 4706** sqlite3_collation_needed16(). The second argument is the database 4707** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4708** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4709** sequence function required. The fourth parameter is the name of the 4710** required collation sequence.)^ 4711** 4712** The callback function should register the desired collation using 4713** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4714** [sqlite3_create_collation_v2()]. 4715*/ 4716int sqlite3_collation_needed( 4717 sqlite3*, 4718 void*, 4719 void(*)(void*,sqlite3*,int eTextRep,const char*) 4720); 4721int sqlite3_collation_needed16( 4722 sqlite3*, 4723 void*, 4724 void(*)(void*,sqlite3*,int eTextRep,const void*) 4725); 4726 4727#ifdef SQLITE_HAS_CODEC 4728/* 4729** Specify the key for an encrypted database. This routine should be 4730** called right after sqlite3_open(). 4731** 4732** The code to implement this API is not available in the public release 4733** of SQLite. 4734*/ 4735int sqlite3_key( 4736 sqlite3 *db, /* Database to be rekeyed */ 4737 const void *pKey, int nKey /* The key */ 4738); 4739int sqlite3_key_v2( 4740 sqlite3 *db, /* Database to be rekeyed */ 4741 const char *zDbName, /* Name of the database */ 4742 const void *pKey, int nKey /* The key */ 4743); 4744 4745/* 4746** Change the key on an open database. If the current database is not 4747** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4748** database is decrypted. 4749** 4750** The code to implement this API is not available in the public release 4751** of SQLite. 4752*/ 4753int sqlite3_rekey( 4754 sqlite3 *db, /* Database to be rekeyed */ 4755 const void *pKey, int nKey /* The new key */ 4756); 4757int sqlite3_rekey_v2( 4758 sqlite3 *db, /* Database to be rekeyed */ 4759 const char *zDbName, /* Name of the database */ 4760 const void *pKey, int nKey /* The new key */ 4761); 4762 4763/* 4764** Specify the activation key for a SEE database. Unless 4765** activated, none of the SEE routines will work. 4766*/ 4767void sqlite3_activate_see( 4768 const char *zPassPhrase /* Activation phrase */ 4769); 4770#endif 4771 4772#ifdef SQLITE_ENABLE_CEROD 4773/* 4774** Specify the activation key for a CEROD database. Unless 4775** activated, none of the CEROD routines will work. 4776*/ 4777void sqlite3_activate_cerod( 4778 const char *zPassPhrase /* Activation phrase */ 4779); 4780#endif 4781 4782/* 4783** CAPI3REF: Suspend Execution For A Short Time 4784** 4785** The sqlite3_sleep() function causes the current thread to suspend execution 4786** for at least a number of milliseconds specified in its parameter. 4787** 4788** If the operating system does not support sleep requests with 4789** millisecond time resolution, then the time will be rounded up to 4790** the nearest second. The number of milliseconds of sleep actually 4791** requested from the operating system is returned. 4792** 4793** ^SQLite implements this interface by calling the xSleep() 4794** method of the default [sqlite3_vfs] object. If the xSleep() method 4795** of the default VFS is not implemented correctly, or not implemented at 4796** all, then the behavior of sqlite3_sleep() may deviate from the description 4797** in the previous paragraphs. 4798*/ 4799int sqlite3_sleep(int); 4800 4801/* 4802** CAPI3REF: Name Of The Folder Holding Temporary Files 4803** 4804** ^(If this global variable is made to point to a string which is 4805** the name of a folder (a.k.a. directory), then all temporary files 4806** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4807** will be placed in that directory.)^ ^If this variable 4808** is a NULL pointer, then SQLite performs a search for an appropriate 4809** temporary file directory. 4810** 4811** Applications are strongly discouraged from using this global variable. 4812** It is required to set a temporary folder on Windows Runtime (WinRT). 4813** But for all other platforms, it is highly recommended that applications 4814** neither read nor write this variable. This global variable is a relic 4815** that exists for backwards compatibility of legacy applications and should 4816** be avoided in new projects. 4817** 4818** It is not safe to read or modify this variable in more than one 4819** thread at a time. It is not safe to read or modify this variable 4820** if a [database connection] is being used at the same time in a separate 4821** thread. 4822** It is intended that this variable be set once 4823** as part of process initialization and before any SQLite interface 4824** routines have been called and that this variable remain unchanged 4825** thereafter. 4826** 4827** ^The [temp_store_directory pragma] may modify this variable and cause 4828** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4829** the [temp_store_directory pragma] always assumes that any string 4830** that this variable points to is held in memory obtained from 4831** [sqlite3_malloc] and the pragma may attempt to free that memory 4832** using [sqlite3_free]. 4833** Hence, if this variable is modified directly, either it should be 4834** made NULL or made to point to memory obtained from [sqlite3_malloc] 4835** or else the use of the [temp_store_directory pragma] should be avoided. 4836** Except when requested by the [temp_store_directory pragma], SQLite 4837** does not free the memory that sqlite3_temp_directory points to. If 4838** the application wants that memory to be freed, it must do 4839** so itself, taking care to only do so after all [database connection] 4840** objects have been destroyed. 4841** 4842** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4843** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4844** features that require the use of temporary files may fail. Here is an 4845** example of how to do this using C++ with the Windows Runtime: 4846** 4847** <blockquote><pre> 4848** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4849** TemporaryFolder->Path->Data(); 4850** char zPathBuf[MAX_PATH + 1]; 4851** memset(zPathBuf, 0, sizeof(zPathBuf)); 4852** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4853** NULL, NULL); 4854** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4855** </pre></blockquote> 4856*/ 4857SQLITE_EXTERN char *sqlite3_temp_directory; 4858 4859/* 4860** CAPI3REF: Name Of The Folder Holding Database Files 4861** 4862** ^(If this global variable is made to point to a string which is 4863** the name of a folder (a.k.a. directory), then all database files 4864** specified with a relative pathname and created or accessed by 4865** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4866** to be relative to that directory.)^ ^If this variable is a NULL 4867** pointer, then SQLite assumes that all database files specified 4868** with a relative pathname are relative to the current directory 4869** for the process. Only the windows VFS makes use of this global 4870** variable; it is ignored by the unix VFS. 4871** 4872** Changing the value of this variable while a database connection is 4873** open can result in a corrupt database. 4874** 4875** It is not safe to read or modify this variable in more than one 4876** thread at a time. It is not safe to read or modify this variable 4877** if a [database connection] is being used at the same time in a separate 4878** thread. 4879** It is intended that this variable be set once 4880** as part of process initialization and before any SQLite interface 4881** routines have been called and that this variable remain unchanged 4882** thereafter. 4883** 4884** ^The [data_store_directory pragma] may modify this variable and cause 4885** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4886** the [data_store_directory pragma] always assumes that any string 4887** that this variable points to is held in memory obtained from 4888** [sqlite3_malloc] and the pragma may attempt to free that memory 4889** using [sqlite3_free]. 4890** Hence, if this variable is modified directly, either it should be 4891** made NULL or made to point to memory obtained from [sqlite3_malloc] 4892** or else the use of the [data_store_directory pragma] should be avoided. 4893*/ 4894SQLITE_EXTERN char *sqlite3_data_directory; 4895 4896/* 4897** CAPI3REF: Test For Auto-Commit Mode 4898** KEYWORDS: {autocommit mode} 4899** 4900** ^The sqlite3_get_autocommit() interface returns non-zero or 4901** zero if the given database connection is or is not in autocommit mode, 4902** respectively. ^Autocommit mode is on by default. 4903** ^Autocommit mode is disabled by a [BEGIN] statement. 4904** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4905** 4906** If certain kinds of errors occur on a statement within a multi-statement 4907** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4908** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4909** transaction might be rolled back automatically. The only way to 4910** find out whether SQLite automatically rolled back the transaction after 4911** an error is to use this function. 4912** 4913** If another thread changes the autocommit status of the database 4914** connection while this routine is running, then the return value 4915** is undefined. 4916*/ 4917int sqlite3_get_autocommit(sqlite3*); 4918 4919/* 4920** CAPI3REF: Find The Database Handle Of A Prepared Statement 4921** 4922** ^The sqlite3_db_handle interface returns the [database connection] handle 4923** to which a [prepared statement] belongs. ^The [database connection] 4924** returned by sqlite3_db_handle is the same [database connection] 4925** that was the first argument 4926** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4927** create the statement in the first place. 4928*/ 4929sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4930 4931/* 4932** CAPI3REF: Return The Filename For A Database Connection 4933** 4934** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4935** associated with database N of connection D. ^The main database file 4936** has the name "main". If there is no attached database N on the database 4937** connection D, or if database N is a temporary or in-memory database, then 4938** a NULL pointer is returned. 4939** 4940** ^The filename returned by this function is the output of the 4941** xFullPathname method of the [VFS]. ^In other words, the filename 4942** will be an absolute pathname, even if the filename used 4943** to open the database originally was a URI or relative pathname. 4944*/ 4945const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4946 4947/* 4948** CAPI3REF: Determine if a database is read-only 4949** 4950** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4951** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4952** the name of a database on connection D. 4953*/ 4954int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4955 4956/* 4957** CAPI3REF: Find the next prepared statement 4958** 4959** ^This interface returns a pointer to the next [prepared statement] after 4960** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4961** then this interface returns a pointer to the first prepared statement 4962** associated with the database connection pDb. ^If no prepared statement 4963** satisfies the conditions of this routine, it returns NULL. 4964** 4965** The [database connection] pointer D in a call to 4966** [sqlite3_next_stmt(D,S)] must refer to an open database 4967** connection and in particular must not be a NULL pointer. 4968*/ 4969sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4970 4971/* 4972** CAPI3REF: Commit And Rollback Notification Callbacks 4973** 4974** ^The sqlite3_commit_hook() interface registers a callback 4975** function to be invoked whenever a transaction is [COMMIT | committed]. 4976** ^Any callback set by a previous call to sqlite3_commit_hook() 4977** for the same database connection is overridden. 4978** ^The sqlite3_rollback_hook() interface registers a callback 4979** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4980** ^Any callback set by a previous call to sqlite3_rollback_hook() 4981** for the same database connection is overridden. 4982** ^The pArg argument is passed through to the callback. 4983** ^If the callback on a commit hook function returns non-zero, 4984** then the commit is converted into a rollback. 4985** 4986** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4987** return the P argument from the previous call of the same function 4988** on the same [database connection] D, or NULL for 4989** the first call for each function on D. 4990** 4991** The commit and rollback hook callbacks are not reentrant. 4992** The callback implementation must not do anything that will modify 4993** the database connection that invoked the callback. Any actions 4994** to modify the database connection must be deferred until after the 4995** completion of the [sqlite3_step()] call that triggered the commit 4996** or rollback hook in the first place. 4997** Note that running any other SQL statements, including SELECT statements, 4998** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4999** the database connections for the meaning of "modify" in this paragraph. 5000** 5001** ^Registering a NULL function disables the callback. 5002** 5003** ^When the commit hook callback routine returns zero, the [COMMIT] 5004** operation is allowed to continue normally. ^If the commit hook 5005** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5006** ^The rollback hook is invoked on a rollback that results from a commit 5007** hook returning non-zero, just as it would be with any other rollback. 5008** 5009** ^For the purposes of this API, a transaction is said to have been 5010** rolled back if an explicit "ROLLBACK" statement is executed, or 5011** an error or constraint causes an implicit rollback to occur. 5012** ^The rollback callback is not invoked if a transaction is 5013** automatically rolled back because the database connection is closed. 5014** 5015** See also the [sqlite3_update_hook()] interface. 5016*/ 5017void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5018void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5019 5020/* 5021** CAPI3REF: Data Change Notification Callbacks 5022** 5023** ^The sqlite3_update_hook() interface registers a callback function 5024** with the [database connection] identified by the first argument 5025** to be invoked whenever a row is updated, inserted or deleted in 5026** a rowid table. 5027** ^Any callback set by a previous call to this function 5028** for the same database connection is overridden. 5029** 5030** ^The second argument is a pointer to the function to invoke when a 5031** row is updated, inserted or deleted in a rowid table. 5032** ^The first argument to the callback is a copy of the third argument 5033** to sqlite3_update_hook(). 5034** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5035** or [SQLITE_UPDATE], depending on the operation that caused the callback 5036** to be invoked. 5037** ^The third and fourth arguments to the callback contain pointers to the 5038** database and table name containing the affected row. 5039** ^The final callback parameter is the [rowid] of the row. 5040** ^In the case of an update, this is the [rowid] after the update takes place. 5041** 5042** ^(The update hook is not invoked when internal system tables are 5043** modified (i.e. sqlite_master and sqlite_sequence).)^ 5044** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5045** 5046** ^In the current implementation, the update hook 5047** is not invoked when duplication rows are deleted because of an 5048** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5049** invoked when rows are deleted using the [truncate optimization]. 5050** The exceptions defined in this paragraph might change in a future 5051** release of SQLite. 5052** 5053** The update hook implementation must not do anything that will modify 5054** the database connection that invoked the update hook. Any actions 5055** to modify the database connection must be deferred until after the 5056** completion of the [sqlite3_step()] call that triggered the update hook. 5057** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5058** database connections for the meaning of "modify" in this paragraph. 5059** 5060** ^The sqlite3_update_hook(D,C,P) function 5061** returns the P argument from the previous call 5062** on the same [database connection] D, or NULL for 5063** the first call on D. 5064** 5065** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 5066** interfaces. 5067*/ 5068void *sqlite3_update_hook( 5069 sqlite3*, 5070 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5071 void* 5072); 5073 5074/* 5075** CAPI3REF: Enable Or Disable Shared Pager Cache 5076** 5077** ^(This routine enables or disables the sharing of the database cache 5078** and schema data structures between [database connection | connections] 5079** to the same database. Sharing is enabled if the argument is true 5080** and disabled if the argument is false.)^ 5081** 5082** ^Cache sharing is enabled and disabled for an entire process. 5083** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5084** sharing was enabled or disabled for each thread separately. 5085** 5086** ^(The cache sharing mode set by this interface effects all subsequent 5087** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5088** Existing database connections continue use the sharing mode 5089** that was in effect at the time they were opened.)^ 5090** 5091** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5092** successfully. An [error code] is returned otherwise.)^ 5093** 5094** ^Shared cache is disabled by default. But this might change in 5095** future releases of SQLite. Applications that care about shared 5096** cache setting should set it explicitly. 5097** 5098** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5099** and will always return SQLITE_MISUSE. On those systems, 5100** shared cache mode should be enabled per-database connection via 5101** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5102** 5103** This interface is threadsafe on processors where writing a 5104** 32-bit integer is atomic. 5105** 5106** See Also: [SQLite Shared-Cache Mode] 5107*/ 5108int sqlite3_enable_shared_cache(int); 5109 5110/* 5111** CAPI3REF: Attempt To Free Heap Memory 5112** 5113** ^The sqlite3_release_memory() interface attempts to free N bytes 5114** of heap memory by deallocating non-essential memory allocations 5115** held by the database library. Memory used to cache database 5116** pages to improve performance is an example of non-essential memory. 5117** ^sqlite3_release_memory() returns the number of bytes actually freed, 5118** which might be more or less than the amount requested. 5119** ^The sqlite3_release_memory() routine is a no-op returning zero 5120** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5121** 5122** See also: [sqlite3_db_release_memory()] 5123*/ 5124int sqlite3_release_memory(int); 5125 5126/* 5127** CAPI3REF: Free Memory Used By A Database Connection 5128** 5129** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5130** memory as possible from database connection D. Unlike the 5131** [sqlite3_release_memory()] interface, this interface is in effect even 5132** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5133** omitted. 5134** 5135** See also: [sqlite3_release_memory()] 5136*/ 5137int sqlite3_db_release_memory(sqlite3*); 5138 5139/* 5140** CAPI3REF: Impose A Limit On Heap Size 5141** 5142** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5143** soft limit on the amount of heap memory that may be allocated by SQLite. 5144** ^SQLite strives to keep heap memory utilization below the soft heap 5145** limit by reducing the number of pages held in the page cache 5146** as heap memory usages approaches the limit. 5147** ^The soft heap limit is "soft" because even though SQLite strives to stay 5148** below the limit, it will exceed the limit rather than generate 5149** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5150** is advisory only. 5151** 5152** ^The return value from sqlite3_soft_heap_limit64() is the size of 5153** the soft heap limit prior to the call, or negative in the case of an 5154** error. ^If the argument N is negative 5155** then no change is made to the soft heap limit. Hence, the current 5156** size of the soft heap limit can be determined by invoking 5157** sqlite3_soft_heap_limit64() with a negative argument. 5158** 5159** ^If the argument N is zero then the soft heap limit is disabled. 5160** 5161** ^(The soft heap limit is not enforced in the current implementation 5162** if one or more of following conditions are true: 5163** 5164** <ul> 5165** <li> The soft heap limit is set to zero. 5166** <li> Memory accounting is disabled using a combination of the 5167** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5168** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5169** <li> An alternative page cache implementation is specified using 5170** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5171** <li> The page cache allocates from its own memory pool supplied 5172** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5173** from the heap. 5174** </ul>)^ 5175** 5176** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5177** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5178** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5179** the soft heap limit is enforced on every memory allocation. Without 5180** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5181** when memory is allocated by the page cache. Testing suggests that because 5182** the page cache is the predominate memory user in SQLite, most 5183** applications will achieve adequate soft heap limit enforcement without 5184** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5185** 5186** The circumstances under which SQLite will enforce the soft heap limit may 5187** changes in future releases of SQLite. 5188*/ 5189sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5190 5191/* 5192** CAPI3REF: Deprecated Soft Heap Limit Interface 5193** DEPRECATED 5194** 5195** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5196** interface. This routine is provided for historical compatibility 5197** only. All new applications should use the 5198** [sqlite3_soft_heap_limit64()] interface rather than this one. 5199*/ 5200SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5201 5202 5203/* 5204** CAPI3REF: Extract Metadata About A Column Of A Table 5205** 5206** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5207** information about column C of table T in database D 5208** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5209** interface returns SQLITE_OK and fills in the non-NULL pointers in 5210** the final five arguments with appropriate values if the specified 5211** column exists. ^The sqlite3_table_column_metadata() interface returns 5212** SQLITE_ERROR and if the specified column does not exist. 5213** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5214** NULL pointer, then this routine simply checks for the existance of the 5215** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5216** does not. 5217** 5218** ^The column is identified by the second, third and fourth parameters to 5219** this function. ^(The second parameter is either the name of the database 5220** (i.e. "main", "temp", or an attached database) containing the specified 5221** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5222** for the table using the same algorithm used by the database engine to 5223** resolve unqualified table references. 5224** 5225** ^The third and fourth parameters to this function are the table and column 5226** name of the desired column, respectively. 5227** 5228** ^Metadata is returned by writing to the memory locations passed as the 5th 5229** and subsequent parameters to this function. ^Any of these arguments may be 5230** NULL, in which case the corresponding element of metadata is omitted. 5231** 5232** ^(<blockquote> 5233** <table border="1"> 5234** <tr><th> Parameter <th> Output<br>Type <th> Description 5235** 5236** <tr><td> 5th <td> const char* <td> Data type 5237** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5238** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5239** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5240** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5241** </table> 5242** </blockquote>)^ 5243** 5244** ^The memory pointed to by the character pointers returned for the 5245** declaration type and collation sequence is valid until the next 5246** call to any SQLite API function. 5247** 5248** ^If the specified table is actually a view, an [error code] is returned. 5249** 5250** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5251** is not a [WITHOUT ROWID] table and an 5252** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5253** parameters are set for the explicitly declared column. ^(If there is no 5254** [INTEGER PRIMARY KEY] column, then the outputs 5255** for the [rowid] are set as follows: 5256** 5257** <pre> 5258** data type: "INTEGER" 5259** collation sequence: "BINARY" 5260** not null: 0 5261** primary key: 1 5262** auto increment: 0 5263** </pre>)^ 5264** 5265** ^This function causes all database schemas to be read from disk and 5266** parsed, if that has not already been done, and returns an error if 5267** any errors are encountered while loading the schema. 5268*/ 5269int sqlite3_table_column_metadata( 5270 sqlite3 *db, /* Connection handle */ 5271 const char *zDbName, /* Database name or NULL */ 5272 const char *zTableName, /* Table name */ 5273 const char *zColumnName, /* Column name */ 5274 char const **pzDataType, /* OUTPUT: Declared data type */ 5275 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5276 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5277 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5278 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5279); 5280 5281/* 5282** CAPI3REF: Load An Extension 5283** 5284** ^This interface loads an SQLite extension library from the named file. 5285** 5286** ^The sqlite3_load_extension() interface attempts to load an 5287** [SQLite extension] library contained in the file zFile. If 5288** the file cannot be loaded directly, attempts are made to load 5289** with various operating-system specific extensions added. 5290** So for example, if "samplelib" cannot be loaded, then names like 5291** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5292** be tried also. 5293** 5294** ^The entry point is zProc. 5295** ^(zProc may be 0, in which case SQLite will try to come up with an 5296** entry point name on its own. It first tries "sqlite3_extension_init". 5297** If that does not work, it constructs a name "sqlite3_X_init" where the 5298** X is consists of the lower-case equivalent of all ASCII alphabetic 5299** characters in the filename from the last "/" to the first following 5300** "." and omitting any initial "lib".)^ 5301** ^The sqlite3_load_extension() interface returns 5302** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5303** ^If an error occurs and pzErrMsg is not 0, then the 5304** [sqlite3_load_extension()] interface shall attempt to 5305** fill *pzErrMsg with error message text stored in memory 5306** obtained from [sqlite3_malloc()]. The calling function 5307** should free this memory by calling [sqlite3_free()]. 5308** 5309** ^Extension loading must be enabled using 5310** [sqlite3_enable_load_extension()] prior to calling this API, 5311** otherwise an error will be returned. 5312** 5313** See also the [load_extension() SQL function]. 5314*/ 5315int sqlite3_load_extension( 5316 sqlite3 *db, /* Load the extension into this database connection */ 5317 const char *zFile, /* Name of the shared library containing extension */ 5318 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5319 char **pzErrMsg /* Put error message here if not 0 */ 5320); 5321 5322/* 5323** CAPI3REF: Enable Or Disable Extension Loading 5324** 5325** ^So as not to open security holes in older applications that are 5326** unprepared to deal with [extension loading], and as a means of disabling 5327** [extension loading] while evaluating user-entered SQL, the following API 5328** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5329** 5330** ^Extension loading is off by default. 5331** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5332** to turn extension loading on and call it with onoff==0 to turn 5333** it back off again. 5334*/ 5335int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5336 5337/* 5338** CAPI3REF: Automatically Load Statically Linked Extensions 5339** 5340** ^This interface causes the xEntryPoint() function to be invoked for 5341** each new [database connection] that is created. The idea here is that 5342** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5343** that is to be automatically loaded into all new database connections. 5344** 5345** ^(Even though the function prototype shows that xEntryPoint() takes 5346** no arguments and returns void, SQLite invokes xEntryPoint() with three 5347** arguments and expects and integer result as if the signature of the 5348** entry point where as follows: 5349** 5350** <blockquote><pre> 5351** int xEntryPoint( 5352** sqlite3 *db, 5353** const char **pzErrMsg, 5354** const struct sqlite3_api_routines *pThunk 5355** ); 5356** </pre></blockquote>)^ 5357** 5358** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5359** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5360** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5361** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5362** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5363** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5364** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5365** 5366** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5367** on the list of automatic extensions is a harmless no-op. ^No entry point 5368** will be called more than once for each database connection that is opened. 5369** 5370** See also: [sqlite3_reset_auto_extension()] 5371** and [sqlite3_cancel_auto_extension()] 5372*/ 5373int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5374 5375/* 5376** CAPI3REF: Cancel Automatic Extension Loading 5377** 5378** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5379** initialization routine X that was registered using a prior call to 5380** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5381** routine returns 1 if initialization routine X was successfully 5382** unregistered and it returns 0 if X was not on the list of initialization 5383** routines. 5384*/ 5385int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5386 5387/* 5388** CAPI3REF: Reset Automatic Extension Loading 5389** 5390** ^This interface disables all automatic extensions previously 5391** registered using [sqlite3_auto_extension()]. 5392*/ 5393void sqlite3_reset_auto_extension(void); 5394 5395/* 5396** The interface to the virtual-table mechanism is currently considered 5397** to be experimental. The interface might change in incompatible ways. 5398** If this is a problem for you, do not use the interface at this time. 5399** 5400** When the virtual-table mechanism stabilizes, we will declare the 5401** interface fixed, support it indefinitely, and remove this comment. 5402*/ 5403 5404/* 5405** Structures used by the virtual table interface 5406*/ 5407typedef struct sqlite3_vtab sqlite3_vtab; 5408typedef struct sqlite3_index_info sqlite3_index_info; 5409typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5410typedef struct sqlite3_module sqlite3_module; 5411 5412/* 5413** CAPI3REF: Virtual Table Object 5414** KEYWORDS: sqlite3_module {virtual table module} 5415** 5416** This structure, sometimes called a "virtual table module", 5417** defines the implementation of a [virtual tables]. 5418** This structure consists mostly of methods for the module. 5419** 5420** ^A virtual table module is created by filling in a persistent 5421** instance of this structure and passing a pointer to that instance 5422** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5423** ^The registration remains valid until it is replaced by a different 5424** module or until the [database connection] closes. The content 5425** of this structure must not change while it is registered with 5426** any database connection. 5427*/ 5428struct sqlite3_module { 5429 int iVersion; 5430 int (*xCreate)(sqlite3*, void *pAux, 5431 int argc, const char *const*argv, 5432 sqlite3_vtab **ppVTab, char**); 5433 int (*xConnect)(sqlite3*, void *pAux, 5434 int argc, const char *const*argv, 5435 sqlite3_vtab **ppVTab, char**); 5436 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5437 int (*xDisconnect)(sqlite3_vtab *pVTab); 5438 int (*xDestroy)(sqlite3_vtab *pVTab); 5439 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5440 int (*xClose)(sqlite3_vtab_cursor*); 5441 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5442 int argc, sqlite3_value **argv); 5443 int (*xNext)(sqlite3_vtab_cursor*); 5444 int (*xEof)(sqlite3_vtab_cursor*); 5445 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5446 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5447 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5448 int (*xBegin)(sqlite3_vtab *pVTab); 5449 int (*xSync)(sqlite3_vtab *pVTab); 5450 int (*xCommit)(sqlite3_vtab *pVTab); 5451 int (*xRollback)(sqlite3_vtab *pVTab); 5452 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5453 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5454 void **ppArg); 5455 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5456 /* The methods above are in version 1 of the sqlite_module object. Those 5457 ** below are for version 2 and greater. */ 5458 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5459 int (*xRelease)(sqlite3_vtab *pVTab, int); 5460 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5461}; 5462 5463/* 5464** CAPI3REF: Virtual Table Indexing Information 5465** KEYWORDS: sqlite3_index_info 5466** 5467** The sqlite3_index_info structure and its substructures is used as part 5468** of the [virtual table] interface to 5469** pass information into and receive the reply from the [xBestIndex] 5470** method of a [virtual table module]. The fields under **Inputs** are the 5471** inputs to xBestIndex and are read-only. xBestIndex inserts its 5472** results into the **Outputs** fields. 5473** 5474** ^(The aConstraint[] array records WHERE clause constraints of the form: 5475** 5476** <blockquote>column OP expr</blockquote> 5477** 5478** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5479** stored in aConstraint[].op using one of the 5480** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5481** ^(The index of the column is stored in 5482** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5483** expr on the right-hand side can be evaluated (and thus the constraint 5484** is usable) and false if it cannot.)^ 5485** 5486** ^The optimizer automatically inverts terms of the form "expr OP column" 5487** and makes other simplifications to the WHERE clause in an attempt to 5488** get as many WHERE clause terms into the form shown above as possible. 5489** ^The aConstraint[] array only reports WHERE clause terms that are 5490** relevant to the particular virtual table being queried. 5491** 5492** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5493** ^Each term of aOrderBy records a column of the ORDER BY clause. 5494** 5495** The [xBestIndex] method must fill aConstraintUsage[] with information 5496** about what parameters to pass to xFilter. ^If argvIndex>0 then 5497** the right-hand side of the corresponding aConstraint[] is evaluated 5498** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5499** is true, then the constraint is assumed to be fully handled by the 5500** virtual table and is not checked again by SQLite.)^ 5501** 5502** ^The idxNum and idxPtr values are recorded and passed into the 5503** [xFilter] method. 5504** ^[sqlite3_free()] is used to free idxPtr if and only if 5505** needToFreeIdxPtr is true. 5506** 5507** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5508** the correct order to satisfy the ORDER BY clause so that no separate 5509** sorting step is required. 5510** 5511** ^The estimatedCost value is an estimate of the cost of a particular 5512** strategy. A cost of N indicates that the cost of the strategy is similar 5513** to a linear scan of an SQLite table with N rows. A cost of log(N) 5514** indicates that the expense of the operation is similar to that of a 5515** binary search on a unique indexed field of an SQLite table with N rows. 5516** 5517** ^The estimatedRows value is an estimate of the number of rows that 5518** will be returned by the strategy. 5519** 5520** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5521** structure for SQLite version 3.8.2. If a virtual table extension is 5522** used with an SQLite version earlier than 3.8.2, the results of attempting 5523** to read or write the estimatedRows field are undefined (but are likely 5524** to included crashing the application). The estimatedRows field should 5525** therefore only be used if [sqlite3_libversion_number()] returns a 5526** value greater than or equal to 3008002. 5527*/ 5528struct sqlite3_index_info { 5529 /* Inputs */ 5530 int nConstraint; /* Number of entries in aConstraint */ 5531 struct sqlite3_index_constraint { 5532 int iColumn; /* Column on left-hand side of constraint */ 5533 unsigned char op; /* Constraint operator */ 5534 unsigned char usable; /* True if this constraint is usable */ 5535 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5536 } *aConstraint; /* Table of WHERE clause constraints */ 5537 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5538 struct sqlite3_index_orderby { 5539 int iColumn; /* Column number */ 5540 unsigned char desc; /* True for DESC. False for ASC. */ 5541 } *aOrderBy; /* The ORDER BY clause */ 5542 /* Outputs */ 5543 struct sqlite3_index_constraint_usage { 5544 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5545 unsigned char omit; /* Do not code a test for this constraint */ 5546 } *aConstraintUsage; 5547 int idxNum; /* Number used to identify the index */ 5548 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5549 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5550 int orderByConsumed; /* True if output is already ordered */ 5551 double estimatedCost; /* Estimated cost of using this index */ 5552 /* Fields below are only available in SQLite 3.8.2 and later */ 5553 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5554}; 5555 5556/* 5557** CAPI3REF: Virtual Table Constraint Operator Codes 5558** 5559** These macros defined the allowed values for the 5560** [sqlite3_index_info].aConstraint[].op field. Each value represents 5561** an operator that is part of a constraint term in the wHERE clause of 5562** a query that uses a [virtual table]. 5563*/ 5564#define SQLITE_INDEX_CONSTRAINT_EQ 2 5565#define SQLITE_INDEX_CONSTRAINT_GT 4 5566#define SQLITE_INDEX_CONSTRAINT_LE 8 5567#define SQLITE_INDEX_CONSTRAINT_LT 16 5568#define SQLITE_INDEX_CONSTRAINT_GE 32 5569#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5570 5571/* 5572** CAPI3REF: Register A Virtual Table Implementation 5573** 5574** ^These routines are used to register a new [virtual table module] name. 5575** ^Module names must be registered before 5576** creating a new [virtual table] using the module and before using a 5577** preexisting [virtual table] for the module. 5578** 5579** ^The module name is registered on the [database connection] specified 5580** by the first parameter. ^The name of the module is given by the 5581** second parameter. ^The third parameter is a pointer to 5582** the implementation of the [virtual table module]. ^The fourth 5583** parameter is an arbitrary client data pointer that is passed through 5584** into the [xCreate] and [xConnect] methods of the virtual table module 5585** when a new virtual table is be being created or reinitialized. 5586** 5587** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5588** is a pointer to a destructor for the pClientData. ^SQLite will 5589** invoke the destructor function (if it is not NULL) when SQLite 5590** no longer needs the pClientData pointer. ^The destructor will also 5591** be invoked if the call to sqlite3_create_module_v2() fails. 5592** ^The sqlite3_create_module() 5593** interface is equivalent to sqlite3_create_module_v2() with a NULL 5594** destructor. 5595*/ 5596int sqlite3_create_module( 5597 sqlite3 *db, /* SQLite connection to register module with */ 5598 const char *zName, /* Name of the module */ 5599 const sqlite3_module *p, /* Methods for the module */ 5600 void *pClientData /* Client data for xCreate/xConnect */ 5601); 5602int sqlite3_create_module_v2( 5603 sqlite3 *db, /* SQLite connection to register module with */ 5604 const char *zName, /* Name of the module */ 5605 const sqlite3_module *p, /* Methods for the module */ 5606 void *pClientData, /* Client data for xCreate/xConnect */ 5607 void(*xDestroy)(void*) /* Module destructor function */ 5608); 5609 5610/* 5611** CAPI3REF: Virtual Table Instance Object 5612** KEYWORDS: sqlite3_vtab 5613** 5614** Every [virtual table module] implementation uses a subclass 5615** of this object to describe a particular instance 5616** of the [virtual table]. Each subclass will 5617** be tailored to the specific needs of the module implementation. 5618** The purpose of this superclass is to define certain fields that are 5619** common to all module implementations. 5620** 5621** ^Virtual tables methods can set an error message by assigning a 5622** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5623** take care that any prior string is freed by a call to [sqlite3_free()] 5624** prior to assigning a new string to zErrMsg. ^After the error message 5625** is delivered up to the client application, the string will be automatically 5626** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5627*/ 5628struct sqlite3_vtab { 5629 const sqlite3_module *pModule; /* The module for this virtual table */ 5630 int nRef; /* NO LONGER USED */ 5631 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5632 /* Virtual table implementations will typically add additional fields */ 5633}; 5634 5635/* 5636** CAPI3REF: Virtual Table Cursor Object 5637** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5638** 5639** Every [virtual table module] implementation uses a subclass of the 5640** following structure to describe cursors that point into the 5641** [virtual table] and are used 5642** to loop through the virtual table. Cursors are created using the 5643** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5644** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5645** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5646** of the module. Each module implementation will define 5647** the content of a cursor structure to suit its own needs. 5648** 5649** This superclass exists in order to define fields of the cursor that 5650** are common to all implementations. 5651*/ 5652struct sqlite3_vtab_cursor { 5653 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5654 /* Virtual table implementations will typically add additional fields */ 5655}; 5656 5657/* 5658** CAPI3REF: Declare The Schema Of A Virtual Table 5659** 5660** ^The [xCreate] and [xConnect] methods of a 5661** [virtual table module] call this interface 5662** to declare the format (the names and datatypes of the columns) of 5663** the virtual tables they implement. 5664*/ 5665int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5666 5667/* 5668** CAPI3REF: Overload A Function For A Virtual Table 5669** 5670** ^(Virtual tables can provide alternative implementations of functions 5671** using the [xFindFunction] method of the [virtual table module]. 5672** But global versions of those functions 5673** must exist in order to be overloaded.)^ 5674** 5675** ^(This API makes sure a global version of a function with a particular 5676** name and number of parameters exists. If no such function exists 5677** before this API is called, a new function is created.)^ ^The implementation 5678** of the new function always causes an exception to be thrown. So 5679** the new function is not good for anything by itself. Its only 5680** purpose is to be a placeholder function that can be overloaded 5681** by a [virtual table]. 5682*/ 5683int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5684 5685/* 5686** The interface to the virtual-table mechanism defined above (back up 5687** to a comment remarkably similar to this one) is currently considered 5688** to be experimental. The interface might change in incompatible ways. 5689** If this is a problem for you, do not use the interface at this time. 5690** 5691** When the virtual-table mechanism stabilizes, we will declare the 5692** interface fixed, support it indefinitely, and remove this comment. 5693*/ 5694 5695/* 5696** CAPI3REF: A Handle To An Open BLOB 5697** KEYWORDS: {BLOB handle} {BLOB handles} 5698** 5699** An instance of this object represents an open BLOB on which 5700** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5701** ^Objects of this type are created by [sqlite3_blob_open()] 5702** and destroyed by [sqlite3_blob_close()]. 5703** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5704** can be used to read or write small subsections of the BLOB. 5705** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5706*/ 5707typedef struct sqlite3_blob sqlite3_blob; 5708 5709/* 5710** CAPI3REF: Open A BLOB For Incremental I/O 5711** 5712** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5713** in row iRow, column zColumn, table zTable in database zDb; 5714** in other words, the same BLOB that would be selected by: 5715** 5716** <pre> 5717** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5718** </pre>)^ 5719** 5720** ^(Parameter zDb is not the filename that contains the database, but 5721** rather the symbolic name of the database. For attached databases, this is 5722** the name that appears after the AS keyword in the [ATTACH] statement. 5723** For the main database file, the database name is "main". For TEMP 5724** tables, the database name is "temp".)^ 5725** 5726** ^If the flags parameter is non-zero, then the BLOB is opened for read 5727** and write access. ^If the flags parameter is zero, the BLOB is opened for 5728** read-only access. 5729** 5730** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 5731** in *ppBlob. Otherwise an [error code] is returned and, unless the error 5732** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 5733** the API is not misused, it is always safe to call [sqlite3_blob_close()] 5734** on *ppBlob after this function it returns. 5735** 5736** This function fails with SQLITE_ERROR if any of the following are true: 5737** <ul> 5738** <li> ^(Database zDb does not exist)^, 5739** <li> ^(Table zTable does not exist within database zDb)^, 5740** <li> ^(Table zTable is a WITHOUT ROWID table)^, 5741** <li> ^(Column zColumn does not exist)^, 5742** <li> ^(Row iRow is not present in the table)^, 5743** <li> ^(The specified column of row iRow contains a value that is not 5744** a TEXT or BLOB value)^, 5745** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 5746** constraint and the blob is being opened for read/write access)^, 5747** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 5748** column zColumn is part of a [child key] definition and the blob is 5749** being opened for read/write access)^. 5750** </ul> 5751** 5752** ^Unless it returns SQLITE_MISUSE, this function sets the 5753** [database connection] error code and message accessible via 5754** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5755** 5756** 5757** ^(If the row that a BLOB handle points to is modified by an 5758** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5759** then the BLOB handle is marked as "expired". 5760** This is true if any column of the row is changed, even a column 5761** other than the one the BLOB handle is open on.)^ 5762** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5763** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5764** ^(Changes written into a BLOB prior to the BLOB expiring are not 5765** rolled back by the expiration of the BLOB. Such changes will eventually 5766** commit if the transaction continues to completion.)^ 5767** 5768** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5769** the opened blob. ^The size of a blob may not be changed by this 5770** interface. Use the [UPDATE] SQL command to change the size of a 5771** blob. 5772** 5773** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5774** and the built-in [zeroblob] SQL function may be used to create a 5775** zero-filled blob to read or write using the incremental-blob interface. 5776** 5777** To avoid a resource leak, every open [BLOB handle] should eventually 5778** be released by a call to [sqlite3_blob_close()]. 5779*/ 5780int sqlite3_blob_open( 5781 sqlite3*, 5782 const char *zDb, 5783 const char *zTable, 5784 const char *zColumn, 5785 sqlite3_int64 iRow, 5786 int flags, 5787 sqlite3_blob **ppBlob 5788); 5789 5790/* 5791** CAPI3REF: Move a BLOB Handle to a New Row 5792** 5793** ^This function is used to move an existing blob handle so that it points 5794** to a different row of the same database table. ^The new row is identified 5795** by the rowid value passed as the second argument. Only the row can be 5796** changed. ^The database, table and column on which the blob handle is open 5797** remain the same. Moving an existing blob handle to a new row can be 5798** faster than closing the existing handle and opening a new one. 5799** 5800** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5801** it must exist and there must be either a blob or text value stored in 5802** the nominated column.)^ ^If the new row is not present in the table, or if 5803** it does not contain a blob or text value, or if another error occurs, an 5804** SQLite error code is returned and the blob handle is considered aborted. 5805** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5806** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5807** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5808** always returns zero. 5809** 5810** ^This function sets the database handle error code and message. 5811*/ 5812SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5813 5814/* 5815** CAPI3REF: Close A BLOB Handle 5816** 5817** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 5818** unconditionally. Even if this routine returns an error code, the 5819** handle is still closed.)^ 5820** 5821** ^If the blob handle being closed was opened for read-write access, and if 5822** the database is in auto-commit mode and there are no other open read-write 5823** blob handles or active write statements, the current transaction is 5824** committed. ^If an error occurs while committing the transaction, an error 5825** code is returned and the transaction rolled back. 5826** 5827** Calling this function with an argument that is not a NULL pointer or an 5828** open blob handle results in undefined behaviour. ^Calling this routine 5829** with a null pointer (such as would be returned by a failed call to 5830** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 5831** is passed a valid open blob handle, the values returned by the 5832** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 5833*/ 5834int sqlite3_blob_close(sqlite3_blob *); 5835 5836/* 5837** CAPI3REF: Return The Size Of An Open BLOB 5838** 5839** ^Returns the size in bytes of the BLOB accessible via the 5840** successfully opened [BLOB handle] in its only argument. ^The 5841** incremental blob I/O routines can only read or overwriting existing 5842** blob content; they cannot change the size of a blob. 5843** 5844** This routine only works on a [BLOB handle] which has been created 5845** by a prior successful call to [sqlite3_blob_open()] and which has not 5846** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5847** to this routine results in undefined and probably undesirable behavior. 5848*/ 5849int sqlite3_blob_bytes(sqlite3_blob *); 5850 5851/* 5852** CAPI3REF: Read Data From A BLOB Incrementally 5853** 5854** ^(This function is used to read data from an open [BLOB handle] into a 5855** caller-supplied buffer. N bytes of data are copied into buffer Z 5856** from the open BLOB, starting at offset iOffset.)^ 5857** 5858** ^If offset iOffset is less than N bytes from the end of the BLOB, 5859** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5860** less than zero, [SQLITE_ERROR] is returned and no data is read. 5861** ^The size of the blob (and hence the maximum value of N+iOffset) 5862** can be determined using the [sqlite3_blob_bytes()] interface. 5863** 5864** ^An attempt to read from an expired [BLOB handle] fails with an 5865** error code of [SQLITE_ABORT]. 5866** 5867** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5868** Otherwise, an [error code] or an [extended error code] is returned.)^ 5869** 5870** This routine only works on a [BLOB handle] which has been created 5871** by a prior successful call to [sqlite3_blob_open()] and which has not 5872** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5873** to this routine results in undefined and probably undesirable behavior. 5874** 5875** See also: [sqlite3_blob_write()]. 5876*/ 5877int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5878 5879/* 5880** CAPI3REF: Write Data Into A BLOB Incrementally 5881** 5882** ^(This function is used to write data into an open [BLOB handle] from a 5883** caller-supplied buffer. N bytes of data are copied from the buffer Z 5884** into the open BLOB, starting at offset iOffset.)^ 5885** 5886** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5887** Otherwise, an [error code] or an [extended error code] is returned.)^ 5888** ^Unless SQLITE_MISUSE is returned, this function sets the 5889** [database connection] error code and message accessible via 5890** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5891** 5892** ^If the [BLOB handle] passed as the first argument was not opened for 5893** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5894** this function returns [SQLITE_READONLY]. 5895** 5896** This function may only modify the contents of the BLOB; it is 5897** not possible to increase the size of a BLOB using this API. 5898** ^If offset iOffset is less than N bytes from the end of the BLOB, 5899** [SQLITE_ERROR] is returned and no data is written. The size of the 5900** BLOB (and hence the maximum value of N+iOffset) can be determined 5901** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 5902** than zero [SQLITE_ERROR] is returned and no data is written. 5903** 5904** ^An attempt to write to an expired [BLOB handle] fails with an 5905** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5906** before the [BLOB handle] expired are not rolled back by the 5907** expiration of the handle, though of course those changes might 5908** have been overwritten by the statement that expired the BLOB handle 5909** or by other independent statements. 5910** 5911** This routine only works on a [BLOB handle] which has been created 5912** by a prior successful call to [sqlite3_blob_open()] and which has not 5913** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5914** to this routine results in undefined and probably undesirable behavior. 5915** 5916** See also: [sqlite3_blob_read()]. 5917*/ 5918int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5919 5920/* 5921** CAPI3REF: Virtual File System Objects 5922** 5923** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5924** that SQLite uses to interact 5925** with the underlying operating system. Most SQLite builds come with a 5926** single default VFS that is appropriate for the host computer. 5927** New VFSes can be registered and existing VFSes can be unregistered. 5928** The following interfaces are provided. 5929** 5930** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5931** ^Names are case sensitive. 5932** ^Names are zero-terminated UTF-8 strings. 5933** ^If there is no match, a NULL pointer is returned. 5934** ^If zVfsName is NULL then the default VFS is returned. 5935** 5936** ^New VFSes are registered with sqlite3_vfs_register(). 5937** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5938** ^The same VFS can be registered multiple times without injury. 5939** ^To make an existing VFS into the default VFS, register it again 5940** with the makeDflt flag set. If two different VFSes with the 5941** same name are registered, the behavior is undefined. If a 5942** VFS is registered with a name that is NULL or an empty string, 5943** then the behavior is undefined. 5944** 5945** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5946** ^(If the default VFS is unregistered, another VFS is chosen as 5947** the default. The choice for the new VFS is arbitrary.)^ 5948*/ 5949sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5950int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5951int sqlite3_vfs_unregister(sqlite3_vfs*); 5952 5953/* 5954** CAPI3REF: Mutexes 5955** 5956** The SQLite core uses these routines for thread 5957** synchronization. Though they are intended for internal 5958** use by SQLite, code that links against SQLite is 5959** permitted to use any of these routines. 5960** 5961** The SQLite source code contains multiple implementations 5962** of these mutex routines. An appropriate implementation 5963** is selected automatically at compile-time. The following 5964** implementations are available in the SQLite core: 5965** 5966** <ul> 5967** <li> SQLITE_MUTEX_PTHREADS 5968** <li> SQLITE_MUTEX_W32 5969** <li> SQLITE_MUTEX_NOOP 5970** </ul> 5971** 5972** The SQLITE_MUTEX_NOOP implementation is a set of routines 5973** that does no real locking and is appropriate for use in 5974** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 5975** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5976** and Windows. 5977** 5978** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5979** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5980** implementation is included with the library. In this case the 5981** application must supply a custom mutex implementation using the 5982** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5983** before calling sqlite3_initialize() or any other public sqlite3_ 5984** function that calls sqlite3_initialize(). 5985** 5986** ^The sqlite3_mutex_alloc() routine allocates a new 5987** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 5988** routine returns NULL if it is unable to allocate the requested 5989** mutex. The argument to sqlite3_mutex_alloc() must one of these 5990** integer constants: 5991** 5992** <ul> 5993** <li> SQLITE_MUTEX_FAST 5994** <li> SQLITE_MUTEX_RECURSIVE 5995** <li> SQLITE_MUTEX_STATIC_MASTER 5996** <li> SQLITE_MUTEX_STATIC_MEM 5997** <li> SQLITE_MUTEX_STATIC_OPEN 5998** <li> SQLITE_MUTEX_STATIC_PRNG 5999** <li> SQLITE_MUTEX_STATIC_LRU 6000** <li> SQLITE_MUTEX_STATIC_PMEM 6001** <li> SQLITE_MUTEX_STATIC_APP1 6002** <li> SQLITE_MUTEX_STATIC_APP2 6003** <li> SQLITE_MUTEX_STATIC_APP3 6004** </ul> 6005** 6006** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6007** cause sqlite3_mutex_alloc() to create 6008** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6009** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6010** The mutex implementation does not need to make a distinction 6011** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6012** not want to. SQLite will only request a recursive mutex in 6013** cases where it really needs one. If a faster non-recursive mutex 6014** implementation is available on the host platform, the mutex subsystem 6015** might return such a mutex in response to SQLITE_MUTEX_FAST. 6016** 6017** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6018** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6019** a pointer to a static preexisting mutex. ^Nine static mutexes are 6020** used by the current version of SQLite. Future versions of SQLite 6021** may add additional static mutexes. Static mutexes are for internal 6022** use by SQLite only. Applications that use SQLite mutexes should 6023** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6024** SQLITE_MUTEX_RECURSIVE. 6025** 6026** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6027** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6028** returns a different mutex on every call. ^For the static 6029** mutex types, the same mutex is returned on every call that has 6030** the same type number. 6031** 6032** ^The sqlite3_mutex_free() routine deallocates a previously 6033** allocated dynamic mutex. Attempting to deallocate a static 6034** mutex results in undefined behavior. 6035** 6036** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6037** to enter a mutex. ^If another thread is already within the mutex, 6038** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6039** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6040** upon successful entry. ^(Mutexes created using 6041** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6042** In such cases, the 6043** mutex must be exited an equal number of times before another thread 6044** can enter.)^ If the same thread tries to enter any mutex other 6045** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6046** 6047** ^(Some systems (for example, Windows 95) do not support the operation 6048** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6049** will always return SQLITE_BUSY. The SQLite core only ever uses 6050** sqlite3_mutex_try() as an optimization so this is acceptable 6051** behavior.)^ 6052** 6053** ^The sqlite3_mutex_leave() routine exits a mutex that was 6054** previously entered by the same thread. The behavior 6055** is undefined if the mutex is not currently entered by the 6056** calling thread or is not currently allocated. 6057** 6058** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6059** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6060** behave as no-ops. 6061** 6062** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6063*/ 6064sqlite3_mutex *sqlite3_mutex_alloc(int); 6065void sqlite3_mutex_free(sqlite3_mutex*); 6066void sqlite3_mutex_enter(sqlite3_mutex*); 6067int sqlite3_mutex_try(sqlite3_mutex*); 6068void sqlite3_mutex_leave(sqlite3_mutex*); 6069 6070/* 6071** CAPI3REF: Mutex Methods Object 6072** 6073** An instance of this structure defines the low-level routines 6074** used to allocate and use mutexes. 6075** 6076** Usually, the default mutex implementations provided by SQLite are 6077** sufficient, however the application has the option of substituting a custom 6078** implementation for specialized deployments or systems for which SQLite 6079** does not provide a suitable implementation. In this case, the application 6080** creates and populates an instance of this structure to pass 6081** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6082** Additionally, an instance of this structure can be used as an 6083** output variable when querying the system for the current mutex 6084** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6085** 6086** ^The xMutexInit method defined by this structure is invoked as 6087** part of system initialization by the sqlite3_initialize() function. 6088** ^The xMutexInit routine is called by SQLite exactly once for each 6089** effective call to [sqlite3_initialize()]. 6090** 6091** ^The xMutexEnd method defined by this structure is invoked as 6092** part of system shutdown by the sqlite3_shutdown() function. The 6093** implementation of this method is expected to release all outstanding 6094** resources obtained by the mutex methods implementation, especially 6095** those obtained by the xMutexInit method. ^The xMutexEnd() 6096** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6097** 6098** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6099** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6100** xMutexNotheld) implement the following interfaces (respectively): 6101** 6102** <ul> 6103** <li> [sqlite3_mutex_alloc()] </li> 6104** <li> [sqlite3_mutex_free()] </li> 6105** <li> [sqlite3_mutex_enter()] </li> 6106** <li> [sqlite3_mutex_try()] </li> 6107** <li> [sqlite3_mutex_leave()] </li> 6108** <li> [sqlite3_mutex_held()] </li> 6109** <li> [sqlite3_mutex_notheld()] </li> 6110** </ul>)^ 6111** 6112** The only difference is that the public sqlite3_XXX functions enumerated 6113** above silently ignore any invocations that pass a NULL pointer instead 6114** of a valid mutex handle. The implementations of the methods defined 6115** by this structure are not required to handle this case, the results 6116** of passing a NULL pointer instead of a valid mutex handle are undefined 6117** (i.e. it is acceptable to provide an implementation that segfaults if 6118** it is passed a NULL pointer). 6119** 6120** The xMutexInit() method must be threadsafe. It must be harmless to 6121** invoke xMutexInit() multiple times within the same process and without 6122** intervening calls to xMutexEnd(). Second and subsequent calls to 6123** xMutexInit() must be no-ops. 6124** 6125** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6126** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6127** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6128** memory allocation for a fast or recursive mutex. 6129** 6130** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6131** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6132** If xMutexInit fails in any way, it is expected to clean up after itself 6133** prior to returning. 6134*/ 6135typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6136struct sqlite3_mutex_methods { 6137 int (*xMutexInit)(void); 6138 int (*xMutexEnd)(void); 6139 sqlite3_mutex *(*xMutexAlloc)(int); 6140 void (*xMutexFree)(sqlite3_mutex *); 6141 void (*xMutexEnter)(sqlite3_mutex *); 6142 int (*xMutexTry)(sqlite3_mutex *); 6143 void (*xMutexLeave)(sqlite3_mutex *); 6144 int (*xMutexHeld)(sqlite3_mutex *); 6145 int (*xMutexNotheld)(sqlite3_mutex *); 6146}; 6147 6148/* 6149** CAPI3REF: Mutex Verification Routines 6150** 6151** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6152** are intended for use inside assert() statements. The SQLite core 6153** never uses these routines except inside an assert() and applications 6154** are advised to follow the lead of the core. The SQLite core only 6155** provides implementations for these routines when it is compiled 6156** with the SQLITE_DEBUG flag. External mutex implementations 6157** are only required to provide these routines if SQLITE_DEBUG is 6158** defined and if NDEBUG is not defined. 6159** 6160** These routines should return true if the mutex in their argument 6161** is held or not held, respectively, by the calling thread. 6162** 6163** The implementation is not required to provide versions of these 6164** routines that actually work. If the implementation does not provide working 6165** versions of these routines, it should at least provide stubs that always 6166** return true so that one does not get spurious assertion failures. 6167** 6168** If the argument to sqlite3_mutex_held() is a NULL pointer then 6169** the routine should return 1. This seems counter-intuitive since 6170** clearly the mutex cannot be held if it does not exist. But 6171** the reason the mutex does not exist is because the build is not 6172** using mutexes. And we do not want the assert() containing the 6173** call to sqlite3_mutex_held() to fail, so a non-zero return is 6174** the appropriate thing to do. The sqlite3_mutex_notheld() 6175** interface should also return 1 when given a NULL pointer. 6176*/ 6177#ifndef NDEBUG 6178int sqlite3_mutex_held(sqlite3_mutex*); 6179int sqlite3_mutex_notheld(sqlite3_mutex*); 6180#endif 6181 6182/* 6183** CAPI3REF: Mutex Types 6184** 6185** The [sqlite3_mutex_alloc()] interface takes a single argument 6186** which is one of these integer constants. 6187** 6188** The set of static mutexes may change from one SQLite release to the 6189** next. Applications that override the built-in mutex logic must be 6190** prepared to accommodate additional static mutexes. 6191*/ 6192#define SQLITE_MUTEX_FAST 0 6193#define SQLITE_MUTEX_RECURSIVE 1 6194#define SQLITE_MUTEX_STATIC_MASTER 2 6195#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6196#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6197#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6198#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6199#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6200#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6201#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6202#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6203#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6204#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6205 6206/* 6207** CAPI3REF: Retrieve the mutex for a database connection 6208** 6209** ^This interface returns a pointer the [sqlite3_mutex] object that 6210** serializes access to the [database connection] given in the argument 6211** when the [threading mode] is Serialized. 6212** ^If the [threading mode] is Single-thread or Multi-thread then this 6213** routine returns a NULL pointer. 6214*/ 6215sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6216 6217/* 6218** CAPI3REF: Low-Level Control Of Database Files 6219** 6220** ^The [sqlite3_file_control()] interface makes a direct call to the 6221** xFileControl method for the [sqlite3_io_methods] object associated 6222** with a particular database identified by the second argument. ^The 6223** name of the database is "main" for the main database or "temp" for the 6224** TEMP database, or the name that appears after the AS keyword for 6225** databases that are added using the [ATTACH] SQL command. 6226** ^A NULL pointer can be used in place of "main" to refer to the 6227** main database file. 6228** ^The third and fourth parameters to this routine 6229** are passed directly through to the second and third parameters of 6230** the xFileControl method. ^The return value of the xFileControl 6231** method becomes the return value of this routine. 6232** 6233** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6234** a pointer to the underlying [sqlite3_file] object to be written into 6235** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6236** case is a short-circuit path which does not actually invoke the 6237** underlying sqlite3_io_methods.xFileControl method. 6238** 6239** ^If the second parameter (zDbName) does not match the name of any 6240** open database file, then SQLITE_ERROR is returned. ^This error 6241** code is not remembered and will not be recalled by [sqlite3_errcode()] 6242** or [sqlite3_errmsg()]. The underlying xFileControl method might 6243** also return SQLITE_ERROR. There is no way to distinguish between 6244** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6245** xFileControl method. 6246** 6247** See also: [SQLITE_FCNTL_LOCKSTATE] 6248*/ 6249int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6250 6251/* 6252** CAPI3REF: Testing Interface 6253** 6254** ^The sqlite3_test_control() interface is used to read out internal 6255** state of SQLite and to inject faults into SQLite for testing 6256** purposes. ^The first parameter is an operation code that determines 6257** the number, meaning, and operation of all subsequent parameters. 6258** 6259** This interface is not for use by applications. It exists solely 6260** for verifying the correct operation of the SQLite library. Depending 6261** on how the SQLite library is compiled, this interface might not exist. 6262** 6263** The details of the operation codes, their meanings, the parameters 6264** they take, and what they do are all subject to change without notice. 6265** Unlike most of the SQLite API, this function is not guaranteed to 6266** operate consistently from one release to the next. 6267*/ 6268int sqlite3_test_control(int op, ...); 6269 6270/* 6271** CAPI3REF: Testing Interface Operation Codes 6272** 6273** These constants are the valid operation code parameters used 6274** as the first argument to [sqlite3_test_control()]. 6275** 6276** These parameters and their meanings are subject to change 6277** without notice. These values are for testing purposes only. 6278** Applications should not use any of these parameters or the 6279** [sqlite3_test_control()] interface. 6280*/ 6281#define SQLITE_TESTCTRL_FIRST 5 6282#define SQLITE_TESTCTRL_PRNG_SAVE 5 6283#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6284#define SQLITE_TESTCTRL_PRNG_RESET 7 6285#define SQLITE_TESTCTRL_BITVEC_TEST 8 6286#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6287#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6288#define SQLITE_TESTCTRL_PENDING_BYTE 11 6289#define SQLITE_TESTCTRL_ASSERT 12 6290#define SQLITE_TESTCTRL_ALWAYS 13 6291#define SQLITE_TESTCTRL_RESERVE 14 6292#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6293#define SQLITE_TESTCTRL_ISKEYWORD 16 6294#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6295#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6296#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6297#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6298#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6299#define SQLITE_TESTCTRL_BYTEORDER 22 6300#define SQLITE_TESTCTRL_ISINIT 23 6301#define SQLITE_TESTCTRL_SORTER_MMAP 24 6302#define SQLITE_TESTCTRL_IMPOSTER 25 6303#define SQLITE_TESTCTRL_LAST 25 6304 6305/* 6306** CAPI3REF: SQLite Runtime Status 6307** 6308** ^This interface is used to retrieve runtime status information 6309** about the performance of SQLite, and optionally to reset various 6310** highwater marks. ^The first argument is an integer code for 6311** the specific parameter to measure. ^(Recognized integer codes 6312** are of the form [status parameters | SQLITE_STATUS_...].)^ 6313** ^The current value of the parameter is returned into *pCurrent. 6314** ^The highest recorded value is returned in *pHighwater. ^If the 6315** resetFlag is true, then the highest record value is reset after 6316** *pHighwater is written. ^(Some parameters do not record the highest 6317** value. For those parameters 6318** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6319** ^(Other parameters record only the highwater mark and not the current 6320** value. For these latter parameters nothing is written into *pCurrent.)^ 6321** 6322** ^The sqlite3_status() routine returns SQLITE_OK on success and a 6323** non-zero [error code] on failure. 6324** 6325** This routine is threadsafe but is not atomic. This routine can be 6326** called while other threads are running the same or different SQLite 6327** interfaces. However the values returned in *pCurrent and 6328** *pHighwater reflect the status of SQLite at different points in time 6329** and it is possible that another thread might change the parameter 6330** in between the times when *pCurrent and *pHighwater are written. 6331** 6332** See also: [sqlite3_db_status()] 6333*/ 6334int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6335 6336 6337/* 6338** CAPI3REF: Status Parameters 6339** KEYWORDS: {status parameters} 6340** 6341** These integer constants designate various run-time status parameters 6342** that can be returned by [sqlite3_status()]. 6343** 6344** <dl> 6345** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6346** <dd>This parameter is the current amount of memory checked out 6347** using [sqlite3_malloc()], either directly or indirectly. The 6348** figure includes calls made to [sqlite3_malloc()] by the application 6349** and internal memory usage by the SQLite library. Scratch memory 6350** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6351** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6352** this parameter. The amount returned is the sum of the allocation 6353** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6354** 6355** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6356** <dd>This parameter records the largest memory allocation request 6357** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6358** internal equivalents). Only the value returned in the 6359** *pHighwater parameter to [sqlite3_status()] is of interest. 6360** The value written into the *pCurrent parameter is undefined.</dd>)^ 6361** 6362** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6363** <dd>This parameter records the number of separate memory allocations 6364** currently checked out.</dd>)^ 6365** 6366** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6367** <dd>This parameter returns the number of pages used out of the 6368** [pagecache memory allocator] that was configured using 6369** [SQLITE_CONFIG_PAGECACHE]. The 6370** value returned is in pages, not in bytes.</dd>)^ 6371** 6372** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6373** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6374** <dd>This parameter returns the number of bytes of page cache 6375** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6376** buffer and where forced to overflow to [sqlite3_malloc()]. The 6377** returned value includes allocations that overflowed because they 6378** where too large (they were larger than the "sz" parameter to 6379** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6380** no space was left in the page cache.</dd>)^ 6381** 6382** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6383** <dd>This parameter records the largest memory allocation request 6384** handed to [pagecache memory allocator]. Only the value returned in the 6385** *pHighwater parameter to [sqlite3_status()] is of interest. 6386** The value written into the *pCurrent parameter is undefined.</dd>)^ 6387** 6388** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6389** <dd>This parameter returns the number of allocations used out of the 6390** [scratch memory allocator] configured using 6391** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6392** in bytes. Since a single thread may only have one scratch allocation 6393** outstanding at time, this parameter also reports the number of threads 6394** using scratch memory at the same time.</dd>)^ 6395** 6396** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6397** <dd>This parameter returns the number of bytes of scratch memory 6398** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6399** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6400** returned include overflows because the requested allocation was too 6401** larger (that is, because the requested allocation was larger than the 6402** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6403** slots were available. 6404** </dd>)^ 6405** 6406** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6407** <dd>This parameter records the largest memory allocation request 6408** handed to [scratch memory allocator]. Only the value returned in the 6409** *pHighwater parameter to [sqlite3_status()] is of interest. 6410** The value written into the *pCurrent parameter is undefined.</dd>)^ 6411** 6412** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6413** <dd>This parameter records the deepest parser stack. It is only 6414** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6415** </dl> 6416** 6417** New status parameters may be added from time to time. 6418*/ 6419#define SQLITE_STATUS_MEMORY_USED 0 6420#define SQLITE_STATUS_PAGECACHE_USED 1 6421#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6422#define SQLITE_STATUS_SCRATCH_USED 3 6423#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6424#define SQLITE_STATUS_MALLOC_SIZE 5 6425#define SQLITE_STATUS_PARSER_STACK 6 6426#define SQLITE_STATUS_PAGECACHE_SIZE 7 6427#define SQLITE_STATUS_SCRATCH_SIZE 8 6428#define SQLITE_STATUS_MALLOC_COUNT 9 6429 6430/* 6431** CAPI3REF: Database Connection Status 6432** 6433** ^This interface is used to retrieve runtime status information 6434** about a single [database connection]. ^The first argument is the 6435** database connection object to be interrogated. ^The second argument 6436** is an integer constant, taken from the set of 6437** [SQLITE_DBSTATUS options], that 6438** determines the parameter to interrogate. The set of 6439** [SQLITE_DBSTATUS options] is likely 6440** to grow in future releases of SQLite. 6441** 6442** ^The current value of the requested parameter is written into *pCur 6443** and the highest instantaneous value is written into *pHiwtr. ^If 6444** the resetFlg is true, then the highest instantaneous value is 6445** reset back down to the current value. 6446** 6447** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6448** non-zero [error code] on failure. 6449** 6450** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6451*/ 6452int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6453 6454/* 6455** CAPI3REF: Status Parameters for database connections 6456** KEYWORDS: {SQLITE_DBSTATUS options} 6457** 6458** These constants are the available integer "verbs" that can be passed as 6459** the second argument to the [sqlite3_db_status()] interface. 6460** 6461** New verbs may be added in future releases of SQLite. Existing verbs 6462** might be discontinued. Applications should check the return code from 6463** [sqlite3_db_status()] to make sure that the call worked. 6464** The [sqlite3_db_status()] interface will return a non-zero error code 6465** if a discontinued or unsupported verb is invoked. 6466** 6467** <dl> 6468** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6469** <dd>This parameter returns the number of lookaside memory slots currently 6470** checked out.</dd>)^ 6471** 6472** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6473** <dd>This parameter returns the number malloc attempts that were 6474** satisfied using lookaside memory. Only the high-water value is meaningful; 6475** the current value is always zero.)^ 6476** 6477** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6478** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6479** <dd>This parameter returns the number malloc attempts that might have 6480** been satisfied using lookaside memory but failed due to the amount of 6481** memory requested being larger than the lookaside slot size. 6482** Only the high-water value is meaningful; 6483** the current value is always zero.)^ 6484** 6485** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6486** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6487** <dd>This parameter returns the number malloc attempts that might have 6488** been satisfied using lookaside memory but failed due to all lookaside 6489** memory already being in use. 6490** Only the high-water value is meaningful; 6491** the current value is always zero.)^ 6492** 6493** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6494** <dd>This parameter returns the approximate number of bytes of heap 6495** memory used by all pager caches associated with the database connection.)^ 6496** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6497** 6498** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6499** <dd>This parameter returns the approximate number of bytes of heap 6500** memory used to store the schema for all databases associated 6501** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6502** ^The full amount of memory used by the schemas is reported, even if the 6503** schema memory is shared with other database connections due to 6504** [shared cache mode] being enabled. 6505** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6506** 6507** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6508** <dd>This parameter returns the approximate number of bytes of heap 6509** and lookaside memory used by all prepared statements associated with 6510** the database connection.)^ 6511** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6512** </dd> 6513** 6514** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6515** <dd>This parameter returns the number of pager cache hits that have 6516** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6517** is always 0. 6518** </dd> 6519** 6520** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6521** <dd>This parameter returns the number of pager cache misses that have 6522** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6523** is always 0. 6524** </dd> 6525** 6526** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6527** <dd>This parameter returns the number of dirty cache entries that have 6528** been written to disk. Specifically, the number of pages written to the 6529** wal file in wal mode databases, or the number of pages written to the 6530** database file in rollback mode databases. Any pages written as part of 6531** transaction rollback or database recovery operations are not included. 6532** If an IO or other error occurs while writing a page to disk, the effect 6533** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6534** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6535** </dd> 6536** 6537** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6538** <dd>This parameter returns zero for the current value if and only if 6539** all foreign key constraints (deferred or immediate) have been 6540** resolved.)^ ^The highwater mark is always 0. 6541** </dd> 6542** </dl> 6543*/ 6544#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6545#define SQLITE_DBSTATUS_CACHE_USED 1 6546#define SQLITE_DBSTATUS_SCHEMA_USED 2 6547#define SQLITE_DBSTATUS_STMT_USED 3 6548#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6549#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6550#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6551#define SQLITE_DBSTATUS_CACHE_HIT 7 6552#define SQLITE_DBSTATUS_CACHE_MISS 8 6553#define SQLITE_DBSTATUS_CACHE_WRITE 9 6554#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6555#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6556 6557 6558/* 6559** CAPI3REF: Prepared Statement Status 6560** 6561** ^(Each prepared statement maintains various 6562** [SQLITE_STMTSTATUS counters] that measure the number 6563** of times it has performed specific operations.)^ These counters can 6564** be used to monitor the performance characteristics of the prepared 6565** statements. For example, if the number of table steps greatly exceeds 6566** the number of table searches or result rows, that would tend to indicate 6567** that the prepared statement is using a full table scan rather than 6568** an index. 6569** 6570** ^(This interface is used to retrieve and reset counter values from 6571** a [prepared statement]. The first argument is the prepared statement 6572** object to be interrogated. The second argument 6573** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6574** to be interrogated.)^ 6575** ^The current value of the requested counter is returned. 6576** ^If the resetFlg is true, then the counter is reset to zero after this 6577** interface call returns. 6578** 6579** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6580*/ 6581int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6582 6583/* 6584** CAPI3REF: Status Parameters for prepared statements 6585** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6586** 6587** These preprocessor macros define integer codes that name counter 6588** values associated with the [sqlite3_stmt_status()] interface. 6589** The meanings of the various counters are as follows: 6590** 6591** <dl> 6592** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6593** <dd>^This is the number of times that SQLite has stepped forward in 6594** a table as part of a full table scan. Large numbers for this counter 6595** may indicate opportunities for performance improvement through 6596** careful use of indices.</dd> 6597** 6598** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6599** <dd>^This is the number of sort operations that have occurred. 6600** A non-zero value in this counter may indicate an opportunity to 6601** improvement performance through careful use of indices.</dd> 6602** 6603** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6604** <dd>^This is the number of rows inserted into transient indices that 6605** were created automatically in order to help joins run faster. 6606** A non-zero value in this counter may indicate an opportunity to 6607** improvement performance by adding permanent indices that do not 6608** need to be reinitialized each time the statement is run.</dd> 6609** 6610** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6611** <dd>^This is the number of virtual machine operations executed 6612** by the prepared statement if that number is less than or equal 6613** to 2147483647. The number of virtual machine operations can be 6614** used as a proxy for the total work done by the prepared statement. 6615** If the number of virtual machine operations exceeds 2147483647 6616** then the value returned by this statement status code is undefined. 6617** </dd> 6618** </dl> 6619*/ 6620#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6621#define SQLITE_STMTSTATUS_SORT 2 6622#define SQLITE_STMTSTATUS_AUTOINDEX 3 6623#define SQLITE_STMTSTATUS_VM_STEP 4 6624 6625/* 6626** CAPI3REF: Custom Page Cache Object 6627** 6628** The sqlite3_pcache type is opaque. It is implemented by 6629** the pluggable module. The SQLite core has no knowledge of 6630** its size or internal structure and never deals with the 6631** sqlite3_pcache object except by holding and passing pointers 6632** to the object. 6633** 6634** See [sqlite3_pcache_methods2] for additional information. 6635*/ 6636typedef struct sqlite3_pcache sqlite3_pcache; 6637 6638/* 6639** CAPI3REF: Custom Page Cache Object 6640** 6641** The sqlite3_pcache_page object represents a single page in the 6642** page cache. The page cache will allocate instances of this 6643** object. Various methods of the page cache use pointers to instances 6644** of this object as parameters or as their return value. 6645** 6646** See [sqlite3_pcache_methods2] for additional information. 6647*/ 6648typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6649struct sqlite3_pcache_page { 6650 void *pBuf; /* The content of the page */ 6651 void *pExtra; /* Extra information associated with the page */ 6652}; 6653 6654/* 6655** CAPI3REF: Application Defined Page Cache. 6656** KEYWORDS: {page cache} 6657** 6658** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6659** register an alternative page cache implementation by passing in an 6660** instance of the sqlite3_pcache_methods2 structure.)^ 6661** In many applications, most of the heap memory allocated by 6662** SQLite is used for the page cache. 6663** By implementing a 6664** custom page cache using this API, an application can better control 6665** the amount of memory consumed by SQLite, the way in which 6666** that memory is allocated and released, and the policies used to 6667** determine exactly which parts of a database file are cached and for 6668** how long. 6669** 6670** The alternative page cache mechanism is an 6671** extreme measure that is only needed by the most demanding applications. 6672** The built-in page cache is recommended for most uses. 6673** 6674** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6675** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6676** the application may discard the parameter after the call to 6677** [sqlite3_config()] returns.)^ 6678** 6679** [[the xInit() page cache method]] 6680** ^(The xInit() method is called once for each effective 6681** call to [sqlite3_initialize()])^ 6682** (usually only once during the lifetime of the process). ^(The xInit() 6683** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6684** The intent of the xInit() method is to set up global data structures 6685** required by the custom page cache implementation. 6686** ^(If the xInit() method is NULL, then the 6687** built-in default page cache is used instead of the application defined 6688** page cache.)^ 6689** 6690** [[the xShutdown() page cache method]] 6691** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6692** It can be used to clean up 6693** any outstanding resources before process shutdown, if required. 6694** ^The xShutdown() method may be NULL. 6695** 6696** ^SQLite automatically serializes calls to the xInit method, 6697** so the xInit method need not be threadsafe. ^The 6698** xShutdown method is only called from [sqlite3_shutdown()] so it does 6699** not need to be threadsafe either. All other methods must be threadsafe 6700** in multithreaded applications. 6701** 6702** ^SQLite will never invoke xInit() more than once without an intervening 6703** call to xShutdown(). 6704** 6705** [[the xCreate() page cache methods]] 6706** ^SQLite invokes the xCreate() method to construct a new cache instance. 6707** SQLite will typically create one cache instance for each open database file, 6708** though this is not guaranteed. ^The 6709** first parameter, szPage, is the size in bytes of the pages that must 6710** be allocated by the cache. ^szPage will always a power of two. ^The 6711** second parameter szExtra is a number of bytes of extra storage 6712** associated with each page cache entry. ^The szExtra parameter will 6713** a number less than 250. SQLite will use the 6714** extra szExtra bytes on each page to store metadata about the underlying 6715** database page on disk. The value passed into szExtra depends 6716** on the SQLite version, the target platform, and how SQLite was compiled. 6717** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6718** created will be used to cache database pages of a file stored on disk, or 6719** false if it is used for an in-memory database. The cache implementation 6720** does not have to do anything special based with the value of bPurgeable; 6721** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6722** never invoke xUnpin() except to deliberately delete a page. 6723** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6724** false will always have the "discard" flag set to true. 6725** ^Hence, a cache created with bPurgeable false will 6726** never contain any unpinned pages. 6727** 6728** [[the xCachesize() page cache method]] 6729** ^(The xCachesize() method may be called at any time by SQLite to set the 6730** suggested maximum cache-size (number of pages stored by) the cache 6731** instance passed as the first argument. This is the value configured using 6732** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6733** parameter, the implementation is not required to do anything with this 6734** value; it is advisory only. 6735** 6736** [[the xPagecount() page cache methods]] 6737** The xPagecount() method must return the number of pages currently 6738** stored in the cache, both pinned and unpinned. 6739** 6740** [[the xFetch() page cache methods]] 6741** The xFetch() method locates a page in the cache and returns a pointer to 6742** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6743** The pBuf element of the returned sqlite3_pcache_page object will be a 6744** pointer to a buffer of szPage bytes used to store the content of a 6745** single database page. The pExtra element of sqlite3_pcache_page will be 6746** a pointer to the szExtra bytes of extra storage that SQLite has requested 6747** for each entry in the page cache. 6748** 6749** The page to be fetched is determined by the key. ^The minimum key value 6750** is 1. After it has been retrieved using xFetch, the page is considered 6751** to be "pinned". 6752** 6753** If the requested page is already in the page cache, then the page cache 6754** implementation must return a pointer to the page buffer with its content 6755** intact. If the requested page is not already in the cache, then the 6756** cache implementation should use the value of the createFlag 6757** parameter to help it determined what action to take: 6758** 6759** <table border=1 width=85% align=center> 6760** <tr><th> createFlag <th> Behavior when page is not already in cache 6761** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6762** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6763** Otherwise return NULL. 6764** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6765** NULL if allocating a new page is effectively impossible. 6766** </table> 6767** 6768** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6769** will only use a createFlag of 2 after a prior call with a createFlag of 1 6770** failed.)^ In between the to xFetch() calls, SQLite may 6771** attempt to unpin one or more cache pages by spilling the content of 6772** pinned pages to disk and synching the operating system disk cache. 6773** 6774** [[the xUnpin() page cache method]] 6775** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6776** as its second argument. If the third parameter, discard, is non-zero, 6777** then the page must be evicted from the cache. 6778** ^If the discard parameter is 6779** zero, then the page may be discarded or retained at the discretion of 6780** page cache implementation. ^The page cache implementation 6781** may choose to evict unpinned pages at any time. 6782** 6783** The cache must not perform any reference counting. A single 6784** call to xUnpin() unpins the page regardless of the number of prior calls 6785** to xFetch(). 6786** 6787** [[the xRekey() page cache methods]] 6788** The xRekey() method is used to change the key value associated with the 6789** page passed as the second argument. If the cache 6790** previously contains an entry associated with newKey, it must be 6791** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6792** to be pinned. 6793** 6794** When SQLite calls the xTruncate() method, the cache must discard all 6795** existing cache entries with page numbers (keys) greater than or equal 6796** to the value of the iLimit parameter passed to xTruncate(). If any 6797** of these pages are pinned, they are implicitly unpinned, meaning that 6798** they can be safely discarded. 6799** 6800** [[the xDestroy() page cache method]] 6801** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6802** All resources associated with the specified cache should be freed. ^After 6803** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6804** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6805** functions. 6806** 6807** [[the xShrink() page cache method]] 6808** ^SQLite invokes the xShrink() method when it wants the page cache to 6809** free up as much of heap memory as possible. The page cache implementation 6810** is not obligated to free any memory, but well-behaved implementations should 6811** do their best. 6812*/ 6813typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6814struct sqlite3_pcache_methods2 { 6815 int iVersion; 6816 void *pArg; 6817 int (*xInit)(void*); 6818 void (*xShutdown)(void*); 6819 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6820 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6821 int (*xPagecount)(sqlite3_pcache*); 6822 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6823 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6824 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6825 unsigned oldKey, unsigned newKey); 6826 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6827 void (*xDestroy)(sqlite3_pcache*); 6828 void (*xShrink)(sqlite3_pcache*); 6829}; 6830 6831/* 6832** This is the obsolete pcache_methods object that has now been replaced 6833** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6834** retained in the header file for backwards compatibility only. 6835*/ 6836typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6837struct sqlite3_pcache_methods { 6838 void *pArg; 6839 int (*xInit)(void*); 6840 void (*xShutdown)(void*); 6841 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6842 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6843 int (*xPagecount)(sqlite3_pcache*); 6844 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6845 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6846 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6847 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6848 void (*xDestroy)(sqlite3_pcache*); 6849}; 6850 6851 6852/* 6853** CAPI3REF: Online Backup Object 6854** 6855** The sqlite3_backup object records state information about an ongoing 6856** online backup operation. ^The sqlite3_backup object is created by 6857** a call to [sqlite3_backup_init()] and is destroyed by a call to 6858** [sqlite3_backup_finish()]. 6859** 6860** See Also: [Using the SQLite Online Backup API] 6861*/ 6862typedef struct sqlite3_backup sqlite3_backup; 6863 6864/* 6865** CAPI3REF: Online Backup API. 6866** 6867** The backup API copies the content of one database into another. 6868** It is useful either for creating backups of databases or 6869** for copying in-memory databases to or from persistent files. 6870** 6871** See Also: [Using the SQLite Online Backup API] 6872** 6873** ^SQLite holds a write transaction open on the destination database file 6874** for the duration of the backup operation. 6875** ^The source database is read-locked only while it is being read; 6876** it is not locked continuously for the entire backup operation. 6877** ^Thus, the backup may be performed on a live source database without 6878** preventing other database connections from 6879** reading or writing to the source database while the backup is underway. 6880** 6881** ^(To perform a backup operation: 6882** <ol> 6883** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6884** backup, 6885** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6886** the data between the two databases, and finally 6887** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6888** associated with the backup operation. 6889** </ol>)^ 6890** There should be exactly one call to sqlite3_backup_finish() for each 6891** successful call to sqlite3_backup_init(). 6892** 6893** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6894** 6895** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6896** [database connection] associated with the destination database 6897** and the database name, respectively. 6898** ^The database name is "main" for the main database, "temp" for the 6899** temporary database, or the name specified after the AS keyword in 6900** an [ATTACH] statement for an attached database. 6901** ^The S and M arguments passed to 6902** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6903** and database name of the source database, respectively. 6904** ^The source and destination [database connections] (parameters S and D) 6905** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6906** an error. 6907** 6908** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 6909** there is already a read or read-write transaction open on the 6910** destination database. 6911** 6912** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6913** returned and an error code and error message are stored in the 6914** destination [database connection] D. 6915** ^The error code and message for the failed call to sqlite3_backup_init() 6916** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6917** [sqlite3_errmsg16()] functions. 6918** ^A successful call to sqlite3_backup_init() returns a pointer to an 6919** [sqlite3_backup] object. 6920** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6921** sqlite3_backup_finish() functions to perform the specified backup 6922** operation. 6923** 6924** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6925** 6926** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6927** the source and destination databases specified by [sqlite3_backup] object B. 6928** ^If N is negative, all remaining source pages are copied. 6929** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6930** are still more pages to be copied, then the function returns [SQLITE_OK]. 6931** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6932** from source to destination, then it returns [SQLITE_DONE]. 6933** ^If an error occurs while running sqlite3_backup_step(B,N), 6934** then an [error code] is returned. ^As well as [SQLITE_OK] and 6935** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6936** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6937** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6938** 6939** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6940** <ol> 6941** <li> the destination database was opened read-only, or 6942** <li> the destination database is using write-ahead-log journaling 6943** and the destination and source page sizes differ, or 6944** <li> the destination database is an in-memory database and the 6945** destination and source page sizes differ. 6946** </ol>)^ 6947** 6948** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6949** the [sqlite3_busy_handler | busy-handler function] 6950** is invoked (if one is specified). ^If the 6951** busy-handler returns non-zero before the lock is available, then 6952** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6953** sqlite3_backup_step() can be retried later. ^If the source 6954** [database connection] 6955** is being used to write to the source database when sqlite3_backup_step() 6956** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6957** case the call to sqlite3_backup_step() can be retried later on. ^(If 6958** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6959** [SQLITE_READONLY] is returned, then 6960** there is no point in retrying the call to sqlite3_backup_step(). These 6961** errors are considered fatal.)^ The application must accept 6962** that the backup operation has failed and pass the backup operation handle 6963** to the sqlite3_backup_finish() to release associated resources. 6964** 6965** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6966** on the destination file. ^The exclusive lock is not released until either 6967** sqlite3_backup_finish() is called or the backup operation is complete 6968** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6969** sqlite3_backup_step() obtains a [shared lock] on the source database that 6970** lasts for the duration of the sqlite3_backup_step() call. 6971** ^Because the source database is not locked between calls to 6972** sqlite3_backup_step(), the source database may be modified mid-way 6973** through the backup process. ^If the source database is modified by an 6974** external process or via a database connection other than the one being 6975** used by the backup operation, then the backup will be automatically 6976** restarted by the next call to sqlite3_backup_step(). ^If the source 6977** database is modified by the using the same database connection as is used 6978** by the backup operation, then the backup database is automatically 6979** updated at the same time. 6980** 6981** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6982** 6983** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6984** application wishes to abandon the backup operation, the application 6985** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6986** ^The sqlite3_backup_finish() interfaces releases all 6987** resources associated with the [sqlite3_backup] object. 6988** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6989** active write-transaction on the destination database is rolled back. 6990** The [sqlite3_backup] object is invalid 6991** and may not be used following a call to sqlite3_backup_finish(). 6992** 6993** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6994** sqlite3_backup_step() errors occurred, regardless or whether or not 6995** sqlite3_backup_step() completed. 6996** ^If an out-of-memory condition or IO error occurred during any prior 6997** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6998** sqlite3_backup_finish() returns the corresponding [error code]. 6999** 7000** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7001** is not a permanent error and does not affect the return value of 7002** sqlite3_backup_finish(). 7003** 7004** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7005** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7006** 7007** ^The sqlite3_backup_remaining() routine returns the number of pages still 7008** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7009** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7010** in the source database at the conclusion of the most recent 7011** sqlite3_backup_step(). 7012** ^(The values returned by these functions are only updated by 7013** sqlite3_backup_step(). If the source database is modified in a way that 7014** changes the size of the source database or the number of pages remaining, 7015** those changes are not reflected in the output of sqlite3_backup_pagecount() 7016** and sqlite3_backup_remaining() until after the next 7017** sqlite3_backup_step().)^ 7018** 7019** <b>Concurrent Usage of Database Handles</b> 7020** 7021** ^The source [database connection] may be used by the application for other 7022** purposes while a backup operation is underway or being initialized. 7023** ^If SQLite is compiled and configured to support threadsafe database 7024** connections, then the source database connection may be used concurrently 7025** from within other threads. 7026** 7027** However, the application must guarantee that the destination 7028** [database connection] is not passed to any other API (by any thread) after 7029** sqlite3_backup_init() is called and before the corresponding call to 7030** sqlite3_backup_finish(). SQLite does not currently check to see 7031** if the application incorrectly accesses the destination [database connection] 7032** and so no error code is reported, but the operations may malfunction 7033** nevertheless. Use of the destination database connection while a 7034** backup is in progress might also also cause a mutex deadlock. 7035** 7036** If running in [shared cache mode], the application must 7037** guarantee that the shared cache used by the destination database 7038** is not accessed while the backup is running. In practice this means 7039** that the application must guarantee that the disk file being 7040** backed up to is not accessed by any connection within the process, 7041** not just the specific connection that was passed to sqlite3_backup_init(). 7042** 7043** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7044** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7045** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7046** APIs are not strictly speaking threadsafe. If they are invoked at the 7047** same time as another thread is invoking sqlite3_backup_step() it is 7048** possible that they return invalid values. 7049*/ 7050sqlite3_backup *sqlite3_backup_init( 7051 sqlite3 *pDest, /* Destination database handle */ 7052 const char *zDestName, /* Destination database name */ 7053 sqlite3 *pSource, /* Source database handle */ 7054 const char *zSourceName /* Source database name */ 7055); 7056int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7057int sqlite3_backup_finish(sqlite3_backup *p); 7058int sqlite3_backup_remaining(sqlite3_backup *p); 7059int sqlite3_backup_pagecount(sqlite3_backup *p); 7060 7061/* 7062** CAPI3REF: Unlock Notification 7063** 7064** ^When running in shared-cache mode, a database operation may fail with 7065** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7066** individual tables within the shared-cache cannot be obtained. See 7067** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7068** ^This API may be used to register a callback that SQLite will invoke 7069** when the connection currently holding the required lock relinquishes it. 7070** ^This API is only available if the library was compiled with the 7071** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7072** 7073** See Also: [Using the SQLite Unlock Notification Feature]. 7074** 7075** ^Shared-cache locks are released when a database connection concludes 7076** its current transaction, either by committing it or rolling it back. 7077** 7078** ^When a connection (known as the blocked connection) fails to obtain a 7079** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7080** identity of the database connection (the blocking connection) that 7081** has locked the required resource is stored internally. ^After an 7082** application receives an SQLITE_LOCKED error, it may call the 7083** sqlite3_unlock_notify() method with the blocked connection handle as 7084** the first argument to register for a callback that will be invoked 7085** when the blocking connections current transaction is concluded. ^The 7086** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7087** call that concludes the blocking connections transaction. 7088** 7089** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7090** there is a chance that the blocking connection will have already 7091** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7092** If this happens, then the specified callback is invoked immediately, 7093** from within the call to sqlite3_unlock_notify().)^ 7094** 7095** ^If the blocked connection is attempting to obtain a write-lock on a 7096** shared-cache table, and more than one other connection currently holds 7097** a read-lock on the same table, then SQLite arbitrarily selects one of 7098** the other connections to use as the blocking connection. 7099** 7100** ^(There may be at most one unlock-notify callback registered by a 7101** blocked connection. If sqlite3_unlock_notify() is called when the 7102** blocked connection already has a registered unlock-notify callback, 7103** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7104** called with a NULL pointer as its second argument, then any existing 7105** unlock-notify callback is canceled. ^The blocked connections 7106** unlock-notify callback may also be canceled by closing the blocked 7107** connection using [sqlite3_close()]. 7108** 7109** The unlock-notify callback is not reentrant. If an application invokes 7110** any sqlite3_xxx API functions from within an unlock-notify callback, a 7111** crash or deadlock may be the result. 7112** 7113** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7114** returns SQLITE_OK. 7115** 7116** <b>Callback Invocation Details</b> 7117** 7118** When an unlock-notify callback is registered, the application provides a 7119** single void* pointer that is passed to the callback when it is invoked. 7120** However, the signature of the callback function allows SQLite to pass 7121** it an array of void* context pointers. The first argument passed to 7122** an unlock-notify callback is a pointer to an array of void* pointers, 7123** and the second is the number of entries in the array. 7124** 7125** When a blocking connections transaction is concluded, there may be 7126** more than one blocked connection that has registered for an unlock-notify 7127** callback. ^If two or more such blocked connections have specified the 7128** same callback function, then instead of invoking the callback function 7129** multiple times, it is invoked once with the set of void* context pointers 7130** specified by the blocked connections bundled together into an array. 7131** This gives the application an opportunity to prioritize any actions 7132** related to the set of unblocked database connections. 7133** 7134** <b>Deadlock Detection</b> 7135** 7136** Assuming that after registering for an unlock-notify callback a 7137** database waits for the callback to be issued before taking any further 7138** action (a reasonable assumption), then using this API may cause the 7139** application to deadlock. For example, if connection X is waiting for 7140** connection Y's transaction to be concluded, and similarly connection 7141** Y is waiting on connection X's transaction, then neither connection 7142** will proceed and the system may remain deadlocked indefinitely. 7143** 7144** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7145** detection. ^If a given call to sqlite3_unlock_notify() would put the 7146** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7147** unlock-notify callback is registered. The system is said to be in 7148** a deadlocked state if connection A has registered for an unlock-notify 7149** callback on the conclusion of connection B's transaction, and connection 7150** B has itself registered for an unlock-notify callback when connection 7151** A's transaction is concluded. ^Indirect deadlock is also detected, so 7152** the system is also considered to be deadlocked if connection B has 7153** registered for an unlock-notify callback on the conclusion of connection 7154** C's transaction, where connection C is waiting on connection A. ^Any 7155** number of levels of indirection are allowed. 7156** 7157** <b>The "DROP TABLE" Exception</b> 7158** 7159** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7160** always appropriate to call sqlite3_unlock_notify(). There is however, 7161** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7162** SQLite checks if there are any currently executing SELECT statements 7163** that belong to the same connection. If there are, SQLITE_LOCKED is 7164** returned. In this case there is no "blocking connection", so invoking 7165** sqlite3_unlock_notify() results in the unlock-notify callback being 7166** invoked immediately. If the application then re-attempts the "DROP TABLE" 7167** or "DROP INDEX" query, an infinite loop might be the result. 7168** 7169** One way around this problem is to check the extended error code returned 7170** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7171** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7172** the special "DROP TABLE/INDEX" case, the extended error code is just 7173** SQLITE_LOCKED.)^ 7174*/ 7175int sqlite3_unlock_notify( 7176 sqlite3 *pBlocked, /* Waiting connection */ 7177 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7178 void *pNotifyArg /* Argument to pass to xNotify */ 7179); 7180 7181 7182/* 7183** CAPI3REF: String Comparison 7184** 7185** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7186** and extensions to compare the contents of two buffers containing UTF-8 7187** strings in a case-independent fashion, using the same definition of "case 7188** independence" that SQLite uses internally when comparing identifiers. 7189*/ 7190int sqlite3_stricmp(const char *, const char *); 7191int sqlite3_strnicmp(const char *, const char *, int); 7192 7193/* 7194** CAPI3REF: String Globbing 7195* 7196** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7197** the glob pattern P, and it returns non-zero if string X does not match 7198** the glob pattern P. ^The definition of glob pattern matching used in 7199** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7200** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7201** sensitive. 7202** 7203** Note that this routine returns zero on a match and non-zero if the strings 7204** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7205*/ 7206int sqlite3_strglob(const char *zGlob, const char *zStr); 7207 7208/* 7209** CAPI3REF: Error Logging Interface 7210** 7211** ^The [sqlite3_log()] interface writes a message into the [error log] 7212** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7213** ^If logging is enabled, the zFormat string and subsequent arguments are 7214** used with [sqlite3_snprintf()] to generate the final output string. 7215** 7216** The sqlite3_log() interface is intended for use by extensions such as 7217** virtual tables, collating functions, and SQL functions. While there is 7218** nothing to prevent an application from calling sqlite3_log(), doing so 7219** is considered bad form. 7220** 7221** The zFormat string must not be NULL. 7222** 7223** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7224** will not use dynamically allocated memory. The log message is stored in 7225** a fixed-length buffer on the stack. If the log message is longer than 7226** a few hundred characters, it will be truncated to the length of the 7227** buffer. 7228*/ 7229void sqlite3_log(int iErrCode, const char *zFormat, ...); 7230 7231/* 7232** CAPI3REF: Write-Ahead Log Commit Hook 7233** 7234** ^The [sqlite3_wal_hook()] function is used to register a callback that 7235** is invoked each time data is committed to a database in wal mode. 7236** 7237** ^(The callback is invoked by SQLite after the commit has taken place and 7238** the associated write-lock on the database released)^, so the implementation 7239** may read, write or [checkpoint] the database as required. 7240** 7241** ^The first parameter passed to the callback function when it is invoked 7242** is a copy of the third parameter passed to sqlite3_wal_hook() when 7243** registering the callback. ^The second is a copy of the database handle. 7244** ^The third parameter is the name of the database that was written to - 7245** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7246** is the number of pages currently in the write-ahead log file, 7247** including those that were just committed. 7248** 7249** The callback function should normally return [SQLITE_OK]. ^If an error 7250** code is returned, that error will propagate back up through the 7251** SQLite code base to cause the statement that provoked the callback 7252** to report an error, though the commit will have still occurred. If the 7253** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7254** that does not correspond to any valid SQLite error code, the results 7255** are undefined. 7256** 7257** A single database handle may have at most a single write-ahead log callback 7258** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7259** previously registered write-ahead log callback. ^Note that the 7260** [sqlite3_wal_autocheckpoint()] interface and the 7261** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7262** those overwrite any prior [sqlite3_wal_hook()] settings. 7263*/ 7264void *sqlite3_wal_hook( 7265 sqlite3*, 7266 int(*)(void *,sqlite3*,const char*,int), 7267 void* 7268); 7269 7270/* 7271** CAPI3REF: Configure an auto-checkpoint 7272** 7273** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7274** [sqlite3_wal_hook()] that causes any database on [database connection] D 7275** to automatically [checkpoint] 7276** after committing a transaction if there are N or 7277** more frames in the [write-ahead log] file. ^Passing zero or 7278** a negative value as the nFrame parameter disables automatic 7279** checkpoints entirely. 7280** 7281** ^The callback registered by this function replaces any existing callback 7282** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7283** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7284** configured by this function. 7285** 7286** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7287** from SQL. 7288** 7289** ^Checkpoints initiated by this mechanism are 7290** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7291** 7292** ^Every new [database connection] defaults to having the auto-checkpoint 7293** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7294** pages. The use of this interface 7295** is only necessary if the default setting is found to be suboptimal 7296** for a particular application. 7297*/ 7298int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7299 7300/* 7301** CAPI3REF: Checkpoint a database 7302** 7303** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7304** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7305** 7306** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7307** [write-ahead log] for database X on [database connection] D to be 7308** transferred into the database file and for the write-ahead log to 7309** be reset. See the [checkpointing] documentation for addition 7310** information. 7311** 7312** This interface used to be the only way to cause a checkpoint to 7313** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7314** interface was added. This interface is retained for backwards 7315** compatibility and as a convenience for applications that need to manually 7316** start a callback but which do not need the full power (and corresponding 7317** complication) of [sqlite3_wal_checkpoint_v2()]. 7318*/ 7319int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7320 7321/* 7322** CAPI3REF: Checkpoint a database 7323** 7324** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7325** operation on database X of [database connection] D in mode M. Status 7326** information is written back into integers pointed to by L and C.)^ 7327** ^(The M parameter must be a valid [checkpoint mode]:)^ 7328** 7329** <dl> 7330** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7331** ^Checkpoint as many frames as possible without waiting for any database 7332** readers or writers to finish, then sync the database file if all frames 7333** in the log were checkpointed. ^The [busy-handler callback] 7334** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7335** ^On the other hand, passive mode might leave the checkpoint unfinished 7336** if there are concurrent readers or writers. 7337** 7338** <dt>SQLITE_CHECKPOINT_FULL<dd> 7339** ^This mode blocks (it invokes the 7340** [sqlite3_busy_handler|busy-handler callback]) until there is no 7341** database writer and all readers are reading from the most recent database 7342** snapshot. ^It then checkpoints all frames in the log file and syncs the 7343** database file. ^This mode blocks new database writers while it is pending, 7344** but new database readers are allowed to continue unimpeded. 7345** 7346** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7347** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7348** that after checkpointing the log file it blocks (calls the 7349** [busy-handler callback]) 7350** until all readers are reading from the database file only. ^This ensures 7351** that the next writer will restart the log file from the beginning. 7352** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7353** database writer attempts while it is pending, but does not impede readers. 7354** 7355** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7356** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7357** addition that it also truncates the log file to zero bytes just prior 7358** to a successful return. 7359** </dl> 7360** 7361** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7362** the log file or to -1 if the checkpoint could not run because 7363** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7364** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7365** log file (including any that were already checkpointed before the function 7366** was called) or to -1 if the checkpoint could not run due to an error or 7367** because the database is not in WAL mode. ^Note that upon successful 7368** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7369** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7370** 7371** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7372** any other process is running a checkpoint operation at the same time, the 7373** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7374** busy-handler configured, it will not be invoked in this case. 7375** 7376** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7377** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7378** obtained immediately, and a busy-handler is configured, it is invoked and 7379** the writer lock retried until either the busy-handler returns 0 or the lock 7380** is successfully obtained. ^The busy-handler is also invoked while waiting for 7381** database readers as described above. ^If the busy-handler returns 0 before 7382** the writer lock is obtained or while waiting for database readers, the 7383** checkpoint operation proceeds from that point in the same way as 7384** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7385** without blocking any further. ^SQLITE_BUSY is returned in this case. 7386** 7387** ^If parameter zDb is NULL or points to a zero length string, then the 7388** specified operation is attempted on all WAL databases [attached] to 7389** [database connection] db. In this case the 7390** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7391** an SQLITE_BUSY error is encountered when processing one or more of the 7392** attached WAL databases, the operation is still attempted on any remaining 7393** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7394** error occurs while processing an attached database, processing is abandoned 7395** and the error code is returned to the caller immediately. ^If no error 7396** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7397** databases, SQLITE_OK is returned. 7398** 7399** ^If database zDb is the name of an attached database that is not in WAL 7400** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7401** zDb is not NULL (or a zero length string) and is not the name of any 7402** attached database, SQLITE_ERROR is returned to the caller. 7403** 7404** ^Unless it returns SQLITE_MISUSE, 7405** the sqlite3_wal_checkpoint_v2() interface 7406** sets the error information that is queried by 7407** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7408** 7409** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7410** from SQL. 7411*/ 7412int sqlite3_wal_checkpoint_v2( 7413 sqlite3 *db, /* Database handle */ 7414 const char *zDb, /* Name of attached database (or NULL) */ 7415 int eMode, /* SQLITE_CHECKPOINT_* value */ 7416 int *pnLog, /* OUT: Size of WAL log in frames */ 7417 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7418); 7419 7420/* 7421** CAPI3REF: Checkpoint Mode Values 7422** KEYWORDS: {checkpoint mode} 7423** 7424** These constants define all valid values for the "checkpoint mode" passed 7425** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7426** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7427** meaning of each of these checkpoint modes. 7428*/ 7429#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7430#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7431#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7432#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7433 7434/* 7435** CAPI3REF: Virtual Table Interface Configuration 7436** 7437** This function may be called by either the [xConnect] or [xCreate] method 7438** of a [virtual table] implementation to configure 7439** various facets of the virtual table interface. 7440** 7441** If this interface is invoked outside the context of an xConnect or 7442** xCreate virtual table method then the behavior is undefined. 7443** 7444** At present, there is only one option that may be configured using 7445** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7446** may be added in the future. 7447*/ 7448int sqlite3_vtab_config(sqlite3*, int op, ...); 7449 7450/* 7451** CAPI3REF: Virtual Table Configuration Options 7452** 7453** These macros define the various options to the 7454** [sqlite3_vtab_config()] interface that [virtual table] implementations 7455** can use to customize and optimize their behavior. 7456** 7457** <dl> 7458** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7459** <dd>Calls of the form 7460** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7461** where X is an integer. If X is zero, then the [virtual table] whose 7462** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7463** support constraints. In this configuration (which is the default) if 7464** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7465** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7466** specified as part of the users SQL statement, regardless of the actual 7467** ON CONFLICT mode specified. 7468** 7469** If X is non-zero, then the virtual table implementation guarantees 7470** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7471** any modifications to internal or persistent data structures have been made. 7472** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7473** is able to roll back a statement or database transaction, and abandon 7474** or continue processing the current SQL statement as appropriate. 7475** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7476** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7477** had been ABORT. 7478** 7479** Virtual table implementations that are required to handle OR REPLACE 7480** must do so within the [xUpdate] method. If a call to the 7481** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7482** CONFLICT policy is REPLACE, the virtual table implementation should 7483** silently replace the appropriate rows within the xUpdate callback and 7484** return SQLITE_OK. Or, if this is not possible, it may return 7485** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7486** constraint handling. 7487** </dl> 7488*/ 7489#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7490 7491/* 7492** CAPI3REF: Determine The Virtual Table Conflict Policy 7493** 7494** This function may only be called from within a call to the [xUpdate] method 7495** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7496** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7497** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7498** of the SQL statement that triggered the call to the [xUpdate] method of the 7499** [virtual table]. 7500*/ 7501int sqlite3_vtab_on_conflict(sqlite3 *); 7502 7503/* 7504** CAPI3REF: Conflict resolution modes 7505** KEYWORDS: {conflict resolution mode} 7506** 7507** These constants are returned by [sqlite3_vtab_on_conflict()] to 7508** inform a [virtual table] implementation what the [ON CONFLICT] mode 7509** is for the SQL statement being evaluated. 7510** 7511** Note that the [SQLITE_IGNORE] constant is also used as a potential 7512** return value from the [sqlite3_set_authorizer()] callback and that 7513** [SQLITE_ABORT] is also a [result code]. 7514*/ 7515#define SQLITE_ROLLBACK 1 7516/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7517#define SQLITE_FAIL 3 7518/* #define SQLITE_ABORT 4 // Also an error code */ 7519#define SQLITE_REPLACE 5 7520 7521/* 7522** CAPI3REF: Prepared Statement Scan Status Opcodes 7523** KEYWORDS: {scanstatus options} 7524** 7525** The following constants can be used for the T parameter to the 7526** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7527** different metric for sqlite3_stmt_scanstatus() to return. 7528** 7529** When the value returned to V is a string, space to hold that string is 7530** managed by the prepared statement S and will be automatically freed when 7531** S is finalized. 7532** 7533** <dl> 7534** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7535** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7536** set to the total number of times that the X-th loop has run.</dd> 7537** 7538** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7539** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7540** to the total number of rows examined by all iterations of the X-th loop.</dd> 7541** 7542** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7543** <dd>^The "double" variable pointed to by the T parameter will be set to the 7544** query planner's estimate for the average number of rows output from each 7545** iteration of the X-th loop. If the query planner's estimates was accurate, 7546** then this value will approximate the quotient NVISIT/NLOOP and the 7547** product of this value for all prior loops with the same SELECTID will 7548** be the NLOOP value for the current loop. 7549** 7550** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 7551** <dd>^The "const char *" variable pointed to by the T parameter will be set 7552** to a zero-terminated UTF-8 string containing the name of the index or table 7553** used for the X-th loop. 7554** 7555** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 7556** <dd>^The "const char *" variable pointed to by the T parameter will be set 7557** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 7558** description for the X-th loop. 7559** 7560** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 7561** <dd>^The "int" variable pointed to by the T parameter will be set to the 7562** "select-id" for the X-th loop. The select-id identifies which query or 7563** subquery the loop is part of. The main query has a select-id of zero. 7564** The select-id is the same value as is output in the first column 7565** of an [EXPLAIN QUERY PLAN] query. 7566** </dl> 7567*/ 7568#define SQLITE_SCANSTAT_NLOOP 0 7569#define SQLITE_SCANSTAT_NVISIT 1 7570#define SQLITE_SCANSTAT_EST 2 7571#define SQLITE_SCANSTAT_NAME 3 7572#define SQLITE_SCANSTAT_EXPLAIN 4 7573#define SQLITE_SCANSTAT_SELECTID 5 7574 7575/* 7576** CAPI3REF: Prepared Statement Scan Status 7577** 7578** This interface returns information about the predicted and measured 7579** performance for pStmt. Advanced applications can use this 7580** interface to compare the predicted and the measured performance and 7581** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 7582** 7583** Since this interface is expected to be rarely used, it is only 7584** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 7585** compile-time option. 7586** 7587** The "iScanStatusOp" parameter determines which status information to return. 7588** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 7589** of this interface is undefined. 7590** ^The requested measurement is written into a variable pointed to by 7591** the "pOut" parameter. 7592** Parameter "idx" identifies the specific loop to retrieve statistics for. 7593** Loops are numbered starting from zero. ^If idx is out of range - less than 7594** zero or greater than or equal to the total number of loops used to implement 7595** the statement - a non-zero value is returned and the variable that pOut 7596** points to is unchanged. 7597** 7598** ^Statistics might not be available for all loops in all statements. ^In cases 7599** where there exist loops with no available statistics, this function behaves 7600** as if the loop did not exist - it returns non-zero and leave the variable 7601** that pOut points to unchanged. 7602** 7603** See also: [sqlite3_stmt_scanstatus_reset()] 7604*/ 7605SQLITE_EXPERIMENTAL int sqlite3_stmt_scanstatus( 7606 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 7607 int idx, /* Index of loop to report on */ 7608 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 7609 void *pOut /* Result written here */ 7610); 7611 7612/* 7613** CAPI3REF: Zero Scan-Status Counters 7614** 7615** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 7616** 7617** This API is only available if the library is built with pre-processor 7618** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 7619*/ 7620SQLITE_EXPERIMENTAL void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 7621 7622 7623/* 7624** Undo the hack that converts floating point types to integer for 7625** builds on processors without floating point support. 7626*/ 7627#ifdef SQLITE_OMIT_FLOATING_POINT 7628# undef double 7629#endif 7630 7631#ifdef __cplusplus 7632} /* End of the 'extern "C"' block */ 7633#endif 7634#endif /* _SQLITE3_H_ */ 7635