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#ifndef SQLITE_API 53# define SQLITE_API 54#endif 55 56 57/* 58** These no-op macros are used in front of interfaces to mark those 59** interfaces as either deprecated or experimental. New applications 60** should not use deprecated interfaces - they are support for backwards 61** compatibility only. Application writers should be aware that 62** experimental interfaces are subject to change in point releases. 63** 64** These macros used to resolve to various kinds of compiler magic that 65** would generate warning messages when they were used. But that 66** compiler magic ended up generating such a flurry of bug reports 67** that we have taken it all out and gone back to using simple 68** noop macros. 69*/ 70#define SQLITE_DEPRECATED 71#define SQLITE_EXPERIMENTAL 72 73/* 74** Ensure these symbols were not defined by some previous header file. 75*/ 76#ifdef SQLITE_VERSION 77# undef SQLITE_VERSION 78#endif 79#ifdef SQLITE_VERSION_NUMBER 80# undef SQLITE_VERSION_NUMBER 81#endif 82 83/* 84** CAPI3REF: Compile-Time Library Version Numbers 85** 86** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 87** evaluates to a string literal that is the SQLite version in the 88** format "X.Y.Z" where X is the major version number (always 3 for 89** SQLite3) and Y is the minor version number and Z is the release number.)^ 90** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 91** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 92** numbers used in [SQLITE_VERSION].)^ 93** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 94** be larger than the release from which it is derived. Either Y will 95** be held constant and Z will be incremented or else Y will be incremented 96** and Z will be reset to zero. 97** 98** Since version 3.6.18, SQLite source code has been stored in the 99** <a href="http://www.fossil-scm.org/">Fossil configuration management 100** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 101** a string which identifies a particular check-in of SQLite 102** within its configuration management system. ^The SQLITE_SOURCE_ID 103** string contains the date and time of the check-in (UTC) and an SHA1 104** hash of the entire source tree. 105** 106** See also: [sqlite3_libversion()], 107** [sqlite3_libversion_number()], [sqlite3_sourceid()], 108** [sqlite_version()] and [sqlite_source_id()]. 109*/ 110#define SQLITE_VERSION "3.7.6.3" 111#define SQLITE_VERSION_NUMBER 3007006 112#define SQLITE_SOURCE_ID "2011-05-19 13:26:54 ed1da510a239ea767a01dc332b667119fa3c908e" 113 114/* 115** CAPI3REF: Run-Time Library Version Numbers 116** KEYWORDS: sqlite3_version, sqlite3_sourceid 117** 118** These interfaces provide the same information as the [SQLITE_VERSION], 119** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 120** but are associated with the library instead of the header file. ^(Cautious 121** programmers might include assert() statements in their application to 122** verify that values returned by these interfaces match the macros in 123** the header, and thus insure that the application is 124** compiled with matching library and header files. 125** 126** <blockquote><pre> 127** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 128** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 129** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 130** </pre></blockquote>)^ 131** 132** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 133** macro. ^The sqlite3_libversion() function returns a pointer to the 134** to the sqlite3_version[] string constant. The sqlite3_libversion() 135** function is provided for use in DLLs since DLL users usually do not have 136** direct access to string constants within the DLL. ^The 137** sqlite3_libversion_number() function returns an integer equal to 138** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 139** a pointer to a string constant whose value is the same as the 140** [SQLITE_SOURCE_ID] C preprocessor macro. 141** 142** See also: [sqlite_version()] and [sqlite_source_id()]. 143*/ 144SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 145SQLITE_API const char *sqlite3_libversion(void); 146SQLITE_API const char *sqlite3_sourceid(void); 147SQLITE_API int sqlite3_libversion_number(void); 148 149/* 150** CAPI3REF: Run-Time Library Compilation Options Diagnostics 151** 152** ^The sqlite3_compileoption_used() function returns 0 or 1 153** indicating whether the specified option was defined at 154** compile time. ^The SQLITE_ prefix may be omitted from the 155** option name passed to sqlite3_compileoption_used(). 156** 157** ^The sqlite3_compileoption_get() function allows iterating 158** over the list of options that were defined at compile time by 159** returning the N-th compile time option string. ^If N is out of range, 160** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 161** prefix is omitted from any strings returned by 162** sqlite3_compileoption_get(). 163** 164** ^Support for the diagnostic functions sqlite3_compileoption_used() 165** and sqlite3_compileoption_get() may be omitted by specifying the 166** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 167** 168** See also: SQL functions [sqlite_compileoption_used()] and 169** [sqlite_compileoption_get()] and the [compile_options pragma]. 170*/ 171#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 172SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 173SQLITE_API const char *sqlite3_compileoption_get(int N); 174#endif 175 176/* 177** CAPI3REF: Test To See If The Library Is Threadsafe 178** 179** ^The sqlite3_threadsafe() function returns zero if and only if 180** SQLite was compiled mutexing code omitted due to the 181** [SQLITE_THREADSAFE] compile-time option being set to 0. 182** 183** SQLite can be compiled with or without mutexes. When 184** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 185** are enabled and SQLite is threadsafe. When the 186** [SQLITE_THREADSAFE] macro is 0, 187** the mutexes are omitted. Without the mutexes, it is not safe 188** to use SQLite concurrently from more than one thread. 189** 190** Enabling mutexes incurs a measurable performance penalty. 191** So if speed is of utmost importance, it makes sense to disable 192** the mutexes. But for maximum safety, mutexes should be enabled. 193** ^The default behavior is for mutexes to be enabled. 194** 195** This interface can be used by an application to make sure that the 196** version of SQLite that it is linking against was compiled with 197** the desired setting of the [SQLITE_THREADSAFE] macro. 198** 199** This interface only reports on the compile-time mutex setting 200** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 201** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 202** can be fully or partially disabled using a call to [sqlite3_config()] 203** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 204** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 205** sqlite3_threadsafe() function shows only the compile-time setting of 206** thread safety, not any run-time changes to that setting made by 207** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 208** is unchanged by calls to sqlite3_config().)^ 209** 210** See the [threading mode] documentation for additional information. 211*/ 212SQLITE_API int sqlite3_threadsafe(void); 213 214/* 215** CAPI3REF: Database Connection Handle 216** KEYWORDS: {database connection} {database connections} 217** 218** Each open SQLite database is represented by a pointer to an instance of 219** the opaque structure named "sqlite3". It is useful to think of an sqlite3 220** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 221** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 222** is its destructor. There are many other interfaces (such as 223** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 224** [sqlite3_busy_timeout()] to name but three) that are methods on an 225** sqlite3 object. 226*/ 227typedef struct sqlite3 sqlite3; 228 229/* 230** CAPI3REF: 64-Bit Integer Types 231** KEYWORDS: sqlite_int64 sqlite_uint64 232** 233** Because there is no cross-platform way to specify 64-bit integer types 234** SQLite includes typedefs for 64-bit signed and unsigned integers. 235** 236** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 237** The sqlite_int64 and sqlite_uint64 types are supported for backwards 238** compatibility only. 239** 240** ^The sqlite3_int64 and sqlite_int64 types can store integer values 241** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 242** sqlite3_uint64 and sqlite_uint64 types can store integer values 243** between 0 and +18446744073709551615 inclusive. 244*/ 245#ifdef SQLITE_INT64_TYPE 246 typedef SQLITE_INT64_TYPE sqlite_int64; 247 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 248#elif defined(_MSC_VER) || defined(__BORLANDC__) 249 typedef __int64 sqlite_int64; 250 typedef unsigned __int64 sqlite_uint64; 251#else 252 typedef long long int sqlite_int64; 253 typedef unsigned long long int sqlite_uint64; 254#endif 255typedef sqlite_int64 sqlite3_int64; 256typedef sqlite_uint64 sqlite3_uint64; 257 258/* 259** If compiling for a processor that lacks floating point support, 260** substitute integer for floating-point. 261*/ 262#ifdef SQLITE_OMIT_FLOATING_POINT 263# define double sqlite3_int64 264#endif 265 266/* 267** CAPI3REF: Closing A Database Connection 268** 269** ^The sqlite3_close() routine is the destructor for the [sqlite3] object. 270** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is 271** successfully destroyed and all associated resources are deallocated. 272** 273** Applications must [sqlite3_finalize | finalize] all [prepared statements] 274** and [sqlite3_blob_close | close] all [BLOB handles] associated with 275** the [sqlite3] object prior to attempting to close the object. ^If 276** sqlite3_close() is called on a [database connection] that still has 277** outstanding [prepared statements] or [BLOB handles], then it returns 278** SQLITE_BUSY. 279** 280** ^If [sqlite3_close()] is invoked while a transaction is open, 281** the transaction is automatically rolled back. 282** 283** The C parameter to [sqlite3_close(C)] must be either a NULL 284** pointer or an [sqlite3] object pointer obtained 285** from [sqlite3_open()], [sqlite3_open16()], or 286** [sqlite3_open_v2()], and not previously closed. 287** ^Calling sqlite3_close() with a NULL pointer argument is a 288** harmless no-op. 289*/ 290SQLITE_API int sqlite3_close(sqlite3 *); 291 292/* 293** The type for a callback function. 294** This is legacy and deprecated. It is included for historical 295** compatibility and is not documented. 296*/ 297typedef int (*sqlite3_callback)(void*,int,char**, char**); 298 299/* 300** CAPI3REF: One-Step Query Execution Interface 301** 302** The sqlite3_exec() interface is a convenience wrapper around 303** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 304** that allows an application to run multiple statements of SQL 305** without having to use a lot of C code. 306** 307** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 308** semicolon-separate SQL statements passed into its 2nd argument, 309** in the context of the [database connection] passed in as its 1st 310** argument. ^If the callback function of the 3rd argument to 311** sqlite3_exec() is not NULL, then it is invoked for each result row 312** coming out of the evaluated SQL statements. ^The 4th argument to 313** to sqlite3_exec() is relayed through to the 1st argument of each 314** callback invocation. ^If the callback pointer to sqlite3_exec() 315** is NULL, then no callback is ever invoked and result rows are 316** ignored. 317** 318** ^If an error occurs while evaluating the SQL statements passed into 319** sqlite3_exec(), then execution of the current statement stops and 320** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 321** is not NULL then any error message is written into memory obtained 322** from [sqlite3_malloc()] and passed back through the 5th parameter. 323** To avoid memory leaks, the application should invoke [sqlite3_free()] 324** on error message strings returned through the 5th parameter of 325** of sqlite3_exec() after the error message string is no longer needed. 326** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 327** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 328** NULL before returning. 329** 330** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 331** routine returns SQLITE_ABORT without invoking the callback again and 332** without running any subsequent SQL statements. 333** 334** ^The 2nd argument to the sqlite3_exec() callback function is the 335** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 336** callback is an array of pointers to strings obtained as if from 337** [sqlite3_column_text()], one for each column. ^If an element of a 338** result row is NULL then the corresponding string pointer for the 339** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 340** sqlite3_exec() callback is an array of pointers to strings where each 341** entry represents the name of corresponding result column as obtained 342** from [sqlite3_column_name()]. 343** 344** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 345** to an empty string, or a pointer that contains only whitespace and/or 346** SQL comments, then no SQL statements are evaluated and the database 347** is not changed. 348** 349** Restrictions: 350** 351** <ul> 352** <li> The application must insure that the 1st parameter to sqlite3_exec() 353** is a valid and open [database connection]. 354** <li> The application must not close [database connection] specified by 355** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 356** <li> The application must not modify the SQL statement text passed into 357** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 358** </ul> 359*/ 360SQLITE_API int sqlite3_exec( 361 sqlite3*, /* An open database */ 362 const char *sql, /* SQL to be evaluated */ 363 int (*callback)(void*,int,char**,char**), /* Callback function */ 364 void *, /* 1st argument to callback */ 365 char **errmsg /* Error msg written here */ 366); 367 368/* 369** CAPI3REF: Result Codes 370** KEYWORDS: SQLITE_OK {error code} {error codes} 371** KEYWORDS: {result code} {result codes} 372** 373** Many SQLite functions return an integer result code from the set shown 374** here in order to indicates success or failure. 375** 376** New error codes may be added in future versions of SQLite. 377** 378** See also: [SQLITE_IOERR_READ | extended result codes] 379*/ 380#define SQLITE_OK 0 /* Successful result */ 381/* beginning-of-error-codes */ 382#define SQLITE_ERROR 1 /* SQL error or missing database */ 383#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 384#define SQLITE_PERM 3 /* Access permission denied */ 385#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 386#define SQLITE_BUSY 5 /* The database file is locked */ 387#define SQLITE_LOCKED 6 /* A table in the database is locked */ 388#define SQLITE_NOMEM 7 /* A malloc() failed */ 389#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 390#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 391#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 392#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 393#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 394#define SQLITE_FULL 13 /* Insertion failed because database is full */ 395#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 396#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 397#define SQLITE_EMPTY 16 /* Database is empty */ 398#define SQLITE_SCHEMA 17 /* The database schema changed */ 399#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 400#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 401#define SQLITE_MISMATCH 20 /* Data type mismatch */ 402#define SQLITE_MISUSE 21 /* Library used incorrectly */ 403#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 404#define SQLITE_AUTH 23 /* Authorization denied */ 405#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 406#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 407#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 408#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 409#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 410/* end-of-error-codes */ 411 412/* 413** CAPI3REF: Extended Result Codes 414** KEYWORDS: {extended error code} {extended error codes} 415** KEYWORDS: {extended result code} {extended result codes} 416** 417** In its default configuration, SQLite API routines return one of 26 integer 418** [SQLITE_OK | result codes]. However, experience has shown that many of 419** these result codes are too coarse-grained. They do not provide as 420** much information about problems as programmers might like. In an effort to 421** address this, newer versions of SQLite (version 3.3.8 and later) include 422** support for additional result codes that provide more detailed information 423** about errors. The extended result codes are enabled or disabled 424** on a per database connection basis using the 425** [sqlite3_extended_result_codes()] API. 426** 427** Some of the available extended result codes are listed here. 428** One may expect the number of extended result codes will be expand 429** over time. Software that uses extended result codes should expect 430** to see new result codes in future releases of SQLite. 431** 432** The SQLITE_OK result code will never be extended. It will always 433** be exactly zero. 434*/ 435#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 436#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 437#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 438#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 439#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 440#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 441#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 442#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 443#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 444#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 445#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 446#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 447#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 448#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 449#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 450#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 451#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 452#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 453#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 454#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 455#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 456#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 457#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 458 459/* 460** CAPI3REF: Flags For File Open Operations 461** 462** These bit values are intended for use in the 463** 3rd parameter to the [sqlite3_open_v2()] interface and 464** in the 4th parameter to the xOpen method of the 465** [sqlite3_vfs] object. 466*/ 467#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 468#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 469#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 470#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 471#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 472#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 473#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 474#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 475#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 476#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 477#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 478#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 479#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 480#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 481#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 482#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 483#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 484#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 485 486/* Reserved: 0x00F00000 */ 487 488/* 489** CAPI3REF: Device Characteristics 490** 491** The xDeviceCharacteristics method of the [sqlite3_io_methods] 492** object returns an integer which is a vector of the these 493** bit values expressing I/O characteristics of the mass storage 494** device that holds the file that the [sqlite3_io_methods] 495** refers to. 496** 497** The SQLITE_IOCAP_ATOMIC property means that all writes of 498** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 499** mean that writes of blocks that are nnn bytes in size and 500** are aligned to an address which is an integer multiple of 501** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 502** that when data is appended to a file, the data is appended 503** first then the size of the file is extended, never the other 504** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 505** information is written to disk in the same order as calls 506** to xWrite(). 507*/ 508#define SQLITE_IOCAP_ATOMIC 0x00000001 509#define SQLITE_IOCAP_ATOMIC512 0x00000002 510#define SQLITE_IOCAP_ATOMIC1K 0x00000004 511#define SQLITE_IOCAP_ATOMIC2K 0x00000008 512#define SQLITE_IOCAP_ATOMIC4K 0x00000010 513#define SQLITE_IOCAP_ATOMIC8K 0x00000020 514#define SQLITE_IOCAP_ATOMIC16K 0x00000040 515#define SQLITE_IOCAP_ATOMIC32K 0x00000080 516#define SQLITE_IOCAP_ATOMIC64K 0x00000100 517#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 518#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 519#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 520 521/* 522** CAPI3REF: File Locking Levels 523** 524** SQLite uses one of these integer values as the second 525** argument to calls it makes to the xLock() and xUnlock() methods 526** of an [sqlite3_io_methods] object. 527*/ 528#define SQLITE_LOCK_NONE 0 529#define SQLITE_LOCK_SHARED 1 530#define SQLITE_LOCK_RESERVED 2 531#define SQLITE_LOCK_PENDING 3 532#define SQLITE_LOCK_EXCLUSIVE 4 533 534/* 535** CAPI3REF: Synchronization Type Flags 536** 537** When SQLite invokes the xSync() method of an 538** [sqlite3_io_methods] object it uses a combination of 539** these integer values as the second argument. 540** 541** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 542** sync operation only needs to flush data to mass storage. Inode 543** information need not be flushed. If the lower four bits of the flag 544** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 545** If the lower four bits equal SQLITE_SYNC_FULL, that means 546** to use Mac OS X style fullsync instead of fsync(). 547** 548** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 549** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 550** settings. The [synchronous pragma] determines when calls to the 551** xSync VFS method occur and applies uniformly across all platforms. 552** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 553** energetic or rigorous or forceful the sync operations are and 554** only make a difference on Mac OSX for the default SQLite code. 555** (Third-party VFS implementations might also make the distinction 556** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 557** operating systems natively supported by SQLite, only Mac OSX 558** cares about the difference.) 559*/ 560#define SQLITE_SYNC_NORMAL 0x00002 561#define SQLITE_SYNC_FULL 0x00003 562#define SQLITE_SYNC_DATAONLY 0x00010 563 564/* 565** CAPI3REF: OS Interface Open File Handle 566** 567** An [sqlite3_file] object represents an open file in the 568** [sqlite3_vfs | OS interface layer]. Individual OS interface 569** implementations will 570** want to subclass this object by appending additional fields 571** for their own use. The pMethods entry is a pointer to an 572** [sqlite3_io_methods] object that defines methods for performing 573** I/O operations on the open file. 574*/ 575typedef struct sqlite3_file sqlite3_file; 576struct sqlite3_file { 577 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 578}; 579 580/* 581** CAPI3REF: OS Interface File Virtual Methods Object 582** 583** Every file opened by the [sqlite3_vfs] xOpen method populates an 584** [sqlite3_file] object (or, more commonly, a subclass of the 585** [sqlite3_file] object) with a pointer to an instance of this object. 586** This object defines the methods used to perform various operations 587** against the open file represented by the [sqlite3_file] object. 588** 589** If the xOpen method sets the sqlite3_file.pMethods element 590** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 591** may be invoked even if the xOpen reported that it failed. The 592** only way to prevent a call to xClose following a failed xOpen 593** is for the xOpen to set the sqlite3_file.pMethods element to NULL. 594** 595** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 596** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 597** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 598** flag may be ORed in to indicate that only the data of the file 599** and not its inode needs to be synced. 600** 601** The integer values to xLock() and xUnlock() are one of 602** <ul> 603** <li> [SQLITE_LOCK_NONE], 604** <li> [SQLITE_LOCK_SHARED], 605** <li> [SQLITE_LOCK_RESERVED], 606** <li> [SQLITE_LOCK_PENDING], or 607** <li> [SQLITE_LOCK_EXCLUSIVE]. 608** </ul> 609** xLock() increases the lock. xUnlock() decreases the lock. 610** The xCheckReservedLock() method checks whether any database connection, 611** either in this process or in some other process, is holding a RESERVED, 612** PENDING, or EXCLUSIVE lock on the file. It returns true 613** if such a lock exists and false otherwise. 614** 615** The xFileControl() method is a generic interface that allows custom 616** VFS implementations to directly control an open file using the 617** [sqlite3_file_control()] interface. The second "op" argument is an 618** integer opcode. The third argument is a generic pointer intended to 619** point to a structure that may contain arguments or space in which to 620** write return values. Potential uses for xFileControl() might be 621** functions to enable blocking locks with timeouts, to change the 622** locking strategy (for example to use dot-file locks), to inquire 623** about the status of a lock, or to break stale locks. The SQLite 624** core reserves all opcodes less than 100 for its own use. 625** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 626** Applications that define a custom xFileControl method should use opcodes 627** greater than 100 to avoid conflicts. VFS implementations should 628** return [SQLITE_NOTFOUND] for file control opcodes that they do not 629** recognize. 630** 631** The xSectorSize() method returns the sector size of the 632** device that underlies the file. The sector size is the 633** minimum write that can be performed without disturbing 634** other bytes in the file. The xDeviceCharacteristics() 635** method returns a bit vector describing behaviors of the 636** underlying device: 637** 638** <ul> 639** <li> [SQLITE_IOCAP_ATOMIC] 640** <li> [SQLITE_IOCAP_ATOMIC512] 641** <li> [SQLITE_IOCAP_ATOMIC1K] 642** <li> [SQLITE_IOCAP_ATOMIC2K] 643** <li> [SQLITE_IOCAP_ATOMIC4K] 644** <li> [SQLITE_IOCAP_ATOMIC8K] 645** <li> [SQLITE_IOCAP_ATOMIC16K] 646** <li> [SQLITE_IOCAP_ATOMIC32K] 647** <li> [SQLITE_IOCAP_ATOMIC64K] 648** <li> [SQLITE_IOCAP_SAFE_APPEND] 649** <li> [SQLITE_IOCAP_SEQUENTIAL] 650** </ul> 651** 652** The SQLITE_IOCAP_ATOMIC property means that all writes of 653** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 654** mean that writes of blocks that are nnn bytes in size and 655** are aligned to an address which is an integer multiple of 656** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 657** that when data is appended to a file, the data is appended 658** first then the size of the file is extended, never the other 659** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 660** information is written to disk in the same order as calls 661** to xWrite(). 662** 663** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 664** in the unread portions of the buffer with zeros. A VFS that 665** fails to zero-fill short reads might seem to work. However, 666** failure to zero-fill short reads will eventually lead to 667** database corruption. 668*/ 669typedef struct sqlite3_io_methods sqlite3_io_methods; 670struct sqlite3_io_methods { 671 int iVersion; 672 int (*xClose)(sqlite3_file*); 673 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 674 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 675 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 676 int (*xSync)(sqlite3_file*, int flags); 677 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 678 int (*xLock)(sqlite3_file*, int); 679 int (*xUnlock)(sqlite3_file*, int); 680 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 681 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 682 int (*xSectorSize)(sqlite3_file*); 683 int (*xDeviceCharacteristics)(sqlite3_file*); 684 /* Methods above are valid for version 1 */ 685 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 686 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 687 void (*xShmBarrier)(sqlite3_file*); 688 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 689 /* Methods above are valid for version 2 */ 690 /* Additional methods may be added in future releases */ 691}; 692 693/* 694** CAPI3REF: Standard File Control Opcodes 695** 696** These integer constants are opcodes for the xFileControl method 697** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 698** interface. 699** 700** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 701** opcode causes the xFileControl method to write the current state of 702** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 703** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 704** into an integer that the pArg argument points to. This capability 705** is used during testing and only needs to be supported when SQLITE_TEST 706** is defined. 707** 708** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 709** layer a hint of how large the database file will grow to be during the 710** current transaction. This hint is not guaranteed to be accurate but it 711** is often close. The underlying VFS might choose to preallocate database 712** file space based on this hint in order to help writes to the database 713** file run faster. 714** 715** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 716** extends and truncates the database file in chunks of a size specified 717** by the user. The fourth argument to [sqlite3_file_control()] should 718** point to an integer (type int) containing the new chunk-size to use 719** for the nominated database. Allocating database file space in large 720** chunks (say 1MB at a time), may reduce file-system fragmentation and 721** improve performance on some systems. 722** 723** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 724** to the [sqlite3_file] object associated with a particular database 725** connection. See the [sqlite3_file_control()] documentation for 726** additional information. 727** 728** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by 729** SQLite and sent to all VFSes in place of a call to the xSync method 730** when the database connection has [PRAGMA synchronous] set to OFF.)^ 731** Some specialized VFSes need this signal in order to operate correctly 732** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 733** VFSes do not need this signal and should silently ignore this opcode. 734** Applications should not call [sqlite3_file_control()] with this 735** opcode as doing so may disrupt the operation of the specialized VFSes 736** that do require it. 737*/ 738#define SQLITE_FCNTL_LOCKSTATE 1 739#define SQLITE_GET_LOCKPROXYFILE 2 740#define SQLITE_SET_LOCKPROXYFILE 3 741#define SQLITE_LAST_ERRNO 4 742#define SQLITE_FCNTL_SIZE_HINT 5 743#define SQLITE_FCNTL_CHUNK_SIZE 6 744#define SQLITE_FCNTL_FILE_POINTER 7 745#define SQLITE_FCNTL_SYNC_OMITTED 8 746 747 748/* 749** CAPI3REF: Mutex Handle 750** 751** The mutex module within SQLite defines [sqlite3_mutex] to be an 752** abstract type for a mutex object. The SQLite core never looks 753** at the internal representation of an [sqlite3_mutex]. It only 754** deals with pointers to the [sqlite3_mutex] object. 755** 756** Mutexes are created using [sqlite3_mutex_alloc()]. 757*/ 758typedef struct sqlite3_mutex sqlite3_mutex; 759 760/* 761** CAPI3REF: OS Interface Object 762** 763** An instance of the sqlite3_vfs object defines the interface between 764** the SQLite core and the underlying operating system. The "vfs" 765** in the name of the object stands for "virtual file system". 766** 767** The value of the iVersion field is initially 1 but may be larger in 768** future versions of SQLite. Additional fields may be appended to this 769** object when the iVersion value is increased. Note that the structure 770** of the sqlite3_vfs object changes in the transaction between 771** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 772** modified. 773** 774** The szOsFile field is the size of the subclassed [sqlite3_file] 775** structure used by this VFS. mxPathname is the maximum length of 776** a pathname in this VFS. 777** 778** Registered sqlite3_vfs objects are kept on a linked list formed by 779** the pNext pointer. The [sqlite3_vfs_register()] 780** and [sqlite3_vfs_unregister()] interfaces manage this list 781** in a thread-safe way. The [sqlite3_vfs_find()] interface 782** searches the list. Neither the application code nor the VFS 783** implementation should use the pNext pointer. 784** 785** The pNext field is the only field in the sqlite3_vfs 786** structure that SQLite will ever modify. SQLite will only access 787** or modify this field while holding a particular static mutex. 788** The application should never modify anything within the sqlite3_vfs 789** object once the object has been registered. 790** 791** The zName field holds the name of the VFS module. The name must 792** be unique across all VFS modules. 793** 794** ^SQLite guarantees that the zFilename parameter to xOpen 795** is either a NULL pointer or string obtained 796** from xFullPathname() with an optional suffix added. 797** ^If a suffix is added to the zFilename parameter, it will 798** consist of a single "-" character followed by no more than 799** 10 alphanumeric and/or "-" characters. 800** ^SQLite further guarantees that 801** the string will be valid and unchanged until xClose() is 802** called. Because of the previous sentence, 803** the [sqlite3_file] can safely store a pointer to the 804** filename if it needs to remember the filename for some reason. 805** If the zFilename parameter to xOpen is a NULL pointer then xOpen 806** must invent its own temporary name for the file. ^Whenever the 807** xFilename parameter is NULL it will also be the case that the 808** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 809** 810** The flags argument to xOpen() includes all bits set in 811** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 812** or [sqlite3_open16()] is used, then flags includes at least 813** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 814** If xOpen() opens a file read-only then it sets *pOutFlags to 815** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 816** 817** ^(SQLite will also add one of the following flags to the xOpen() 818** call, depending on the object being opened: 819** 820** <ul> 821** <li> [SQLITE_OPEN_MAIN_DB] 822** <li> [SQLITE_OPEN_MAIN_JOURNAL] 823** <li> [SQLITE_OPEN_TEMP_DB] 824** <li> [SQLITE_OPEN_TEMP_JOURNAL] 825** <li> [SQLITE_OPEN_TRANSIENT_DB] 826** <li> [SQLITE_OPEN_SUBJOURNAL] 827** <li> [SQLITE_OPEN_MASTER_JOURNAL] 828** <li> [SQLITE_OPEN_WAL] 829** </ul>)^ 830** 831** The file I/O implementation can use the object type flags to 832** change the way it deals with files. For example, an application 833** that does not care about crash recovery or rollback might make 834** the open of a journal file a no-op. Writes to this journal would 835** also be no-ops, and any attempt to read the journal would return 836** SQLITE_IOERR. Or the implementation might recognize that a database 837** file will be doing page-aligned sector reads and writes in a random 838** order and set up its I/O subsystem accordingly. 839** 840** SQLite might also add one of the following flags to the xOpen method: 841** 842** <ul> 843** <li> [SQLITE_OPEN_DELETEONCLOSE] 844** <li> [SQLITE_OPEN_EXCLUSIVE] 845** </ul> 846** 847** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 848** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 849** will be set for TEMP databases and their journals, transient 850** databases, and subjournals. 851** 852** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 853** with the [SQLITE_OPEN_CREATE] flag, which are both directly 854** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 855** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 856** SQLITE_OPEN_CREATE, is used to indicate that file should always 857** be created, and that it is an error if it already exists. 858** It is <i>not</i> used to indicate the file should be opened 859** for exclusive access. 860** 861** ^At least szOsFile bytes of memory are allocated by SQLite 862** to hold the [sqlite3_file] structure passed as the third 863** argument to xOpen. The xOpen method does not have to 864** allocate the structure; it should just fill it in. Note that 865** the xOpen method must set the sqlite3_file.pMethods to either 866** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 867** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 868** element will be valid after xOpen returns regardless of the success 869** or failure of the xOpen call. 870** 871** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 872** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 873** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 874** to test whether a file is at least readable. The file can be a 875** directory. 876** 877** ^SQLite will always allocate at least mxPathname+1 bytes for the 878** output buffer xFullPathname. The exact size of the output buffer 879** is also passed as a parameter to both methods. If the output buffer 880** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 881** handled as a fatal error by SQLite, vfs implementations should endeavor 882** to prevent this by setting mxPathname to a sufficiently large value. 883** 884** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 885** interfaces are not strictly a part of the filesystem, but they are 886** included in the VFS structure for completeness. 887** The xRandomness() function attempts to return nBytes bytes 888** of good-quality randomness into zOut. The return value is 889** the actual number of bytes of randomness obtained. 890** The xSleep() method causes the calling thread to sleep for at 891** least the number of microseconds given. ^The xCurrentTime() 892** method returns a Julian Day Number for the current date and time as 893** a floating point value. 894** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 895** Day Number multipled by 86400000 (the number of milliseconds in 896** a 24-hour day). 897** ^SQLite will use the xCurrentTimeInt64() method to get the current 898** date and time if that method is available (if iVersion is 2 or 899** greater and the function pointer is not NULL) and will fall back 900** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 901** 902** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 903** are not used by the SQLite core. These optional interfaces are provided 904** by some VFSes to facilitate testing of the VFS code. By overriding 905** system calls with functions under its control, a test program can 906** simulate faults and error conditions that would otherwise be difficult 907** or impossible to induce. The set of system calls that can be overridden 908** varies from one VFS to another, and from one version of the same VFS to the 909** next. Applications that use these interfaces must be prepared for any 910** or all of these interfaces to be NULL or for their behavior to change 911** from one release to the next. Applications must not attempt to access 912** any of these methods if the iVersion of the VFS is less than 3. 913*/ 914typedef struct sqlite3_vfs sqlite3_vfs; 915typedef void (*sqlite3_syscall_ptr)(void); 916struct sqlite3_vfs { 917 int iVersion; /* Structure version number (currently 3) */ 918 int szOsFile; /* Size of subclassed sqlite3_file */ 919 int mxPathname; /* Maximum file pathname length */ 920 sqlite3_vfs *pNext; /* Next registered VFS */ 921 const char *zName; /* Name of this virtual file system */ 922 void *pAppData; /* Pointer to application-specific data */ 923 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 924 int flags, int *pOutFlags); 925 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 926 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 927 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 928 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 929 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 930 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 931 void (*xDlClose)(sqlite3_vfs*, void*); 932 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 933 int (*xSleep)(sqlite3_vfs*, int microseconds); 934 int (*xCurrentTime)(sqlite3_vfs*, double*); 935 int (*xGetLastError)(sqlite3_vfs*, int, char *); 936 /* 937 ** The methods above are in version 1 of the sqlite_vfs object 938 ** definition. Those that follow are added in version 2 or later 939 */ 940 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 941 /* 942 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 943 ** Those below are for version 3 and greater. 944 */ 945 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 946 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 947 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 948 /* 949 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 950 ** New fields may be appended in figure versions. The iVersion 951 ** value will increment whenever this happens. 952 */ 953}; 954 955/* 956** CAPI3REF: Flags for the xAccess VFS method 957** 958** These integer constants can be used as the third parameter to 959** the xAccess method of an [sqlite3_vfs] object. They determine 960** what kind of permissions the xAccess method is looking for. 961** With SQLITE_ACCESS_EXISTS, the xAccess method 962** simply checks whether the file exists. 963** With SQLITE_ACCESS_READWRITE, the xAccess method 964** checks whether the named directory is both readable and writable 965** (in other words, if files can be added, removed, and renamed within 966** the directory). 967** The SQLITE_ACCESS_READWRITE constant is currently used only by the 968** [temp_store_directory pragma], though this could change in a future 969** release of SQLite. 970** With SQLITE_ACCESS_READ, the xAccess method 971** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 972** currently unused, though it might be used in a future release of 973** SQLite. 974*/ 975#define SQLITE_ACCESS_EXISTS 0 976#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 977#define SQLITE_ACCESS_READ 2 /* Unused */ 978 979/* 980** CAPI3REF: Flags for the xShmLock VFS method 981** 982** These integer constants define the various locking operations 983** allowed by the xShmLock method of [sqlite3_io_methods]. The 984** following are the only legal combinations of flags to the 985** xShmLock method: 986** 987** <ul> 988** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 989** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 990** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 991** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 992** </ul> 993** 994** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 995** was given no the corresponding lock. 996** 997** The xShmLock method can transition between unlocked and SHARED or 998** between unlocked and EXCLUSIVE. It cannot transition between SHARED 999** and EXCLUSIVE. 1000*/ 1001#define SQLITE_SHM_UNLOCK 1 1002#define SQLITE_SHM_LOCK 2 1003#define SQLITE_SHM_SHARED 4 1004#define SQLITE_SHM_EXCLUSIVE 8 1005 1006/* 1007** CAPI3REF: Maximum xShmLock index 1008** 1009** The xShmLock method on [sqlite3_io_methods] may use values 1010** between 0 and this upper bound as its "offset" argument. 1011** The SQLite core will never attempt to acquire or release a 1012** lock outside of this range 1013*/ 1014#define SQLITE_SHM_NLOCK 8 1015 1016 1017/* 1018** CAPI3REF: Initialize The SQLite Library 1019** 1020** ^The sqlite3_initialize() routine initializes the 1021** SQLite library. ^The sqlite3_shutdown() routine 1022** deallocates any resources that were allocated by sqlite3_initialize(). 1023** These routines are designed to aid in process initialization and 1024** shutdown on embedded systems. Workstation applications using 1025** SQLite normally do not need to invoke either of these routines. 1026** 1027** A call to sqlite3_initialize() is an "effective" call if it is 1028** the first time sqlite3_initialize() is invoked during the lifetime of 1029** the process, or if it is the first time sqlite3_initialize() is invoked 1030** following a call to sqlite3_shutdown(). ^(Only an effective call 1031** of sqlite3_initialize() does any initialization. All other calls 1032** are harmless no-ops.)^ 1033** 1034** A call to sqlite3_shutdown() is an "effective" call if it is the first 1035** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1036** an effective call to sqlite3_shutdown() does any deinitialization. 1037** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1038** 1039** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1040** is not. The sqlite3_shutdown() interface must only be called from a 1041** single thread. All open [database connections] must be closed and all 1042** other SQLite resources must be deallocated prior to invoking 1043** sqlite3_shutdown(). 1044** 1045** Among other things, ^sqlite3_initialize() will invoke 1046** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1047** will invoke sqlite3_os_end(). 1048** 1049** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1050** ^If for some reason, sqlite3_initialize() is unable to initialize 1051** the library (perhaps it is unable to allocate a needed resource such 1052** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1053** 1054** ^The sqlite3_initialize() routine is called internally by many other 1055** SQLite interfaces so that an application usually does not need to 1056** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1057** calls sqlite3_initialize() so the SQLite library will be automatically 1058** initialized when [sqlite3_open()] is called if it has not be initialized 1059** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1060** compile-time option, then the automatic calls to sqlite3_initialize() 1061** are omitted and the application must call sqlite3_initialize() directly 1062** prior to using any other SQLite interface. For maximum portability, 1063** it is recommended that applications always invoke sqlite3_initialize() 1064** directly prior to using any other SQLite interface. Future releases 1065** of SQLite may require this. In other words, the behavior exhibited 1066** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1067** default behavior in some future release of SQLite. 1068** 1069** The sqlite3_os_init() routine does operating-system specific 1070** initialization of the SQLite library. The sqlite3_os_end() 1071** routine undoes the effect of sqlite3_os_init(). Typical tasks 1072** performed by these routines include allocation or deallocation 1073** of static resources, initialization of global variables, 1074** setting up a default [sqlite3_vfs] module, or setting up 1075** a default configuration using [sqlite3_config()]. 1076** 1077** The application should never invoke either sqlite3_os_init() 1078** or sqlite3_os_end() directly. The application should only invoke 1079** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1080** interface is called automatically by sqlite3_initialize() and 1081** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1082** implementations for sqlite3_os_init() and sqlite3_os_end() 1083** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1084** When [custom builds | built for other platforms] 1085** (using the [SQLITE_OS_OTHER=1] compile-time 1086** option) the application must supply a suitable implementation for 1087** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1088** implementation of sqlite3_os_init() or sqlite3_os_end() 1089** must return [SQLITE_OK] on success and some other [error code] upon 1090** failure. 1091*/ 1092SQLITE_API int sqlite3_initialize(void); 1093SQLITE_API int sqlite3_shutdown(void); 1094SQLITE_API int sqlite3_os_init(void); 1095SQLITE_API int sqlite3_os_end(void); 1096 1097/* 1098** CAPI3REF: Configuring The SQLite Library 1099** 1100** The sqlite3_config() interface is used to make global configuration 1101** changes to SQLite in order to tune SQLite to the specific needs of 1102** the application. The default configuration is recommended for most 1103** applications and so this routine is usually not necessary. It is 1104** provided to support rare applications with unusual needs. 1105** 1106** The sqlite3_config() interface is not threadsafe. The application 1107** must insure that no other SQLite interfaces are invoked by other 1108** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1109** may only be invoked prior to library initialization using 1110** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1111** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1112** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1113** Note, however, that ^sqlite3_config() can be called as part of the 1114** implementation of an application-defined [sqlite3_os_init()]. 1115** 1116** The first argument to sqlite3_config() is an integer 1117** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines 1118** what property of SQLite is to be configured. Subsequent arguments 1119** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] 1120** in the first argument. 1121** 1122** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1123** ^If the option is unknown or SQLite is unable to set the option 1124** then this routine returns a non-zero [error code]. 1125*/ 1126SQLITE_API int sqlite3_config(int, ...); 1127 1128/* 1129** CAPI3REF: Configure database connections 1130** 1131** The sqlite3_db_config() interface is used to make configuration 1132** changes to a [database connection]. The interface is similar to 1133** [sqlite3_config()] except that the changes apply to a single 1134** [database connection] (specified in the first argument). 1135** 1136** The second argument to sqlite3_db_config(D,V,...) is the 1137** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1138** that indicates what aspect of the [database connection] is being configured. 1139** Subsequent arguments vary depending on the configuration verb. 1140** 1141** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1142** the call is considered successful. 1143*/ 1144SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1145 1146/* 1147** CAPI3REF: Memory Allocation Routines 1148** 1149** An instance of this object defines the interface between SQLite 1150** and low-level memory allocation routines. 1151** 1152** This object is used in only one place in the SQLite interface. 1153** A pointer to an instance of this object is the argument to 1154** [sqlite3_config()] when the configuration option is 1155** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1156** By creating an instance of this object 1157** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1158** during configuration, an application can specify an alternative 1159** memory allocation subsystem for SQLite to use for all of its 1160** dynamic memory needs. 1161** 1162** Note that SQLite comes with several [built-in memory allocators] 1163** that are perfectly adequate for the overwhelming majority of applications 1164** and that this object is only useful to a tiny minority of applications 1165** with specialized memory allocation requirements. This object is 1166** also used during testing of SQLite in order to specify an alternative 1167** memory allocator that simulates memory out-of-memory conditions in 1168** order to verify that SQLite recovers gracefully from such 1169** conditions. 1170** 1171** The xMalloc and xFree methods must work like the 1172** malloc() and free() functions from the standard C library. 1173** The xRealloc method must work like realloc() from the standard C library 1174** with the exception that if the second argument to xRealloc is zero, 1175** xRealloc must be a no-op - it must not perform any allocation or 1176** deallocation. ^SQLite guarantees that the second argument to 1177** xRealloc is always a value returned by a prior call to xRoundup. 1178** And so in cases where xRoundup always returns a positive number, 1179** xRealloc can perform exactly as the standard library realloc() and 1180** still be in compliance with this specification. 1181** 1182** xSize should return the allocated size of a memory allocation 1183** previously obtained from xMalloc or xRealloc. The allocated size 1184** is always at least as big as the requested size but may be larger. 1185** 1186** The xRoundup method returns what would be the allocated size of 1187** a memory allocation given a particular requested size. Most memory 1188** allocators round up memory allocations at least to the next multiple 1189** of 8. Some allocators round up to a larger multiple or to a power of 2. 1190** Every memory allocation request coming in through [sqlite3_malloc()] 1191** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1192** that causes the corresponding memory allocation to fail. 1193** 1194** The xInit method initializes the memory allocator. (For example, 1195** it might allocate any require mutexes or initialize internal data 1196** structures. The xShutdown method is invoked (indirectly) by 1197** [sqlite3_shutdown()] and should deallocate any resources acquired 1198** by xInit. The pAppData pointer is used as the only parameter to 1199** xInit and xShutdown. 1200** 1201** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1202** the xInit method, so the xInit method need not be threadsafe. The 1203** xShutdown method is only called from [sqlite3_shutdown()] so it does 1204** not need to be threadsafe either. For all other methods, SQLite 1205** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1206** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1207** it is by default) and so the methods are automatically serialized. 1208** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1209** methods must be threadsafe or else make their own arrangements for 1210** serialization. 1211** 1212** SQLite will never invoke xInit() more than once without an intervening 1213** call to xShutdown(). 1214*/ 1215typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1216struct sqlite3_mem_methods { 1217 void *(*xMalloc)(int); /* Memory allocation function */ 1218 void (*xFree)(void*); /* Free a prior allocation */ 1219 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1220 int (*xSize)(void*); /* Return the size of an allocation */ 1221 int (*xRoundup)(int); /* Round up request size to allocation size */ 1222 int (*xInit)(void*); /* Initialize the memory allocator */ 1223 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1224 void *pAppData; /* Argument to xInit() and xShutdown() */ 1225}; 1226 1227/* 1228** CAPI3REF: Configuration Options 1229** 1230** These constants are the available integer configuration options that 1231** can be passed as the first argument to the [sqlite3_config()] interface. 1232** 1233** New configuration options may be added in future releases of SQLite. 1234** Existing configuration options might be discontinued. Applications 1235** should check the return code from [sqlite3_config()] to make sure that 1236** the call worked. The [sqlite3_config()] interface will return a 1237** non-zero [error code] if a discontinued or unsupported configuration option 1238** is invoked. 1239** 1240** <dl> 1241** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1242** <dd>There are no arguments to this option. ^This option sets the 1243** [threading mode] to Single-thread. In other words, it disables 1244** all mutexing and puts SQLite into a mode where it can only be used 1245** by a single thread. ^If SQLite is compiled with 1246** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1247** it is not possible to change the [threading mode] from its default 1248** value of Single-thread and so [sqlite3_config()] will return 1249** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1250** configuration option.</dd> 1251** 1252** <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1253** <dd>There are no arguments to this option. ^This option sets the 1254** [threading mode] to Multi-thread. In other words, it disables 1255** mutexing on [database connection] and [prepared statement] objects. 1256** The application is responsible for serializing access to 1257** [database connections] and [prepared statements]. But other mutexes 1258** are enabled so that SQLite will be safe to use in a multi-threaded 1259** environment as long as no two threads attempt to use the same 1260** [database connection] at the same time. ^If SQLite is compiled with 1261** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1262** it is not possible to set the Multi-thread [threading mode] and 1263** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1264** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1265** 1266** <dt>SQLITE_CONFIG_SERIALIZED</dt> 1267** <dd>There are no arguments to this option. ^This option sets the 1268** [threading mode] to Serialized. In other words, this option enables 1269** all mutexes including the recursive 1270** mutexes on [database connection] and [prepared statement] objects. 1271** In this mode (which is the default when SQLite is compiled with 1272** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1273** to [database connections] and [prepared statements] so that the 1274** application is free to use the same [database connection] or the 1275** same [prepared statement] in different threads at the same time. 1276** ^If SQLite is compiled with 1277** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1278** it is not possible to set the Serialized [threading mode] and 1279** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1280** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1281** 1282** <dt>SQLITE_CONFIG_MALLOC</dt> 1283** <dd> ^(This option takes a single argument which is a pointer to an 1284** instance of the [sqlite3_mem_methods] structure. The argument specifies 1285** alternative low-level memory allocation routines to be used in place of 1286** the memory allocation routines built into SQLite.)^ ^SQLite makes 1287** its own private copy of the content of the [sqlite3_mem_methods] structure 1288** before the [sqlite3_config()] call returns.</dd> 1289** 1290** <dt>SQLITE_CONFIG_GETMALLOC</dt> 1291** <dd> ^(This option takes a single argument which is a pointer to an 1292** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1293** structure is filled with the currently defined memory allocation routines.)^ 1294** This option can be used to overload the default memory allocation 1295** routines with a wrapper that simulations memory allocation failure or 1296** tracks memory usage, for example. </dd> 1297** 1298** <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1299** <dd> ^This option takes single argument of type int, interpreted as a 1300** boolean, which enables or disables the collection of memory allocation 1301** statistics. ^(When memory allocation statistics are disabled, the 1302** following SQLite interfaces become non-operational: 1303** <ul> 1304** <li> [sqlite3_memory_used()] 1305** <li> [sqlite3_memory_highwater()] 1306** <li> [sqlite3_soft_heap_limit64()] 1307** <li> [sqlite3_status()] 1308** </ul>)^ 1309** ^Memory allocation statistics are enabled by default unless SQLite is 1310** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1311** allocation statistics are disabled by default. 1312** </dd> 1313** 1314** <dt>SQLITE_CONFIG_SCRATCH</dt> 1315** <dd> ^This option specifies a static memory buffer that SQLite can use for 1316** scratch memory. There are three arguments: A pointer an 8-byte 1317** aligned memory buffer from which the scratch allocations will be 1318** drawn, the size of each scratch allocation (sz), 1319** and the maximum number of scratch allocations (N). The sz 1320** argument must be a multiple of 16. 1321** The first argument must be a pointer to an 8-byte aligned buffer 1322** of at least sz*N bytes of memory. 1323** ^SQLite will use no more than two scratch buffers per thread. So 1324** N should be set to twice the expected maximum number of threads. 1325** ^SQLite will never require a scratch buffer that is more than 6 1326** times the database page size. ^If SQLite needs needs additional 1327** scratch memory beyond what is provided by this configuration option, then 1328** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1329** 1330** <dt>SQLITE_CONFIG_PAGECACHE</dt> 1331** <dd> ^This option specifies a static memory buffer that SQLite can use for 1332** the database page cache with the default page cache implemenation. 1333** This configuration should not be used if an application-define page 1334** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. 1335** There are three arguments to this option: A pointer to 8-byte aligned 1336** memory, the size of each page buffer (sz), and the number of pages (N). 1337** The sz argument should be the size of the largest database page 1338** (a power of two between 512 and 32768) plus a little extra for each 1339** page header. ^The page header size is 20 to 40 bytes depending on 1340** the host architecture. ^It is harmless, apart from the wasted memory, 1341** to make sz a little too large. The first 1342** argument should point to an allocation of at least sz*N bytes of memory. 1343** ^SQLite will use the memory provided by the first argument to satisfy its 1344** memory needs for the first N pages that it adds to cache. ^If additional 1345** page cache memory is needed beyond what is provided by this option, then 1346** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1347** The pointer in the first argument must 1348** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1349** will be undefined.</dd> 1350** 1351** <dt>SQLITE_CONFIG_HEAP</dt> 1352** <dd> ^This option specifies a static memory buffer that SQLite will use 1353** for all of its dynamic memory allocation needs beyond those provided 1354** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1355** There are three arguments: An 8-byte aligned pointer to the memory, 1356** the number of bytes in the memory buffer, and the minimum allocation size. 1357** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1358** to using its default memory allocator (the system malloc() implementation), 1359** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1360** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1361** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1362** allocator is engaged to handle all of SQLites memory allocation needs. 1363** The first pointer (the memory pointer) must be aligned to an 8-byte 1364** boundary or subsequent behavior of SQLite will be undefined. 1365** The minimum allocation size is capped at 2^12. Reasonable values 1366** for the minimum allocation size are 2^5 through 2^8.</dd> 1367** 1368** <dt>SQLITE_CONFIG_MUTEX</dt> 1369** <dd> ^(This option takes a single argument which is a pointer to an 1370** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1371** alternative low-level mutex routines to be used in place 1372** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1373** content of the [sqlite3_mutex_methods] structure before the call to 1374** [sqlite3_config()] returns. ^If SQLite is compiled with 1375** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1376** the entire mutexing subsystem is omitted from the build and hence calls to 1377** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1378** return [SQLITE_ERROR].</dd> 1379** 1380** <dt>SQLITE_CONFIG_GETMUTEX</dt> 1381** <dd> ^(This option takes a single argument which is a pointer to an 1382** instance of the [sqlite3_mutex_methods] structure. The 1383** [sqlite3_mutex_methods] 1384** structure is filled with the currently defined mutex routines.)^ 1385** This option can be used to overload the default mutex allocation 1386** routines with a wrapper used to track mutex usage for performance 1387** profiling or testing, for example. ^If SQLite is compiled with 1388** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1389** the entire mutexing subsystem is omitted from the build and hence calls to 1390** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1391** return [SQLITE_ERROR].</dd> 1392** 1393** <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1394** <dd> ^(This option takes two arguments that determine the default 1395** memory allocation for the lookaside memory allocator on each 1396** [database connection]. The first argument is the 1397** size of each lookaside buffer slot and the second is the number of 1398** slots allocated to each database connection.)^ ^(This option sets the 1399** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1400** verb to [sqlite3_db_config()] can be used to change the lookaside 1401** configuration on individual connections.)^ </dd> 1402** 1403** <dt>SQLITE_CONFIG_PCACHE</dt> 1404** <dd> ^(This option takes a single argument which is a pointer to 1405** an [sqlite3_pcache_methods] object. This object specifies the interface 1406** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1407** object and uses it for page cache memory allocations.</dd> 1408** 1409** <dt>SQLITE_CONFIG_GETPCACHE</dt> 1410** <dd> ^(This option takes a single argument which is a pointer to an 1411** [sqlite3_pcache_methods] object. SQLite copies of the current 1412** page cache implementation into that object.)^ </dd> 1413** 1414** <dt>SQLITE_CONFIG_LOG</dt> 1415** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1416** function with a call signature of void(*)(void*,int,const char*), 1417** and a pointer to void. ^If the function pointer is not NULL, it is 1418** invoked by [sqlite3_log()] to process each logging event. ^If the 1419** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1420** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1421** passed through as the first parameter to the application-defined logger 1422** function whenever that function is invoked. ^The second parameter to 1423** the logger function is a copy of the first parameter to the corresponding 1424** [sqlite3_log()] call and is intended to be a [result code] or an 1425** [extended result code]. ^The third parameter passed to the logger is 1426** log message after formatting via [sqlite3_snprintf()]. 1427** The SQLite logging interface is not reentrant; the logger function 1428** supplied by the application must not invoke any SQLite interface. 1429** In a multi-threaded application, the application-defined logger 1430** function must be threadsafe. </dd> 1431** 1432** </dl> 1433*/ 1434#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1435#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1436#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1437#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1438#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1439#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1440#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1441#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1442#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1443#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1444#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1445/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1446#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1447#define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ 1448#define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ 1449#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1450 1451/* 1452** CAPI3REF: Database Connection Configuration Options 1453** 1454** These constants are the available integer configuration options that 1455** can be passed as the second argument to the [sqlite3_db_config()] interface. 1456** 1457** New configuration options may be added in future releases of SQLite. 1458** Existing configuration options might be discontinued. Applications 1459** should check the return code from [sqlite3_db_config()] to make sure that 1460** the call worked. ^The [sqlite3_db_config()] interface will return a 1461** non-zero [error code] if a discontinued or unsupported configuration option 1462** is invoked. 1463** 1464** <dl> 1465** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1466** <dd> ^This option takes three additional arguments that determine the 1467** [lookaside memory allocator] configuration for the [database connection]. 1468** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1469** pointer to a memory buffer to use for lookaside memory. 1470** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1471** may be NULL in which case SQLite will allocate the 1472** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1473** size of each lookaside buffer slot. ^The third argument is the number of 1474** slots. The size of the buffer in the first argument must be greater than 1475** or equal to the product of the second and third arguments. The buffer 1476** must be aligned to an 8-byte boundary. ^If the second argument to 1477** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1478** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1479** configuration for a database connection can only be changed when that 1480** connection is not currently using lookaside memory, or in other words 1481** when the "current value" returned by 1482** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1483** Any attempt to change the lookaside memory configuration when lookaside 1484** memory is in use leaves the configuration unchanged and returns 1485** [SQLITE_BUSY].)^</dd> 1486** 1487** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1488** <dd> ^This option is used to enable or disable the enforcement of 1489** [foreign key constraints]. There should be two additional arguments. 1490** The first argument is an integer which is 0 to disable FK enforcement, 1491** positive to enable FK enforcement or negative to leave FK enforcement 1492** unchanged. The second parameter is a pointer to an integer into which 1493** is written 0 or 1 to indicate whether FK enforcement is off or on 1494** following this call. The second parameter may be a NULL pointer, in 1495** which case the FK enforcement setting is not reported back. </dd> 1496** 1497** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1498** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1499** There should be two additional arguments. 1500** The first argument is an integer which is 0 to disable triggers, 1501** positive to enable triggers or negative to leave the setting unchanged. 1502** The second parameter is a pointer to an integer into which 1503** is written 0 or 1 to indicate whether triggers are disabled or enabled 1504** following this call. The second parameter may be a NULL pointer, in 1505** which case the trigger setting is not reported back. </dd> 1506** 1507** </dl> 1508*/ 1509#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1510#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1511#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1512 1513 1514/* 1515** CAPI3REF: Enable Or Disable Extended Result Codes 1516** 1517** ^The sqlite3_extended_result_codes() routine enables or disables the 1518** [extended result codes] feature of SQLite. ^The extended result 1519** codes are disabled by default for historical compatibility. 1520*/ 1521SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 1522 1523/* 1524** CAPI3REF: Last Insert Rowid 1525** 1526** ^Each entry in an SQLite table has a unique 64-bit signed 1527** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1528** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1529** names are not also used by explicitly declared columns. ^If 1530** the table has a column of type [INTEGER PRIMARY KEY] then that column 1531** is another alias for the rowid. 1532** 1533** ^This routine returns the [rowid] of the most recent 1534** successful [INSERT] into the database from the [database connection] 1535** in the first argument. ^If no successful [INSERT]s 1536** have ever occurred on that database connection, zero is returned. 1537** 1538** ^(If an [INSERT] occurs within a trigger, then the [rowid] of the inserted 1539** row is returned by this routine as long as the trigger is running. 1540** But once the trigger terminates, the value returned by this routine 1541** reverts to the last value inserted before the trigger fired.)^ 1542** 1543** ^An [INSERT] that fails due to a constraint violation is not a 1544** successful [INSERT] and does not change the value returned by this 1545** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1546** and INSERT OR ABORT make no changes to the return value of this 1547** routine when their insertion fails. ^(When INSERT OR REPLACE 1548** encounters a constraint violation, it does not fail. The 1549** INSERT continues to completion after deleting rows that caused 1550** the constraint problem so INSERT OR REPLACE will always change 1551** the return value of this interface.)^ 1552** 1553** ^For the purposes of this routine, an [INSERT] is considered to 1554** be successful even if it is subsequently rolled back. 1555** 1556** This function is accessible to SQL statements via the 1557** [last_insert_rowid() SQL function]. 1558** 1559** If a separate thread performs a new [INSERT] on the same 1560** database connection while the [sqlite3_last_insert_rowid()] 1561** function is running and thus changes the last insert [rowid], 1562** then the value returned by [sqlite3_last_insert_rowid()] is 1563** unpredictable and might not equal either the old or the new 1564** last insert [rowid]. 1565*/ 1566SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1567 1568/* 1569** CAPI3REF: Count The Number Of Rows Modified 1570** 1571** ^This function returns the number of database rows that were changed 1572** or inserted or deleted by the most recently completed SQL statement 1573** on the [database connection] specified by the first parameter. 1574** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1575** or [DELETE] statement are counted. Auxiliary changes caused by 1576** triggers or [foreign key actions] are not counted.)^ Use the 1577** [sqlite3_total_changes()] function to find the total number of changes 1578** including changes caused by triggers and foreign key actions. 1579** 1580** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1581** are not counted. Only real table changes are counted. 1582** 1583** ^(A "row change" is a change to a single row of a single table 1584** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1585** are changed as side effects of [REPLACE] constraint resolution, 1586** rollback, ABORT processing, [DROP TABLE], or by any other 1587** mechanisms do not count as direct row changes.)^ 1588** 1589** A "trigger context" is a scope of execution that begins and 1590** ends with the script of a [CREATE TRIGGER | trigger]. 1591** Most SQL statements are 1592** evaluated outside of any trigger. This is the "top level" 1593** trigger context. If a trigger fires from the top level, a 1594** new trigger context is entered for the duration of that one 1595** trigger. Subtriggers create subcontexts for their duration. 1596** 1597** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1598** not create a new trigger context. 1599** 1600** ^This function returns the number of direct row changes in the 1601** most recent INSERT, UPDATE, or DELETE statement within the same 1602** trigger context. 1603** 1604** ^Thus, when called from the top level, this function returns the 1605** number of changes in the most recent INSERT, UPDATE, or DELETE 1606** that also occurred at the top level. ^(Within the body of a trigger, 1607** the sqlite3_changes() interface can be called to find the number of 1608** changes in the most recently completed INSERT, UPDATE, or DELETE 1609** statement within the body of the same trigger. 1610** However, the number returned does not include changes 1611** caused by subtriggers since those have their own context.)^ 1612** 1613** See also the [sqlite3_total_changes()] interface, the 1614** [count_changes pragma], and the [changes() SQL function]. 1615** 1616** If a separate thread makes changes on the same database connection 1617** while [sqlite3_changes()] is running then the value returned 1618** is unpredictable and not meaningful. 1619*/ 1620SQLITE_API int sqlite3_changes(sqlite3*); 1621 1622/* 1623** CAPI3REF: Total Number Of Rows Modified 1624** 1625** ^This function returns the number of row changes caused by [INSERT], 1626** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1627** ^(The count returned by sqlite3_total_changes() includes all changes 1628** from all [CREATE TRIGGER | trigger] contexts and changes made by 1629** [foreign key actions]. However, 1630** the count does not include changes used to implement [REPLACE] constraints, 1631** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1632** count does not include rows of views that fire an [INSTEAD OF trigger], 1633** though if the INSTEAD OF trigger makes changes of its own, those changes 1634** are counted.)^ 1635** ^The sqlite3_total_changes() function counts the changes as soon as 1636** the statement that makes them is completed (when the statement handle 1637** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1638** 1639** See also the [sqlite3_changes()] interface, the 1640** [count_changes pragma], and the [total_changes() SQL function]. 1641** 1642** If a separate thread makes changes on the same database connection 1643** while [sqlite3_total_changes()] is running then the value 1644** returned is unpredictable and not meaningful. 1645*/ 1646SQLITE_API int sqlite3_total_changes(sqlite3*); 1647 1648/* 1649** CAPI3REF: Interrupt A Long-Running Query 1650** 1651** ^This function causes any pending database operation to abort and 1652** return at its earliest opportunity. This routine is typically 1653** called in response to a user action such as pressing "Cancel" 1654** or Ctrl-C where the user wants a long query operation to halt 1655** immediately. 1656** 1657** ^It is safe to call this routine from a thread different from the 1658** thread that is currently running the database operation. But it 1659** is not safe to call this routine with a [database connection] that 1660** is closed or might close before sqlite3_interrupt() returns. 1661** 1662** ^If an SQL operation is very nearly finished at the time when 1663** sqlite3_interrupt() is called, then it might not have an opportunity 1664** to be interrupted and might continue to completion. 1665** 1666** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1667** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1668** that is inside an explicit transaction, then the entire transaction 1669** will be rolled back automatically. 1670** 1671** ^The sqlite3_interrupt(D) call is in effect until all currently running 1672** SQL statements on [database connection] D complete. ^Any new SQL statements 1673** that are started after the sqlite3_interrupt() call and before the 1674** running statements reaches zero are interrupted as if they had been 1675** running prior to the sqlite3_interrupt() call. ^New SQL statements 1676** that are started after the running statement count reaches zero are 1677** not effected by the sqlite3_interrupt(). 1678** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1679** SQL statements is a no-op and has no effect on SQL statements 1680** that are started after the sqlite3_interrupt() call returns. 1681** 1682** If the database connection closes while [sqlite3_interrupt()] 1683** is running then bad things will likely happen. 1684*/ 1685SQLITE_API void sqlite3_interrupt(sqlite3*); 1686 1687/* 1688** CAPI3REF: Determine If An SQL Statement Is Complete 1689** 1690** These routines are useful during command-line input to determine if the 1691** currently entered text seems to form a complete SQL statement or 1692** if additional input is needed before sending the text into 1693** SQLite for parsing. ^These routines return 1 if the input string 1694** appears to be a complete SQL statement. ^A statement is judged to be 1695** complete if it ends with a semicolon token and is not a prefix of a 1696** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1697** string literals or quoted identifier names or comments are not 1698** independent tokens (they are part of the token in which they are 1699** embedded) and thus do not count as a statement terminator. ^Whitespace 1700** and comments that follow the final semicolon are ignored. 1701** 1702** ^These routines return 0 if the statement is incomplete. ^If a 1703** memory allocation fails, then SQLITE_NOMEM is returned. 1704** 1705** ^These routines do not parse the SQL statements thus 1706** will not detect syntactically incorrect SQL. 1707** 1708** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 1709** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 1710** automatically by sqlite3_complete16(). If that initialization fails, 1711** then the return value from sqlite3_complete16() will be non-zero 1712** regardless of whether or not the input SQL is complete.)^ 1713** 1714** The input to [sqlite3_complete()] must be a zero-terminated 1715** UTF-8 string. 1716** 1717** The input to [sqlite3_complete16()] must be a zero-terminated 1718** UTF-16 string in native byte order. 1719*/ 1720SQLITE_API int sqlite3_complete(const char *sql); 1721SQLITE_API int sqlite3_complete16(const void *sql); 1722 1723/* 1724** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 1725** 1726** ^This routine sets a callback function that might be invoked whenever 1727** an attempt is made to open a database table that another thread 1728** or process has locked. 1729** 1730** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1731** is returned immediately upon encountering the lock. ^If the busy callback 1732** is not NULL, then the callback might be invoked with two arguments. 1733** 1734** ^The first argument to the busy handler is a copy of the void* pointer which 1735** is the third argument to sqlite3_busy_handler(). ^The second argument to 1736** the busy handler callback is the number of times that the busy handler has 1737** been invoked for this locking event. ^If the 1738** busy callback returns 0, then no additional attempts are made to 1739** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1740** ^If the callback returns non-zero, then another attempt 1741** is made to open the database for reading and the cycle repeats. 1742** 1743** The presence of a busy handler does not guarantee that it will be invoked 1744** when there is lock contention. ^If SQLite determines that invoking the busy 1745** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1746** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1747** Consider a scenario where one process is holding a read lock that 1748** it is trying to promote to a reserved lock and 1749** a second process is holding a reserved lock that it is trying 1750** to promote to an exclusive lock. The first process cannot proceed 1751** because it is blocked by the second and the second process cannot 1752** proceed because it is blocked by the first. If both processes 1753** invoke the busy handlers, neither will make any progress. Therefore, 1754** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1755** will induce the first process to release its read lock and allow 1756** the second process to proceed. 1757** 1758** ^The default busy callback is NULL. 1759** 1760** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1761** when SQLite is in the middle of a large transaction where all the 1762** changes will not fit into the in-memory cache. SQLite will 1763** already hold a RESERVED lock on the database file, but it needs 1764** to promote this lock to EXCLUSIVE so that it can spill cache 1765** pages into the database file without harm to concurrent 1766** readers. ^If it is unable to promote the lock, then the in-memory 1767** cache will be left in an inconsistent state and so the error 1768** code is promoted from the relatively benign [SQLITE_BUSY] to 1769** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 1770** forces an automatic rollback of the changes. See the 1771** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1772** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1773** this is important. 1774** 1775** ^(There can only be a single busy handler defined for each 1776** [database connection]. Setting a new busy handler clears any 1777** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 1778** will also set or clear the busy handler. 1779** 1780** The busy callback should not take any actions which modify the 1781** database connection that invoked the busy handler. Any such actions 1782** result in undefined behavior. 1783** 1784** A busy handler must not close the database connection 1785** or [prepared statement] that invoked the busy handler. 1786*/ 1787SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1788 1789/* 1790** CAPI3REF: Set A Busy Timeout 1791** 1792** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1793** for a specified amount of time when a table is locked. ^The handler 1794** will sleep multiple times until at least "ms" milliseconds of sleeping 1795** have accumulated. ^After at least "ms" milliseconds of sleeping, 1796** the handler returns 0 which causes [sqlite3_step()] to return 1797** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1798** 1799** ^Calling this routine with an argument less than or equal to zero 1800** turns off all busy handlers. 1801** 1802** ^(There can only be a single busy handler for a particular 1803** [database connection] any any given moment. If another busy handler 1804** was defined (using [sqlite3_busy_handler()]) prior to calling 1805** this routine, that other busy handler is cleared.)^ 1806*/ 1807SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 1808 1809/* 1810** CAPI3REF: Convenience Routines For Running Queries 1811** 1812** This is a legacy interface that is preserved for backwards compatibility. 1813** Use of this interface is not recommended. 1814** 1815** Definition: A <b>result table</b> is memory data structure created by the 1816** [sqlite3_get_table()] interface. A result table records the 1817** complete query results from one or more queries. 1818** 1819** The table conceptually has a number of rows and columns. But 1820** these numbers are not part of the result table itself. These 1821** numbers are obtained separately. Let N be the number of rows 1822** and M be the number of columns. 1823** 1824** A result table is an array of pointers to zero-terminated UTF-8 strings. 1825** There are (N+1)*M elements in the array. The first M pointers point 1826** to zero-terminated strings that contain the names of the columns. 1827** The remaining entries all point to query results. NULL values result 1828** in NULL pointers. All other values are in their UTF-8 zero-terminated 1829** string representation as returned by [sqlite3_column_text()]. 1830** 1831** A result table might consist of one or more memory allocations. 1832** It is not safe to pass a result table directly to [sqlite3_free()]. 1833** A result table should be deallocated using [sqlite3_free_table()]. 1834** 1835** ^(As an example of the result table format, suppose a query result 1836** is as follows: 1837** 1838** <blockquote><pre> 1839** Name | Age 1840** ----------------------- 1841** Alice | 43 1842** Bob | 28 1843** Cindy | 21 1844** </pre></blockquote> 1845** 1846** There are two column (M==2) and three rows (N==3). Thus the 1847** result table has 8 entries. Suppose the result table is stored 1848** in an array names azResult. Then azResult holds this content: 1849** 1850** <blockquote><pre> 1851** azResult[0] = "Name"; 1852** azResult[1] = "Age"; 1853** azResult[2] = "Alice"; 1854** azResult[3] = "43"; 1855** azResult[4] = "Bob"; 1856** azResult[5] = "28"; 1857** azResult[6] = "Cindy"; 1858** azResult[7] = "21"; 1859** </pre></blockquote>)^ 1860** 1861** ^The sqlite3_get_table() function evaluates one or more 1862** semicolon-separated SQL statements in the zero-terminated UTF-8 1863** string of its 2nd parameter and returns a result table to the 1864** pointer given in its 3rd parameter. 1865** 1866** After the application has finished with the result from sqlite3_get_table(), 1867** it must pass the result table pointer to sqlite3_free_table() in order to 1868** release the memory that was malloced. Because of the way the 1869** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1870** function must not try to call [sqlite3_free()] directly. Only 1871** [sqlite3_free_table()] is able to release the memory properly and safely. 1872** 1873** The sqlite3_get_table() interface is implemented as a wrapper around 1874** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1875** to any internal data structures of SQLite. It uses only the public 1876** interface defined here. As a consequence, errors that occur in the 1877** wrapper layer outside of the internal [sqlite3_exec()] call are not 1878** reflected in subsequent calls to [sqlite3_errcode()] or 1879** [sqlite3_errmsg()]. 1880*/ 1881SQLITE_API int sqlite3_get_table( 1882 sqlite3 *db, /* An open database */ 1883 const char *zSql, /* SQL to be evaluated */ 1884 char ***pazResult, /* Results of the query */ 1885 int *pnRow, /* Number of result rows written here */ 1886 int *pnColumn, /* Number of result columns written here */ 1887 char **pzErrmsg /* Error msg written here */ 1888); 1889SQLITE_API void sqlite3_free_table(char **result); 1890 1891/* 1892** CAPI3REF: Formatted String Printing Functions 1893** 1894** These routines are work-alikes of the "printf()" family of functions 1895** from the standard C library. 1896** 1897** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1898** results into memory obtained from [sqlite3_malloc()]. 1899** The strings returned by these two routines should be 1900** released by [sqlite3_free()]. ^Both routines return a 1901** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1902** memory to hold the resulting string. 1903** 1904** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 1905** the standard C library. The result is written into the 1906** buffer supplied as the second parameter whose size is given by 1907** the first parameter. Note that the order of the 1908** first two parameters is reversed from snprintf().)^ This is an 1909** historical accident that cannot be fixed without breaking 1910** backwards compatibility. ^(Note also that sqlite3_snprintf() 1911** returns a pointer to its buffer instead of the number of 1912** characters actually written into the buffer.)^ We admit that 1913** the number of characters written would be a more useful return 1914** value but we cannot change the implementation of sqlite3_snprintf() 1915** now without breaking compatibility. 1916** 1917** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 1918** guarantees that the buffer is always zero-terminated. ^The first 1919** parameter "n" is the total size of the buffer, including space for 1920** the zero terminator. So the longest string that can be completely 1921** written will be n-1 characters. 1922** 1923** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 1924** 1925** These routines all implement some additional formatting 1926** options that are useful for constructing SQL statements. 1927** All of the usual printf() formatting options apply. In addition, there 1928** is are "%q", "%Q", and "%z" options. 1929** 1930** ^(The %q option works like %s in that it substitutes a null-terminated 1931** string from the argument list. But %q also doubles every '\'' character. 1932** %q is designed for use inside a string literal.)^ By doubling each '\'' 1933** character it escapes that character and allows it to be inserted into 1934** the string. 1935** 1936** For example, assume the string variable zText contains text as follows: 1937** 1938** <blockquote><pre> 1939** char *zText = "It's a happy day!"; 1940** </pre></blockquote> 1941** 1942** One can use this text in an SQL statement as follows: 1943** 1944** <blockquote><pre> 1945** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1946** sqlite3_exec(db, zSQL, 0, 0, 0); 1947** sqlite3_free(zSQL); 1948** </pre></blockquote> 1949** 1950** Because the %q format string is used, the '\'' character in zText 1951** is escaped and the SQL generated is as follows: 1952** 1953** <blockquote><pre> 1954** INSERT INTO table1 VALUES('It''s a happy day!') 1955** </pre></blockquote> 1956** 1957** This is correct. Had we used %s instead of %q, the generated SQL 1958** would have looked like this: 1959** 1960** <blockquote><pre> 1961** INSERT INTO table1 VALUES('It's a happy day!'); 1962** </pre></blockquote> 1963** 1964** This second example is an SQL syntax error. As a general rule you should 1965** always use %q instead of %s when inserting text into a string literal. 1966** 1967** ^(The %Q option works like %q except it also adds single quotes around 1968** the outside of the total string. Additionally, if the parameter in the 1969** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 1970** single quotes).)^ So, for example, one could say: 1971** 1972** <blockquote><pre> 1973** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1974** sqlite3_exec(db, zSQL, 0, 0, 0); 1975** sqlite3_free(zSQL); 1976** </pre></blockquote> 1977** 1978** The code above will render a correct SQL statement in the zSQL 1979** variable even if the zText variable is a NULL pointer. 1980** 1981** ^(The "%z" formatting option works like "%s" but with the 1982** addition that after the string has been read and copied into 1983** the result, [sqlite3_free()] is called on the input string.)^ 1984*/ 1985SQLITE_API char *sqlite3_mprintf(const char*,...); 1986SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 1987SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 1988SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 1989 1990/* 1991** CAPI3REF: Memory Allocation Subsystem 1992** 1993** The SQLite core uses these three routines for all of its own 1994** internal memory allocation needs. "Core" in the previous sentence 1995** does not include operating-system specific VFS implementation. The 1996** Windows VFS uses native malloc() and free() for some operations. 1997** 1998** ^The sqlite3_malloc() routine returns a pointer to a block 1999** of memory at least N bytes in length, where N is the parameter. 2000** ^If sqlite3_malloc() is unable to obtain sufficient free 2001** memory, it returns a NULL pointer. ^If the parameter N to 2002** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2003** a NULL pointer. 2004** 2005** ^Calling sqlite3_free() with a pointer previously returned 2006** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2007** that it might be reused. ^The sqlite3_free() routine is 2008** a no-op if is called with a NULL pointer. Passing a NULL pointer 2009** to sqlite3_free() is harmless. After being freed, memory 2010** should neither be read nor written. Even reading previously freed 2011** memory might result in a segmentation fault or other severe error. 2012** Memory corruption, a segmentation fault, or other severe error 2013** might result if sqlite3_free() is called with a non-NULL pointer that 2014** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2015** 2016** ^(The sqlite3_realloc() interface attempts to resize a 2017** prior memory allocation to be at least N bytes, where N is the 2018** second parameter. The memory allocation to be resized is the first 2019** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2020** is a NULL pointer then its behavior is identical to calling 2021** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2022** ^If the second parameter to sqlite3_realloc() is zero or 2023** negative then the behavior is exactly the same as calling 2024** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2025** ^sqlite3_realloc() returns a pointer to a memory allocation 2026** of at least N bytes in size or NULL if sufficient memory is unavailable. 2027** ^If M is the size of the prior allocation, then min(N,M) bytes 2028** of the prior allocation are copied into the beginning of buffer returned 2029** by sqlite3_realloc() and the prior allocation is freed. 2030** ^If sqlite3_realloc() returns NULL, then the prior allocation 2031** is not freed. 2032** 2033** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2034** is always aligned to at least an 8 byte boundary, or to a 2035** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2036** option is used. 2037** 2038** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2039** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2040** implementation of these routines to be omitted. That capability 2041** is no longer provided. Only built-in memory allocators can be used. 2042** 2043** The Windows OS interface layer calls 2044** the system malloc() and free() directly when converting 2045** filenames between the UTF-8 encoding used by SQLite 2046** and whatever filename encoding is used by the particular Windows 2047** installation. Memory allocation errors are detected, but 2048** they are reported back as [SQLITE_CANTOPEN] or 2049** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2050** 2051** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2052** must be either NULL or else pointers obtained from a prior 2053** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2054** not yet been released. 2055** 2056** The application must not read or write any part of 2057** a block of memory after it has been released using 2058** [sqlite3_free()] or [sqlite3_realloc()]. 2059*/ 2060SQLITE_API void *sqlite3_malloc(int); 2061SQLITE_API void *sqlite3_realloc(void*, int); 2062SQLITE_API void sqlite3_free(void*); 2063 2064/* 2065** CAPI3REF: Memory Allocator Statistics 2066** 2067** SQLite provides these two interfaces for reporting on the status 2068** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2069** routines, which form the built-in memory allocation subsystem. 2070** 2071** ^The [sqlite3_memory_used()] routine returns the number of bytes 2072** of memory currently outstanding (malloced but not freed). 2073** ^The [sqlite3_memory_highwater()] routine returns the maximum 2074** value of [sqlite3_memory_used()] since the high-water mark 2075** was last reset. ^The values returned by [sqlite3_memory_used()] and 2076** [sqlite3_memory_highwater()] include any overhead 2077** added by SQLite in its implementation of [sqlite3_malloc()], 2078** but not overhead added by the any underlying system library 2079** routines that [sqlite3_malloc()] may call. 2080** 2081** ^The memory high-water mark is reset to the current value of 2082** [sqlite3_memory_used()] if and only if the parameter to 2083** [sqlite3_memory_highwater()] is true. ^The value returned 2084** by [sqlite3_memory_highwater(1)] is the high-water mark 2085** prior to the reset. 2086*/ 2087SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2088SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2089 2090/* 2091** CAPI3REF: Pseudo-Random Number Generator 2092** 2093** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2094** select random [ROWID | ROWIDs] when inserting new records into a table that 2095** already uses the largest possible [ROWID]. The PRNG is also used for 2096** the build-in random() and randomblob() SQL functions. This interface allows 2097** applications to access the same PRNG for other purposes. 2098** 2099** ^A call to this routine stores N bytes of randomness into buffer P. 2100** 2101** ^The first time this routine is invoked (either internally or by 2102** the application) the PRNG is seeded using randomness obtained 2103** from the xRandomness method of the default [sqlite3_vfs] object. 2104** ^On all subsequent invocations, the pseudo-randomness is generated 2105** internally and without recourse to the [sqlite3_vfs] xRandomness 2106** method. 2107*/ 2108SQLITE_API void sqlite3_randomness(int N, void *P); 2109 2110/* 2111** CAPI3REF: Compile-Time Authorization Callbacks 2112** 2113** ^This routine registers an authorizer callback with a particular 2114** [database connection], supplied in the first argument. 2115** ^The authorizer callback is invoked as SQL statements are being compiled 2116** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2117** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2118** points during the compilation process, as logic is being created 2119** to perform various actions, the authorizer callback is invoked to 2120** see if those actions are allowed. ^The authorizer callback should 2121** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2122** specific action but allow the SQL statement to continue to be 2123** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2124** rejected with an error. ^If the authorizer callback returns 2125** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2126** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2127** the authorizer will fail with an error message. 2128** 2129** When the callback returns [SQLITE_OK], that means the operation 2130** requested is ok. ^When the callback returns [SQLITE_DENY], the 2131** [sqlite3_prepare_v2()] or equivalent call that triggered the 2132** authorizer will fail with an error message explaining that 2133** access is denied. 2134** 2135** ^The first parameter to the authorizer callback is a copy of the third 2136** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2137** to the callback is an integer [SQLITE_COPY | action code] that specifies 2138** the particular action to be authorized. ^The third through sixth parameters 2139** to the callback are zero-terminated strings that contain additional 2140** details about the action to be authorized. 2141** 2142** ^If the action code is [SQLITE_READ] 2143** and the callback returns [SQLITE_IGNORE] then the 2144** [prepared statement] statement is constructed to substitute 2145** a NULL value in place of the table column that would have 2146** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2147** return can be used to deny an untrusted user access to individual 2148** columns of a table. 2149** ^If the action code is [SQLITE_DELETE] and the callback returns 2150** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2151** [truncate optimization] is disabled and all rows are deleted individually. 2152** 2153** An authorizer is used when [sqlite3_prepare | preparing] 2154** SQL statements from an untrusted source, to ensure that the SQL statements 2155** do not try to access data they are not allowed to see, or that they do not 2156** try to execute malicious statements that damage the database. For 2157** example, an application may allow a user to enter arbitrary 2158** SQL queries for evaluation by a database. But the application does 2159** not want the user to be able to make arbitrary changes to the 2160** database. An authorizer could then be put in place while the 2161** user-entered SQL is being [sqlite3_prepare | prepared] that 2162** disallows everything except [SELECT] statements. 2163** 2164** Applications that need to process SQL from untrusted sources 2165** might also consider lowering resource limits using [sqlite3_limit()] 2166** and limiting database size using the [max_page_count] [PRAGMA] 2167** in addition to using an authorizer. 2168** 2169** ^(Only a single authorizer can be in place on a database connection 2170** at a time. Each call to sqlite3_set_authorizer overrides the 2171** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2172** The authorizer is disabled by default. 2173** 2174** The authorizer callback must not do anything that will modify 2175** the database connection that invoked the authorizer callback. 2176** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2177** database connections for the meaning of "modify" in this paragraph. 2178** 2179** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2180** statement might be re-prepared during [sqlite3_step()] due to a 2181** schema change. Hence, the application should ensure that the 2182** correct authorizer callback remains in place during the [sqlite3_step()]. 2183** 2184** ^Note that the authorizer callback is invoked only during 2185** [sqlite3_prepare()] or its variants. Authorization is not 2186** performed during statement evaluation in [sqlite3_step()], unless 2187** as stated in the previous paragraph, sqlite3_step() invokes 2188** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2189*/ 2190SQLITE_API int sqlite3_set_authorizer( 2191 sqlite3*, 2192 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2193 void *pUserData 2194); 2195 2196/* 2197** CAPI3REF: Authorizer Return Codes 2198** 2199** The [sqlite3_set_authorizer | authorizer callback function] must 2200** return either [SQLITE_OK] or one of these two constants in order 2201** to signal SQLite whether or not the action is permitted. See the 2202** [sqlite3_set_authorizer | authorizer documentation] for additional 2203** information. 2204*/ 2205#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2206#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2207 2208/* 2209** CAPI3REF: Authorizer Action Codes 2210** 2211** The [sqlite3_set_authorizer()] interface registers a callback function 2212** that is invoked to authorize certain SQL statement actions. The 2213** second parameter to the callback is an integer code that specifies 2214** what action is being authorized. These are the integer action codes that 2215** the authorizer callback may be passed. 2216** 2217** These action code values signify what kind of operation is to be 2218** authorized. The 3rd and 4th parameters to the authorization 2219** callback function will be parameters or NULL depending on which of these 2220** codes is used as the second parameter. ^(The 5th parameter to the 2221** authorizer callback is the name of the database ("main", "temp", 2222** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2223** is the name of the inner-most trigger or view that is responsible for 2224** the access attempt or NULL if this access attempt is directly from 2225** top-level SQL code. 2226*/ 2227/******************************************* 3rd ************ 4th ***********/ 2228#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2229#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2230#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2231#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2232#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2233#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2234#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2235#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2236#define SQLITE_DELETE 9 /* Table Name NULL */ 2237#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2238#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2239#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2240#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2241#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2242#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2243#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2244#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2245#define SQLITE_INSERT 18 /* Table Name NULL */ 2246#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2247#define SQLITE_READ 20 /* Table Name Column Name */ 2248#define SQLITE_SELECT 21 /* NULL NULL */ 2249#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2250#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2251#define SQLITE_ATTACH 24 /* Filename NULL */ 2252#define SQLITE_DETACH 25 /* Database Name NULL */ 2253#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2254#define SQLITE_REINDEX 27 /* Index Name NULL */ 2255#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2256#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2257#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2258#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2259#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2260#define SQLITE_COPY 0 /* No longer used */ 2261 2262/* 2263** CAPI3REF: Tracing And Profiling Functions 2264** 2265** These routines register callback functions that can be used for 2266** tracing and profiling the execution of SQL statements. 2267** 2268** ^The callback function registered by sqlite3_trace() is invoked at 2269** various times when an SQL statement is being run by [sqlite3_step()]. 2270** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2271** SQL statement text as the statement first begins executing. 2272** ^(Additional sqlite3_trace() callbacks might occur 2273** as each triggered subprogram is entered. The callbacks for triggers 2274** contain a UTF-8 SQL comment that identifies the trigger.)^ 2275** 2276** ^The callback function registered by sqlite3_profile() is invoked 2277** as each SQL statement finishes. ^The profile callback contains 2278** the original statement text and an estimate of wall-clock time 2279** of how long that statement took to run. ^The profile callback 2280** time is in units of nanoseconds, however the current implementation 2281** is only capable of millisecond resolution so the six least significant 2282** digits in the time are meaningless. Future versions of SQLite 2283** might provide greater resolution on the profiler callback. The 2284** sqlite3_profile() function is considered experimental and is 2285** subject to change in future versions of SQLite. 2286*/ 2287SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2288SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2289 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2290 2291/* 2292** CAPI3REF: Query Progress Callbacks 2293** 2294** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2295** function X to be invoked periodically during long running calls to 2296** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2297** database connection D. An example use for this 2298** interface is to keep a GUI updated during a large query. 2299** 2300** ^The parameter P is passed through as the only parameter to the 2301** callback function X. ^The parameter N is the number of 2302** [virtual machine instructions] that are evaluated between successive 2303** invocations of the callback X. 2304** 2305** ^Only a single progress handler may be defined at one time per 2306** [database connection]; setting a new progress handler cancels the 2307** old one. ^Setting parameter X to NULL disables the progress handler. 2308** ^The progress handler is also disabled by setting N to a value less 2309** than 1. 2310** 2311** ^If the progress callback returns non-zero, the operation is 2312** interrupted. This feature can be used to implement a 2313** "Cancel" button on a GUI progress dialog box. 2314** 2315** The progress handler callback must not do anything that will modify 2316** the database connection that invoked the progress handler. 2317** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2318** database connections for the meaning of "modify" in this paragraph. 2319** 2320*/ 2321SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2322 2323/* 2324** CAPI3REF: Opening A New Database Connection 2325** 2326** ^These routines open an SQLite database file whose name is given by the 2327** filename argument. ^The filename argument is interpreted as UTF-8 for 2328** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2329** order for sqlite3_open16(). ^(A [database connection] handle is usually 2330** returned in *ppDb, even if an error occurs. The only exception is that 2331** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2332** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2333** object.)^ ^(If the database is opened (and/or created) successfully, then 2334** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2335** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2336** an English language description of the error following a failure of any 2337** of the sqlite3_open() routines. 2338** 2339** ^The default encoding for the database will be UTF-8 if 2340** sqlite3_open() or sqlite3_open_v2() is called and 2341** UTF-16 in the native byte order if sqlite3_open16() is used. 2342** 2343** Whether or not an error occurs when it is opened, resources 2344** associated with the [database connection] handle should be released by 2345** passing it to [sqlite3_close()] when it is no longer required. 2346** 2347** The sqlite3_open_v2() interface works like sqlite3_open() 2348** except that it accepts two additional parameters for additional control 2349** over the new database connection. ^(The flags parameter to 2350** sqlite3_open_v2() can take one of 2351** the following three values, optionally combined with the 2352** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2353** and/or [SQLITE_OPEN_PRIVATECACHE] flags:)^ 2354** 2355** <dl> 2356** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2357** <dd>The database is opened in read-only mode. If the database does not 2358** already exist, an error is returned.</dd>)^ 2359** 2360** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2361** <dd>The database is opened for reading and writing if possible, or reading 2362** only if the file is write protected by the operating system. In either 2363** case the database must already exist, otherwise an error is returned.</dd>)^ 2364** 2365** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2366** <dd>The database is opened for reading and writing, and is created if 2367** it does not already exist. This is the behavior that is always used for 2368** sqlite3_open() and sqlite3_open16().</dd>)^ 2369** </dl> 2370** 2371** If the 3rd parameter to sqlite3_open_v2() is not one of the 2372** combinations shown above or one of the combinations shown above combined 2373** with the [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], 2374** [SQLITE_OPEN_SHAREDCACHE] and/or [SQLITE_OPEN_PRIVATECACHE] flags, 2375** then the behavior is undefined. 2376** 2377** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2378** opens in the multi-thread [threading mode] as long as the single-thread 2379** mode has not been set at compile-time or start-time. ^If the 2380** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2381** in the serialized [threading mode] unless single-thread was 2382** previously selected at compile-time or start-time. 2383** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2384** eligible to use [shared cache mode], regardless of whether or not shared 2385** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2386** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2387** participate in [shared cache mode] even if it is enabled. 2388** 2389** ^If the filename is ":memory:", then a private, temporary in-memory database 2390** is created for the connection. ^This in-memory database will vanish when 2391** the database connection is closed. Future versions of SQLite might 2392** make use of additional special filenames that begin with the ":" character. 2393** It is recommended that when a database filename actually does begin with 2394** a ":" character you should prefix the filename with a pathname such as 2395** "./" to avoid ambiguity. 2396** 2397** ^If the filename is an empty string, then a private, temporary 2398** on-disk database will be created. ^This private database will be 2399** automatically deleted as soon as the database connection is closed. 2400** 2401** ^The fourth parameter to sqlite3_open_v2() is the name of the 2402** [sqlite3_vfs] object that defines the operating system interface that 2403** the new database connection should use. ^If the fourth parameter is 2404** a NULL pointer then the default [sqlite3_vfs] object is used. 2405** 2406** <b>Note to Windows users:</b> The encoding used for the filename argument 2407** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2408** codepage is currently defined. Filenames containing international 2409** characters must be converted to UTF-8 prior to passing them into 2410** sqlite3_open() or sqlite3_open_v2(). 2411*/ 2412SQLITE_API int sqlite3_open( 2413 const char *filename, /* Database filename (UTF-8) */ 2414 sqlite3 **ppDb /* OUT: SQLite db handle */ 2415); 2416SQLITE_API int sqlite3_open16( 2417 const void *filename, /* Database filename (UTF-16) */ 2418 sqlite3 **ppDb /* OUT: SQLite db handle */ 2419); 2420SQLITE_API int sqlite3_open_v2( 2421 const char *filename, /* Database filename (UTF-8) */ 2422 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2423 int flags, /* Flags */ 2424 const char *zVfs /* Name of VFS module to use */ 2425); 2426 2427/* 2428** CAPI3REF: Error Codes And Messages 2429** 2430** ^The sqlite3_errcode() interface returns the numeric [result code] or 2431** [extended result code] for the most recent failed sqlite3_* API call 2432** associated with a [database connection]. If a prior API call failed 2433** but the most recent API call succeeded, the return value from 2434** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2435** interface is the same except that it always returns the 2436** [extended result code] even when extended result codes are 2437** disabled. 2438** 2439** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2440** text that describes the error, as either UTF-8 or UTF-16 respectively. 2441** ^(Memory to hold the error message string is managed internally. 2442** The application does not need to worry about freeing the result. 2443** However, the error string might be overwritten or deallocated by 2444** subsequent calls to other SQLite interface functions.)^ 2445** 2446** When the serialized [threading mode] is in use, it might be the 2447** case that a second error occurs on a separate thread in between 2448** the time of the first error and the call to these interfaces. 2449** When that happens, the second error will be reported since these 2450** interfaces always report the most recent result. To avoid 2451** this, each thread can obtain exclusive use of the [database connection] D 2452** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2453** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2454** all calls to the interfaces listed here are completed. 2455** 2456** If an interface fails with SQLITE_MISUSE, that means the interface 2457** was invoked incorrectly by the application. In that case, the 2458** error code and message may or may not be set. 2459*/ 2460SQLITE_API int sqlite3_errcode(sqlite3 *db); 2461SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 2462SQLITE_API const char *sqlite3_errmsg(sqlite3*); 2463SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 2464 2465/* 2466** CAPI3REF: SQL Statement Object 2467** KEYWORDS: {prepared statement} {prepared statements} 2468** 2469** An instance of this object represents a single SQL statement. 2470** This object is variously known as a "prepared statement" or a 2471** "compiled SQL statement" or simply as a "statement". 2472** 2473** The life of a statement object goes something like this: 2474** 2475** <ol> 2476** <li> Create the object using [sqlite3_prepare_v2()] or a related 2477** function. 2478** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2479** interfaces. 2480** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2481** <li> Reset the statement using [sqlite3_reset()] then go back 2482** to step 2. Do this zero or more times. 2483** <li> Destroy the object using [sqlite3_finalize()]. 2484** </ol> 2485** 2486** Refer to documentation on individual methods above for additional 2487** information. 2488*/ 2489typedef struct sqlite3_stmt sqlite3_stmt; 2490 2491/* 2492** CAPI3REF: Run-time Limits 2493** 2494** ^(This interface allows the size of various constructs to be limited 2495** on a connection by connection basis. The first parameter is the 2496** [database connection] whose limit is to be set or queried. The 2497** second parameter is one of the [limit categories] that define a 2498** class of constructs to be size limited. The third parameter is the 2499** new limit for that construct.)^ 2500** 2501** ^If the new limit is a negative number, the limit is unchanged. 2502** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2503** [limits | hard upper bound] 2504** set at compile-time by a C preprocessor macro called 2505** [limits | SQLITE_MAX_<i>NAME</i>]. 2506** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2507** ^Attempts to increase a limit above its hard upper bound are 2508** silently truncated to the hard upper bound. 2509** 2510** ^Regardless of whether or not the limit was changed, the 2511** [sqlite3_limit()] interface returns the prior value of the limit. 2512** ^Hence, to find the current value of a limit without changing it, 2513** simply invoke this interface with the third parameter set to -1. 2514** 2515** Run-time limits are intended for use in applications that manage 2516** both their own internal database and also databases that are controlled 2517** by untrusted external sources. An example application might be a 2518** web browser that has its own databases for storing history and 2519** separate databases controlled by JavaScript applications downloaded 2520** off the Internet. The internal databases can be given the 2521** large, default limits. Databases managed by external sources can 2522** be given much smaller limits designed to prevent a denial of service 2523** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2524** interface to further control untrusted SQL. The size of the database 2525** created by an untrusted script can be contained using the 2526** [max_page_count] [PRAGMA]. 2527** 2528** New run-time limit categories may be added in future releases. 2529*/ 2530SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 2531 2532/* 2533** CAPI3REF: Run-Time Limit Categories 2534** KEYWORDS: {limit category} {*limit categories} 2535** 2536** These constants define various performance limits 2537** that can be lowered at run-time using [sqlite3_limit()]. 2538** The synopsis of the meanings of the various limits is shown below. 2539** Additional information is available at [limits | Limits in SQLite]. 2540** 2541** <dl> 2542** ^(<dt>SQLITE_LIMIT_LENGTH</dt> 2543** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 2544** 2545** ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2546** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 2547** 2548** ^(<dt>SQLITE_LIMIT_COLUMN</dt> 2549** <dd>The maximum number of columns in a table definition or in the 2550** result set of a [SELECT] or the maximum number of columns in an index 2551** or in an ORDER BY or GROUP BY clause.</dd>)^ 2552** 2553** ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2554** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 2555** 2556** ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2557** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 2558** 2559** ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 2560** <dd>The maximum number of instructions in a virtual machine program 2561** used to implement an SQL statement. This limit is not currently 2562** enforced, though that might be added in some future release of 2563** SQLite.</dd>)^ 2564** 2565** ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2566** <dd>The maximum number of arguments on a function.</dd>)^ 2567** 2568** ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 2569** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 2570** 2571** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2572** <dd>The maximum length of the pattern argument to the [LIKE] or 2573** [GLOB] operators.</dd>)^ 2574** 2575** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2576** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 2577** 2578** ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 2579** <dd>The maximum depth of recursion for triggers.</dd>)^ 2580** </dl> 2581*/ 2582#define SQLITE_LIMIT_LENGTH 0 2583#define SQLITE_LIMIT_SQL_LENGTH 1 2584#define SQLITE_LIMIT_COLUMN 2 2585#define SQLITE_LIMIT_EXPR_DEPTH 3 2586#define SQLITE_LIMIT_COMPOUND_SELECT 4 2587#define SQLITE_LIMIT_VDBE_OP 5 2588#define SQLITE_LIMIT_FUNCTION_ARG 6 2589#define SQLITE_LIMIT_ATTACHED 7 2590#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2591#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2592#define SQLITE_LIMIT_TRIGGER_DEPTH 10 2593 2594/* 2595** CAPI3REF: Compiling An SQL Statement 2596** KEYWORDS: {SQL statement compiler} 2597** 2598** To execute an SQL query, it must first be compiled into a byte-code 2599** program using one of these routines. 2600** 2601** The first argument, "db", is a [database connection] obtained from a 2602** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 2603** [sqlite3_open16()]. The database connection must not have been closed. 2604** 2605** The second argument, "zSql", is the statement to be compiled, encoded 2606** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2607** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2608** use UTF-16. 2609** 2610** ^If the nByte argument is less than zero, then zSql is read up to the 2611** first zero terminator. ^If nByte is non-negative, then it is the maximum 2612** number of bytes read from zSql. ^When nByte is non-negative, the 2613** zSql string ends at either the first '\000' or '\u0000' character or 2614** the nByte-th byte, whichever comes first. If the caller knows 2615** that the supplied string is nul-terminated, then there is a small 2616** performance advantage to be gained by passing an nByte parameter that 2617** is equal to the number of bytes in the input string <i>including</i> 2618** the nul-terminator bytes. 2619** 2620** ^If pzTail is not NULL then *pzTail is made to point to the first byte 2621** past the end of the first SQL statement in zSql. These routines only 2622** compile the first statement in zSql, so *pzTail is left pointing to 2623** what remains uncompiled. 2624** 2625** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 2626** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 2627** to NULL. ^If the input text contains no SQL (if the input is an empty 2628** string or a comment) then *ppStmt is set to NULL. 2629** The calling procedure is responsible for deleting the compiled 2630** SQL statement using [sqlite3_finalize()] after it has finished with it. 2631** ppStmt may not be NULL. 2632** 2633** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 2634** otherwise an [error code] is returned. 2635** 2636** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2637** recommended for all new programs. The two older interfaces are retained 2638** for backwards compatibility, but their use is discouraged. 2639** ^In the "v2" interfaces, the prepared statement 2640** that is returned (the [sqlite3_stmt] object) contains a copy of the 2641** original SQL text. This causes the [sqlite3_step()] interface to 2642** behave differently in three ways: 2643** 2644** <ol> 2645** <li> 2646** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2647** always used to do, [sqlite3_step()] will automatically recompile the SQL 2648** statement and try to run it again. 2649** </li> 2650** 2651** <li> 2652** ^When an error occurs, [sqlite3_step()] will return one of the detailed 2653** [error codes] or [extended error codes]. ^The legacy behavior was that 2654** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2655** and the application would have to make a second call to [sqlite3_reset()] 2656** in order to find the underlying cause of the problem. With the "v2" prepare 2657** interfaces, the underlying reason for the error is returned immediately. 2658** </li> 2659** 2660** <li> 2661** ^If the specific value bound to [parameter | host parameter] in the 2662** WHERE clause might influence the choice of query plan for a statement, 2663** then the statement will be automatically recompiled, as if there had been 2664** a schema change, on the first [sqlite3_step()] call following any change 2665** to the [sqlite3_bind_text | bindings] of that [parameter]. 2666** ^The specific value of WHERE-clause [parameter] might influence the 2667** choice of query plan if the parameter is the left-hand side of a [LIKE] 2668** or [GLOB] operator or if the parameter is compared to an indexed column 2669** and the [SQLITE_ENABLE_STAT2] compile-time option is enabled. 2670** the 2671** </li> 2672** </ol> 2673*/ 2674SQLITE_API int sqlite3_prepare( 2675 sqlite3 *db, /* Database handle */ 2676 const char *zSql, /* SQL statement, UTF-8 encoded */ 2677 int nByte, /* Maximum length of zSql in bytes. */ 2678 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2679 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2680); 2681SQLITE_API int sqlite3_prepare_v2( 2682 sqlite3 *db, /* Database handle */ 2683 const char *zSql, /* SQL statement, UTF-8 encoded */ 2684 int nByte, /* Maximum length of zSql in bytes. */ 2685 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2686 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2687); 2688SQLITE_API int sqlite3_prepare16( 2689 sqlite3 *db, /* Database handle */ 2690 const void *zSql, /* SQL statement, UTF-16 encoded */ 2691 int nByte, /* Maximum length of zSql in bytes. */ 2692 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2693 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2694); 2695SQLITE_API int sqlite3_prepare16_v2( 2696 sqlite3 *db, /* Database handle */ 2697 const void *zSql, /* SQL statement, UTF-16 encoded */ 2698 int nByte, /* Maximum length of zSql in bytes. */ 2699 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2700 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2701); 2702 2703/* 2704** CAPI3REF: Retrieving Statement SQL 2705** 2706** ^This interface can be used to retrieve a saved copy of the original 2707** SQL text used to create a [prepared statement] if that statement was 2708** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 2709*/ 2710SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 2711 2712/* 2713** CAPI3REF: Determine If An SQL Statement Writes The Database 2714** 2715** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 2716** and only if the [prepared statement] X makes no direct changes to 2717** the content of the database file. 2718** 2719** Note that [application-defined SQL functions] or 2720** [virtual tables] might change the database indirectly as a side effect. 2721** ^(For example, if an application defines a function "eval()" that 2722** calls [sqlite3_exec()], then the following SQL statement would 2723** change the database file through side-effects: 2724** 2725** <blockquote><pre> 2726** SELECT eval('DELETE FROM t1') FROM t2; 2727** </pre></blockquote> 2728** 2729** But because the [SELECT] statement does not change the database file 2730** directly, sqlite3_stmt_readonly() would still return true.)^ 2731** 2732** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 2733** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 2734** since the statements themselves do not actually modify the database but 2735** rather they control the timing of when other statements modify the 2736** database. ^The [ATTACH] and [DETACH] statements also cause 2737** sqlite3_stmt_readonly() to return true since, while those statements 2738** change the configuration of a database connection, they do not make 2739** changes to the content of the database files on disk. 2740*/ 2741SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 2742 2743/* 2744** CAPI3REF: Dynamically Typed Value Object 2745** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2746** 2747** SQLite uses the sqlite3_value object to represent all values 2748** that can be stored in a database table. SQLite uses dynamic typing 2749** for the values it stores. ^Values stored in sqlite3_value objects 2750** can be integers, floating point values, strings, BLOBs, or NULL. 2751** 2752** An sqlite3_value object may be either "protected" or "unprotected". 2753** Some interfaces require a protected sqlite3_value. Other interfaces 2754** will accept either a protected or an unprotected sqlite3_value. 2755** Every interface that accepts sqlite3_value arguments specifies 2756** whether or not it requires a protected sqlite3_value. 2757** 2758** The terms "protected" and "unprotected" refer to whether or not 2759** a mutex is held. An internal mutex is held for a protected 2760** sqlite3_value object but no mutex is held for an unprotected 2761** sqlite3_value object. If SQLite is compiled to be single-threaded 2762** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 2763** or if SQLite is run in one of reduced mutex modes 2764** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 2765** then there is no distinction between protected and unprotected 2766** sqlite3_value objects and they can be used interchangeably. However, 2767** for maximum code portability it is recommended that applications 2768** still make the distinction between protected and unprotected 2769** sqlite3_value objects even when not strictly required. 2770** 2771** ^The sqlite3_value objects that are passed as parameters into the 2772** implementation of [application-defined SQL functions] are protected. 2773** ^The sqlite3_value object returned by 2774** [sqlite3_column_value()] is unprotected. 2775** Unprotected sqlite3_value objects may only be used with 2776** [sqlite3_result_value()] and [sqlite3_bind_value()]. 2777** The [sqlite3_value_blob | sqlite3_value_type()] family of 2778** interfaces require protected sqlite3_value objects. 2779*/ 2780typedef struct Mem sqlite3_value; 2781 2782/* 2783** CAPI3REF: SQL Function Context Object 2784** 2785** The context in which an SQL function executes is stored in an 2786** sqlite3_context object. ^A pointer to an sqlite3_context object 2787** is always first parameter to [application-defined SQL functions]. 2788** The application-defined SQL function implementation will pass this 2789** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 2790** [sqlite3_aggregate_context()], [sqlite3_user_data()], 2791** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 2792** and/or [sqlite3_set_auxdata()]. 2793*/ 2794typedef struct sqlite3_context sqlite3_context; 2795 2796/* 2797** CAPI3REF: Binding Values To Prepared Statements 2798** KEYWORDS: {host parameter} {host parameters} {host parameter name} 2799** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 2800** 2801** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 2802** literals may be replaced by a [parameter] that matches one of following 2803** templates: 2804** 2805** <ul> 2806** <li> ? 2807** <li> ?NNN 2808** <li> :VVV 2809** <li> @VVV 2810** <li> $VVV 2811** </ul> 2812** 2813** In the templates above, NNN represents an integer literal, 2814** and VVV represents an alphanumeric identifier.)^ ^The values of these 2815** parameters (also called "host parameter names" or "SQL parameters") 2816** can be set using the sqlite3_bind_*() routines defined here. 2817** 2818** ^The first argument to the sqlite3_bind_*() routines is always 2819** a pointer to the [sqlite3_stmt] object returned from 2820** [sqlite3_prepare_v2()] or its variants. 2821** 2822** ^The second argument is the index of the SQL parameter to be set. 2823** ^The leftmost SQL parameter has an index of 1. ^When the same named 2824** SQL parameter is used more than once, second and subsequent 2825** occurrences have the same index as the first occurrence. 2826** ^The index for named parameters can be looked up using the 2827** [sqlite3_bind_parameter_index()] API if desired. ^The index 2828** for "?NNN" parameters is the value of NNN. 2829** ^The NNN value must be between 1 and the [sqlite3_limit()] 2830** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 2831** 2832** ^The third argument is the value to bind to the parameter. 2833** 2834** ^(In those routines that have a fourth argument, its value is the 2835** number of bytes in the parameter. To be clear: the value is the 2836** number of <u>bytes</u> in the value, not the number of characters.)^ 2837** ^If the fourth parameter is negative, the length of the string is 2838** the number of bytes up to the first zero terminator. 2839** 2840** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 2841** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 2842** string after SQLite has finished with it. ^The destructor is called 2843** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 2844** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 2845** ^If the fifth argument is 2846** the special value [SQLITE_STATIC], then SQLite assumes that the 2847** information is in static, unmanaged space and does not need to be freed. 2848** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 2849** SQLite makes its own private copy of the data immediately, before 2850** the sqlite3_bind_*() routine returns. 2851** 2852** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 2853** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 2854** (just an integer to hold its size) while it is being processed. 2855** Zeroblobs are intended to serve as placeholders for BLOBs whose 2856** content is later written using 2857** [sqlite3_blob_open | incremental BLOB I/O] routines. 2858** ^A negative value for the zeroblob results in a zero-length BLOB. 2859** 2860** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 2861** for the [prepared statement] or with a prepared statement for which 2862** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 2863** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 2864** routine is passed a [prepared statement] that has been finalized, the 2865** result is undefined and probably harmful. 2866** 2867** ^Bindings are not cleared by the [sqlite3_reset()] routine. 2868** ^Unbound parameters are interpreted as NULL. 2869** 2870** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 2871** [error code] if anything goes wrong. 2872** ^[SQLITE_RANGE] is returned if the parameter 2873** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 2874** 2875** See also: [sqlite3_bind_parameter_count()], 2876** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 2877*/ 2878SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 2879SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 2880SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 2881SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 2882SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 2883SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 2884SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 2885SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 2886SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 2887 2888/* 2889** CAPI3REF: Number Of SQL Parameters 2890** 2891** ^This routine can be used to find the number of [SQL parameters] 2892** in a [prepared statement]. SQL parameters are tokens of the 2893** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 2894** placeholders for values that are [sqlite3_bind_blob | bound] 2895** to the parameters at a later time. 2896** 2897** ^(This routine actually returns the index of the largest (rightmost) 2898** parameter. For all forms except ?NNN, this will correspond to the 2899** number of unique parameters. If parameters of the ?NNN form are used, 2900** there may be gaps in the list.)^ 2901** 2902** See also: [sqlite3_bind_blob|sqlite3_bind()], 2903** [sqlite3_bind_parameter_name()], and 2904** [sqlite3_bind_parameter_index()]. 2905*/ 2906SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 2907 2908/* 2909** CAPI3REF: Name Of A Host Parameter 2910** 2911** ^The sqlite3_bind_parameter_name(P,N) interface returns 2912** the name of the N-th [SQL parameter] in the [prepared statement] P. 2913** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 2914** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 2915** respectively. 2916** In other words, the initial ":" or "$" or "@" or "?" 2917** is included as part of the name.)^ 2918** ^Parameters of the form "?" without a following integer have no name 2919** and are referred to as "nameless" or "anonymous parameters". 2920** 2921** ^The first host parameter has an index of 1, not 0. 2922** 2923** ^If the value N is out of range or if the N-th parameter is 2924** nameless, then NULL is returned. ^The returned string is 2925** always in UTF-8 encoding even if the named parameter was 2926** originally specified as UTF-16 in [sqlite3_prepare16()] or 2927** [sqlite3_prepare16_v2()]. 2928** 2929** See also: [sqlite3_bind_blob|sqlite3_bind()], 2930** [sqlite3_bind_parameter_count()], and 2931** [sqlite3_bind_parameter_index()]. 2932*/ 2933SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 2934 2935/* 2936** CAPI3REF: Index Of A Parameter With A Given Name 2937** 2938** ^Return the index of an SQL parameter given its name. ^The 2939** index value returned is suitable for use as the second 2940** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 2941** is returned if no matching parameter is found. ^The parameter 2942** name must be given in UTF-8 even if the original statement 2943** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 2944** 2945** See also: [sqlite3_bind_blob|sqlite3_bind()], 2946** [sqlite3_bind_parameter_count()], and 2947** [sqlite3_bind_parameter_index()]. 2948*/ 2949SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 2950 2951/* 2952** CAPI3REF: Reset All Bindings On A Prepared Statement 2953** 2954** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 2955** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 2956** ^Use this routine to reset all host parameters to NULL. 2957*/ 2958SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 2959 2960/* 2961** CAPI3REF: Number Of Columns In A Result Set 2962** 2963** ^Return the number of columns in the result set returned by the 2964** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 2965** statement that does not return data (for example an [UPDATE]). 2966** 2967** See also: [sqlite3_data_count()] 2968*/ 2969SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 2970 2971/* 2972** CAPI3REF: Column Names In A Result Set 2973** 2974** ^These routines return the name assigned to a particular column 2975** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 2976** interface returns a pointer to a zero-terminated UTF-8 string 2977** and sqlite3_column_name16() returns a pointer to a zero-terminated 2978** UTF-16 string. ^The first parameter is the [prepared statement] 2979** that implements the [SELECT] statement. ^The second parameter is the 2980** column number. ^The leftmost column is number 0. 2981** 2982** ^The returned string pointer is valid until either the [prepared statement] 2983** is destroyed by [sqlite3_finalize()] or until the statement is automatically 2984** reprepared by the first call to [sqlite3_step()] for a particular run 2985** or until the next call to 2986** sqlite3_column_name() or sqlite3_column_name16() on the same column. 2987** 2988** ^If sqlite3_malloc() fails during the processing of either routine 2989** (for example during a conversion from UTF-8 to UTF-16) then a 2990** NULL pointer is returned. 2991** 2992** ^The name of a result column is the value of the "AS" clause for 2993** that column, if there is an AS clause. If there is no AS clause 2994** then the name of the column is unspecified and may change from 2995** one release of SQLite to the next. 2996*/ 2997SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 2998SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 2999 3000/* 3001** CAPI3REF: Source Of Data In A Query Result 3002** 3003** ^These routines provide a means to determine the database, table, and 3004** table column that is the origin of a particular result column in 3005** [SELECT] statement. 3006** ^The name of the database or table or column can be returned as 3007** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3008** the database name, the _table_ routines return the table name, and 3009** the origin_ routines return the column name. 3010** ^The returned string is valid until the [prepared statement] is destroyed 3011** using [sqlite3_finalize()] or until the statement is automatically 3012** reprepared by the first call to [sqlite3_step()] for a particular run 3013** or until the same information is requested 3014** again in a different encoding. 3015** 3016** ^The names returned are the original un-aliased names of the 3017** database, table, and column. 3018** 3019** ^The first argument to these interfaces is a [prepared statement]. 3020** ^These functions return information about the Nth result column returned by 3021** the statement, where N is the second function argument. 3022** ^The left-most column is column 0 for these routines. 3023** 3024** ^If the Nth column returned by the statement is an expression or 3025** subquery and is not a column value, then all of these functions return 3026** NULL. ^These routine might also return NULL if a memory allocation error 3027** occurs. ^Otherwise, they return the name of the attached database, table, 3028** or column that query result column was extracted from. 3029** 3030** ^As with all other SQLite APIs, those whose names end with "16" return 3031** UTF-16 encoded strings and the other functions return UTF-8. 3032** 3033** ^These APIs are only available if the library was compiled with the 3034** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3035** 3036** If two or more threads call one or more of these routines against the same 3037** prepared statement and column at the same time then the results are 3038** undefined. 3039** 3040** If two or more threads call one or more 3041** [sqlite3_column_database_name | column metadata interfaces] 3042** for the same [prepared statement] and result column 3043** at the same time then the results are undefined. 3044*/ 3045SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3046SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3047SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3048SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3049SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3050SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3051 3052/* 3053** CAPI3REF: Declared Datatype Of A Query Result 3054** 3055** ^(The first parameter is a [prepared statement]. 3056** If this statement is a [SELECT] statement and the Nth column of the 3057** returned result set of that [SELECT] is a table column (not an 3058** expression or subquery) then the declared type of the table 3059** column is returned.)^ ^If the Nth column of the result set is an 3060** expression or subquery, then a NULL pointer is returned. 3061** ^The returned string is always UTF-8 encoded. 3062** 3063** ^(For example, given the database schema: 3064** 3065** CREATE TABLE t1(c1 VARIANT); 3066** 3067** and the following statement to be compiled: 3068** 3069** SELECT c1 + 1, c1 FROM t1; 3070** 3071** this routine would return the string "VARIANT" for the second result 3072** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3073** 3074** ^SQLite uses dynamic run-time typing. ^So just because a column 3075** is declared to contain a particular type does not mean that the 3076** data stored in that column is of the declared type. SQLite is 3077** strongly typed, but the typing is dynamic not static. ^Type 3078** is associated with individual values, not with the containers 3079** used to hold those values. 3080*/ 3081SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3082SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3083 3084/* 3085** CAPI3REF: Evaluate An SQL Statement 3086** 3087** After a [prepared statement] has been prepared using either 3088** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3089** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3090** must be called one or more times to evaluate the statement. 3091** 3092** The details of the behavior of the sqlite3_step() interface depend 3093** on whether the statement was prepared using the newer "v2" interface 3094** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3095** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3096** new "v2" interface is recommended for new applications but the legacy 3097** interface will continue to be supported. 3098** 3099** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3100** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3101** ^With the "v2" interface, any of the other [result codes] or 3102** [extended result codes] might be returned as well. 3103** 3104** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3105** database locks it needs to do its job. ^If the statement is a [COMMIT] 3106** or occurs outside of an explicit transaction, then you can retry the 3107** statement. If the statement is not a [COMMIT] and occurs within a 3108** explicit transaction then you should rollback the transaction before 3109** continuing. 3110** 3111** ^[SQLITE_DONE] means that the statement has finished executing 3112** successfully. sqlite3_step() should not be called again on this virtual 3113** machine without first calling [sqlite3_reset()] to reset the virtual 3114** machine back to its initial state. 3115** 3116** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3117** is returned each time a new row of data is ready for processing by the 3118** caller. The values may be accessed using the [column access functions]. 3119** sqlite3_step() is called again to retrieve the next row of data. 3120** 3121** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3122** violation) has occurred. sqlite3_step() should not be called again on 3123** the VM. More information may be found by calling [sqlite3_errmsg()]. 3124** ^With the legacy interface, a more specific error code (for example, 3125** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3126** can be obtained by calling [sqlite3_reset()] on the 3127** [prepared statement]. ^In the "v2" interface, 3128** the more specific error code is returned directly by sqlite3_step(). 3129** 3130** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3131** Perhaps it was called on a [prepared statement] that has 3132** already been [sqlite3_finalize | finalized] or on one that had 3133** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3134** be the case that the same database connection is being used by two or 3135** more threads at the same moment in time. 3136** 3137** For all versions of SQLite up to and including 3.6.23.1, a call to 3138** [sqlite3_reset()] was required after sqlite3_step() returned anything 3139** other than [SQLITE_ROW] before any subsequent invocation of 3140** sqlite3_step(). Failure to reset the prepared statement using 3141** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3142** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3143** calling [sqlite3_reset()] automatically in this circumstance rather 3144** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3145** break because any application that ever receives an SQLITE_MISUSE error 3146** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3147** can be used to restore the legacy behavior. 3148** 3149** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3150** API always returns a generic error code, [SQLITE_ERROR], following any 3151** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3152** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3153** specific [error codes] that better describes the error. 3154** We admit that this is a goofy design. The problem has been fixed 3155** with the "v2" interface. If you prepare all of your SQL statements 3156** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3157** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3158** then the more specific [error codes] are returned directly 3159** by sqlite3_step(). The use of the "v2" interface is recommended. 3160*/ 3161SQLITE_API int sqlite3_step(sqlite3_stmt*); 3162 3163/* 3164** CAPI3REF: Number of columns in a result set 3165** 3166** ^The sqlite3_data_count(P) interface returns the number of columns in the 3167** current row of the result set of [prepared statement] P. 3168** ^If prepared statement P does not have results ready to return 3169** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3170** interfaces) then sqlite3_data_count(P) returns 0. 3171** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3172** 3173** See also: [sqlite3_column_count()] 3174*/ 3175SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 3176 3177/* 3178** CAPI3REF: Fundamental Datatypes 3179** KEYWORDS: SQLITE_TEXT 3180** 3181** ^(Every value in SQLite has one of five fundamental datatypes: 3182** 3183** <ul> 3184** <li> 64-bit signed integer 3185** <li> 64-bit IEEE floating point number 3186** <li> string 3187** <li> BLOB 3188** <li> NULL 3189** </ul>)^ 3190** 3191** These constants are codes for each of those types. 3192** 3193** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3194** for a completely different meaning. Software that links against both 3195** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3196** SQLITE_TEXT. 3197*/ 3198#define SQLITE_INTEGER 1 3199#define SQLITE_FLOAT 2 3200#define SQLITE_BLOB 4 3201#define SQLITE_NULL 5 3202#ifdef SQLITE_TEXT 3203# undef SQLITE_TEXT 3204#else 3205# define SQLITE_TEXT 3 3206#endif 3207#define SQLITE3_TEXT 3 3208 3209/* 3210** CAPI3REF: Result Values From A Query 3211** KEYWORDS: {column access functions} 3212** 3213** These routines form the "result set" interface. 3214** 3215** ^These routines return information about a single column of the current 3216** result row of a query. ^In every case the first argument is a pointer 3217** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3218** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3219** and the second argument is the index of the column for which information 3220** should be returned. ^The leftmost column of the result set has the index 0. 3221** ^The number of columns in the result can be determined using 3222** [sqlite3_column_count()]. 3223** 3224** If the SQL statement does not currently point to a valid row, or if the 3225** column index is out of range, the result is undefined. 3226** These routines may only be called when the most recent call to 3227** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3228** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3229** If any of these routines are called after [sqlite3_reset()] or 3230** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3231** something other than [SQLITE_ROW], the results are undefined. 3232** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3233** are called from a different thread while any of these routines 3234** are pending, then the results are undefined. 3235** 3236** ^The sqlite3_column_type() routine returns the 3237** [SQLITE_INTEGER | datatype code] for the initial data type 3238** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3239** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3240** returned by sqlite3_column_type() is only meaningful if no type 3241** conversions have occurred as described below. After a type conversion, 3242** the value returned by sqlite3_column_type() is undefined. Future 3243** versions of SQLite may change the behavior of sqlite3_column_type() 3244** following a type conversion. 3245** 3246** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3247** routine returns the number of bytes in that BLOB or string. 3248** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3249** the string to UTF-8 and then returns the number of bytes. 3250** ^If the result is a numeric value then sqlite3_column_bytes() uses 3251** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3252** the number of bytes in that string. 3253** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3254** 3255** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3256** routine returns the number of bytes in that BLOB or string. 3257** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3258** the string to UTF-16 and then returns the number of bytes. 3259** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3260** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3261** the number of bytes in that string. 3262** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3263** 3264** ^The values returned by [sqlite3_column_bytes()] and 3265** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3266** of the string. ^For clarity: the values returned by 3267** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3268** bytes in the string, not the number of characters. 3269** 3270** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3271** even empty strings, are always zero terminated. ^The return 3272** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3273** 3274** ^The object returned by [sqlite3_column_value()] is an 3275** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3276** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3277** If the [unprotected sqlite3_value] object returned by 3278** [sqlite3_column_value()] is used in any other way, including calls 3279** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3280** or [sqlite3_value_bytes()], then the behavior is undefined. 3281** 3282** These routines attempt to convert the value where appropriate. ^For 3283** example, if the internal representation is FLOAT and a text result 3284** is requested, [sqlite3_snprintf()] is used internally to perform the 3285** conversion automatically. ^(The following table details the conversions 3286** that are applied: 3287** 3288** <blockquote> 3289** <table border="1"> 3290** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3291** 3292** <tr><td> NULL <td> INTEGER <td> Result is 0 3293** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3294** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3295** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3296** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3297** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3298** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3299** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3300** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3301** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3302** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3303** <tr><td> TEXT <td> FLOAT <td> Use atof() 3304** <tr><td> TEXT <td> BLOB <td> No change 3305** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3306** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3307** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3308** </table> 3309** </blockquote>)^ 3310** 3311** The table above makes reference to standard C library functions atoi() 3312** and atof(). SQLite does not really use these functions. It has its 3313** own equivalent internal routines. The atoi() and atof() names are 3314** used in the table for brevity and because they are familiar to most 3315** C programmers. 3316** 3317** Note that when type conversions occur, pointers returned by prior 3318** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3319** sqlite3_column_text16() may be invalidated. 3320** Type conversions and pointer invalidations might occur 3321** in the following cases: 3322** 3323** <ul> 3324** <li> The initial content is a BLOB and sqlite3_column_text() or 3325** sqlite3_column_text16() is called. A zero-terminator might 3326** need to be added to the string.</li> 3327** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3328** sqlite3_column_text16() is called. The content must be converted 3329** to UTF-16.</li> 3330** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3331** sqlite3_column_text() is called. The content must be converted 3332** to UTF-8.</li> 3333** </ul> 3334** 3335** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3336** not invalidate a prior pointer, though of course the content of the buffer 3337** that the prior pointer references will have been modified. Other kinds 3338** of conversion are done in place when it is possible, but sometimes they 3339** are not possible and in those cases prior pointers are invalidated. 3340** 3341** The safest and easiest to remember policy is to invoke these routines 3342** in one of the following ways: 3343** 3344** <ul> 3345** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3346** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3347** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3348** </ul> 3349** 3350** In other words, you should call sqlite3_column_text(), 3351** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3352** into the desired format, then invoke sqlite3_column_bytes() or 3353** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3354** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3355** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3356** with calls to sqlite3_column_bytes(). 3357** 3358** ^The pointers returned are valid until a type conversion occurs as 3359** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3360** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3361** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3362** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3363** [sqlite3_free()]. 3364** 3365** ^(If a memory allocation error occurs during the evaluation of any 3366** of these routines, a default value is returned. The default value 3367** is either the integer 0, the floating point number 0.0, or a NULL 3368** pointer. Subsequent calls to [sqlite3_errcode()] will return 3369** [SQLITE_NOMEM].)^ 3370*/ 3371SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3372SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3373SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3374SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 3375SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 3376SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3377SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3378SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3379SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 3380SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3381 3382/* 3383** CAPI3REF: Destroy A Prepared Statement Object 3384** 3385** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3386** ^If the most recent evaluation of the statement encountered no errors or 3387** or if the statement is never been evaluated, then sqlite3_finalize() returns 3388** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3389** sqlite3_finalize(S) returns the appropriate [error code] or 3390** [extended error code]. 3391** 3392** ^The sqlite3_finalize(S) routine can be called at any point during 3393** the life cycle of [prepared statement] S: 3394** before statement S is ever evaluated, after 3395** one or more calls to [sqlite3_reset()], or after any call 3396** to [sqlite3_step()] regardless of whether or not the statement has 3397** completed execution. 3398** 3399** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3400** 3401** The application must finalize every [prepared statement] in order to avoid 3402** resource leaks. It is a grievous error for the application to try to use 3403** a prepared statement after it has been finalized. Any use of a prepared 3404** statement after it has been finalized can result in undefined and 3405** undesirable behavior such as segfaults and heap corruption. 3406*/ 3407SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 3408 3409/* 3410** CAPI3REF: Reset A Prepared Statement Object 3411** 3412** The sqlite3_reset() function is called to reset a [prepared statement] 3413** object back to its initial state, ready to be re-executed. 3414** ^Any SQL statement variables that had values bound to them using 3415** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3416** Use [sqlite3_clear_bindings()] to reset the bindings. 3417** 3418** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3419** back to the beginning of its program. 3420** 3421** ^If the most recent call to [sqlite3_step(S)] for the 3422** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3423** or if [sqlite3_step(S)] has never before been called on S, 3424** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3425** 3426** ^If the most recent call to [sqlite3_step(S)] for the 3427** [prepared statement] S indicated an error, then 3428** [sqlite3_reset(S)] returns an appropriate [error code]. 3429** 3430** ^The [sqlite3_reset(S)] interface does not change the values 3431** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3432*/ 3433SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 3434 3435/* 3436** CAPI3REF: Create Or Redefine SQL Functions 3437** KEYWORDS: {function creation routines} 3438** KEYWORDS: {application-defined SQL function} 3439** KEYWORDS: {application-defined SQL functions} 3440** 3441** ^These functions (collectively known as "function creation routines") 3442** are used to add SQL functions or aggregates or to redefine the behavior 3443** of existing SQL functions or aggregates. The only differences between 3444** these routines are the text encoding expected for 3445** the second parameter (the name of the function being created) 3446** and the presence or absence of a destructor callback for 3447** the application data pointer. 3448** 3449** ^The first parameter is the [database connection] to which the SQL 3450** function is to be added. ^If an application uses more than one database 3451** connection then application-defined SQL functions must be added 3452** to each database connection separately. 3453** 3454** ^The second parameter is the name of the SQL function to be created or 3455** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3456** representation, exclusive of the zero-terminator. ^Note that the name 3457** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3458** ^Any attempt to create a function with a longer name 3459** will result in [SQLITE_MISUSE] being returned. 3460** 3461** ^The third parameter (nArg) 3462** is the number of arguments that the SQL function or 3463** aggregate takes. ^If this parameter is -1, then the SQL function or 3464** aggregate may take any number of arguments between 0 and the limit 3465** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3466** parameter is less than -1 or greater than 127 then the behavior is 3467** undefined. 3468** 3469** ^The fourth parameter, eTextRep, specifies what 3470** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3471** its parameters. Every SQL function implementation must be able to work 3472** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3473** more efficient with one encoding than another. ^An application may 3474** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3475** times with the same function but with different values of eTextRep. 3476** ^When multiple implementations of the same function are available, SQLite 3477** will pick the one that involves the least amount of data conversion. 3478** If there is only a single implementation which does not care what text 3479** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3480** 3481** ^(The fifth parameter is an arbitrary pointer. The implementation of the 3482** function can gain access to this pointer using [sqlite3_user_data()].)^ 3483** 3484** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 3485** pointers to C-language functions that implement the SQL function or 3486** aggregate. ^A scalar SQL function requires an implementation of the xFunc 3487** callback only; NULL pointers must be passed as the xStep and xFinal 3488** parameters. ^An aggregate SQL function requires an implementation of xStep 3489** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 3490** SQL function or aggregate, pass NULL pointers for all three function 3491** callbacks. 3492** 3493** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 3494** then it is destructor for the application data pointer. 3495** The destructor is invoked when the function is deleted, either by being 3496** overloaded or when the database connection closes.)^ 3497** ^The destructor is also invoked if the call to 3498** sqlite3_create_function_v2() fails. 3499** ^When the destructor callback of the tenth parameter is invoked, it 3500** is passed a single argument which is a copy of the application data 3501** pointer which was the fifth parameter to sqlite3_create_function_v2(). 3502** 3503** ^It is permitted to register multiple implementations of the same 3504** functions with the same name but with either differing numbers of 3505** arguments or differing preferred text encodings. ^SQLite will use 3506** the implementation that most closely matches the way in which the 3507** SQL function is used. ^A function implementation with a non-negative 3508** nArg parameter is a better match than a function implementation with 3509** a negative nArg. ^A function where the preferred text encoding 3510** matches the database encoding is a better 3511** match than a function where the encoding is different. 3512** ^A function where the encoding difference is between UTF16le and UTF16be 3513** is a closer match than a function where the encoding difference is 3514** between UTF8 and UTF16. 3515** 3516** ^Built-in functions may be overloaded by new application-defined functions. 3517** 3518** ^An application-defined function is permitted to call other 3519** SQLite interfaces. However, such calls must not 3520** close the database connection nor finalize or reset the prepared 3521** statement in which the function is running. 3522*/ 3523SQLITE_API int sqlite3_create_function( 3524 sqlite3 *db, 3525 const char *zFunctionName, 3526 int nArg, 3527 int eTextRep, 3528 void *pApp, 3529 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3530 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3531 void (*xFinal)(sqlite3_context*) 3532); 3533SQLITE_API int sqlite3_create_function16( 3534 sqlite3 *db, 3535 const void *zFunctionName, 3536 int nArg, 3537 int eTextRep, 3538 void *pApp, 3539 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3540 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3541 void (*xFinal)(sqlite3_context*) 3542); 3543SQLITE_API int sqlite3_create_function_v2( 3544 sqlite3 *db, 3545 const char *zFunctionName, 3546 int nArg, 3547 int eTextRep, 3548 void *pApp, 3549 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3550 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3551 void (*xFinal)(sqlite3_context*), 3552 void(*xDestroy)(void*) 3553); 3554 3555/* 3556** CAPI3REF: Text Encodings 3557** 3558** These constant define integer codes that represent the various 3559** text encodings supported by SQLite. 3560*/ 3561#define SQLITE_UTF8 1 3562#define SQLITE_UTF16LE 2 3563#define SQLITE_UTF16BE 3 3564#define SQLITE_UTF16 4 /* Use native byte order */ 3565#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3566#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3567 3568/* 3569** CAPI3REF: Deprecated Functions 3570** DEPRECATED 3571** 3572** These functions are [deprecated]. In order to maintain 3573** backwards compatibility with older code, these functions continue 3574** to be supported. However, new applications should avoid 3575** the use of these functions. To help encourage people to avoid 3576** using these functions, we are not going to tell you what they do. 3577*/ 3578#ifndef SQLITE_OMIT_DEPRECATED 3579SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3580SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3581SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3582SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 3583SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3584SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3585#endif 3586 3587/* 3588** CAPI3REF: Obtaining SQL Function Parameter Values 3589** 3590** The C-language implementation of SQL functions and aggregates uses 3591** this set of interface routines to access the parameter values on 3592** the function or aggregate. 3593** 3594** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3595** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3596** define callbacks that implement the SQL functions and aggregates. 3597** The 3rd parameter to these callbacks is an array of pointers to 3598** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3599** each parameter to the SQL function. These routines are used to 3600** extract values from the [sqlite3_value] objects. 3601** 3602** These routines work only with [protected sqlite3_value] objects. 3603** Any attempt to use these routines on an [unprotected sqlite3_value] 3604** object results in undefined behavior. 3605** 3606** ^These routines work just like the corresponding [column access functions] 3607** except that these routines take a single [protected sqlite3_value] object 3608** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3609** 3610** ^The sqlite3_value_text16() interface extracts a UTF-16 string 3611** in the native byte-order of the host machine. ^The 3612** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3613** extract UTF-16 strings as big-endian and little-endian respectively. 3614** 3615** ^(The sqlite3_value_numeric_type() interface attempts to apply 3616** numeric affinity to the value. This means that an attempt is 3617** made to convert the value to an integer or floating point. If 3618** such a conversion is possible without loss of information (in other 3619** words, if the value is a string that looks like a number) 3620** then the conversion is performed. Otherwise no conversion occurs. 3621** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 3622** 3623** Please pay particular attention to the fact that the pointer returned 3624** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3625** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3626** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3627** or [sqlite3_value_text16()]. 3628** 3629** These routines must be called from the same thread as 3630** the SQL function that supplied the [sqlite3_value*] parameters. 3631*/ 3632SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 3633SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 3634SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 3635SQLITE_API double sqlite3_value_double(sqlite3_value*); 3636SQLITE_API int sqlite3_value_int(sqlite3_value*); 3637SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3638SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 3639SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 3640SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 3641SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 3642SQLITE_API int sqlite3_value_type(sqlite3_value*); 3643SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 3644 3645/* 3646** CAPI3REF: Obtain Aggregate Function Context 3647** 3648** Implementations of aggregate SQL functions use this 3649** routine to allocate memory for storing their state. 3650** 3651** ^The first time the sqlite3_aggregate_context(C,N) routine is called 3652** for a particular aggregate function, SQLite 3653** allocates N of memory, zeroes out that memory, and returns a pointer 3654** to the new memory. ^On second and subsequent calls to 3655** sqlite3_aggregate_context() for the same aggregate function instance, 3656** the same buffer is returned. Sqlite3_aggregate_context() is normally 3657** called once for each invocation of the xStep callback and then one 3658** last time when the xFinal callback is invoked. ^(When no rows match 3659** an aggregate query, the xStep() callback of the aggregate function 3660** implementation is never called and xFinal() is called exactly once. 3661** In those cases, sqlite3_aggregate_context() might be called for the 3662** first time from within xFinal().)^ 3663** 3664** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is 3665** less than or equal to zero or if a memory allocate error occurs. 3666** 3667** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 3668** determined by the N parameter on first successful call. Changing the 3669** value of N in subsequent call to sqlite3_aggregate_context() within 3670** the same aggregate function instance will not resize the memory 3671** allocation.)^ 3672** 3673** ^SQLite automatically frees the memory allocated by 3674** sqlite3_aggregate_context() when the aggregate query concludes. 3675** 3676** The first parameter must be a copy of the 3677** [sqlite3_context | SQL function context] that is the first parameter 3678** to the xStep or xFinal callback routine that implements the aggregate 3679** function. 3680** 3681** This routine must be called from the same thread in which 3682** the aggregate SQL function is running. 3683*/ 3684SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3685 3686/* 3687** CAPI3REF: User Data For Functions 3688** 3689** ^The sqlite3_user_data() interface returns a copy of 3690** the pointer that was the pUserData parameter (the 5th parameter) 3691** of the [sqlite3_create_function()] 3692** and [sqlite3_create_function16()] routines that originally 3693** registered the application defined function. 3694** 3695** This routine must be called from the same thread in which 3696** the application-defined function is running. 3697*/ 3698SQLITE_API void *sqlite3_user_data(sqlite3_context*); 3699 3700/* 3701** CAPI3REF: Database Connection For Functions 3702** 3703** ^The sqlite3_context_db_handle() interface returns a copy of 3704** the pointer to the [database connection] (the 1st parameter) 3705** of the [sqlite3_create_function()] 3706** and [sqlite3_create_function16()] routines that originally 3707** registered the application defined function. 3708*/ 3709SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3710 3711/* 3712** CAPI3REF: Function Auxiliary Data 3713** 3714** The following two functions may be used by scalar SQL functions to 3715** associate metadata with argument values. If the same value is passed to 3716** multiple invocations of the same SQL function during query execution, under 3717** some circumstances the associated metadata may be preserved. This may 3718** be used, for example, to add a regular-expression matching scalar 3719** function. The compiled version of the regular expression is stored as 3720** metadata associated with the SQL value passed as the regular expression 3721** pattern. The compiled regular expression can be reused on multiple 3722** invocations of the same function so that the original pattern string 3723** does not need to be recompiled on each invocation. 3724** 3725** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 3726** associated by the sqlite3_set_auxdata() function with the Nth argument 3727** value to the application-defined function. ^If no metadata has been ever 3728** been set for the Nth argument of the function, or if the corresponding 3729** function parameter has changed since the meta-data was set, 3730** then sqlite3_get_auxdata() returns a NULL pointer. 3731** 3732** ^The sqlite3_set_auxdata() interface saves the metadata 3733** pointed to by its 3rd parameter as the metadata for the N-th 3734** argument of the application-defined function. Subsequent 3735** calls to sqlite3_get_auxdata() might return this data, if it has 3736** not been destroyed. 3737** ^If it is not NULL, SQLite will invoke the destructor 3738** function given by the 4th parameter to sqlite3_set_auxdata() on 3739** the metadata when the corresponding function parameter changes 3740** or when the SQL statement completes, whichever comes first. 3741** 3742** SQLite is free to call the destructor and drop metadata on any 3743** parameter of any function at any time. ^The only guarantee is that 3744** the destructor will be called before the metadata is dropped. 3745** 3746** ^(In practice, metadata is preserved between function calls for 3747** expressions that are constant at compile time. This includes literal 3748** values and [parameters].)^ 3749** 3750** These routines must be called from the same thread in which 3751** the SQL function is running. 3752*/ 3753SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 3754SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 3755 3756 3757/* 3758** CAPI3REF: Constants Defining Special Destructor Behavior 3759** 3760** These are special values for the destructor that is passed in as the 3761** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 3762** argument is SQLITE_STATIC, it means that the content pointer is constant 3763** and will never change. It does not need to be destroyed. ^The 3764** SQLITE_TRANSIENT value means that the content will likely change in 3765** the near future and that SQLite should make its own private copy of 3766** the content before returning. 3767** 3768** The typedef is necessary to work around problems in certain 3769** C++ compilers. See ticket #2191. 3770*/ 3771typedef void (*sqlite3_destructor_type)(void*); 3772#define SQLITE_STATIC ((sqlite3_destructor_type)0) 3773#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 3774 3775/* 3776** CAPI3REF: Setting The Result Of An SQL Function 3777** 3778** These routines are used by the xFunc or xFinal callbacks that 3779** implement SQL functions and aggregates. See 3780** [sqlite3_create_function()] and [sqlite3_create_function16()] 3781** for additional information. 3782** 3783** These functions work very much like the [parameter binding] family of 3784** functions used to bind values to host parameters in prepared statements. 3785** Refer to the [SQL parameter] documentation for additional information. 3786** 3787** ^The sqlite3_result_blob() interface sets the result from 3788** an application-defined function to be the BLOB whose content is pointed 3789** to by the second parameter and which is N bytes long where N is the 3790** third parameter. 3791** 3792** ^The sqlite3_result_zeroblob() interfaces set the result of 3793** the application-defined function to be a BLOB containing all zero 3794** bytes and N bytes in size, where N is the value of the 2nd parameter. 3795** 3796** ^The sqlite3_result_double() interface sets the result from 3797** an application-defined function to be a floating point value specified 3798** by its 2nd argument. 3799** 3800** ^The sqlite3_result_error() and sqlite3_result_error16() functions 3801** cause the implemented SQL function to throw an exception. 3802** ^SQLite uses the string pointed to by the 3803** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 3804** as the text of an error message. ^SQLite interprets the error 3805** message string from sqlite3_result_error() as UTF-8. ^SQLite 3806** interprets the string from sqlite3_result_error16() as UTF-16 in native 3807** byte order. ^If the third parameter to sqlite3_result_error() 3808** or sqlite3_result_error16() is negative then SQLite takes as the error 3809** message all text up through the first zero character. 3810** ^If the third parameter to sqlite3_result_error() or 3811** sqlite3_result_error16() is non-negative then SQLite takes that many 3812** bytes (not characters) from the 2nd parameter as the error message. 3813** ^The sqlite3_result_error() and sqlite3_result_error16() 3814** routines make a private copy of the error message text before 3815** they return. Hence, the calling function can deallocate or 3816** modify the text after they return without harm. 3817** ^The sqlite3_result_error_code() function changes the error code 3818** returned by SQLite as a result of an error in a function. ^By default, 3819** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 3820** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 3821** 3822** ^The sqlite3_result_toobig() interface causes SQLite to throw an error 3823** indicating that a string or BLOB is too long to represent. 3824** 3825** ^The sqlite3_result_nomem() interface causes SQLite to throw an error 3826** indicating that a memory allocation failed. 3827** 3828** ^The sqlite3_result_int() interface sets the return value 3829** of the application-defined function to be the 32-bit signed integer 3830** value given in the 2nd argument. 3831** ^The sqlite3_result_int64() interface sets the return value 3832** of the application-defined function to be the 64-bit signed integer 3833** value given in the 2nd argument. 3834** 3835** ^The sqlite3_result_null() interface sets the return value 3836** of the application-defined function to be NULL. 3837** 3838** ^The sqlite3_result_text(), sqlite3_result_text16(), 3839** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 3840** set the return value of the application-defined function to be 3841** a text string which is represented as UTF-8, UTF-16 native byte order, 3842** UTF-16 little endian, or UTF-16 big endian, respectively. 3843** ^SQLite takes the text result from the application from 3844** the 2nd parameter of the sqlite3_result_text* interfaces. 3845** ^If the 3rd parameter to the sqlite3_result_text* interfaces 3846** is negative, then SQLite takes result text from the 2nd parameter 3847** through the first zero character. 3848** ^If the 3rd parameter to the sqlite3_result_text* interfaces 3849** is non-negative, then as many bytes (not characters) of the text 3850** pointed to by the 2nd parameter are taken as the application-defined 3851** function result. 3852** ^If the 4th parameter to the sqlite3_result_text* interfaces 3853** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 3854** function as the destructor on the text or BLOB result when it has 3855** finished using that result. 3856** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 3857** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 3858** assumes that the text or BLOB result is in constant space and does not 3859** copy the content of the parameter nor call a destructor on the content 3860** when it has finished using that result. 3861** ^If the 4th parameter to the sqlite3_result_text* interfaces 3862** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 3863** then SQLite makes a copy of the result into space obtained from 3864** from [sqlite3_malloc()] before it returns. 3865** 3866** ^The sqlite3_result_value() interface sets the result of 3867** the application-defined function to be a copy the 3868** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 3869** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 3870** so that the [sqlite3_value] specified in the parameter may change or 3871** be deallocated after sqlite3_result_value() returns without harm. 3872** ^A [protected sqlite3_value] object may always be used where an 3873** [unprotected sqlite3_value] object is required, so either 3874** kind of [sqlite3_value] object can be used with this interface. 3875** 3876** If these routines are called from within the different thread 3877** than the one containing the application-defined function that received 3878** the [sqlite3_context] pointer, the results are undefined. 3879*/ 3880SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 3881SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 3882SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 3883SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 3884SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 3885SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 3886SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 3887SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 3888SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 3889SQLITE_API void sqlite3_result_null(sqlite3_context*); 3890SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 3891SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 3892SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 3893SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 3894SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 3895SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 3896 3897/* 3898** CAPI3REF: Define New Collating Sequences 3899** 3900** ^These functions add, remove, or modify a [collation] associated 3901** with the [database connection] specified as the first argument. 3902** 3903** ^The name of the collation is a UTF-8 string 3904** for sqlite3_create_collation() and sqlite3_create_collation_v2() 3905** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 3906** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 3907** considered to be the same name. 3908** 3909** ^(The third argument (eTextRep) must be one of the constants: 3910** <ul> 3911** <li> [SQLITE_UTF8], 3912** <li> [SQLITE_UTF16LE], 3913** <li> [SQLITE_UTF16BE], 3914** <li> [SQLITE_UTF16], or 3915** <li> [SQLITE_UTF16_ALIGNED]. 3916** </ul>)^ 3917** ^The eTextRep argument determines the encoding of strings passed 3918** to the collating function callback, xCallback. 3919** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 3920** force strings to be UTF16 with native byte order. 3921** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 3922** on an even byte address. 3923** 3924** ^The fourth argument, pArg, is an application data pointer that is passed 3925** through as the first argument to the collating function callback. 3926** 3927** ^The fifth argument, xCallback, is a pointer to the collating function. 3928** ^Multiple collating functions can be registered using the same name but 3929** with different eTextRep parameters and SQLite will use whichever 3930** function requires the least amount of data transformation. 3931** ^If the xCallback argument is NULL then the collating function is 3932** deleted. ^When all collating functions having the same name are deleted, 3933** that collation is no longer usable. 3934** 3935** ^The collating function callback is invoked with a copy of the pArg 3936** application data pointer and with two strings in the encoding specified 3937** by the eTextRep argument. The collating function must return an 3938** integer that is negative, zero, or positive 3939** if the first string is less than, equal to, or greater than the second, 3940** respectively. A collating function must always return the same answer 3941** given the same inputs. If two or more collating functions are registered 3942** to the same collation name (using different eTextRep values) then all 3943** must give an equivalent answer when invoked with equivalent strings. 3944** The collating function must obey the following properties for all 3945** strings A, B, and C: 3946** 3947** <ol> 3948** <li> If A==B then B==A. 3949** <li> If A==B and B==C then A==C. 3950** <li> If A<B THEN B>A. 3951** <li> If A<B and B<C then A<C. 3952** </ol> 3953** 3954** If a collating function fails any of the above constraints and that 3955** collating function is registered and used, then the behavior of SQLite 3956** is undefined. 3957** 3958** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 3959** with the addition that the xDestroy callback is invoked on pArg when 3960** the collating function is deleted. 3961** ^Collating functions are deleted when they are overridden by later 3962** calls to the collation creation functions or when the 3963** [database connection] is closed using [sqlite3_close()]. 3964** 3965** ^The xDestroy callback is <u>not</u> called if the 3966** sqlite3_create_collation_v2() function fails. Applications that invoke 3967** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 3968** check the return code and dispose of the application data pointer 3969** themselves rather than expecting SQLite to deal with it for them. 3970** This is different from every other SQLite interface. The inconsistency 3971** is unfortunate but cannot be changed without breaking backwards 3972** compatibility. 3973** 3974** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 3975*/ 3976SQLITE_API int sqlite3_create_collation( 3977 sqlite3*, 3978 const char *zName, 3979 int eTextRep, 3980 void *pArg, 3981 int(*xCompare)(void*,int,const void*,int,const void*) 3982); 3983SQLITE_API int sqlite3_create_collation_v2( 3984 sqlite3*, 3985 const char *zName, 3986 int eTextRep, 3987 void *pArg, 3988 int(*xCompare)(void*,int,const void*,int,const void*), 3989 void(*xDestroy)(void*) 3990); 3991SQLITE_API int sqlite3_create_collation16( 3992 sqlite3*, 3993 const void *zName, 3994 int eTextRep, 3995 void *pArg, 3996 int(*xCompare)(void*,int,const void*,int,const void*) 3997); 3998 3999/* 4000** CAPI3REF: Collation Needed Callbacks 4001** 4002** ^To avoid having to register all collation sequences before a database 4003** can be used, a single callback function may be registered with the 4004** [database connection] to be invoked whenever an undefined collation 4005** sequence is required. 4006** 4007** ^If the function is registered using the sqlite3_collation_needed() API, 4008** then it is passed the names of undefined collation sequences as strings 4009** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4010** the names are passed as UTF-16 in machine native byte order. 4011** ^A call to either function replaces the existing collation-needed callback. 4012** 4013** ^(When the callback is invoked, the first argument passed is a copy 4014** of the second argument to sqlite3_collation_needed() or 4015** sqlite3_collation_needed16(). The second argument is the database 4016** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4017** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4018** sequence function required. The fourth parameter is the name of the 4019** required collation sequence.)^ 4020** 4021** The callback function should register the desired collation using 4022** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4023** [sqlite3_create_collation_v2()]. 4024*/ 4025SQLITE_API int sqlite3_collation_needed( 4026 sqlite3*, 4027 void*, 4028 void(*)(void*,sqlite3*,int eTextRep,const char*) 4029); 4030SQLITE_API int sqlite3_collation_needed16( 4031 sqlite3*, 4032 void*, 4033 void(*)(void*,sqlite3*,int eTextRep,const void*) 4034); 4035 4036#ifdef SQLITE_HAS_CODEC 4037/* 4038** Specify the key for an encrypted database. This routine should be 4039** called right after sqlite3_open(). 4040** 4041** The code to implement this API is not available in the public release 4042** of SQLite. 4043*/ 4044SQLITE_API int sqlite3_key( 4045 sqlite3 *db, /* Database to be rekeyed */ 4046 const void *pKey, int nKey /* The key */ 4047); 4048 4049/* 4050** Change the key on an open database. If the current database is not 4051** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4052** database is decrypted. 4053** 4054** The code to implement this API is not available in the public release 4055** of SQLite. 4056*/ 4057SQLITE_API int sqlite3_rekey( 4058 sqlite3 *db, /* Database to be rekeyed */ 4059 const void *pKey, int nKey /* The new key */ 4060); 4061 4062/* 4063** Specify the activation key for a SEE database. Unless 4064** activated, none of the SEE routines will work. 4065*/ 4066SQLITE_API void sqlite3_activate_see( 4067 const char *zPassPhrase /* Activation phrase */ 4068); 4069#endif 4070 4071#ifdef SQLITE_ENABLE_CEROD 4072/* 4073** Specify the activation key for a CEROD database. Unless 4074** activated, none of the CEROD routines will work. 4075*/ 4076SQLITE_API void sqlite3_activate_cerod( 4077 const char *zPassPhrase /* Activation phrase */ 4078); 4079#endif 4080 4081/* 4082** CAPI3REF: Suspend Execution For A Short Time 4083** 4084** The sqlite3_sleep() function causes the current thread to suspend execution 4085** for at least a number of milliseconds specified in its parameter. 4086** 4087** If the operating system does not support sleep requests with 4088** millisecond time resolution, then the time will be rounded up to 4089** the nearest second. The number of milliseconds of sleep actually 4090** requested from the operating system is returned. 4091** 4092** ^SQLite implements this interface by calling the xSleep() 4093** method of the default [sqlite3_vfs] object. If the xSleep() method 4094** of the default VFS is not implemented correctly, or not implemented at 4095** all, then the behavior of sqlite3_sleep() may deviate from the description 4096** in the previous paragraphs. 4097*/ 4098SQLITE_API int sqlite3_sleep(int); 4099 4100/* 4101** CAPI3REF: Name Of The Folder Holding Temporary Files 4102** 4103** ^(If this global variable is made to point to a string which is 4104** the name of a folder (a.k.a. directory), then all temporary files 4105** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4106** will be placed in that directory.)^ ^If this variable 4107** is a NULL pointer, then SQLite performs a search for an appropriate 4108** temporary file directory. 4109** 4110** It is not safe to read or modify this variable in more than one 4111** thread at a time. It is not safe to read or modify this variable 4112** if a [database connection] is being used at the same time in a separate 4113** thread. 4114** It is intended that this variable be set once 4115** as part of process initialization and before any SQLite interface 4116** routines have been called and that this variable remain unchanged 4117** thereafter. 4118** 4119** ^The [temp_store_directory pragma] may modify this variable and cause 4120** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4121** the [temp_store_directory pragma] always assumes that any string 4122** that this variable points to is held in memory obtained from 4123** [sqlite3_malloc] and the pragma may attempt to free that memory 4124** using [sqlite3_free]. 4125** Hence, if this variable is modified directly, either it should be 4126** made NULL or made to point to memory obtained from [sqlite3_malloc] 4127** or else the use of the [temp_store_directory pragma] should be avoided. 4128*/ 4129SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4130 4131/* 4132** CAPI3REF: Test For Auto-Commit Mode 4133** KEYWORDS: {autocommit mode} 4134** 4135** ^The sqlite3_get_autocommit() interface returns non-zero or 4136** zero if the given database connection is or is not in autocommit mode, 4137** respectively. ^Autocommit mode is on by default. 4138** ^Autocommit mode is disabled by a [BEGIN] statement. 4139** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4140** 4141** If certain kinds of errors occur on a statement within a multi-statement 4142** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4143** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4144** transaction might be rolled back automatically. The only way to 4145** find out whether SQLite automatically rolled back the transaction after 4146** an error is to use this function. 4147** 4148** If another thread changes the autocommit status of the database 4149** connection while this routine is running, then the return value 4150** is undefined. 4151*/ 4152SQLITE_API int sqlite3_get_autocommit(sqlite3*); 4153 4154/* 4155** CAPI3REF: Find The Database Handle Of A Prepared Statement 4156** 4157** ^The sqlite3_db_handle interface returns the [database connection] handle 4158** to which a [prepared statement] belongs. ^The [database connection] 4159** returned by sqlite3_db_handle is the same [database connection] 4160** that was the first argument 4161** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4162** create the statement in the first place. 4163*/ 4164SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4165 4166/* 4167** CAPI3REF: Find the next prepared statement 4168** 4169** ^This interface returns a pointer to the next [prepared statement] after 4170** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4171** then this interface returns a pointer to the first prepared statement 4172** associated with the database connection pDb. ^If no prepared statement 4173** satisfies the conditions of this routine, it returns NULL. 4174** 4175** The [database connection] pointer D in a call to 4176** [sqlite3_next_stmt(D,S)] must refer to an open database 4177** connection and in particular must not be a NULL pointer. 4178*/ 4179SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4180 4181/* 4182** CAPI3REF: Commit And Rollback Notification Callbacks 4183** 4184** ^The sqlite3_commit_hook() interface registers a callback 4185** function to be invoked whenever a transaction is [COMMIT | committed]. 4186** ^Any callback set by a previous call to sqlite3_commit_hook() 4187** for the same database connection is overridden. 4188** ^The sqlite3_rollback_hook() interface registers a callback 4189** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4190** ^Any callback set by a previous call to sqlite3_rollback_hook() 4191** for the same database connection is overridden. 4192** ^The pArg argument is passed through to the callback. 4193** ^If the callback on a commit hook function returns non-zero, 4194** then the commit is converted into a rollback. 4195** 4196** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4197** return the P argument from the previous call of the same function 4198** on the same [database connection] D, or NULL for 4199** the first call for each function on D. 4200** 4201** The callback implementation must not do anything that will modify 4202** the database connection that invoked the callback. Any actions 4203** to modify the database connection must be deferred until after the 4204** completion of the [sqlite3_step()] call that triggered the commit 4205** or rollback hook in the first place. 4206** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4207** database connections for the meaning of "modify" in this paragraph. 4208** 4209** ^Registering a NULL function disables the callback. 4210** 4211** ^When the commit hook callback routine returns zero, the [COMMIT] 4212** operation is allowed to continue normally. ^If the commit hook 4213** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4214** ^The rollback hook is invoked on a rollback that results from a commit 4215** hook returning non-zero, just as it would be with any other rollback. 4216** 4217** ^For the purposes of this API, a transaction is said to have been 4218** rolled back if an explicit "ROLLBACK" statement is executed, or 4219** an error or constraint causes an implicit rollback to occur. 4220** ^The rollback callback is not invoked if a transaction is 4221** automatically rolled back because the database connection is closed. 4222** 4223** See also the [sqlite3_update_hook()] interface. 4224*/ 4225SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4226SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4227 4228/* 4229** CAPI3REF: Data Change Notification Callbacks 4230** 4231** ^The sqlite3_update_hook() interface registers a callback function 4232** with the [database connection] identified by the first argument 4233** to be invoked whenever a row is updated, inserted or deleted. 4234** ^Any callback set by a previous call to this function 4235** for the same database connection is overridden. 4236** 4237** ^The second argument is a pointer to the function to invoke when a 4238** row is updated, inserted or deleted. 4239** ^The first argument to the callback is a copy of the third argument 4240** to sqlite3_update_hook(). 4241** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4242** or [SQLITE_UPDATE], depending on the operation that caused the callback 4243** to be invoked. 4244** ^The third and fourth arguments to the callback contain pointers to the 4245** database and table name containing the affected row. 4246** ^The final callback parameter is the [rowid] of the row. 4247** ^In the case of an update, this is the [rowid] after the update takes place. 4248** 4249** ^(The update hook is not invoked when internal system tables are 4250** modified (i.e. sqlite_master and sqlite_sequence).)^ 4251** 4252** ^In the current implementation, the update hook 4253** is not invoked when duplication rows are deleted because of an 4254** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4255** invoked when rows are deleted using the [truncate optimization]. 4256** The exceptions defined in this paragraph might change in a future 4257** release of SQLite. 4258** 4259** The update hook implementation must not do anything that will modify 4260** the database connection that invoked the update hook. Any actions 4261** to modify the database connection must be deferred until after the 4262** completion of the [sqlite3_step()] call that triggered the update hook. 4263** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4264** database connections for the meaning of "modify" in this paragraph. 4265** 4266** ^The sqlite3_update_hook(D,C,P) function 4267** returns the P argument from the previous call 4268** on the same [database connection] D, or NULL for 4269** the first call on D. 4270** 4271** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4272** interfaces. 4273*/ 4274SQLITE_API void *sqlite3_update_hook( 4275 sqlite3*, 4276 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4277 void* 4278); 4279 4280/* 4281** CAPI3REF: Enable Or Disable Shared Pager Cache 4282** KEYWORDS: {shared cache} 4283** 4284** ^(This routine enables or disables the sharing of the database cache 4285** and schema data structures between [database connection | connections] 4286** to the same database. Sharing is enabled if the argument is true 4287** and disabled if the argument is false.)^ 4288** 4289** ^Cache sharing is enabled and disabled for an entire process. 4290** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4291** sharing was enabled or disabled for each thread separately. 4292** 4293** ^(The cache sharing mode set by this interface effects all subsequent 4294** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4295** Existing database connections continue use the sharing mode 4296** that was in effect at the time they were opened.)^ 4297** 4298** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4299** successfully. An [error code] is returned otherwise.)^ 4300** 4301** ^Shared cache is disabled by default. But this might change in 4302** future releases of SQLite. Applications that care about shared 4303** cache setting should set it explicitly. 4304** 4305** See Also: [SQLite Shared-Cache Mode] 4306*/ 4307SQLITE_API int sqlite3_enable_shared_cache(int); 4308 4309/* 4310** CAPI3REF: Attempt To Free Heap Memory 4311** 4312** ^The sqlite3_release_memory() interface attempts to free N bytes 4313** of heap memory by deallocating non-essential memory allocations 4314** held by the database library. Memory used to cache database 4315** pages to improve performance is an example of non-essential memory. 4316** ^sqlite3_release_memory() returns the number of bytes actually freed, 4317** which might be more or less than the amount requested. 4318** ^The sqlite3_release_memory() routine is a no-op returning zero 4319** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4320*/ 4321SQLITE_API int sqlite3_release_memory(int); 4322 4323/* 4324** CAPI3REF: Impose A Limit On Heap Size 4325** 4326** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4327** soft limit on the amount of heap memory that may be allocated by SQLite. 4328** ^SQLite strives to keep heap memory utilization below the soft heap 4329** limit by reducing the number of pages held in the page cache 4330** as heap memory usages approaches the limit. 4331** ^The soft heap limit is "soft" because even though SQLite strives to stay 4332** below the limit, it will exceed the limit rather than generate 4333** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4334** is advisory only. 4335** 4336** ^The return value from sqlite3_soft_heap_limit64() is the size of 4337** the soft heap limit prior to the call. ^If the argument N is negative 4338** then no change is made to the soft heap limit. Hence, the current 4339** size of the soft heap limit can be determined by invoking 4340** sqlite3_soft_heap_limit64() with a negative argument. 4341** 4342** ^If the argument N is zero then the soft heap limit is disabled. 4343** 4344** ^(The soft heap limit is not enforced in the current implementation 4345** if one or more of following conditions are true: 4346** 4347** <ul> 4348** <li> The soft heap limit is set to zero. 4349** <li> Memory accounting is disabled using a combination of the 4350** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 4351** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 4352** <li> An alternative page cache implementation is specified using 4353** [sqlite3_config]([SQLITE_CONFIG_PCACHE],...). 4354** <li> The page cache allocates from its own memory pool supplied 4355** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 4356** from the heap. 4357** </ul>)^ 4358** 4359** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 4360** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 4361** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 4362** the soft heap limit is enforced on every memory allocation. Without 4363** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 4364** when memory is allocated by the page cache. Testing suggests that because 4365** the page cache is the predominate memory user in SQLite, most 4366** applications will achieve adequate soft heap limit enforcement without 4367** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4368** 4369** The circumstances under which SQLite will enforce the soft heap limit may 4370** changes in future releases of SQLite. 4371*/ 4372SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 4373 4374/* 4375** CAPI3REF: Deprecated Soft Heap Limit Interface 4376** DEPRECATED 4377** 4378** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 4379** interface. This routine is provided for historical compatibility 4380** only. All new applications should use the 4381** [sqlite3_soft_heap_limit64()] interface rather than this one. 4382*/ 4383SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 4384 4385 4386/* 4387** CAPI3REF: Extract Metadata About A Column Of A Table 4388** 4389** ^This routine returns metadata about a specific column of a specific 4390** database table accessible using the [database connection] handle 4391** passed as the first function argument. 4392** 4393** ^The column is identified by the second, third and fourth parameters to 4394** this function. ^The second parameter is either the name of the database 4395** (i.e. "main", "temp", or an attached database) containing the specified 4396** table or NULL. ^If it is NULL, then all attached databases are searched 4397** for the table using the same algorithm used by the database engine to 4398** resolve unqualified table references. 4399** 4400** ^The third and fourth parameters to this function are the table and column 4401** name of the desired column, respectively. Neither of these parameters 4402** may be NULL. 4403** 4404** ^Metadata is returned by writing to the memory locations passed as the 5th 4405** and subsequent parameters to this function. ^Any of these arguments may be 4406** NULL, in which case the corresponding element of metadata is omitted. 4407** 4408** ^(<blockquote> 4409** <table border="1"> 4410** <tr><th> Parameter <th> Output<br>Type <th> Description 4411** 4412** <tr><td> 5th <td> const char* <td> Data type 4413** <tr><td> 6th <td> const char* <td> Name of default collation sequence 4414** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 4415** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 4416** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 4417** </table> 4418** </blockquote>)^ 4419** 4420** ^The memory pointed to by the character pointers returned for the 4421** declaration type and collation sequence is valid only until the next 4422** call to any SQLite API function. 4423** 4424** ^If the specified table is actually a view, an [error code] is returned. 4425** 4426** ^If the specified column is "rowid", "oid" or "_rowid_" and an 4427** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 4428** parameters are set for the explicitly declared column. ^(If there is no 4429** explicitly declared [INTEGER PRIMARY KEY] column, then the output 4430** parameters are set as follows: 4431** 4432** <pre> 4433** data type: "INTEGER" 4434** collation sequence: "BINARY" 4435** not null: 0 4436** primary key: 1 4437** auto increment: 0 4438** </pre>)^ 4439** 4440** ^(This function may load one or more schemas from database files. If an 4441** error occurs during this process, or if the requested table or column 4442** cannot be found, an [error code] is returned and an error message left 4443** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 4444** 4445** ^This API is only available if the library was compiled with the 4446** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 4447*/ 4448SQLITE_API int sqlite3_table_column_metadata( 4449 sqlite3 *db, /* Connection handle */ 4450 const char *zDbName, /* Database name or NULL */ 4451 const char *zTableName, /* Table name */ 4452 const char *zColumnName, /* Column name */ 4453 char const **pzDataType, /* OUTPUT: Declared data type */ 4454 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4455 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4456 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4457 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4458); 4459 4460/* 4461** CAPI3REF: Load An Extension 4462** 4463** ^This interface loads an SQLite extension library from the named file. 4464** 4465** ^The sqlite3_load_extension() interface attempts to load an 4466** SQLite extension library contained in the file zFile. 4467** 4468** ^The entry point is zProc. 4469** ^zProc may be 0, in which case the name of the entry point 4470** defaults to "sqlite3_extension_init". 4471** ^The sqlite3_load_extension() interface returns 4472** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4473** ^If an error occurs and pzErrMsg is not 0, then the 4474** [sqlite3_load_extension()] interface shall attempt to 4475** fill *pzErrMsg with error message text stored in memory 4476** obtained from [sqlite3_malloc()]. The calling function 4477** should free this memory by calling [sqlite3_free()]. 4478** 4479** ^Extension loading must be enabled using 4480** [sqlite3_enable_load_extension()] prior to calling this API, 4481** otherwise an error will be returned. 4482** 4483** See also the [load_extension() SQL function]. 4484*/ 4485SQLITE_API int sqlite3_load_extension( 4486 sqlite3 *db, /* Load the extension into this database connection */ 4487 const char *zFile, /* Name of the shared library containing extension */ 4488 const char *zProc, /* Entry point. Derived from zFile if 0 */ 4489 char **pzErrMsg /* Put error message here if not 0 */ 4490); 4491 4492/* 4493** CAPI3REF: Enable Or Disable Extension Loading 4494** 4495** ^So as not to open security holes in older applications that are 4496** unprepared to deal with extension loading, and as a means of disabling 4497** extension loading while evaluating user-entered SQL, the following API 4498** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 4499** 4500** ^Extension loading is off by default. See ticket #1863. 4501** ^Call the sqlite3_enable_load_extension() routine with onoff==1 4502** to turn extension loading on and call it with onoff==0 to turn 4503** it back off again. 4504*/ 4505SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4506 4507/* 4508** CAPI3REF: Automatically Load Statically Linked Extensions 4509** 4510** ^This interface causes the xEntryPoint() function to be invoked for 4511** each new [database connection] that is created. The idea here is that 4512** xEntryPoint() is the entry point for a statically linked SQLite extension 4513** that is to be automatically loaded into all new database connections. 4514** 4515** ^(Even though the function prototype shows that xEntryPoint() takes 4516** no arguments and returns void, SQLite invokes xEntryPoint() with three 4517** arguments and expects and integer result as if the signature of the 4518** entry point where as follows: 4519** 4520** <blockquote><pre> 4521** int xEntryPoint( 4522** sqlite3 *db, 4523** const char **pzErrMsg, 4524** const struct sqlite3_api_routines *pThunk 4525** ); 4526** </pre></blockquote>)^ 4527** 4528** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 4529** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 4530** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 4531** is NULL before calling the xEntryPoint(). ^SQLite will invoke 4532** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 4533** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 4534** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 4535** 4536** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 4537** on the list of automatic extensions is a harmless no-op. ^No entry point 4538** will be called more than once for each database connection that is opened. 4539** 4540** See also: [sqlite3_reset_auto_extension()]. 4541*/ 4542SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); 4543 4544/* 4545** CAPI3REF: Reset Automatic Extension Loading 4546** 4547** ^This interface disables all automatic extensions previously 4548** registered using [sqlite3_auto_extension()]. 4549*/ 4550SQLITE_API void sqlite3_reset_auto_extension(void); 4551 4552/* 4553** The interface to the virtual-table mechanism is currently considered 4554** to be experimental. The interface might change in incompatible ways. 4555** If this is a problem for you, do not use the interface at this time. 4556** 4557** When the virtual-table mechanism stabilizes, we will declare the 4558** interface fixed, support it indefinitely, and remove this comment. 4559*/ 4560 4561/* 4562** Structures used by the virtual table interface 4563*/ 4564typedef struct sqlite3_vtab sqlite3_vtab; 4565typedef struct sqlite3_index_info sqlite3_index_info; 4566typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4567typedef struct sqlite3_module sqlite3_module; 4568 4569/* 4570** CAPI3REF: Virtual Table Object 4571** KEYWORDS: sqlite3_module {virtual table module} 4572** 4573** This structure, sometimes called a "virtual table module", 4574** defines the implementation of a [virtual tables]. 4575** This structure consists mostly of methods for the module. 4576** 4577** ^A virtual table module is created by filling in a persistent 4578** instance of this structure and passing a pointer to that instance 4579** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 4580** ^The registration remains valid until it is replaced by a different 4581** module or until the [database connection] closes. The content 4582** of this structure must not change while it is registered with 4583** any database connection. 4584*/ 4585struct sqlite3_module { 4586 int iVersion; 4587 int (*xCreate)(sqlite3*, void *pAux, 4588 int argc, const char *const*argv, 4589 sqlite3_vtab **ppVTab, char**); 4590 int (*xConnect)(sqlite3*, void *pAux, 4591 int argc, const char *const*argv, 4592 sqlite3_vtab **ppVTab, char**); 4593 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4594 int (*xDisconnect)(sqlite3_vtab *pVTab); 4595 int (*xDestroy)(sqlite3_vtab *pVTab); 4596 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4597 int (*xClose)(sqlite3_vtab_cursor*); 4598 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4599 int argc, sqlite3_value **argv); 4600 int (*xNext)(sqlite3_vtab_cursor*); 4601 int (*xEof)(sqlite3_vtab_cursor*); 4602 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4603 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4604 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4605 int (*xBegin)(sqlite3_vtab *pVTab); 4606 int (*xSync)(sqlite3_vtab *pVTab); 4607 int (*xCommit)(sqlite3_vtab *pVTab); 4608 int (*xRollback)(sqlite3_vtab *pVTab); 4609 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4610 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4611 void **ppArg); 4612 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4613}; 4614 4615/* 4616** CAPI3REF: Virtual Table Indexing Information 4617** KEYWORDS: sqlite3_index_info 4618** 4619** The sqlite3_index_info structure and its substructures is used as part 4620** of the [virtual table] interface to 4621** pass information into and receive the reply from the [xBestIndex] 4622** method of a [virtual table module]. The fields under **Inputs** are the 4623** inputs to xBestIndex and are read-only. xBestIndex inserts its 4624** results into the **Outputs** fields. 4625** 4626** ^(The aConstraint[] array records WHERE clause constraints of the form: 4627** 4628** <blockquote>column OP expr</blockquote> 4629** 4630** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 4631** stored in aConstraint[].op using one of the 4632** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 4633** ^(The index of the column is stored in 4634** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 4635** expr on the right-hand side can be evaluated (and thus the constraint 4636** is usable) and false if it cannot.)^ 4637** 4638** ^The optimizer automatically inverts terms of the form "expr OP column" 4639** and makes other simplifications to the WHERE clause in an attempt to 4640** get as many WHERE clause terms into the form shown above as possible. 4641** ^The aConstraint[] array only reports WHERE clause terms that are 4642** relevant to the particular virtual table being queried. 4643** 4644** ^Information about the ORDER BY clause is stored in aOrderBy[]. 4645** ^Each term of aOrderBy records a column of the ORDER BY clause. 4646** 4647** The [xBestIndex] method must fill aConstraintUsage[] with information 4648** about what parameters to pass to xFilter. ^If argvIndex>0 then 4649** the right-hand side of the corresponding aConstraint[] is evaluated 4650** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 4651** is true, then the constraint is assumed to be fully handled by the 4652** virtual table and is not checked again by SQLite.)^ 4653** 4654** ^The idxNum and idxPtr values are recorded and passed into the 4655** [xFilter] method. 4656** ^[sqlite3_free()] is used to free idxPtr if and only if 4657** needToFreeIdxPtr is true. 4658** 4659** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 4660** the correct order to satisfy the ORDER BY clause so that no separate 4661** sorting step is required. 4662** 4663** ^The estimatedCost value is an estimate of the cost of doing the 4664** particular lookup. A full scan of a table with N entries should have 4665** a cost of N. A binary search of a table of N entries should have a 4666** cost of approximately log(N). 4667*/ 4668struct sqlite3_index_info { 4669 /* Inputs */ 4670 int nConstraint; /* Number of entries in aConstraint */ 4671 struct sqlite3_index_constraint { 4672 int iColumn; /* Column on left-hand side of constraint */ 4673 unsigned char op; /* Constraint operator */ 4674 unsigned char usable; /* True if this constraint is usable */ 4675 int iTermOffset; /* Used internally - xBestIndex should ignore */ 4676 } *aConstraint; /* Table of WHERE clause constraints */ 4677 int nOrderBy; /* Number of terms in the ORDER BY clause */ 4678 struct sqlite3_index_orderby { 4679 int iColumn; /* Column number */ 4680 unsigned char desc; /* True for DESC. False for ASC. */ 4681 } *aOrderBy; /* The ORDER BY clause */ 4682 /* Outputs */ 4683 struct sqlite3_index_constraint_usage { 4684 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4685 unsigned char omit; /* Do not code a test for this constraint */ 4686 } *aConstraintUsage; 4687 int idxNum; /* Number used to identify the index */ 4688 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 4689 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 4690 int orderByConsumed; /* True if output is already ordered */ 4691 double estimatedCost; /* Estimated cost of using this index */ 4692}; 4693 4694/* 4695** CAPI3REF: Virtual Table Constraint Operator Codes 4696** 4697** These macros defined the allowed values for the 4698** [sqlite3_index_info].aConstraint[].op field. Each value represents 4699** an operator that is part of a constraint term in the wHERE clause of 4700** a query that uses a [virtual table]. 4701*/ 4702#define SQLITE_INDEX_CONSTRAINT_EQ 2 4703#define SQLITE_INDEX_CONSTRAINT_GT 4 4704#define SQLITE_INDEX_CONSTRAINT_LE 8 4705#define SQLITE_INDEX_CONSTRAINT_LT 16 4706#define SQLITE_INDEX_CONSTRAINT_GE 32 4707#define SQLITE_INDEX_CONSTRAINT_MATCH 64 4708 4709/* 4710** CAPI3REF: Register A Virtual Table Implementation 4711** 4712** ^These routines are used to register a new [virtual table module] name. 4713** ^Module names must be registered before 4714** creating a new [virtual table] using the module and before using a 4715** preexisting [virtual table] for the module. 4716** 4717** ^The module name is registered on the [database connection] specified 4718** by the first parameter. ^The name of the module is given by the 4719** second parameter. ^The third parameter is a pointer to 4720** the implementation of the [virtual table module]. ^The fourth 4721** parameter is an arbitrary client data pointer that is passed through 4722** into the [xCreate] and [xConnect] methods of the virtual table module 4723** when a new virtual table is be being created or reinitialized. 4724** 4725** ^The sqlite3_create_module_v2() interface has a fifth parameter which 4726** is a pointer to a destructor for the pClientData. ^SQLite will 4727** invoke the destructor function (if it is not NULL) when SQLite 4728** no longer needs the pClientData pointer. ^The destructor will also 4729** be invoked if the call to sqlite3_create_module_v2() fails. 4730** ^The sqlite3_create_module() 4731** interface is equivalent to sqlite3_create_module_v2() with a NULL 4732** destructor. 4733*/ 4734SQLITE_API int sqlite3_create_module( 4735 sqlite3 *db, /* SQLite connection to register module with */ 4736 const char *zName, /* Name of the module */ 4737 const sqlite3_module *p, /* Methods for the module */ 4738 void *pClientData /* Client data for xCreate/xConnect */ 4739); 4740SQLITE_API int sqlite3_create_module_v2( 4741 sqlite3 *db, /* SQLite connection to register module with */ 4742 const char *zName, /* Name of the module */ 4743 const sqlite3_module *p, /* Methods for the module */ 4744 void *pClientData, /* Client data for xCreate/xConnect */ 4745 void(*xDestroy)(void*) /* Module destructor function */ 4746); 4747 4748/* 4749** CAPI3REF: Virtual Table Instance Object 4750** KEYWORDS: sqlite3_vtab 4751** 4752** Every [virtual table module] implementation uses a subclass 4753** of this object to describe a particular instance 4754** of the [virtual table]. Each subclass will 4755** be tailored to the specific needs of the module implementation. 4756** The purpose of this superclass is to define certain fields that are 4757** common to all module implementations. 4758** 4759** ^Virtual tables methods can set an error message by assigning a 4760** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 4761** take care that any prior string is freed by a call to [sqlite3_free()] 4762** prior to assigning a new string to zErrMsg. ^After the error message 4763** is delivered up to the client application, the string will be automatically 4764** freed by sqlite3_free() and the zErrMsg field will be zeroed. 4765*/ 4766struct sqlite3_vtab { 4767 const sqlite3_module *pModule; /* The module for this virtual table */ 4768 int nRef; /* NO LONGER USED */ 4769 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 4770 /* Virtual table implementations will typically add additional fields */ 4771}; 4772 4773/* 4774** CAPI3REF: Virtual Table Cursor Object 4775** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 4776** 4777** Every [virtual table module] implementation uses a subclass of the 4778** following structure to describe cursors that point into the 4779** [virtual table] and are used 4780** to loop through the virtual table. Cursors are created using the 4781** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 4782** by the [sqlite3_module.xClose | xClose] method. Cursors are used 4783** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 4784** of the module. Each module implementation will define 4785** the content of a cursor structure to suit its own needs. 4786** 4787** This superclass exists in order to define fields of the cursor that 4788** are common to all implementations. 4789*/ 4790struct sqlite3_vtab_cursor { 4791 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 4792 /* Virtual table implementations will typically add additional fields */ 4793}; 4794 4795/* 4796** CAPI3REF: Declare The Schema Of A Virtual Table 4797** 4798** ^The [xCreate] and [xConnect] methods of a 4799** [virtual table module] call this interface 4800** to declare the format (the names and datatypes of the columns) of 4801** the virtual tables they implement. 4802*/ 4803SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 4804 4805/* 4806** CAPI3REF: Overload A Function For A Virtual Table 4807** 4808** ^(Virtual tables can provide alternative implementations of functions 4809** using the [xFindFunction] method of the [virtual table module]. 4810** But global versions of those functions 4811** must exist in order to be overloaded.)^ 4812** 4813** ^(This API makes sure a global version of a function with a particular 4814** name and number of parameters exists. If no such function exists 4815** before this API is called, a new function is created.)^ ^The implementation 4816** of the new function always causes an exception to be thrown. So 4817** the new function is not good for anything by itself. Its only 4818** purpose is to be a placeholder function that can be overloaded 4819** by a [virtual table]. 4820*/ 4821SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 4822 4823/* 4824** The interface to the virtual-table mechanism defined above (back up 4825** to a comment remarkably similar to this one) is currently considered 4826** to be experimental. The interface might change in incompatible ways. 4827** If this is a problem for you, do not use the interface at this time. 4828** 4829** When the virtual-table mechanism stabilizes, we will declare the 4830** interface fixed, support it indefinitely, and remove this comment. 4831*/ 4832 4833/* 4834** CAPI3REF: A Handle To An Open BLOB 4835** KEYWORDS: {BLOB handle} {BLOB handles} 4836** 4837** An instance of this object represents an open BLOB on which 4838** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 4839** ^Objects of this type are created by [sqlite3_blob_open()] 4840** and destroyed by [sqlite3_blob_close()]. 4841** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 4842** can be used to read or write small subsections of the BLOB. 4843** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 4844*/ 4845typedef struct sqlite3_blob sqlite3_blob; 4846 4847/* 4848** CAPI3REF: Open A BLOB For Incremental I/O 4849** 4850** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 4851** in row iRow, column zColumn, table zTable in database zDb; 4852** in other words, the same BLOB that would be selected by: 4853** 4854** <pre> 4855** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 4856** </pre>)^ 4857** 4858** ^If the flags parameter is non-zero, then the BLOB is opened for read 4859** and write access. ^If it is zero, the BLOB is opened for read access. 4860** ^It is not possible to open a column that is part of an index or primary 4861** key for writing. ^If [foreign key constraints] are enabled, it is 4862** not possible to open a column that is part of a [child key] for writing. 4863** 4864** ^Note that the database name is not the filename that contains 4865** the database but rather the symbolic name of the database that 4866** appears after the AS keyword when the database is connected using [ATTACH]. 4867** ^For the main database file, the database name is "main". 4868** ^For TEMP tables, the database name is "temp". 4869** 4870** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 4871** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 4872** to be a null pointer.)^ 4873** ^This function sets the [database connection] error code and message 4874** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 4875** functions. ^Note that the *ppBlob variable is always initialized in a 4876** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 4877** regardless of the success or failure of this routine. 4878** 4879** ^(If the row that a BLOB handle points to is modified by an 4880** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 4881** then the BLOB handle is marked as "expired". 4882** This is true if any column of the row is changed, even a column 4883** other than the one the BLOB handle is open on.)^ 4884** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 4885** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 4886** ^(Changes written into a BLOB prior to the BLOB expiring are not 4887** rolled back by the expiration of the BLOB. Such changes will eventually 4888** commit if the transaction continues to completion.)^ 4889** 4890** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 4891** the opened blob. ^The size of a blob may not be changed by this 4892** interface. Use the [UPDATE] SQL command to change the size of a 4893** blob. 4894** 4895** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 4896** and the built-in [zeroblob] SQL function can be used, if desired, 4897** to create an empty, zero-filled blob in which to read or write using 4898** this interface. 4899** 4900** To avoid a resource leak, every open [BLOB handle] should eventually 4901** be released by a call to [sqlite3_blob_close()]. 4902*/ 4903SQLITE_API int sqlite3_blob_open( 4904 sqlite3*, 4905 const char *zDb, 4906 const char *zTable, 4907 const char *zColumn, 4908 sqlite3_int64 iRow, 4909 int flags, 4910 sqlite3_blob **ppBlob 4911); 4912 4913/* 4914** CAPI3REF: Move a BLOB Handle to a New Row 4915** 4916** ^This function is used to move an existing blob handle so that it points 4917** to a different row of the same database table. ^The new row is identified 4918** by the rowid value passed as the second argument. Only the row can be 4919** changed. ^The database, table and column on which the blob handle is open 4920** remain the same. Moving an existing blob handle to a new row can be 4921** faster than closing the existing handle and opening a new one. 4922** 4923** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 4924** it must exist and there must be either a blob or text value stored in 4925** the nominated column.)^ ^If the new row is not present in the table, or if 4926** it does not contain a blob or text value, or if another error occurs, an 4927** SQLite error code is returned and the blob handle is considered aborted. 4928** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 4929** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 4930** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 4931** always returns zero. 4932** 4933** ^This function sets the database handle error code and message. 4934*/ 4935SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 4936 4937/* 4938** CAPI3REF: Close A BLOB Handle 4939** 4940** ^Closes an open [BLOB handle]. 4941** 4942** ^Closing a BLOB shall cause the current transaction to commit 4943** if there are no other BLOBs, no pending prepared statements, and the 4944** database connection is in [autocommit mode]. 4945** ^If any writes were made to the BLOB, they might be held in cache 4946** until the close operation if they will fit. 4947** 4948** ^(Closing the BLOB often forces the changes 4949** out to disk and so if any I/O errors occur, they will likely occur 4950** at the time when the BLOB is closed. Any errors that occur during 4951** closing are reported as a non-zero return value.)^ 4952** 4953** ^(The BLOB is closed unconditionally. Even if this routine returns 4954** an error code, the BLOB is still closed.)^ 4955** 4956** ^Calling this routine with a null pointer (such as would be returned 4957** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 4958*/ 4959SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 4960 4961/* 4962** CAPI3REF: Return The Size Of An Open BLOB 4963** 4964** ^Returns the size in bytes of the BLOB accessible via the 4965** successfully opened [BLOB handle] in its only argument. ^The 4966** incremental blob I/O routines can only read or overwriting existing 4967** blob content; they cannot change the size of a blob. 4968** 4969** This routine only works on a [BLOB handle] which has been created 4970** by a prior successful call to [sqlite3_blob_open()] and which has not 4971** been closed by [sqlite3_blob_close()]. Passing any other pointer in 4972** to this routine results in undefined and probably undesirable behavior. 4973*/ 4974SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 4975 4976/* 4977** CAPI3REF: Read Data From A BLOB Incrementally 4978** 4979** ^(This function is used to read data from an open [BLOB handle] into a 4980** caller-supplied buffer. N bytes of data are copied into buffer Z 4981** from the open BLOB, starting at offset iOffset.)^ 4982** 4983** ^If offset iOffset is less than N bytes from the end of the BLOB, 4984** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 4985** less than zero, [SQLITE_ERROR] is returned and no data is read. 4986** ^The size of the blob (and hence the maximum value of N+iOffset) 4987** can be determined using the [sqlite3_blob_bytes()] interface. 4988** 4989** ^An attempt to read from an expired [BLOB handle] fails with an 4990** error code of [SQLITE_ABORT]. 4991** 4992** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 4993** Otherwise, an [error code] or an [extended error code] is returned.)^ 4994** 4995** This routine only works on a [BLOB handle] which has been created 4996** by a prior successful call to [sqlite3_blob_open()] and which has not 4997** been closed by [sqlite3_blob_close()]. Passing any other pointer in 4998** to this routine results in undefined and probably undesirable behavior. 4999** 5000** See also: [sqlite3_blob_write()]. 5001*/ 5002SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5003 5004/* 5005** CAPI3REF: Write Data Into A BLOB Incrementally 5006** 5007** ^This function is used to write data into an open [BLOB handle] from a 5008** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5009** into the open BLOB, starting at offset iOffset. 5010** 5011** ^If the [BLOB handle] passed as the first argument was not opened for 5012** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5013** this function returns [SQLITE_READONLY]. 5014** 5015** ^This function may only modify the contents of the BLOB; it is 5016** not possible to increase the size of a BLOB using this API. 5017** ^If offset iOffset is less than N bytes from the end of the BLOB, 5018** [SQLITE_ERROR] is returned and no data is written. ^If N is 5019** less than zero [SQLITE_ERROR] is returned and no data is written. 5020** The size of the BLOB (and hence the maximum value of N+iOffset) 5021** can be determined using the [sqlite3_blob_bytes()] interface. 5022** 5023** ^An attempt to write to an expired [BLOB handle] fails with an 5024** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5025** before the [BLOB handle] expired are not rolled back by the 5026** expiration of the handle, though of course those changes might 5027** have been overwritten by the statement that expired the BLOB handle 5028** or by other independent statements. 5029** 5030** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5031** Otherwise, an [error code] or an [extended error code] is returned.)^ 5032** 5033** This routine only works on a [BLOB handle] which has been created 5034** by a prior successful call to [sqlite3_blob_open()] and which has not 5035** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5036** to this routine results in undefined and probably undesirable behavior. 5037** 5038** See also: [sqlite3_blob_read()]. 5039*/ 5040SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5041 5042/* 5043** CAPI3REF: Virtual File System Objects 5044** 5045** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5046** that SQLite uses to interact 5047** with the underlying operating system. Most SQLite builds come with a 5048** single default VFS that is appropriate for the host computer. 5049** New VFSes can be registered and existing VFSes can be unregistered. 5050** The following interfaces are provided. 5051** 5052** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5053** ^Names are case sensitive. 5054** ^Names are zero-terminated UTF-8 strings. 5055** ^If there is no match, a NULL pointer is returned. 5056** ^If zVfsName is NULL then the default VFS is returned. 5057** 5058** ^New VFSes are registered with sqlite3_vfs_register(). 5059** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5060** ^The same VFS can be registered multiple times without injury. 5061** ^To make an existing VFS into the default VFS, register it again 5062** with the makeDflt flag set. If two different VFSes with the 5063** same name are registered, the behavior is undefined. If a 5064** VFS is registered with a name that is NULL or an empty string, 5065** then the behavior is undefined. 5066** 5067** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5068** ^(If the default VFS is unregistered, another VFS is chosen as 5069** the default. The choice for the new VFS is arbitrary.)^ 5070*/ 5071SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5072SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5073SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 5074 5075/* 5076** CAPI3REF: Mutexes 5077** 5078** The SQLite core uses these routines for thread 5079** synchronization. Though they are intended for internal 5080** use by SQLite, code that links against SQLite is 5081** permitted to use any of these routines. 5082** 5083** The SQLite source code contains multiple implementations 5084** of these mutex routines. An appropriate implementation 5085** is selected automatically at compile-time. ^(The following 5086** implementations are available in the SQLite core: 5087** 5088** <ul> 5089** <li> SQLITE_MUTEX_OS2 5090** <li> SQLITE_MUTEX_PTHREAD 5091** <li> SQLITE_MUTEX_W32 5092** <li> SQLITE_MUTEX_NOOP 5093** </ul>)^ 5094** 5095** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5096** that does no real locking and is appropriate for use in 5097** a single-threaded application. ^The SQLITE_MUTEX_OS2, 5098** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 5099** are appropriate for use on OS/2, Unix, and Windows. 5100** 5101** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5102** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5103** implementation is included with the library. In this case the 5104** application must supply a custom mutex implementation using the 5105** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5106** before calling sqlite3_initialize() or any other public sqlite3_ 5107** function that calls sqlite3_initialize().)^ 5108** 5109** ^The sqlite3_mutex_alloc() routine allocates a new 5110** mutex and returns a pointer to it. ^If it returns NULL 5111** that means that a mutex could not be allocated. ^SQLite 5112** will unwind its stack and return an error. ^(The argument 5113** to sqlite3_mutex_alloc() is one of these integer constants: 5114** 5115** <ul> 5116** <li> SQLITE_MUTEX_FAST 5117** <li> SQLITE_MUTEX_RECURSIVE 5118** <li> SQLITE_MUTEX_STATIC_MASTER 5119** <li> SQLITE_MUTEX_STATIC_MEM 5120** <li> SQLITE_MUTEX_STATIC_MEM2 5121** <li> SQLITE_MUTEX_STATIC_PRNG 5122** <li> SQLITE_MUTEX_STATIC_LRU 5123** <li> SQLITE_MUTEX_STATIC_LRU2 5124** </ul>)^ 5125** 5126** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5127** cause sqlite3_mutex_alloc() to create 5128** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5129** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5130** The mutex implementation does not need to make a distinction 5131** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5132** not want to. ^SQLite will only request a recursive mutex in 5133** cases where it really needs one. ^If a faster non-recursive mutex 5134** implementation is available on the host platform, the mutex subsystem 5135** might return such a mutex in response to SQLITE_MUTEX_FAST. 5136** 5137** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5138** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5139** a pointer to a static preexisting mutex. ^Six static mutexes are 5140** used by the current version of SQLite. Future versions of SQLite 5141** may add additional static mutexes. Static mutexes are for internal 5142** use by SQLite only. Applications that use SQLite mutexes should 5143** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5144** SQLITE_MUTEX_RECURSIVE. 5145** 5146** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5147** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5148** returns a different mutex on every call. ^But for the static 5149** mutex types, the same mutex is returned on every call that has 5150** the same type number. 5151** 5152** ^The sqlite3_mutex_free() routine deallocates a previously 5153** allocated dynamic mutex. ^SQLite is careful to deallocate every 5154** dynamic mutex that it allocates. The dynamic mutexes must not be in 5155** use when they are deallocated. Attempting to deallocate a static 5156** mutex results in undefined behavior. ^SQLite never deallocates 5157** a static mutex. 5158** 5159** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5160** to enter a mutex. ^If another thread is already within the mutex, 5161** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5162** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5163** upon successful entry. ^(Mutexes created using 5164** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5165** In such cases the, 5166** mutex must be exited an equal number of times before another thread 5167** can enter.)^ ^(If the same thread tries to enter any other 5168** kind of mutex more than once, the behavior is undefined. 5169** SQLite will never exhibit 5170** such behavior in its own use of mutexes.)^ 5171** 5172** ^(Some systems (for example, Windows 95) do not support the operation 5173** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5174** will always return SQLITE_BUSY. The SQLite core only ever uses 5175** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5176** 5177** ^The sqlite3_mutex_leave() routine exits a mutex that was 5178** previously entered by the same thread. ^(The behavior 5179** is undefined if the mutex is not currently entered by the 5180** calling thread or is not currently allocated. SQLite will 5181** never do either.)^ 5182** 5183** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5184** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5185** behave as no-ops. 5186** 5187** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5188*/ 5189SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 5190SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 5191SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 5192SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 5193SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 5194 5195/* 5196** CAPI3REF: Mutex Methods Object 5197** 5198** An instance of this structure defines the low-level routines 5199** used to allocate and use mutexes. 5200** 5201** Usually, the default mutex implementations provided by SQLite are 5202** sufficient, however the user has the option of substituting a custom 5203** implementation for specialized deployments or systems for which SQLite 5204** does not provide a suitable implementation. In this case, the user 5205** creates and populates an instance of this structure to pass 5206** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5207** Additionally, an instance of this structure can be used as an 5208** output variable when querying the system for the current mutex 5209** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5210** 5211** ^The xMutexInit method defined by this structure is invoked as 5212** part of system initialization by the sqlite3_initialize() function. 5213** ^The xMutexInit routine is called by SQLite exactly once for each 5214** effective call to [sqlite3_initialize()]. 5215** 5216** ^The xMutexEnd method defined by this structure is invoked as 5217** part of system shutdown by the sqlite3_shutdown() function. The 5218** implementation of this method is expected to release all outstanding 5219** resources obtained by the mutex methods implementation, especially 5220** those obtained by the xMutexInit method. ^The xMutexEnd() 5221** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5222** 5223** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5224** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5225** xMutexNotheld) implement the following interfaces (respectively): 5226** 5227** <ul> 5228** <li> [sqlite3_mutex_alloc()] </li> 5229** <li> [sqlite3_mutex_free()] </li> 5230** <li> [sqlite3_mutex_enter()] </li> 5231** <li> [sqlite3_mutex_try()] </li> 5232** <li> [sqlite3_mutex_leave()] </li> 5233** <li> [sqlite3_mutex_held()] </li> 5234** <li> [sqlite3_mutex_notheld()] </li> 5235** </ul>)^ 5236** 5237** The only difference is that the public sqlite3_XXX functions enumerated 5238** above silently ignore any invocations that pass a NULL pointer instead 5239** of a valid mutex handle. The implementations of the methods defined 5240** by this structure are not required to handle this case, the results 5241** of passing a NULL pointer instead of a valid mutex handle are undefined 5242** (i.e. it is acceptable to provide an implementation that segfaults if 5243** it is passed a NULL pointer). 5244** 5245** The xMutexInit() method must be threadsafe. ^It must be harmless to 5246** invoke xMutexInit() multiple times within the same process and without 5247** intervening calls to xMutexEnd(). Second and subsequent calls to 5248** xMutexInit() must be no-ops. 5249** 5250** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5251** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5252** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5253** memory allocation for a fast or recursive mutex. 5254** 5255** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5256** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5257** If xMutexInit fails in any way, it is expected to clean up after itself 5258** prior to returning. 5259*/ 5260typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5261struct sqlite3_mutex_methods { 5262 int (*xMutexInit)(void); 5263 int (*xMutexEnd)(void); 5264 sqlite3_mutex *(*xMutexAlloc)(int); 5265 void (*xMutexFree)(sqlite3_mutex *); 5266 void (*xMutexEnter)(sqlite3_mutex *); 5267 int (*xMutexTry)(sqlite3_mutex *); 5268 void (*xMutexLeave)(sqlite3_mutex *); 5269 int (*xMutexHeld)(sqlite3_mutex *); 5270 int (*xMutexNotheld)(sqlite3_mutex *); 5271}; 5272 5273/* 5274** CAPI3REF: Mutex Verification Routines 5275** 5276** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5277** are intended for use inside assert() statements. ^The SQLite core 5278** never uses these routines except inside an assert() and applications 5279** are advised to follow the lead of the core. ^The SQLite core only 5280** provides implementations for these routines when it is compiled 5281** with the SQLITE_DEBUG flag. ^External mutex implementations 5282** are only required to provide these routines if SQLITE_DEBUG is 5283** defined and if NDEBUG is not defined. 5284** 5285** ^These routines should return true if the mutex in their argument 5286** is held or not held, respectively, by the calling thread. 5287** 5288** ^The implementation is not required to provided versions of these 5289** routines that actually work. If the implementation does not provide working 5290** versions of these routines, it should at least provide stubs that always 5291** return true so that one does not get spurious assertion failures. 5292** 5293** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5294** the routine should return 1. This seems counter-intuitive since 5295** clearly the mutex cannot be held if it does not exist. But the 5296** the reason the mutex does not exist is because the build is not 5297** using mutexes. And we do not want the assert() containing the 5298** call to sqlite3_mutex_held() to fail, so a non-zero return is 5299** the appropriate thing to do. ^The sqlite3_mutex_notheld() 5300** interface should also return 1 when given a NULL pointer. 5301*/ 5302#ifndef NDEBUG 5303SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 5304SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 5305#endif 5306 5307/* 5308** CAPI3REF: Mutex Types 5309** 5310** The [sqlite3_mutex_alloc()] interface takes a single argument 5311** which is one of these integer constants. 5312** 5313** The set of static mutexes may change from one SQLite release to the 5314** next. Applications that override the built-in mutex logic must be 5315** prepared to accommodate additional static mutexes. 5316*/ 5317#define SQLITE_MUTEX_FAST 0 5318#define SQLITE_MUTEX_RECURSIVE 1 5319#define SQLITE_MUTEX_STATIC_MASTER 2 5320#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5321#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 5322#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 5323#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5324#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5325#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 5326#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 5327 5328/* 5329** CAPI3REF: Retrieve the mutex for a database connection 5330** 5331** ^This interface returns a pointer the [sqlite3_mutex] object that 5332** serializes access to the [database connection] given in the argument 5333** when the [threading mode] is Serialized. 5334** ^If the [threading mode] is Single-thread or Multi-thread then this 5335** routine returns a NULL pointer. 5336*/ 5337SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 5338 5339/* 5340** CAPI3REF: Low-Level Control Of Database Files 5341** 5342** ^The [sqlite3_file_control()] interface makes a direct call to the 5343** xFileControl method for the [sqlite3_io_methods] object associated 5344** with a particular database identified by the second argument. ^The 5345** name of the database is "main" for the main database or "temp" for the 5346** TEMP database, or the name that appears after the AS keyword for 5347** databases that are added using the [ATTACH] SQL command. 5348** ^A NULL pointer can be used in place of "main" to refer to the 5349** main database file. 5350** ^The third and fourth parameters to this routine 5351** are passed directly through to the second and third parameters of 5352** the xFileControl method. ^The return value of the xFileControl 5353** method becomes the return value of this routine. 5354** 5355** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 5356** a pointer to the underlying [sqlite3_file] object to be written into 5357** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 5358** case is a short-circuit path which does not actually invoke the 5359** underlying sqlite3_io_methods.xFileControl method. 5360** 5361** ^If the second parameter (zDbName) does not match the name of any 5362** open database file, then SQLITE_ERROR is returned. ^This error 5363** code is not remembered and will not be recalled by [sqlite3_errcode()] 5364** or [sqlite3_errmsg()]. The underlying xFileControl method might 5365** also return SQLITE_ERROR. There is no way to distinguish between 5366** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5367** xFileControl method. 5368** 5369** See also: [SQLITE_FCNTL_LOCKSTATE] 5370*/ 5371SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5372 5373/* 5374** CAPI3REF: Testing Interface 5375** 5376** ^The sqlite3_test_control() interface is used to read out internal 5377** state of SQLite and to inject faults into SQLite for testing 5378** purposes. ^The first parameter is an operation code that determines 5379** the number, meaning, and operation of all subsequent parameters. 5380** 5381** This interface is not for use by applications. It exists solely 5382** for verifying the correct operation of the SQLite library. Depending 5383** on how the SQLite library is compiled, this interface might not exist. 5384** 5385** The details of the operation codes, their meanings, the parameters 5386** they take, and what they do are all subject to change without notice. 5387** Unlike most of the SQLite API, this function is not guaranteed to 5388** operate consistently from one release to the next. 5389*/ 5390SQLITE_API int sqlite3_test_control(int op, ...); 5391 5392/* 5393** CAPI3REF: Testing Interface Operation Codes 5394** 5395** These constants are the valid operation code parameters used 5396** as the first argument to [sqlite3_test_control()]. 5397** 5398** These parameters and their meanings are subject to change 5399** without notice. These values are for testing purposes only. 5400** Applications should not use any of these parameters or the 5401** [sqlite3_test_control()] interface. 5402*/ 5403#define SQLITE_TESTCTRL_FIRST 5 5404#define SQLITE_TESTCTRL_PRNG_SAVE 5 5405#define SQLITE_TESTCTRL_PRNG_RESTORE 6 5406#define SQLITE_TESTCTRL_PRNG_RESET 7 5407#define SQLITE_TESTCTRL_BITVEC_TEST 8 5408#define SQLITE_TESTCTRL_FAULT_INSTALL 9 5409#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 5410#define SQLITE_TESTCTRL_PENDING_BYTE 11 5411#define SQLITE_TESTCTRL_ASSERT 12 5412#define SQLITE_TESTCTRL_ALWAYS 13 5413#define SQLITE_TESTCTRL_RESERVE 14 5414#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 5415#define SQLITE_TESTCTRL_ISKEYWORD 16 5416#define SQLITE_TESTCTRL_PGHDRSZ 17 5417#define SQLITE_TESTCTRL_SCRATCHMALLOC 18 5418#define SQLITE_TESTCTRL_LAST 18 5419 5420/* 5421** CAPI3REF: SQLite Runtime Status 5422** 5423** ^This interface is used to retrieve runtime status information 5424** about the performance of SQLite, and optionally to reset various 5425** highwater marks. ^The first argument is an integer code for 5426** the specific parameter to measure. ^(Recognized integer codes 5427** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...].)^ 5428** ^The current value of the parameter is returned into *pCurrent. 5429** ^The highest recorded value is returned in *pHighwater. ^If the 5430** resetFlag is true, then the highest record value is reset after 5431** *pHighwater is written. ^(Some parameters do not record the highest 5432** value. For those parameters 5433** nothing is written into *pHighwater and the resetFlag is ignored.)^ 5434** ^(Other parameters record only the highwater mark and not the current 5435** value. For these latter parameters nothing is written into *pCurrent.)^ 5436** 5437** ^The sqlite3_status() routine returns SQLITE_OK on success and a 5438** non-zero [error code] on failure. 5439** 5440** This routine is threadsafe but is not atomic. This routine can be 5441** called while other threads are running the same or different SQLite 5442** interfaces. However the values returned in *pCurrent and 5443** *pHighwater reflect the status of SQLite at different points in time 5444** and it is possible that another thread might change the parameter 5445** in between the times when *pCurrent and *pHighwater are written. 5446** 5447** See also: [sqlite3_db_status()] 5448*/ 5449SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 5450 5451 5452/* 5453** CAPI3REF: Status Parameters 5454** 5455** These integer constants designate various run-time status parameters 5456** that can be returned by [sqlite3_status()]. 5457** 5458** <dl> 5459** ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 5460** <dd>This parameter is the current amount of memory checked out 5461** using [sqlite3_malloc()], either directly or indirectly. The 5462** figure includes calls made to [sqlite3_malloc()] by the application 5463** and internal memory usage by the SQLite library. Scratch memory 5464** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 5465** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 5466** this parameter. The amount returned is the sum of the allocation 5467** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 5468** 5469** ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 5470** <dd>This parameter records the largest memory allocation request 5471** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 5472** internal equivalents). Only the value returned in the 5473** *pHighwater parameter to [sqlite3_status()] is of interest. 5474** The value written into the *pCurrent parameter is undefined.</dd>)^ 5475** 5476** ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 5477** <dd>This parameter records the number of separate memory allocations 5478** currently checked out.</dd>)^ 5479** 5480** ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 5481** <dd>This parameter returns the number of pages used out of the 5482** [pagecache memory allocator] that was configured using 5483** [SQLITE_CONFIG_PAGECACHE]. The 5484** value returned is in pages, not in bytes.</dd>)^ 5485** 5486** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 5487** <dd>This parameter returns the number of bytes of page cache 5488** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 5489** buffer and where forced to overflow to [sqlite3_malloc()]. The 5490** returned value includes allocations that overflowed because they 5491** where too large (they were larger than the "sz" parameter to 5492** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 5493** no space was left in the page cache.</dd>)^ 5494** 5495** ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 5496** <dd>This parameter records the largest memory allocation request 5497** handed to [pagecache memory allocator]. Only the value returned in the 5498** *pHighwater parameter to [sqlite3_status()] is of interest. 5499** The value written into the *pCurrent parameter is undefined.</dd>)^ 5500** 5501** ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 5502** <dd>This parameter returns the number of allocations used out of the 5503** [scratch memory allocator] configured using 5504** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 5505** in bytes. Since a single thread may only have one scratch allocation 5506** outstanding at time, this parameter also reports the number of threads 5507** using scratch memory at the same time.</dd>)^ 5508** 5509** ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 5510** <dd>This parameter returns the number of bytes of scratch memory 5511** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 5512** buffer and where forced to overflow to [sqlite3_malloc()]. The values 5513** returned include overflows because the requested allocation was too 5514** larger (that is, because the requested allocation was larger than the 5515** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 5516** slots were available. 5517** </dd>)^ 5518** 5519** ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 5520** <dd>This parameter records the largest memory allocation request 5521** handed to [scratch memory allocator]. Only the value returned in the 5522** *pHighwater parameter to [sqlite3_status()] is of interest. 5523** The value written into the *pCurrent parameter is undefined.</dd>)^ 5524** 5525** ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 5526** <dd>This parameter records the deepest parser stack. It is only 5527** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 5528** </dl> 5529** 5530** New status parameters may be added from time to time. 5531*/ 5532#define SQLITE_STATUS_MEMORY_USED 0 5533#define SQLITE_STATUS_PAGECACHE_USED 1 5534#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 5535#define SQLITE_STATUS_SCRATCH_USED 3 5536#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 5537#define SQLITE_STATUS_MALLOC_SIZE 5 5538#define SQLITE_STATUS_PARSER_STACK 6 5539#define SQLITE_STATUS_PAGECACHE_SIZE 7 5540#define SQLITE_STATUS_SCRATCH_SIZE 8 5541#define SQLITE_STATUS_MALLOC_COUNT 9 5542 5543/* 5544** CAPI3REF: Database Connection Status 5545** 5546** ^This interface is used to retrieve runtime status information 5547** about a single [database connection]. ^The first argument is the 5548** database connection object to be interrogated. ^The second argument 5549** is an integer constant, taken from the set of 5550** [SQLITE_DBSTATUS_LOOKASIDE_USED | SQLITE_DBSTATUS_*] macros, that 5551** determines the parameter to interrogate. The set of 5552** [SQLITE_DBSTATUS_LOOKASIDE_USED | SQLITE_DBSTATUS_*] macros is likely 5553** to grow in future releases of SQLite. 5554** 5555** ^The current value of the requested parameter is written into *pCur 5556** and the highest instantaneous value is written into *pHiwtr. ^If 5557** the resetFlg is true, then the highest instantaneous value is 5558** reset back down to the current value. 5559** 5560** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 5561** non-zero [error code] on failure. 5562** 5563** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 5564*/ 5565SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 5566 5567/* 5568** CAPI3REF: Status Parameters for database connections 5569** 5570** These constants are the available integer "verbs" that can be passed as 5571** the second argument to the [sqlite3_db_status()] interface. 5572** 5573** New verbs may be added in future releases of SQLite. Existing verbs 5574** might be discontinued. Applications should check the return code from 5575** [sqlite3_db_status()] to make sure that the call worked. 5576** The [sqlite3_db_status()] interface will return a non-zero error code 5577** if a discontinued or unsupported verb is invoked. 5578** 5579** <dl> 5580** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 5581** <dd>This parameter returns the number of lookaside memory slots currently 5582** checked out.</dd>)^ 5583** 5584** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 5585** <dd>This parameter returns the number malloc attempts that were 5586** satisfied using lookaside memory. Only the high-water value is meaningful; 5587** the current value is always zero.)^ 5588** 5589** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 5590** <dd>This parameter returns the number malloc attempts that might have 5591** been satisfied using lookaside memory but failed due to the amount of 5592** memory requested being larger than the lookaside slot size. 5593** Only the high-water value is meaningful; 5594** the current value is always zero.)^ 5595** 5596** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 5597** <dd>This parameter returns the number malloc attempts that might have 5598** been satisfied using lookaside memory but failed due to all lookaside 5599** memory already being in use. 5600** Only the high-water value is meaningful; 5601** the current value is always zero.)^ 5602** 5603** ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 5604** <dd>This parameter returns the approximate number of of bytes of heap 5605** memory used by all pager caches associated with the database connection.)^ 5606** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 5607** 5608** ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 5609** <dd>This parameter returns the approximate number of of bytes of heap 5610** memory used to store the schema for all databases associated 5611** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 5612** ^The full amount of memory used by the schemas is reported, even if the 5613** schema memory is shared with other database connections due to 5614** [shared cache mode] being enabled. 5615** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 5616** 5617** ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 5618** <dd>This parameter returns the approximate number of of bytes of heap 5619** and lookaside memory used by all prepared statements associated with 5620** the database connection.)^ 5621** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 5622** </dd> 5623** </dl> 5624*/ 5625#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 5626#define SQLITE_DBSTATUS_CACHE_USED 1 5627#define SQLITE_DBSTATUS_SCHEMA_USED 2 5628#define SQLITE_DBSTATUS_STMT_USED 3 5629#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 5630#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 5631#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 5632#define SQLITE_DBSTATUS_MAX 6 /* Largest defined DBSTATUS */ 5633 5634 5635/* 5636** CAPI3REF: Prepared Statement Status 5637** 5638** ^(Each prepared statement maintains various 5639** [SQLITE_STMTSTATUS_SORT | counters] that measure the number 5640** of times it has performed specific operations.)^ These counters can 5641** be used to monitor the performance characteristics of the prepared 5642** statements. For example, if the number of table steps greatly exceeds 5643** the number of table searches or result rows, that would tend to indicate 5644** that the prepared statement is using a full table scan rather than 5645** an index. 5646** 5647** ^(This interface is used to retrieve and reset counter values from 5648** a [prepared statement]. The first argument is the prepared statement 5649** object to be interrogated. The second argument 5650** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter] 5651** to be interrogated.)^ 5652** ^The current value of the requested counter is returned. 5653** ^If the resetFlg is true, then the counter is reset to zero after this 5654** interface call returns. 5655** 5656** See also: [sqlite3_status()] and [sqlite3_db_status()]. 5657*/ 5658SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 5659 5660/* 5661** CAPI3REF: Status Parameters for prepared statements 5662** 5663** These preprocessor macros define integer codes that name counter 5664** values associated with the [sqlite3_stmt_status()] interface. 5665** The meanings of the various counters are as follows: 5666** 5667** <dl> 5668** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 5669** <dd>^This is the number of times that SQLite has stepped forward in 5670** a table as part of a full table scan. Large numbers for this counter 5671** may indicate opportunities for performance improvement through 5672** careful use of indices.</dd> 5673** 5674** <dt>SQLITE_STMTSTATUS_SORT</dt> 5675** <dd>^This is the number of sort operations that have occurred. 5676** A non-zero value in this counter may indicate an opportunity to 5677** improvement performance through careful use of indices.</dd> 5678** 5679** <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 5680** <dd>^This is the number of rows inserted into transient indices that 5681** were created automatically in order to help joins run faster. 5682** A non-zero value in this counter may indicate an opportunity to 5683** improvement performance by adding permanent indices that do not 5684** need to be reinitialized each time the statement is run.</dd> 5685** 5686** </dl> 5687*/ 5688#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 5689#define SQLITE_STMTSTATUS_SORT 2 5690#define SQLITE_STMTSTATUS_AUTOINDEX 3 5691 5692/* 5693** CAPI3REF: Custom Page Cache Object 5694** 5695** The sqlite3_pcache type is opaque. It is implemented by 5696** the pluggable module. The SQLite core has no knowledge of 5697** its size or internal structure and never deals with the 5698** sqlite3_pcache object except by holding and passing pointers 5699** to the object. 5700** 5701** See [sqlite3_pcache_methods] for additional information. 5702*/ 5703typedef struct sqlite3_pcache sqlite3_pcache; 5704 5705/* 5706** CAPI3REF: Application Defined Page Cache. 5707** KEYWORDS: {page cache} 5708** 5709** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can 5710** register an alternative page cache implementation by passing in an 5711** instance of the sqlite3_pcache_methods structure.)^ 5712** In many applications, most of the heap memory allocated by 5713** SQLite is used for the page cache. 5714** By implementing a 5715** custom page cache using this API, an application can better control 5716** the amount of memory consumed by SQLite, the way in which 5717** that memory is allocated and released, and the policies used to 5718** determine exactly which parts of a database file are cached and for 5719** how long. 5720** 5721** The alternative page cache mechanism is an 5722** extreme measure that is only needed by the most demanding applications. 5723** The built-in page cache is recommended for most uses. 5724** 5725** ^(The contents of the sqlite3_pcache_methods structure are copied to an 5726** internal buffer by SQLite within the call to [sqlite3_config]. Hence 5727** the application may discard the parameter after the call to 5728** [sqlite3_config()] returns.)^ 5729** 5730** ^(The xInit() method is called once for each effective 5731** call to [sqlite3_initialize()])^ 5732** (usually only once during the lifetime of the process). ^(The xInit() 5733** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^ 5734** The intent of the xInit() method is to set up global data structures 5735** required by the custom page cache implementation. 5736** ^(If the xInit() method is NULL, then the 5737** built-in default page cache is used instead of the application defined 5738** page cache.)^ 5739** 5740** ^The xShutdown() method is called by [sqlite3_shutdown()]. 5741** It can be used to clean up 5742** any outstanding resources before process shutdown, if required. 5743** ^The xShutdown() method may be NULL. 5744** 5745** ^SQLite automatically serializes calls to the xInit method, 5746** so the xInit method need not be threadsafe. ^The 5747** xShutdown method is only called from [sqlite3_shutdown()] so it does 5748** not need to be threadsafe either. All other methods must be threadsafe 5749** in multithreaded applications. 5750** 5751** ^SQLite will never invoke xInit() more than once without an intervening 5752** call to xShutdown(). 5753** 5754** ^SQLite invokes the xCreate() method to construct a new cache instance. 5755** SQLite will typically create one cache instance for each open database file, 5756** though this is not guaranteed. ^The 5757** first parameter, szPage, is the size in bytes of the pages that must 5758** be allocated by the cache. ^szPage will not be a power of two. ^szPage 5759** will the page size of the database file that is to be cached plus an 5760** increment (here called "R") of less than 250. SQLite will use the 5761** extra R bytes on each page to store metadata about the underlying 5762** database page on disk. The value of R depends 5763** on the SQLite version, the target platform, and how SQLite was compiled. 5764** ^(R is constant for a particular build of SQLite. Except, there are two 5765** distinct values of R when SQLite is compiled with the proprietary 5766** ZIPVFS extension.)^ ^The second argument to 5767** xCreate(), bPurgeable, is true if the cache being created will 5768** be used to cache database pages of a file stored on disk, or 5769** false if it is used for an in-memory database. The cache implementation 5770** does not have to do anything special based with the value of bPurgeable; 5771** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 5772** never invoke xUnpin() except to deliberately delete a page. 5773** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 5774** false will always have the "discard" flag set to true. 5775** ^Hence, a cache created with bPurgeable false will 5776** never contain any unpinned pages. 5777** 5778** ^(The xCachesize() method may be called at any time by SQLite to set the 5779** suggested maximum cache-size (number of pages stored by) the cache 5780** instance passed as the first argument. This is the value configured using 5781** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 5782** parameter, the implementation is not required to do anything with this 5783** value; it is advisory only. 5784** 5785** The xPagecount() method must return the number of pages currently 5786** stored in the cache, both pinned and unpinned. 5787** 5788** The xFetch() method locates a page in the cache and returns a pointer to 5789** the page, or a NULL pointer. 5790** A "page", in this context, means a buffer of szPage bytes aligned at an 5791** 8-byte boundary. The page to be fetched is determined by the key. ^The 5792** mimimum key value is 1. After it has been retrieved using xFetch, the page 5793** is considered to be "pinned". 5794** 5795** If the requested page is already in the page cache, then the page cache 5796** implementation must return a pointer to the page buffer with its content 5797** intact. If the requested page is not already in the cache, then the 5798** cache implementation should use the value of the createFlag 5799** parameter to help it determined what action to take: 5800** 5801** <table border=1 width=85% align=center> 5802** <tr><th> createFlag <th> Behaviour when page is not already in cache 5803** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 5804** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 5805** Otherwise return NULL. 5806** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 5807** NULL if allocating a new page is effectively impossible. 5808** </table> 5809** 5810** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 5811** will only use a createFlag of 2 after a prior call with a createFlag of 1 5812** failed.)^ In between the to xFetch() calls, SQLite may 5813** attempt to unpin one or more cache pages by spilling the content of 5814** pinned pages to disk and synching the operating system disk cache. 5815** 5816** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 5817** as its second argument. If the third parameter, discard, is non-zero, 5818** then the page must be evicted from the cache. 5819** ^If the discard parameter is 5820** zero, then the page may be discarded or retained at the discretion of 5821** page cache implementation. ^The page cache implementation 5822** may choose to evict unpinned pages at any time. 5823** 5824** The cache must not perform any reference counting. A single 5825** call to xUnpin() unpins the page regardless of the number of prior calls 5826** to xFetch(). 5827** 5828** The xRekey() method is used to change the key value associated with the 5829** page passed as the second argument. If the cache 5830** previously contains an entry associated with newKey, it must be 5831** discarded. ^Any prior cache entry associated with newKey is guaranteed not 5832** to be pinned. 5833** 5834** When SQLite calls the xTruncate() method, the cache must discard all 5835** existing cache entries with page numbers (keys) greater than or equal 5836** to the value of the iLimit parameter passed to xTruncate(). If any 5837** of these pages are pinned, they are implicitly unpinned, meaning that 5838** they can be safely discarded. 5839** 5840** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 5841** All resources associated with the specified cache should be freed. ^After 5842** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 5843** handle invalid, and will not use it with any other sqlite3_pcache_methods 5844** functions. 5845*/ 5846typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 5847struct sqlite3_pcache_methods { 5848 void *pArg; 5849 int (*xInit)(void*); 5850 void (*xShutdown)(void*); 5851 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 5852 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 5853 int (*xPagecount)(sqlite3_pcache*); 5854 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 5855 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 5856 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 5857 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 5858 void (*xDestroy)(sqlite3_pcache*); 5859}; 5860 5861/* 5862** CAPI3REF: Online Backup Object 5863** 5864** The sqlite3_backup object records state information about an ongoing 5865** online backup operation. ^The sqlite3_backup object is created by 5866** a call to [sqlite3_backup_init()] and is destroyed by a call to 5867** [sqlite3_backup_finish()]. 5868** 5869** See Also: [Using the SQLite Online Backup API] 5870*/ 5871typedef struct sqlite3_backup sqlite3_backup; 5872 5873/* 5874** CAPI3REF: Online Backup API. 5875** 5876** The backup API copies the content of one database into another. 5877** It is useful either for creating backups of databases or 5878** for copying in-memory databases to or from persistent files. 5879** 5880** See Also: [Using the SQLite Online Backup API] 5881** 5882** ^SQLite holds a write transaction open on the destination database file 5883** for the duration of the backup operation. 5884** ^The source database is read-locked only while it is being read; 5885** it is not locked continuously for the entire backup operation. 5886** ^Thus, the backup may be performed on a live source database without 5887** preventing other database connections from 5888** reading or writing to the source database while the backup is underway. 5889** 5890** ^(To perform a backup operation: 5891** <ol> 5892** <li><b>sqlite3_backup_init()</b> is called once to initialize the 5893** backup, 5894** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 5895** the data between the two databases, and finally 5896** <li><b>sqlite3_backup_finish()</b> is called to release all resources 5897** associated with the backup operation. 5898** </ol>)^ 5899** There should be exactly one call to sqlite3_backup_finish() for each 5900** successful call to sqlite3_backup_init(). 5901** 5902** <b>sqlite3_backup_init()</b> 5903** 5904** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 5905** [database connection] associated with the destination database 5906** and the database name, respectively. 5907** ^The database name is "main" for the main database, "temp" for the 5908** temporary database, or the name specified after the AS keyword in 5909** an [ATTACH] statement for an attached database. 5910** ^The S and M arguments passed to 5911** sqlite3_backup_init(D,N,S,M) identify the [database connection] 5912** and database name of the source database, respectively. 5913** ^The source and destination [database connections] (parameters S and D) 5914** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 5915** an error. 5916** 5917** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 5918** returned and an error code and error message are stored in the 5919** destination [database connection] D. 5920** ^The error code and message for the failed call to sqlite3_backup_init() 5921** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 5922** [sqlite3_errmsg16()] functions. 5923** ^A successful call to sqlite3_backup_init() returns a pointer to an 5924** [sqlite3_backup] object. 5925** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 5926** sqlite3_backup_finish() functions to perform the specified backup 5927** operation. 5928** 5929** <b>sqlite3_backup_step()</b> 5930** 5931** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 5932** the source and destination databases specified by [sqlite3_backup] object B. 5933** ^If N is negative, all remaining source pages are copied. 5934** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 5935** are still more pages to be copied, then the function returns [SQLITE_OK]. 5936** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 5937** from source to destination, then it returns [SQLITE_DONE]. 5938** ^If an error occurs while running sqlite3_backup_step(B,N), 5939** then an [error code] is returned. ^As well as [SQLITE_OK] and 5940** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 5941** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 5942** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 5943** 5944** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 5945** <ol> 5946** <li> the destination database was opened read-only, or 5947** <li> the destination database is using write-ahead-log journaling 5948** and the destination and source page sizes differ, or 5949** <li> the destination database is an in-memory database and the 5950** destination and source page sizes differ. 5951** </ol>)^ 5952** 5953** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 5954** the [sqlite3_busy_handler | busy-handler function] 5955** is invoked (if one is specified). ^If the 5956** busy-handler returns non-zero before the lock is available, then 5957** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 5958** sqlite3_backup_step() can be retried later. ^If the source 5959** [database connection] 5960** is being used to write to the source database when sqlite3_backup_step() 5961** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 5962** case the call to sqlite3_backup_step() can be retried later on. ^(If 5963** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 5964** [SQLITE_READONLY] is returned, then 5965** there is no point in retrying the call to sqlite3_backup_step(). These 5966** errors are considered fatal.)^ The application must accept 5967** that the backup operation has failed and pass the backup operation handle 5968** to the sqlite3_backup_finish() to release associated resources. 5969** 5970** ^The first call to sqlite3_backup_step() obtains an exclusive lock 5971** on the destination file. ^The exclusive lock is not released until either 5972** sqlite3_backup_finish() is called or the backup operation is complete 5973** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 5974** sqlite3_backup_step() obtains a [shared lock] on the source database that 5975** lasts for the duration of the sqlite3_backup_step() call. 5976** ^Because the source database is not locked between calls to 5977** sqlite3_backup_step(), the source database may be modified mid-way 5978** through the backup process. ^If the source database is modified by an 5979** external process or via a database connection other than the one being 5980** used by the backup operation, then the backup will be automatically 5981** restarted by the next call to sqlite3_backup_step(). ^If the source 5982** database is modified by the using the same database connection as is used 5983** by the backup operation, then the backup database is automatically 5984** updated at the same time. 5985** 5986** <b>sqlite3_backup_finish()</b> 5987** 5988** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 5989** application wishes to abandon the backup operation, the application 5990** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 5991** ^The sqlite3_backup_finish() interfaces releases all 5992** resources associated with the [sqlite3_backup] object. 5993** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 5994** active write-transaction on the destination database is rolled back. 5995** The [sqlite3_backup] object is invalid 5996** and may not be used following a call to sqlite3_backup_finish(). 5997** 5998** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 5999** sqlite3_backup_step() errors occurred, regardless or whether or not 6000** sqlite3_backup_step() completed. 6001** ^If an out-of-memory condition or IO error occurred during any prior 6002** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6003** sqlite3_backup_finish() returns the corresponding [error code]. 6004** 6005** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6006** is not a permanent error and does not affect the return value of 6007** sqlite3_backup_finish(). 6008** 6009** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b> 6010** 6011** ^Each call to sqlite3_backup_step() sets two values inside 6012** the [sqlite3_backup] object: the number of pages still to be backed 6013** up and the total number of pages in the source database file. 6014** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6015** retrieve these two values, respectively. 6016** 6017** ^The values returned by these functions are only updated by 6018** sqlite3_backup_step(). ^If the source database is modified during a backup 6019** operation, then the values are not updated to account for any extra 6020** pages that need to be updated or the size of the source database file 6021** changing. 6022** 6023** <b>Concurrent Usage of Database Handles</b> 6024** 6025** ^The source [database connection] may be used by the application for other 6026** purposes while a backup operation is underway or being initialized. 6027** ^If SQLite is compiled and configured to support threadsafe database 6028** connections, then the source database connection may be used concurrently 6029** from within other threads. 6030** 6031** However, the application must guarantee that the destination 6032** [database connection] is not passed to any other API (by any thread) after 6033** sqlite3_backup_init() is called and before the corresponding call to 6034** sqlite3_backup_finish(). SQLite does not currently check to see 6035** if the application incorrectly accesses the destination [database connection] 6036** and so no error code is reported, but the operations may malfunction 6037** nevertheless. Use of the destination database connection while a 6038** backup is in progress might also also cause a mutex deadlock. 6039** 6040** If running in [shared cache mode], the application must 6041** guarantee that the shared cache used by the destination database 6042** is not accessed while the backup is running. In practice this means 6043** that the application must guarantee that the disk file being 6044** backed up to is not accessed by any connection within the process, 6045** not just the specific connection that was passed to sqlite3_backup_init(). 6046** 6047** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6048** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6049** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6050** APIs are not strictly speaking threadsafe. If they are invoked at the 6051** same time as another thread is invoking sqlite3_backup_step() it is 6052** possible that they return invalid values. 6053*/ 6054SQLITE_API sqlite3_backup *sqlite3_backup_init( 6055 sqlite3 *pDest, /* Destination database handle */ 6056 const char *zDestName, /* Destination database name */ 6057 sqlite3 *pSource, /* Source database handle */ 6058 const char *zSourceName /* Source database name */ 6059); 6060SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6061SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 6062SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 6063SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 6064 6065/* 6066** CAPI3REF: Unlock Notification 6067** 6068** ^When running in shared-cache mode, a database operation may fail with 6069** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6070** individual tables within the shared-cache cannot be obtained. See 6071** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6072** ^This API may be used to register a callback that SQLite will invoke 6073** when the connection currently holding the required lock relinquishes it. 6074** ^This API is only available if the library was compiled with the 6075** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6076** 6077** See Also: [Using the SQLite Unlock Notification Feature]. 6078** 6079** ^Shared-cache locks are released when a database connection concludes 6080** its current transaction, either by committing it or rolling it back. 6081** 6082** ^When a connection (known as the blocked connection) fails to obtain a 6083** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6084** identity of the database connection (the blocking connection) that 6085** has locked the required resource is stored internally. ^After an 6086** application receives an SQLITE_LOCKED error, it may call the 6087** sqlite3_unlock_notify() method with the blocked connection handle as 6088** the first argument to register for a callback that will be invoked 6089** when the blocking connections current transaction is concluded. ^The 6090** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6091** call that concludes the blocking connections transaction. 6092** 6093** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6094** there is a chance that the blocking connection will have already 6095** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6096** If this happens, then the specified callback is invoked immediately, 6097** from within the call to sqlite3_unlock_notify().)^ 6098** 6099** ^If the blocked connection is attempting to obtain a write-lock on a 6100** shared-cache table, and more than one other connection currently holds 6101** a read-lock on the same table, then SQLite arbitrarily selects one of 6102** the other connections to use as the blocking connection. 6103** 6104** ^(There may be at most one unlock-notify callback registered by a 6105** blocked connection. If sqlite3_unlock_notify() is called when the 6106** blocked connection already has a registered unlock-notify callback, 6107** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6108** called with a NULL pointer as its second argument, then any existing 6109** unlock-notify callback is canceled. ^The blocked connections 6110** unlock-notify callback may also be canceled by closing the blocked 6111** connection using [sqlite3_close()]. 6112** 6113** The unlock-notify callback is not reentrant. If an application invokes 6114** any sqlite3_xxx API functions from within an unlock-notify callback, a 6115** crash or deadlock may be the result. 6116** 6117** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6118** returns SQLITE_OK. 6119** 6120** <b>Callback Invocation Details</b> 6121** 6122** When an unlock-notify callback is registered, the application provides a 6123** single void* pointer that is passed to the callback when it is invoked. 6124** However, the signature of the callback function allows SQLite to pass 6125** it an array of void* context pointers. The first argument passed to 6126** an unlock-notify callback is a pointer to an array of void* pointers, 6127** and the second is the number of entries in the array. 6128** 6129** When a blocking connections transaction is concluded, there may be 6130** more than one blocked connection that has registered for an unlock-notify 6131** callback. ^If two or more such blocked connections have specified the 6132** same callback function, then instead of invoking the callback function 6133** multiple times, it is invoked once with the set of void* context pointers 6134** specified by the blocked connections bundled together into an array. 6135** This gives the application an opportunity to prioritize any actions 6136** related to the set of unblocked database connections. 6137** 6138** <b>Deadlock Detection</b> 6139** 6140** Assuming that after registering for an unlock-notify callback a 6141** database waits for the callback to be issued before taking any further 6142** action (a reasonable assumption), then using this API may cause the 6143** application to deadlock. For example, if connection X is waiting for 6144** connection Y's transaction to be concluded, and similarly connection 6145** Y is waiting on connection X's transaction, then neither connection 6146** will proceed and the system may remain deadlocked indefinitely. 6147** 6148** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6149** detection. ^If a given call to sqlite3_unlock_notify() would put the 6150** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6151** unlock-notify callback is registered. The system is said to be in 6152** a deadlocked state if connection A has registered for an unlock-notify 6153** callback on the conclusion of connection B's transaction, and connection 6154** B has itself registered for an unlock-notify callback when connection 6155** A's transaction is concluded. ^Indirect deadlock is also detected, so 6156** the system is also considered to be deadlocked if connection B has 6157** registered for an unlock-notify callback on the conclusion of connection 6158** C's transaction, where connection C is waiting on connection A. ^Any 6159** number of levels of indirection are allowed. 6160** 6161** <b>The "DROP TABLE" Exception</b> 6162** 6163** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6164** always appropriate to call sqlite3_unlock_notify(). There is however, 6165** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6166** SQLite checks if there are any currently executing SELECT statements 6167** that belong to the same connection. If there are, SQLITE_LOCKED is 6168** returned. In this case there is no "blocking connection", so invoking 6169** sqlite3_unlock_notify() results in the unlock-notify callback being 6170** invoked immediately. If the application then re-attempts the "DROP TABLE" 6171** or "DROP INDEX" query, an infinite loop might be the result. 6172** 6173** One way around this problem is to check the extended error code returned 6174** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6175** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6176** the special "DROP TABLE/INDEX" case, the extended error code is just 6177** SQLITE_LOCKED.)^ 6178*/ 6179SQLITE_API int sqlite3_unlock_notify( 6180 sqlite3 *pBlocked, /* Waiting connection */ 6181 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6182 void *pNotifyArg /* Argument to pass to xNotify */ 6183); 6184 6185 6186/* 6187** CAPI3REF: String Comparison 6188** 6189** ^The [sqlite3_strnicmp()] API allows applications and extensions to 6190** compare the contents of two buffers containing UTF-8 strings in a 6191** case-independent fashion, using the same definition of case independence 6192** that SQLite uses internally when comparing identifiers. 6193*/ 6194SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 6195 6196/* 6197** CAPI3REF: Error Logging Interface 6198** 6199** ^The [sqlite3_log()] interface writes a message into the error log 6200** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 6201** ^If logging is enabled, the zFormat string and subsequent arguments are 6202** used with [sqlite3_snprintf()] to generate the final output string. 6203** 6204** The sqlite3_log() interface is intended for use by extensions such as 6205** virtual tables, collating functions, and SQL functions. While there is 6206** nothing to prevent an application from calling sqlite3_log(), doing so 6207** is considered bad form. 6208** 6209** The zFormat string must not be NULL. 6210** 6211** To avoid deadlocks and other threading problems, the sqlite3_log() routine 6212** will not use dynamically allocated memory. The log message is stored in 6213** a fixed-length buffer on the stack. If the log message is longer than 6214** a few hundred characters, it will be truncated to the length of the 6215** buffer. 6216*/ 6217SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 6218 6219/* 6220** CAPI3REF: Write-Ahead Log Commit Hook 6221** 6222** ^The [sqlite3_wal_hook()] function is used to register a callback that 6223** will be invoked each time a database connection commits data to a 6224** [write-ahead log] (i.e. whenever a transaction is committed in 6225** [journal_mode | journal_mode=WAL mode]). 6226** 6227** ^The callback is invoked by SQLite after the commit has taken place and 6228** the associated write-lock on the database released, so the implementation 6229** may read, write or [checkpoint] the database as required. 6230** 6231** ^The first parameter passed to the callback function when it is invoked 6232** is a copy of the third parameter passed to sqlite3_wal_hook() when 6233** registering the callback. ^The second is a copy of the database handle. 6234** ^The third parameter is the name of the database that was written to - 6235** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 6236** is the number of pages currently in the write-ahead log file, 6237** including those that were just committed. 6238** 6239** The callback function should normally return [SQLITE_OK]. ^If an error 6240** code is returned, that error will propagate back up through the 6241** SQLite code base to cause the statement that provoked the callback 6242** to report an error, though the commit will have still occurred. If the 6243** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 6244** that does not correspond to any valid SQLite error code, the results 6245** are undefined. 6246** 6247** A single database handle may have at most a single write-ahead log callback 6248** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 6249** previously registered write-ahead log callback. ^Note that the 6250** [sqlite3_wal_autocheckpoint()] interface and the 6251** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 6252** those overwrite any prior [sqlite3_wal_hook()] settings. 6253*/ 6254SQLITE_API void *sqlite3_wal_hook( 6255 sqlite3*, 6256 int(*)(void *,sqlite3*,const char*,int), 6257 void* 6258); 6259 6260/* 6261** CAPI3REF: Configure an auto-checkpoint 6262** 6263** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 6264** [sqlite3_wal_hook()] that causes any database on [database connection] D 6265** to automatically [checkpoint] 6266** after committing a transaction if there are N or 6267** more frames in the [write-ahead log] file. ^Passing zero or 6268** a negative value as the nFrame parameter disables automatic 6269** checkpoints entirely. 6270** 6271** ^The callback registered by this function replaces any existing callback 6272** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 6273** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 6274** configured by this function. 6275** 6276** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 6277** from SQL. 6278** 6279** ^Every new [database connection] defaults to having the auto-checkpoint 6280** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 6281** pages. The use of this interface 6282** is only necessary if the default setting is found to be suboptimal 6283** for a particular application. 6284*/ 6285SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 6286 6287/* 6288** CAPI3REF: Checkpoint a database 6289** 6290** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 6291** on [database connection] D to be [checkpointed]. ^If X is NULL or an 6292** empty string, then a checkpoint is run on all databases of 6293** connection D. ^If the database connection D is not in 6294** [WAL | write-ahead log mode] then this interface is a harmless no-op. 6295** 6296** ^The [wal_checkpoint pragma] can be used to invoke this interface 6297** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 6298** [wal_autocheckpoint pragma] can be used to cause this interface to be 6299** run whenever the WAL reaches a certain size threshold. 6300** 6301** See also: [sqlite3_wal_checkpoint_v2()] 6302*/ 6303SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 6304 6305/* 6306** CAPI3REF: Checkpoint a database 6307** 6308** Run a checkpoint operation on WAL database zDb attached to database 6309** handle db. The specific operation is determined by the value of the 6310** eMode parameter: 6311** 6312** <dl> 6313** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 6314** Checkpoint as many frames as possible without waiting for any database 6315** readers or writers to finish. Sync the db file if all frames in the log 6316** are checkpointed. This mode is the same as calling 6317** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 6318** 6319** <dt>SQLITE_CHECKPOINT_FULL<dd> 6320** This mode blocks (calls the busy-handler callback) until there is no 6321** database writer and all readers are reading from the most recent database 6322** snapshot. It then checkpoints all frames in the log file and syncs the 6323** database file. This call blocks database writers while it is running, 6324** but not database readers. 6325** 6326** <dt>SQLITE_CHECKPOINT_RESTART<dd> 6327** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 6328** checkpointing the log file it blocks (calls the busy-handler callback) 6329** until all readers are reading from the database file only. This ensures 6330** that the next client to write to the database file restarts the log file 6331** from the beginning. This call blocks database writers while it is running, 6332** but not database readers. 6333** </dl> 6334** 6335** If pnLog is not NULL, then *pnLog is set to the total number of frames in 6336** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 6337** the total number of checkpointed frames (including any that were already 6338** checkpointed when this function is called). *pnLog and *pnCkpt may be 6339** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 6340** If no values are available because of an error, they are both set to -1 6341** before returning to communicate this to the caller. 6342** 6343** All calls obtain an exclusive "checkpoint" lock on the database file. If 6344** any other process is running a checkpoint operation at the same time, the 6345** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 6346** busy-handler configured, it will not be invoked in this case. 6347** 6348** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 6349** "writer" lock on the database file. If the writer lock cannot be obtained 6350** immediately, and a busy-handler is configured, it is invoked and the writer 6351** lock retried until either the busy-handler returns 0 or the lock is 6352** successfully obtained. The busy-handler is also invoked while waiting for 6353** database readers as described above. If the busy-handler returns 0 before 6354** the writer lock is obtained or while waiting for database readers, the 6355** checkpoint operation proceeds from that point in the same way as 6356** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 6357** without blocking any further. SQLITE_BUSY is returned in this case. 6358** 6359** If parameter zDb is NULL or points to a zero length string, then the 6360** specified operation is attempted on all WAL databases. In this case the 6361** values written to output parameters *pnLog and *pnCkpt are undefined. If 6362** an SQLITE_BUSY error is encountered when processing one or more of the 6363** attached WAL databases, the operation is still attempted on any remaining 6364** attached databases and SQLITE_BUSY is returned to the caller. If any other 6365** error occurs while processing an attached database, processing is abandoned 6366** and the error code returned to the caller immediately. If no error 6367** (SQLITE_BUSY or otherwise) is encountered while processing the attached 6368** databases, SQLITE_OK is returned. 6369** 6370** If database zDb is the name of an attached database that is not in WAL 6371** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 6372** zDb is not NULL (or a zero length string) and is not the name of any 6373** attached database, SQLITE_ERROR is returned to the caller. 6374*/ 6375SQLITE_API int sqlite3_wal_checkpoint_v2( 6376 sqlite3 *db, /* Database handle */ 6377 const char *zDb, /* Name of attached database (or NULL) */ 6378 int eMode, /* SQLITE_CHECKPOINT_* value */ 6379 int *pnLog, /* OUT: Size of WAL log in frames */ 6380 int *pnCkpt /* OUT: Total number of frames checkpointed */ 6381); 6382 6383/* 6384** CAPI3REF: Checkpoint operation parameters 6385** 6386** These constants can be used as the 3rd parameter to 6387** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 6388** documentation for additional information about the meaning and use of 6389** each of these values. 6390*/ 6391#define SQLITE_CHECKPOINT_PASSIVE 0 6392#define SQLITE_CHECKPOINT_FULL 1 6393#define SQLITE_CHECKPOINT_RESTART 2 6394 6395 6396/* Begin recover.patch for Chromium */ 6397/* 6398** Call to initialize the recover virtual-table modules (see recover.c). 6399** 6400** This could be loaded by default in main.c, but that would make the 6401** virtual table available to Web SQL. Breaking it out allows only 6402** selected users to enable it (currently sql/recovery.cc). 6403*/ 6404int recoverVtableInit(sqlite3 *db); 6405/* End recover.patch for Chromium */ 6406 6407/* 6408** Undo the hack that converts floating point types to integer for 6409** builds on processors without floating point support. 6410*/ 6411#ifdef SQLITE_OMIT_FLOATING_POINT 6412# undef double 6413#endif 6414 6415#ifdef __cplusplus 6416} /* End of the 'extern "C"' block */ 6417#endif 6418#endif 6419 6420/* 6421** 2010 August 30 6422** 6423** The author disclaims copyright to this source code. In place of 6424** a legal notice, here is a blessing: 6425** 6426** May you do good and not evil. 6427** May you find forgiveness for yourself and forgive others. 6428** May you share freely, never taking more than you give. 6429** 6430************************************************************************* 6431*/ 6432 6433#ifndef _SQLITE3RTREE_H_ 6434#define _SQLITE3RTREE_H_ 6435 6436 6437#ifdef __cplusplus 6438extern "C" { 6439#endif 6440 6441typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 6442 6443/* 6444** Register a geometry callback named zGeom that can be used as part of an 6445** R-Tree geometry query as follows: 6446** 6447** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 6448*/ 6449SQLITE_API int sqlite3_rtree_geometry_callback( 6450 sqlite3 *db, 6451 const char *zGeom, 6452 int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes), 6453 void *pContext 6454); 6455 6456 6457/* 6458** A pointer to a structure of the following type is passed as the first 6459** argument to callbacks registered using rtree_geometry_callback(). 6460*/ 6461struct sqlite3_rtree_geometry { 6462 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 6463 int nParam; /* Size of array aParam[] */ 6464 double *aParam; /* Parameters passed to SQL geom function */ 6465 void *pUser; /* Callback implementation user data */ 6466 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 6467}; 6468 6469 6470#ifdef __cplusplus 6471} /* end of the 'extern "C"' block */ 6472#endif 6473 6474#endif /* ifndef _SQLITE3RTREE_H_ */ 6475 6476