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 to make minor changes if 22** 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** @(#) $Id: sqlite.h.in,v 1.373 2008/07/22 18:45:09 drh Exp $ 34*/ 35#ifndef _SQLITE3_H_ 36#define _SQLITE3_H_ 37#include <stdarg.h> /* Needed for the definition of va_list */ 38 39/* 40** Make sure we can call this stuff from C++. 41*/ 42#ifdef __cplusplus 43extern "C" { 44#endif 45 46 47/* 48** Add the ability to override 'extern' 49*/ 50#ifndef SQLITE_EXTERN 51# define SQLITE_EXTERN extern 52#endif 53 54/* 55** Ensure these symbols were not defined by some previous header file. 56*/ 57#ifdef SQLITE_VERSION 58# undef SQLITE_VERSION 59#endif 60#ifdef SQLITE_VERSION_NUMBER 61# undef SQLITE_VERSION_NUMBER 62#endif 63 64/* 65** CAPI3REF: Compile-Time Library Version Numbers {H10010}<S60100> 66** 67** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in 68** the sqlite3.h file specify the version of SQLite with which 69** that header file is associated. 70** 71** The "version" of SQLite is a string of the form "X.Y.Z". 72** The phrase "alpha" or "beta" might be appended after the Z. 73** The X value is major version number always 3 in SQLite3. 74** The X value only changes when backwards compatibility is 75** broken and we intend to never break backwards compatibility. 76** The Y value is the minor version number and only changes when 77** there are major feature enhancements that are forwards compatible 78** but not backwards compatible. 79** The Z value is the release number and is incremented with 80** each release but resets back to 0 whenever Y is incremented. 81** 82** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()]. 83** 84** INVARIANTS: 85** 86** {H10011} The SQLITE_VERSION #define in the sqlite3.h header file shall 87** evaluate to a string literal that is the SQLite version 88** with which the header file is associated. <S60100> 89** 90** {H10014} The SQLITE_VERSION_NUMBER #define shall resolve to an integer 91** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z 92** are the major version, minor version, and release number. 93** <S60100> 94*/ 95#define SQLITE_VERSION "--VERS--" 96#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 97 98/* 99** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100> 100** KEYWORDS: sqlite3_version 101** 102** These features provide the same information as the [SQLITE_VERSION] 103** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated 104** with the library instead of the header file. Cautious programmers might 105** include a check in their application to verify that 106** sqlite3_libversion_number() always returns the value 107** [SQLITE_VERSION_NUMBER]. 108** 109** The sqlite3_libversion() function returns the same information as is 110** in the sqlite3_version[] string constant. The function is provided 111** for use in DLLs since DLL users usually do not have direct access to string 112** constants within the DLL. 113** 114** INVARIANTS: 115** 116** {H10021} The [sqlite3_libversion_number()] interface shall return 117** an integer equal to [SQLITE_VERSION_NUMBER]. <S60100> 118** 119** {H10022} The [sqlite3_version] string constant shall contain 120** the text of the [SQLITE_VERSION] string. <S60100> 121** 122** {H10023} The [sqlite3_libversion()] function shall return 123** a pointer to the [sqlite3_version] string constant. <S60100> 124*/ 125SQLITE_EXTERN const char sqlite3_version[]; 126const char *sqlite3_libversion(void); 127int sqlite3_libversion_number(void); 128 129/* 130** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100> 131** 132** SQLite can be compiled with or without mutexes. When 133** the [SQLITE_THREADSAFE] C preprocessor macro is true, mutexes 134** are enabled and SQLite is threadsafe. When that macro is false, 135** the mutexes are omitted. Without the mutexes, it is not safe 136** to use SQLite concurrently from more than one thread. 137** 138** Enabling mutexes incurs a measurable performance penalty. 139** So if speed is of utmost importance, it makes sense to disable 140** the mutexes. But for maximum safety, mutexes should be enabled. 141** The default behavior is for mutexes to be enabled. 142** 143** This interface can be used by a program to make sure that the 144** version of SQLite that it is linking against was compiled with 145** the desired setting of the [SQLITE_THREADSAFE] macro. 146** 147** This interface only reports on the compile-time mutex setting 148** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 149** SQLITE_THREADSAFE=1 then mutexes are enabled by default but 150** can be fully or partially disabled using a call to [sqlite3_config()] 151** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 152** or [SQLITE_CONFIG_MUTEX]. The return value of this function shows 153** only the default compile-time setting, not any run-time changes 154** to that setting. 155** 156** INVARIANTS: 157** 158** {H10101} The [sqlite3_threadsafe()] function shall return nonzero if 159** SQLite was compiled with the its mutexes enabled by default 160** or zero if SQLite was compiled such that mutexes are 161** permanently disabled. <S60100> 162** 163** {H10102} The value returned by the [sqlite3_threadsafe()] function 164** shall not change when mutex setting are modified at 165** runtime using the [sqlite3_config()] interface and 166** especially the [SQLITE_CONFIG_SINGLETHREAD], 167** [SQLITE_CONFIG_MULTITHREAD], [SQLITE_CONFIG_SERIALIZED], 168** and [SQLITE_CONFIG_MUTEX] verbs. <S60100> 169*/ 170int sqlite3_threadsafe(void); 171 172/* 173** CAPI3REF: Database Connection Handle {H12000} 174** KEYWORDS: {database connection} {database connections} 175** 176** Each open SQLite database is represented by a pointer to an instance of 177** the opaque structure named "sqlite3". It is useful to think of an sqlite3 178** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 179** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 180** is its destructor. There are many other interfaces (such as 181** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 182** [sqlite3_busy_timeout()] to name but three) that are methods on an 183** sqlite3 object. 184*/ 185typedef struct sqlite3 sqlite3; 186 187/* 188** CAPI3REF: 64-Bit Integer Types {H10200} 189** KEYWORDS: sqlite_int64 sqlite_uint64 190** 191** Because there is no cross-platform way to specify 64-bit integer types 192** SQLite includes typedefs for 64-bit signed and unsigned integers. 193** 194** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 195** The sqlite_int64 and sqlite_uint64 types are supported for backwards 196** compatibility only. 197** 198** INVARIANTS: 199** 200** {H10201} The [sqlite_int64] and [sqlite3_int64] type shall specify 201** a 64-bit signed integer. 202** 203** {H10202} The [sqlite_uint64] and [sqlite3_uint64] type shall specify 204** a 64-bit unsigned integer. 205*/ 206#ifdef SQLITE_INT64_TYPE 207 typedef SQLITE_INT64_TYPE sqlite_int64; 208 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 209#elif defined(_MSC_VER) || defined(__BORLANDC__) 210 typedef __int64 sqlite_int64; 211 typedef unsigned __int64 sqlite_uint64; 212#else 213 typedef long long int sqlite_int64; 214 typedef unsigned long long int sqlite_uint64; 215#endif 216typedef sqlite_int64 sqlite3_int64; 217typedef sqlite_uint64 sqlite3_uint64; 218 219/* 220** If compiling for a processor that lacks floating point support, 221** substitute integer for floating-point. 222*/ 223#ifdef SQLITE_OMIT_FLOATING_POINT 224# define double sqlite3_int64 225#endif 226 227/* 228** CAPI3REF: Closing A Database Connection {H12010} 229** 230** This routine is the destructor for the [sqlite3] object. 231** 232** Applications should [sqlite3_finalize | finalize] all [prepared statements] 233** and [sqlite3_blob_close | close] all [BLOB handles] associated with 234** the [sqlite3] object prior to attempting to close the object. 235** The [sqlite3_next_stmt()] interface can be used to locate all 236** [prepared statements] associated with a [database connection] if desired. 237** Typical code might look like this: 238** 239** <blockquote><pre> 240** sqlite3_stmt *pStmt; 241** while( (pStmt = sqlite3_next_stmt(db, 0))!=0 ){ 242** sqlite3_finalize(pStmt); 243** } 244** </pre></blockquote> 245** 246** If [sqlite3_close()] is invoked while a transaction is open, 247** the transaction is automatically rolled back. 248** 249** INVARIANTS: 250** 251** {H12011} A successful call to [sqlite3_close(C)] shall destroy the 252** [database connection] object C. 253** 254** {H12012} A successful call to [sqlite3_close(C)] shall return SQLITE_OK. 255** 256** {H12013} A successful call to [sqlite3_close(C)] shall release all 257** memory and system resources associated with [database connection] 258** C. 259** 260** {H12014} A call to [sqlite3_close(C)] on a [database connection] C that 261** has one or more open [prepared statements] shall fail with 262** an [SQLITE_BUSY] error code. 263** 264** {H12015} A call to [sqlite3_close(C)] where C is a NULL pointer shall 265** return SQLITE_OK. 266** 267** {H12019} When [sqlite3_close(C)] is invoked on a [database connection] C 268** that has a pending transaction, the transaction shall be 269** rolled back. 270** 271** ASSUMPTIONS: 272** 273** {A12016} The C parameter to [sqlite3_close(C)] must be either a NULL 274** pointer or an [sqlite3] object pointer previously obtained 275** from [sqlite3_open()], [sqlite3_open16()], or 276** [sqlite3_open_v2()], and not previously closed. 277*/ 278int sqlite3_close(sqlite3 *); 279 280/* 281** The type for a callback function. 282** This is legacy and deprecated. It is included for historical 283** compatibility and is not documented. 284*/ 285typedef int (*sqlite3_callback)(void*,int,char**, char**); 286 287/* 288** CAPI3REF: One-Step Query Execution Interface {H12100} 289** 290** The sqlite3_exec() interface is a convenient way of running one or more 291** SQL statements without having to write a lot of C code. The UTF-8 encoded 292** SQL statements are passed in as the second parameter to sqlite3_exec(). 293** The statements are evaluated one by one until either an error or 294** an interrupt is encountered, or until they are all done. The 3rd parameter 295** is an optional callback that is invoked once for each row of any query 296** results produced by the SQL statements. The 5th parameter tells where 297** to write any error messages. 298** 299** The error message passed back through the 5th parameter is held 300** in memory obtained from [sqlite3_malloc()]. To avoid a memory leak, 301** the calling application should call [sqlite3_free()] on any error 302** message returned through the 5th parameter when it has finished using 303** the error message. 304** 305** If the SQL statement in the 2nd parameter is NULL or an empty string 306** or a string containing only whitespace and comments, then no SQL 307** statements are evaluated and the database is not changed. 308** 309** The sqlite3_exec() interface is implemented in terms of 310** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 311** The sqlite3_exec() routine does nothing to the database that cannot be done 312** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 313** 314** INVARIANTS: 315** 316** {H12101} A successful invocation of [sqlite3_exec(D,S,C,A,E)] 317** shall sequentially evaluate all of the UTF-8 encoded, 318** semicolon-separated SQL statements in the zero-terminated 319** string S within the context of the [database connection] D. 320** 321** {H12102} If the S parameter to [sqlite3_exec(D,S,C,A,E)] is NULL then 322** the actions of the interface shall be the same as if the 323** S parameter were an empty string. 324** 325** {H12104} The return value of [sqlite3_exec()] shall be [SQLITE_OK] if all 326** SQL statements run successfully and to completion. 327** 328** {H12105} The return value of [sqlite3_exec()] shall be an appropriate 329** non-zero [error code] if any SQL statement fails. 330** 331** {H12107} If one or more of the SQL statements handed to [sqlite3_exec()] 332** return results and the 3rd parameter is not NULL, then 333** the callback function specified by the 3rd parameter shall be 334** invoked once for each row of result. 335** 336** {H12110} If the callback returns a non-zero value then [sqlite3_exec()] 337** shall abort the SQL statement it is currently evaluating, 338** skip all subsequent SQL statements, and return [SQLITE_ABORT]. 339** 340** {H12113} The [sqlite3_exec()] routine shall pass its 4th parameter through 341** as the 1st parameter of the callback. 342** 343** {H12116} The [sqlite3_exec()] routine shall set the 2nd parameter of its 344** callback to be the number of columns in the current row of 345** result. 346** 347** {H12119} The [sqlite3_exec()] routine shall set the 3rd parameter of its 348** callback to be an array of pointers to strings holding the 349** values for each column in the current result set row as 350** obtained from [sqlite3_column_text()]. 351** 352** {H12122} The [sqlite3_exec()] routine shall set the 4th parameter of its 353** callback to be an array of pointers to strings holding the 354** names of result columns as obtained from [sqlite3_column_name()]. 355** 356** {H12125} If the 3rd parameter to [sqlite3_exec()] is NULL then 357** [sqlite3_exec()] shall silently discard query results. 358** 359** {H12131} If an error occurs while parsing or evaluating any of the SQL 360** statements in the S parameter of [sqlite3_exec(D,S,C,A,E)] and if 361** the E parameter is not NULL, then [sqlite3_exec()] shall store 362** in *E an appropriate error message written into memory obtained 363** from [sqlite3_malloc()]. 364** 365** {H12134} The [sqlite3_exec(D,S,C,A,E)] routine shall set the value of 366** *E to NULL if E is not NULL and there are no errors. 367** 368** {H12137} The [sqlite3_exec(D,S,C,A,E)] function shall set the [error code] 369** and message accessible via [sqlite3_errcode()], 370** [sqlite3_errmsg()], and [sqlite3_errmsg16()]. 371** 372** {H12138} If the S parameter to [sqlite3_exec(D,S,C,A,E)] is NULL or an 373** empty string or contains nothing other than whitespace, comments, 374** and/or semicolons, then results of [sqlite3_errcode()], 375** [sqlite3_errmsg()], and [sqlite3_errmsg16()] 376** shall reset to indicate no errors. 377** 378** ASSUMPTIONS: 379** 380** {A12141} The first parameter to [sqlite3_exec()] must be an valid and open 381** [database connection]. 382** 383** {A12142} The database connection must not be closed while 384** [sqlite3_exec()] is running. 385** 386** {A12143} The calling function should use [sqlite3_free()] to free 387** the memory that *errmsg is left pointing at once the error 388** message is no longer needed. 389** 390** {A12145} The SQL statement text in the 2nd parameter to [sqlite3_exec()] 391** must remain unchanged while [sqlite3_exec()] is running. 392*/ 393int sqlite3_exec( 394 sqlite3*, /* An open database */ 395 const char *sql, /* SQL to be evaluated */ 396 int (*callback)(void*,int,char**,char**), /* Callback function */ 397 void *, /* 1st argument to callback */ 398 char **errmsg /* Error msg written here */ 399); 400 401/* 402** CAPI3REF: Result Codes {H10210} 403** KEYWORDS: SQLITE_OK {error code} {error codes} 404** KEYWORDS: {result code} {result codes} 405** 406** Many SQLite functions return an integer result code from the set shown 407** here in order to indicates success or failure. 408** 409** New error codes may be added in future versions of SQLite. 410** 411** See also: [SQLITE_IOERR_READ | extended result codes] 412*/ 413#define SQLITE_OK 0 /* Successful result */ 414/* beginning-of-error-codes */ 415#define SQLITE_ERROR 1 /* SQL error or missing database */ 416#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 417#define SQLITE_PERM 3 /* Access permission denied */ 418#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 419#define SQLITE_BUSY 5 /* The database file is locked */ 420#define SQLITE_LOCKED 6 /* A table in the database is locked */ 421#define SQLITE_NOMEM 7 /* A malloc() failed */ 422#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 423#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 424#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 425#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 426#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ 427#define SQLITE_FULL 13 /* Insertion failed because database is full */ 428#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 429#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ 430#define SQLITE_EMPTY 16 /* Database is empty */ 431#define SQLITE_SCHEMA 17 /* The database schema changed */ 432#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 433#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 434#define SQLITE_MISMATCH 20 /* Data type mismatch */ 435#define SQLITE_MISUSE 21 /* Library used incorrectly */ 436#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 437#define SQLITE_AUTH 23 /* Authorization denied */ 438#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 439#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 440#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 441#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 442#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 443/* end-of-error-codes */ 444 445/* 446** CAPI3REF: Extended Result Codes {H10220} 447** KEYWORDS: {extended error code} {extended error codes} 448** KEYWORDS: {extended result code} {extended result codes} 449** 450** In its default configuration, SQLite API routines return one of 26 integer 451** [SQLITE_OK | result codes]. However, experience has shown that many of 452** these result codes are too coarse-grained. They do not provide as 453** much information about problems as programmers might like. In an effort to 454** address this, newer versions of SQLite (version 3.3.8 and later) include 455** support for additional result codes that provide more detailed information 456** about errors. The extended result codes are enabled or disabled 457** on a per database connection basis using the 458** [sqlite3_extended_result_codes()] API. 459** 460** Some of the available extended result codes are listed here. 461** One may expect the number of extended result codes will be expand 462** over time. Software that uses extended result codes should expect 463** to see new result codes in future releases of SQLite. 464** 465** The SQLITE_OK result code will never be extended. It will always 466** be exactly zero. 467** 468** INVARIANTS: 469** 470** {H10223} The symbolic name for an extended result code shall contains 471** a related primary result code as a prefix. 472** 473** {H10224} Primary result code names shall contain a single "_" character. 474** 475** {H10225} Extended result code names shall contain two or more "_" characters. 476** 477** {H10226} The numeric value of an extended result code shall contain the 478** numeric value of its corresponding primary result code in 479** its least significant 8 bits. 480*/ 481#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 482#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 483#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 484#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 485#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 486#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 487#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 488#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 489#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 490#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 491#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 492#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 493#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 494#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 495 496/* 497** CAPI3REF: Flags For File Open Operations {H10230} 498** 499** These bit values are intended for use in the 500** 3rd parameter to the [sqlite3_open_v2()] interface and 501** in the 4th parameter to the xOpen method of the 502** [sqlite3_vfs] object. 503*/ 504#define SQLITE_OPEN_READONLY 0x00000001 505#define SQLITE_OPEN_READWRITE 0x00000002 506#define SQLITE_OPEN_CREATE 0x00000004 507#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 508#define SQLITE_OPEN_EXCLUSIVE 0x00000010 509#define SQLITE_OPEN_MAIN_DB 0x00000100 510#define SQLITE_OPEN_TEMP_DB 0x00000200 511#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 512#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 513#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 514#define SQLITE_OPEN_SUBJOURNAL 0x00002000 515#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 516#define SQLITE_OPEN_NOMUTEX 0x00008000 517 518/* 519** CAPI3REF: Device Characteristics {H10240} 520** 521** The xDeviceCapabilities method of the [sqlite3_io_methods] 522** object returns an integer which is a vector of the these 523** bit values expressing I/O characteristics of the mass storage 524** device that holds the file that the [sqlite3_io_methods] 525** refers to. 526** 527** The SQLITE_IOCAP_ATOMIC property means that all writes of 528** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 529** mean that writes of blocks that are nnn bytes in size and 530** are aligned to an address which is an integer multiple of 531** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 532** that when data is appended to a file, the data is appended 533** first then the size of the file is extended, never the other 534** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 535** information is written to disk in the same order as calls 536** to xWrite(). 537*/ 538#define SQLITE_IOCAP_ATOMIC 0x00000001 539#define SQLITE_IOCAP_ATOMIC512 0x00000002 540#define SQLITE_IOCAP_ATOMIC1K 0x00000004 541#define SQLITE_IOCAP_ATOMIC2K 0x00000008 542#define SQLITE_IOCAP_ATOMIC4K 0x00000010 543#define SQLITE_IOCAP_ATOMIC8K 0x00000020 544#define SQLITE_IOCAP_ATOMIC16K 0x00000040 545#define SQLITE_IOCAP_ATOMIC32K 0x00000080 546#define SQLITE_IOCAP_ATOMIC64K 0x00000100 547#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 548#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 549 550/* 551** CAPI3REF: File Locking Levels {H10250} 552** 553** SQLite uses one of these integer values as the second 554** argument to calls it makes to the xLock() and xUnlock() methods 555** of an [sqlite3_io_methods] object. 556*/ 557#define SQLITE_LOCK_NONE 0 558#define SQLITE_LOCK_SHARED 1 559#define SQLITE_LOCK_RESERVED 2 560#define SQLITE_LOCK_PENDING 3 561#define SQLITE_LOCK_EXCLUSIVE 4 562 563/* 564** CAPI3REF: Synchronization Type Flags {H10260} 565** 566** When SQLite invokes the xSync() method of an 567** [sqlite3_io_methods] object it uses a combination of 568** these integer values as the second argument. 569** 570** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 571** sync operation only needs to flush data to mass storage. Inode 572** information need not be flushed. The SQLITE_SYNC_NORMAL flag means 573** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means 574** to use Mac OS-X style fullsync instead of fsync(). 575*/ 576#define SQLITE_SYNC_NORMAL 0x00002 577#define SQLITE_SYNC_FULL 0x00003 578#define SQLITE_SYNC_DATAONLY 0x00010 579 580/* 581** CAPI3REF: OS Interface Open File Handle {H11110} 582** 583** An [sqlite3_file] object represents an open file in the OS 584** interface layer. Individual OS interface implementations will 585** want to subclass this object by appending additional fields 586** for their own use. The pMethods entry is a pointer to an 587** [sqlite3_io_methods] object that defines methods for performing 588** I/O operations on the open file. 589*/ 590typedef struct sqlite3_file sqlite3_file; 591struct sqlite3_file { 592 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 593}; 594 595/* 596** CAPI3REF: OS Interface File Virtual Methods Object {H11120} 597** 598** Every file opened by the [sqlite3_vfs] xOpen method populates an 599** [sqlite3_file] object (or, more commonly, a subclass of the 600** [sqlite3_file] object) with a pointer to an instance of this object. 601** This object defines the methods used to perform various operations 602** against the open file represented by the [sqlite3_file] object. 603** 604** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 605** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 606** The second choice is a Mac OS-X style fullsync. The [SQLITE_SYNC_DATAONLY] 607** flag may be ORed in to indicate that only the data of the file 608** and not its inode needs to be synced. 609** 610** The integer values to xLock() and xUnlock() are one of 611** <ul> 612** <li> [SQLITE_LOCK_NONE], 613** <li> [SQLITE_LOCK_SHARED], 614** <li> [SQLITE_LOCK_RESERVED], 615** <li> [SQLITE_LOCK_PENDING], or 616** <li> [SQLITE_LOCK_EXCLUSIVE]. 617** </ul> 618** xLock() increases the lock. xUnlock() decreases the lock. 619** The xCheckReservedLock() method checks whether any database connection, 620** either in this process or in some other process, is holding a RESERVED, 621** PENDING, or EXCLUSIVE lock on the file. It returns true 622** if such a lock exists and false otherwise. 623** 624** The xFileControl() method is a generic interface that allows custom 625** VFS implementations to directly control an open file using the 626** [sqlite3_file_control()] interface. The second "op" argument is an 627** integer opcode. The third argument is a generic pointer intended to 628** point to a structure that may contain arguments or space in which to 629** write return values. Potential uses for xFileControl() might be 630** functions to enable blocking locks with timeouts, to change the 631** locking strategy (for example to use dot-file locks), to inquire 632** about the status of a lock, or to break stale locks. The SQLite 633** core reserves all opcodes less than 100 for its own use. 634** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 635** Applications that define a custom xFileControl method should use opcodes 636** greater than 100 to avoid conflicts. 637** 638** The xSectorSize() method returns the sector size of the 639** device that underlies the file. The sector size is the 640** minimum write that can be performed without disturbing 641** other bytes in the file. The xDeviceCharacteristics() 642** method returns a bit vector describing behaviors of the 643** underlying device: 644** 645** <ul> 646** <li> [SQLITE_IOCAP_ATOMIC] 647** <li> [SQLITE_IOCAP_ATOMIC512] 648** <li> [SQLITE_IOCAP_ATOMIC1K] 649** <li> [SQLITE_IOCAP_ATOMIC2K] 650** <li> [SQLITE_IOCAP_ATOMIC4K] 651** <li> [SQLITE_IOCAP_ATOMIC8K] 652** <li> [SQLITE_IOCAP_ATOMIC16K] 653** <li> [SQLITE_IOCAP_ATOMIC32K] 654** <li> [SQLITE_IOCAP_ATOMIC64K] 655** <li> [SQLITE_IOCAP_SAFE_APPEND] 656** <li> [SQLITE_IOCAP_SEQUENTIAL] 657** </ul> 658** 659** The SQLITE_IOCAP_ATOMIC property means that all writes of 660** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 661** mean that writes of blocks that are nnn bytes in size and 662** are aligned to an address which is an integer multiple of 663** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 664** that when data is appended to a file, the data is appended 665** first then the size of the file is extended, never the other 666** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 667** information is written to disk in the same order as calls 668** to xWrite(). 669*/ 670typedef struct sqlite3_io_methods sqlite3_io_methods; 671struct sqlite3_io_methods { 672 int iVersion; 673 int (*xClose)(sqlite3_file*); 674 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 675 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 676 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 677 int (*xSync)(sqlite3_file*, int flags); 678 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 679 int (*xLock)(sqlite3_file*, int); 680 int (*xUnlock)(sqlite3_file*, int); 681 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 682 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 683 int (*xSectorSize)(sqlite3_file*); 684 int (*xDeviceCharacteristics)(sqlite3_file*); 685 /* Additional methods may be added in future releases */ 686}; 687 688/* 689** CAPI3REF: Standard File Control Opcodes {H11310} 690** 691** These integer constants are opcodes for the xFileControl method 692** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 693** interface. 694** 695** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 696** opcode causes the xFileControl method to write the current state of 697** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 698** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 699** into an integer that the pArg argument points to. This capability 700** is used during testing and only needs to be supported when SQLITE_TEST 701** is defined. 702*/ 703#define SQLITE_FCNTL_LOCKSTATE 1 704 705/* 706** CAPI3REF: Mutex Handle {H17110} 707** 708** The mutex module within SQLite defines [sqlite3_mutex] to be an 709** abstract type for a mutex object. The SQLite core never looks 710** at the internal representation of an [sqlite3_mutex]. It only 711** deals with pointers to the [sqlite3_mutex] object. 712** 713** Mutexes are created using [sqlite3_mutex_alloc()]. 714*/ 715typedef struct sqlite3_mutex sqlite3_mutex; 716 717/* 718** CAPI3REF: OS Interface Object {H11140} 719** 720** An instance of the sqlite3_vfs object defines the interface between 721** the SQLite core and the underlying operating system. The "vfs" 722** in the name of the object stands for "virtual file system". 723** 724** The value of the iVersion field is initially 1 but may be larger in 725** future versions of SQLite. Additional fields may be appended to this 726** object when the iVersion value is increased. Note that the structure 727** of the sqlite3_vfs object changes in the transaction between 728** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 729** modified. 730** 731** The szOsFile field is the size of the subclassed [sqlite3_file] 732** structure used by this VFS. mxPathname is the maximum length of 733** a pathname in this VFS. 734** 735** Registered sqlite3_vfs objects are kept on a linked list formed by 736** the pNext pointer. The [sqlite3_vfs_register()] 737** and [sqlite3_vfs_unregister()] interfaces manage this list 738** in a thread-safe way. The [sqlite3_vfs_find()] interface 739** searches the list. Neither the application code nor the VFS 740** implementation should use the pNext pointer. 741** 742** The pNext field is the only field in the sqlite3_vfs 743** structure that SQLite will ever modify. SQLite will only access 744** or modify this field while holding a particular static mutex. 745** The application should never modify anything within the sqlite3_vfs 746** object once the object has been registered. 747** 748** The zName field holds the name of the VFS module. The name must 749** be unique across all VFS modules. 750** 751** {H11141} SQLite will guarantee that the zFilename parameter to xOpen 752** is either a NULL pointer or string obtained 753** from xFullPathname(). SQLite further guarantees that 754** the string will be valid and unchanged until xClose() is 755** called. {END} Becasue of the previous sentense, 756** the [sqlite3_file] can safely store a pointer to the 757** filename if it needs to remember the filename for some reason. 758** If the zFilename parameter is xOpen is a NULL pointer then xOpen 759** must invite its own temporary name for the file. Whenever the 760** xFilename parameter is NULL it will also be the case that the 761** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 762** 763** {H11142} The flags argument to xOpen() includes all bits set in 764** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 765** or [sqlite3_open16()] is used, then flags includes at least 766** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. {END} 767** If xOpen() opens a file read-only then it sets *pOutFlags to 768** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 769** 770** {H11143} SQLite will also add one of the following flags to the xOpen() 771** call, depending on the object being opened: 772** 773** <ul> 774** <li> [SQLITE_OPEN_MAIN_DB] 775** <li> [SQLITE_OPEN_MAIN_JOURNAL] 776** <li> [SQLITE_OPEN_TEMP_DB] 777** <li> [SQLITE_OPEN_TEMP_JOURNAL] 778** <li> [SQLITE_OPEN_TRANSIENT_DB] 779** <li> [SQLITE_OPEN_SUBJOURNAL] 780** <li> [SQLITE_OPEN_MASTER_JOURNAL] 781** </ul> {END} 782** 783** The file I/O implementation can use the object type flags to 784** change the way it deals with files. For example, an application 785** that does not care about crash recovery or rollback might make 786** the open of a journal file a no-op. Writes to this journal would 787** also be no-ops, and any attempt to read the journal would return 788** SQLITE_IOERR. Or the implementation might recognize that a database 789** file will be doing page-aligned sector reads and writes in a random 790** order and set up its I/O subsystem accordingly. 791** 792** SQLite might also add one of the following flags to the xOpen method: 793** 794** <ul> 795** <li> [SQLITE_OPEN_DELETEONCLOSE] 796** <li> [SQLITE_OPEN_EXCLUSIVE] 797** </ul> 798** 799** {H11145} The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 800** deleted when it is closed. {H11146} The [SQLITE_OPEN_DELETEONCLOSE] 801** will be set for TEMP databases, journals and for subjournals. 802** 803** {H11147} The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened 804** for exclusive access. This flag is set for all files except 805** for the main database file. 806** 807** {H11148} At least szOsFile bytes of memory are allocated by SQLite 808** to hold the [sqlite3_file] structure passed as the third 809** argument to xOpen. {END} The xOpen method does not have to 810** allocate the structure; it should just fill it in. 811** 812** {H11149} The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 813** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 814** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 815** to test whether a file is at least readable. {END} The file can be a 816** directory. 817** 818** {H11150} SQLite will always allocate at least mxPathname+1 bytes for the 819** output buffer xFullPathname. {H11151} The exact size of the output buffer 820** is also passed as a parameter to both methods. {END} If the output buffer 821** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 822** handled as a fatal error by SQLite, vfs implementations should endeavor 823** to prevent this by setting mxPathname to a sufficiently large value. 824** 825** The xRandomness(), xSleep(), and xCurrentTime() interfaces 826** are not strictly a part of the filesystem, but they are 827** included in the VFS structure for completeness. 828** The xRandomness() function attempts to return nBytes bytes 829** of good-quality randomness into zOut. The return value is 830** the actual number of bytes of randomness obtained. 831** The xSleep() method causes the calling thread to sleep for at 832** least the number of microseconds given. The xCurrentTime() 833** method returns a Julian Day Number for the current date and time. 834*/ 835typedef struct sqlite3_vfs sqlite3_vfs; 836struct sqlite3_vfs { 837 int iVersion; /* Structure version number */ 838 int szOsFile; /* Size of subclassed sqlite3_file */ 839 int mxPathname; /* Maximum file pathname length */ 840 sqlite3_vfs *pNext; /* Next registered VFS */ 841 const char *zName; /* Name of this virtual file system */ 842 void *pAppData; /* Pointer to application-specific data */ 843 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 844 int flags, int *pOutFlags); 845 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 846 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 847 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 848 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 849 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 850 void *(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol); 851 void (*xDlClose)(sqlite3_vfs*, void*); 852 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 853 int (*xSleep)(sqlite3_vfs*, int microseconds); 854 int (*xCurrentTime)(sqlite3_vfs*, double*); 855 int (*xGetLastError)(sqlite3_vfs*, int, char *); 856 /* New fields may be appended in figure versions. The iVersion 857 ** value will increment whenever this happens. */ 858}; 859 860/* 861** CAPI3REF: Flags for the xAccess VFS method {H11190} 862** 863** {H11191} These integer constants can be used as the third parameter to 864** the xAccess method of an [sqlite3_vfs] object. {END} They determine 865** what kind of permissions the xAccess method is looking for. 866** {H11192} With SQLITE_ACCESS_EXISTS, the xAccess method 867** simply checks whether the file exists. 868** {H11193} With SQLITE_ACCESS_READWRITE, the xAccess method 869** checks whether the file is both readable and writable. 870** {H11194} With SQLITE_ACCESS_READ, the xAccess method 871** checks whether the file is readable. 872*/ 873#define SQLITE_ACCESS_EXISTS 0 874#define SQLITE_ACCESS_READWRITE 1 875#define SQLITE_ACCESS_READ 2 876 877/* 878** CAPI3REF: Initialize The SQLite Library {H10130} 879** 880** The sqlite3_initialize() routine initializes the 881** SQLite library. The sqlite3_shutdown() routine 882** deallocates any resources that were allocated by sqlite3_initialize(). 883** 884** A call to sqlite3_initialize() is an "effective" call if it is 885** the first time sqlite3_initialize() is invoked during the lifetime of 886** the process, or if it is the first time sqlite3_initialize() is invoked 887** following a call to sqlite3_shutdown(). Only an effective call 888** of sqlite3_initialize() does any initialization. All other calls 889** are harmless no-ops. 890** 891** Among other things, sqlite3_initialize() shall invoke 892** sqlite3_os_init(). Similarly, sqlite3_shutdown() 893** shall invoke sqlite3_os_end(). 894** 895** The sqlite3_initialize() routine returns SQLITE_OK on success. 896** If for some reason, sqlite3_initialize() is unable to initialize 897** the library (perhaps it is unable to allocate a needed resource such 898** as a mutex) it returns an [error code] other than SQLITE_OK. 899** 900** The sqlite3_initialize() routine is called internally by many other 901** SQLite interfaces so that an application usually does not need to 902** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 903** calls sqlite3_initialize() so the SQLite library will be automatically 904** initialized when [sqlite3_open()] is called if it has not be initialized 905** already. However, if SQLite is compiled with the SQLITE_OMIT_AUTOINIT 906** compile-time option, then the automatic calls to sqlite3_initialize() 907** are omitted and the application must call sqlite3_initialize() directly 908** prior to using any other SQLite interface. For maximum portability, 909** it is recommended that applications always invoke sqlite3_initialize() 910** directly prior to using any other SQLite interface. Future releases 911** of SQLite may require this. In other words, the behavior exhibited 912** when SQLite is compiled with SQLITE_OMIT_AUTOINIT might become the 913** default behavior in some future release of SQLite. 914** 915** The sqlite3_os_init() routine does operating-system specific 916** initialization of the SQLite library. The sqlite3_os_end() 917** routine undoes the effect of sqlite3_os_init(). Typical tasks 918** performed by these routines include allocation or deallocation 919** of static resources, initialization of global variables, 920** setting up a default [sqlite3_vfs] module, or setting up 921** a default configuration using [sqlite3_config()]. 922** 923** The application should never invoke either sqlite3_os_init() 924** or sqlite3_os_end() directly. The application should only invoke 925** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 926** interface is called automatically by sqlite3_initialize() and 927** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 928** implementations for sqlite3_os_init() and sqlite3_os_end() 929** are built into SQLite when it is compiled for unix, windows, or os/2. 930** When built for other platforms (using the SQLITE_OS_OTHER=1 compile-time 931** option) the application must supply a suitable implementation for 932** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 933** implementation of sqlite3_os_init() or sqlite3_os_end() 934** must return SQLITE_OK on success and some other [error code] upon 935** failure. 936*/ 937int sqlite3_initialize(void); 938int sqlite3_shutdown(void); 939int sqlite3_os_init(void); 940int sqlite3_os_end(void); 941 942/* 943** CAPI3REF: Configuring The SQLite Library {H10145} 944** 945** The sqlite3_config() interface is used to make global configuration 946** changes to SQLite in order to tune SQLite to the specific needs of 947** the application. The default configuration is recommended for most 948** applications and so this routine is usually not necessary. It is 949** provided to support rare applications with unusual needs. 950** 951** The sqlite3_config() interface is not threadsafe. The application 952** must insure that no other SQLite interfaces are invoked by other 953** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 954** may only be invoked prior to library initialization using 955** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 956** Note, however, that sqlite3_config() can be called as part of the 957** implementation of an application-defined [sqlite3_os_init()]. 958** 959** The first argument to sqlite3_config() is an integer 960** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines 961** what property of SQLite is to be configured. Subsequent arguments 962** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] 963** in the first argument. 964** 965** When a configuration option is set, sqlite3_config() returns SQLITE_OK. 966** If the option is unknown or SQLite is unable to set the option 967** then this routine returns a non-zero [error code]. 968** 969** The sqlite3_config() interface is considered experimental in that 970** new configuration options may be added in future releases and existing 971** configuration options may be discontinued or modified. 972*/ 973int sqlite3_config(int, ...); 974 975/* 976** CAPI3REF: Memory Allocation Routines {H10155} 977** 978** An instance of this object defines the interface between SQLite 979** and low-level memory allocation routines. 980** 981** This object is used in only one place in the SQLite interface. 982** A pointer to an instance of this object is the argument to 983** [sqlite3_config()] when the configuration option is 984** [SQLITE_CONFIG_MALLOC]. By creating an instance of this object 985** and passing it to [sqlite3_config()] during configuration, an 986** application can specify an alternative memory allocation subsystem 987** for SQLite to use for all of its dynamic memory needs. 988** 989** Note that SQLite comes with a built-in memory allocator that is 990** perfectly adequate for the overwhelming majority of applications 991** and that this object is only useful to a tiny minority of applications 992** with specialized memory allocation requirements. This object is 993** also used during testing of SQLite in order to specify an alternative 994** memory allocator that simulates memory out-of-memory conditions in 995** order to verify that SQLite recovers gracefully from such 996** conditions. 997** 998** The xMalloc, xFree, and xRealloc methods must work like the 999** malloc(), free(), and realloc() functions from the standard library. 1000** 1001** xSize should return the allocated size of a memory allocation 1002** previously obtained from xMalloc or xRealloc. The allocated size 1003** is always at least as big as the requested size but may be larger. 1004** 1005** The xRoundup method returns what would be the allocated size of 1006** a memory allocation given a particular requested size. Most memory 1007** allocators round up memory allocations at least to the next multiple 1008** of 8. Some allocators round up to a larger multiple or to a power of 2. 1009** 1010** The xInit method initializes the memory allocator. (For example, 1011** it might allocate any require mutexes or initialize internal data 1012** structures. The xShutdown method is invoked (indirectly) by 1013** [sqlite3_shutdown()] and should deallocate any resources acquired 1014** by xInit. The pAppData pointer is used as the only parameter to 1015** xInit and xShutdown. 1016*/ 1017typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1018struct sqlite3_mem_methods { 1019 void *(*xMalloc)(int); /* Memory allocation function */ 1020 void (*xFree)(void*); /* Free a prior allocation */ 1021 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1022 int (*xSize)(void*); /* Return the size of an allocation */ 1023 int (*xRoundup)(int); /* Round up request size to allocation size */ 1024 int (*xInit)(void*); /* Initialize the memory allocator */ 1025 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1026 void *pAppData; /* Argument to xInit() and xShutdown() */ 1027}; 1028 1029/* 1030** CAPI3REF: Configuration Options {H10160} 1031** 1032** These constants are the available integer configuration options that 1033** can be passed as the first argument to the [sqlite3_config()] interface. 1034** 1035** New configuration options may be added in future releases of SQLite. 1036** Existing configuration options might be discontinued. Applications 1037** should check the return code from [sqlite3_config()] to make sure that 1038** the call worked. The [sqlite3_config()] interface will return a 1039** non-zero [error code] if a discontinued or unsupported configuration option 1040** is invoked. 1041** 1042** <dl> 1043** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1044** <dd>There are no arguments to this option. This option disables 1045** all mutexing and puts SQLite into a mode where it can only be used 1046** by a single thread.</dd> 1047** 1048** <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1049** <dd>There are no arguments to this option. This option disables 1050** mutexing on [database connection] and [prepared statement] objects. 1051** The application is responsible for serializing access to 1052** [database connections] and [prepared statements]. But other mutexes 1053** are enabled so that SQLite will be safe to use in a multi-threaded 1054** environment.</dd> 1055** 1056** <dt>SQLITE_CONFIG_SERIALIZED</dt> 1057** <dd>There are no arguments to this option. This option enables 1058** all mutexes including the recursive 1059** mutexes on [database connection] and [prepared statement] objects. 1060** In this mode (which is the default when SQLite is compiled with 1061** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1062** to [database connections] and [prepared statements] so that the 1063** application is free to use the same [database connection] or the 1064** same [prepared statement] in different threads at the same time. 1065** 1066** <p>This configuration option merely sets the default mutex 1067** behavior to serialize access to [database connections]. Individual 1068** [database connections] can override this setting 1069** using the [SQLITE_OPEN_NOMUTEX] flag to [sqlite3_open_v2()].</p></dd> 1070** 1071** <dt>SQLITE_CONFIG_MALLOC</dt> 1072** <dd>This option takes a single argument which is a pointer to an 1073** instance of the [sqlite3_mem_methods] structure. The argument specifies 1074** alternative low-level memory allocation routines to be used in place of 1075** the memory allocation routines built into SQLite.</dd> 1076** 1077** <dt>SQLITE_CONFIG_GETMALLOC</dt> 1078** <dd>This option takes a single argument which is a pointer to an 1079** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1080** structure is filled with the currently defined memory allocation routines. 1081** This option can be used to overload the default memory allocation 1082** routines with a wrapper that simulations memory allocation failure or 1083** tracks memory usage, for example.</dd> 1084** 1085** <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1086** <dd>This option takes single boolean argument which enables or disables 1087** the collection of memory allocation statistics. When disabled, the 1088** following SQLite interfaces become non-operational: 1089** <ul> 1090** <li> [sqlite3_memory_used()] 1091** <li> [sqlite3_memory_highwater()] 1092** <li> [sqlite3_soft_heap_limit()] 1093** <li> sqlite3_memory_status() 1094** </ul> 1095** </dd> 1096** 1097** <dt>SQLITE_CONFIG_SCRATCH</dt> 1098** <dd>This option specifies a static memory buffer that SQLite can use for 1099** scratch memory. There are three arguments: A pointer to the memory, the 1100** size of each scratch buffer (sz), and the number of buffers (N). The sz 1101** argument must be a multiple of 16. The first 1102** argument should point to an allocation of at least (sz+4)*N bytes of memory. 1103** SQLite will use no more than one scratch buffer at once per thread, so 1104** N should be set to the expected maximum number of threads. The sz 1105** parameter should be 6 times the size of the largest database page size. 1106** Scratch buffers are used as part of the btree balance operation. If 1107** The btree balancer needs additional memory beyond what is provided by 1108** scratch buffers or if no scratch buffer space is specified, then SQLite 1109** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd> 1110** 1111** <dt>SQLITE_CONFIG_PAGECACHE</dt> 1112** <dd>This option specifies a static memory buffer that SQLite can use for 1113** the database page cache. There are three arguments: A pointer to the 1114** memory, the size of each page buffer (sz), and the number of pages (N). 1115** The sz argument must be a power of two between 512 and 32768. The first 1116** argument should point to an allocation of at least (sz+4)*N bytes of memory. 1117** SQLite will use the memory provided by the first argument to satisfy its 1118** memory needs for the first N pages that it adds to cache. If additional 1119** page cache memory is needed beyond what is provided by this option, then 1120** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd> 1121** 1122** <dt>SQLITE_CONFIG_HEAP</dt> 1123** <dd>This option specifies a static memory buffer that SQLite will use 1124** for all of its dynamic memory allocation needs beyond those provided 1125** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1126** There are three arguments: A pointer to the memory, the number of 1127** bytes in the memory buffer, and the minimum allocation size. If 1128** the first pointer (the memory pointer) is NULL, then SQLite reverts 1129** to using its default memory allocator (the system malloc() implementation), 1130** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. If the 1131** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1132** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1133** allocator is engaged to handle all of SQLites memory allocation needs.</dd> 1134** 1135** <dt>SQLITE_CONFIG_MUTEX</dt> 1136** <dd>This option takes a single argument which is a pointer to an 1137** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1138** alternative low-level mutex routines to be used in place 1139** the mutex routines built into SQLite.</dd> 1140** 1141** <dt>SQLITE_CONFIG_GETMUTEX</dt> 1142** <dd>This option takes a single argument which is a pointer to an 1143** instance of the [sqlite3_mutex_methods] structure. The 1144** [sqlite3_mutex_methods] 1145** structure is filled with the currently defined mutex routines. 1146** This option can be used to overload the default mutex allocation 1147** routines with a wrapper used to track mutex usage for performance 1148** profiling or testing, for example.</dd> 1149*/ 1150#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1151#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1152#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1153#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1154#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1155#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1156#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1157#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1158#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1159#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1160#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1161 1162 1163/* 1164** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} 1165** 1166** The sqlite3_extended_result_codes() routine enables or disables the 1167** [extended result codes] feature of SQLite. The extended result 1168** codes are disabled by default for historical compatibility considerations. 1169** 1170** INVARIANTS: 1171** 1172** {H12201} Each new [database connection] shall have the 1173** [extended result codes] feature disabled by default. 1174** 1175** {H12202} The [sqlite3_extended_result_codes(D,F)] interface shall enable 1176** [extended result codes] for the [database connection] D 1177** if the F parameter is true, or disable them if F is false. 1178*/ 1179int sqlite3_extended_result_codes(sqlite3*, int onoff); 1180 1181/* 1182** CAPI3REF: Last Insert Rowid {H12220} 1183** 1184** Each entry in an SQLite table has a unique 64-bit signed 1185** integer key called the "rowid". The rowid is always available 1186** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1187** names are not also used by explicitly declared columns. If 1188** the table has a column of type INTEGER PRIMARY KEY then that column 1189** is another alias for the rowid. 1190** 1191** This routine returns the rowid of the most recent 1192** successful INSERT into the database from the [database connection] 1193** in the first argument. If no successful INSERTs 1194** have ever occurred on that database connection, zero is returned. 1195** 1196** If an INSERT occurs within a trigger, then the rowid of the inserted 1197** row is returned by this routine as long as the trigger is running. 1198** But once the trigger terminates, the value returned by this routine 1199** reverts to the last value inserted before the trigger fired. 1200** 1201** An INSERT that fails due to a constraint violation is not a 1202** successful INSERT and does not change the value returned by this 1203** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1204** and INSERT OR ABORT make no changes to the return value of this 1205** routine when their insertion fails. When INSERT OR REPLACE 1206** encounters a constraint violation, it does not fail. The 1207** INSERT continues to completion after deleting rows that caused 1208** the constraint problem so INSERT OR REPLACE will always change 1209** the return value of this interface. 1210** 1211** For the purposes of this routine, an INSERT is considered to 1212** be successful even if it is subsequently rolled back. 1213** 1214** INVARIANTS: 1215** 1216** {H12221} The [sqlite3_last_insert_rowid()] function returns the rowid 1217** of the most recent successful INSERT performed on the same 1218** [database connection] and within the same or higher level 1219** trigger context, or zero if there have been no qualifying inserts. 1220** 1221** {H12223} The [sqlite3_last_insert_rowid()] function returns the 1222** same value when called from the same trigger context 1223** immediately before and after a ROLLBACK. 1224** 1225** ASSUMPTIONS: 1226** 1227** {A12232} If a separate thread performs a new INSERT on the same 1228** database connection while the [sqlite3_last_insert_rowid()] 1229** function is running and thus changes the last insert rowid, 1230** then the value returned by [sqlite3_last_insert_rowid()] is 1231** unpredictable and might not equal either the old or the new 1232** last insert rowid. 1233*/ 1234sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1235 1236/* 1237** CAPI3REF: Count The Number Of Rows Modified {H12240} 1238** 1239** This function returns the number of database rows that were changed 1240** or inserted or deleted by the most recently completed SQL statement 1241** on the [database connection] specified by the first parameter. 1242** Only changes that are directly specified by the INSERT, UPDATE, 1243** or DELETE statement are counted. Auxiliary changes caused by 1244** triggers are not counted. Use the [sqlite3_total_changes()] function 1245** to find the total number of changes including changes caused by triggers. 1246** 1247** A "row change" is a change to a single row of a single table 1248** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1249** are changed as side effects of REPLACE constraint resolution, 1250** rollback, ABORT processing, DROP TABLE, or by any other 1251** mechanisms do not count as direct row changes. 1252** 1253** A "trigger context" is a scope of execution that begins and 1254** ends with the script of a trigger. Most SQL statements are 1255** evaluated outside of any trigger. This is the "top level" 1256** trigger context. If a trigger fires from the top level, a 1257** new trigger context is entered for the duration of that one 1258** trigger. Subtriggers create subcontexts for their duration. 1259** 1260** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1261** not create a new trigger context. 1262** 1263** This function returns the number of direct row changes in the 1264** most recent INSERT, UPDATE, or DELETE statement within the same 1265** trigger context. 1266** 1267** Thus, when called from the top level, this function returns the 1268** number of changes in the most recent INSERT, UPDATE, or DELETE 1269** that also occurred at the top level. Within the body of a trigger, 1270** the sqlite3_changes() interface can be called to find the number of 1271** changes in the most recently completed INSERT, UPDATE, or DELETE 1272** statement within the body of the same trigger. 1273** However, the number returned does not include changes 1274** caused by subtriggers since those have their own context. 1275** 1276** SQLite implements the command "DELETE FROM table" without a WHERE clause 1277** by dropping and recreating the table. (This is much faster than going 1278** through and deleting individual elements from the table.) Because of this 1279** optimization, the deletions in "DELETE FROM table" are not row changes and 1280** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] 1281** functions, regardless of the number of elements that were originally 1282** in the table. To get an accurate count of the number of rows deleted, use 1283** "DELETE FROM table WHERE 1" instead. 1284** 1285** INVARIANTS: 1286** 1287** {H12241} The [sqlite3_changes()] function shall return the number of 1288** row changes caused by the most recent INSERT, UPDATE, 1289** or DELETE statement on the same database connection and 1290** within the same or higher trigger context, or zero if there have 1291** not been any qualifying row changes. 1292** 1293** {H12243} Statements of the form "DELETE FROM tablename" with no 1294** WHERE clause shall cause subsequent calls to 1295** [sqlite3_changes()] to return zero, regardless of the 1296** number of rows originally in the table. 1297** 1298** ASSUMPTIONS: 1299** 1300** {A12252} If a separate thread makes changes on the same database connection 1301** while [sqlite3_changes()] is running then the value returned 1302** is unpredictable and not meaningful. 1303*/ 1304int sqlite3_changes(sqlite3*); 1305 1306/* 1307** CAPI3REF: Total Number Of Rows Modified {H12260} 1308** 1309** This function returns the number of row changes caused by INSERT, 1310** UPDATE or DELETE statements since the [database connection] was opened. 1311** The count includes all changes from all trigger contexts. However, 1312** the count does not include changes used to implement REPLACE constraints, 1313** do rollbacks or ABORT processing, or DROP table processing. 1314** The changes are counted as soon as the statement that makes them is 1315** completed (when the statement handle is passed to [sqlite3_reset()] or 1316** [sqlite3_finalize()]). 1317** 1318** SQLite implements the command "DELETE FROM table" without a WHERE clause 1319** by dropping and recreating the table. (This is much faster than going 1320** through and deleting individual elements from the table.) Because of this 1321** optimization, the deletions in "DELETE FROM table" are not row changes and 1322** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] 1323** functions, regardless of the number of elements that were originally 1324** in the table. To get an accurate count of the number of rows deleted, use 1325** "DELETE FROM table WHERE 1" instead. 1326** 1327** See also the [sqlite3_changes()] interface. 1328** 1329** INVARIANTS: 1330** 1331** {H12261} The [sqlite3_total_changes()] returns the total number 1332** of row changes caused by INSERT, UPDATE, and/or DELETE 1333** statements on the same [database connection], in any 1334** trigger context, since the database connection was created. 1335** 1336** {H12263} Statements of the form "DELETE FROM tablename" with no 1337** WHERE clause shall not change the value returned 1338** by [sqlite3_total_changes()]. 1339** 1340** ASSUMPTIONS: 1341** 1342** {A12264} If a separate thread makes changes on the same database connection 1343** while [sqlite3_total_changes()] is running then the value 1344** returned is unpredictable and not meaningful. 1345*/ 1346int sqlite3_total_changes(sqlite3*); 1347 1348/* 1349** CAPI3REF: Interrupt A Long-Running Query {H12270} 1350** 1351** This function causes any pending database operation to abort and 1352** return at its earliest opportunity. This routine is typically 1353** called in response to a user action such as pressing "Cancel" 1354** or Ctrl-C where the user wants a long query operation to halt 1355** immediately. 1356** 1357** It is safe to call this routine from a thread different from the 1358** thread that is currently running the database operation. But it 1359** is not safe to call this routine with a [database connection] that 1360** is closed or might close before sqlite3_interrupt() returns. 1361** 1362** If an SQL operation is very nearly finished at the time when 1363** sqlite3_interrupt() is called, then it might not have an opportunity 1364** to be interrupted and might continue to completion. 1365** 1366** An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1367** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1368** that is inside an explicit transaction, then the entire transaction 1369** will be rolled back automatically. 1370** 1371** A call to sqlite3_interrupt() has no effect on SQL statements 1372** that are started after sqlite3_interrupt() returns. 1373** 1374** INVARIANTS: 1375** 1376** {H12271} The [sqlite3_interrupt()] interface will force all running 1377** SQL statements associated with the same database connection 1378** to halt after processing at most one additional row of data. 1379** 1380** {H12272} Any SQL statement that is interrupted by [sqlite3_interrupt()] 1381** will return [SQLITE_INTERRUPT]. 1382** 1383** ASSUMPTIONS: 1384** 1385** {A12279} If the database connection closes while [sqlite3_interrupt()] 1386** is running then bad things will likely happen. 1387*/ 1388void sqlite3_interrupt(sqlite3*); 1389 1390/* 1391** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} 1392** 1393** These routines are useful for command-line input to determine if the 1394** currently entered text seems to form complete a SQL statement or 1395** if additional input is needed before sending the text into 1396** SQLite for parsing. These routines return true if the input string 1397** appears to be a complete SQL statement. A statement is judged to be 1398** complete if it ends with a semicolon token and is not a fragment of a 1399** CREATE TRIGGER statement. Semicolons that are embedded within 1400** string literals or quoted identifier names or comments are not 1401** independent tokens (they are part of the token in which they are 1402** embedded) and thus do not count as a statement terminator. 1403** 1404** These routines do not parse the SQL statements thus 1405** will not detect syntactically incorrect SQL. 1406** 1407** INVARIANTS: 1408** 1409** {H10511} A successful evaluation of [sqlite3_complete()] or 1410** [sqlite3_complete16()] functions shall 1411** return a numeric 1 if and only if the last non-whitespace 1412** token in their input is a semicolon that is not in between 1413** the BEGIN and END of a CREATE TRIGGER statement. 1414** 1415** {H10512} If a memory allocation error occurs during an invocation 1416** of [sqlite3_complete()] or [sqlite3_complete16()] then the 1417** routine shall return [SQLITE_NOMEM]. 1418** 1419** ASSUMPTIONS: 1420** 1421** {A10512} The input to [sqlite3_complete()] must be a zero-terminated 1422** UTF-8 string. 1423** 1424** {A10513} The input to [sqlite3_complete16()] must be a zero-terminated 1425** UTF-16 string in native byte order. 1426*/ 1427int sqlite3_complete(const char *sql); 1428int sqlite3_complete16(const void *sql); 1429 1430/* 1431** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} 1432** 1433** This routine sets a callback function that might be invoked whenever 1434** an attempt is made to open a database table that another thread 1435** or process has locked. 1436** 1437** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1438** is returned immediately upon encountering the lock. If the busy callback 1439** is not NULL, then the callback will be invoked with two arguments. 1440** 1441** The first argument to the handler is a copy of the void* pointer which 1442** is the third argument to sqlite3_busy_handler(). The second argument to 1443** the handler callback is the number of times that the busy handler has 1444** been invoked for this locking event. If the 1445** busy callback returns 0, then no additional attempts are made to 1446** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1447** If the callback returns non-zero, then another attempt 1448** is made to open the database for reading and the cycle repeats. 1449** 1450** The presence of a busy handler does not guarantee that it will be invoked 1451** when there is lock contention. If SQLite determines that invoking the busy 1452** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1453** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1454** Consider a scenario where one process is holding a read lock that 1455** it is trying to promote to a reserved lock and 1456** a second process is holding a reserved lock that it is trying 1457** to promote to an exclusive lock. The first process cannot proceed 1458** because it is blocked by the second and the second process cannot 1459** proceed because it is blocked by the first. If both processes 1460** invoke the busy handlers, neither will make any progress. Therefore, 1461** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1462** will induce the first process to release its read lock and allow 1463** the second process to proceed. 1464** 1465** The default busy callback is NULL. 1466** 1467** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1468** when SQLite is in the middle of a large transaction where all the 1469** changes will not fit into the in-memory cache. SQLite will 1470** already hold a RESERVED lock on the database file, but it needs 1471** to promote this lock to EXCLUSIVE so that it can spill cache 1472** pages into the database file without harm to concurrent 1473** readers. If it is unable to promote the lock, then the in-memory 1474** cache will be left in an inconsistent state and so the error 1475** code is promoted from the relatively benign [SQLITE_BUSY] to 1476** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion 1477** forces an automatic rollback of the changes. See the 1478** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1479** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1480** this is important. 1481** 1482** There can only be a single busy handler defined for each 1483** [database connection]. Setting a new busy handler clears any 1484** previously set handler. Note that calling [sqlite3_busy_timeout()] 1485** will also set or clear the busy handler. 1486** 1487** INVARIANTS: 1488** 1489** {H12311} The [sqlite3_busy_handler(D,C,A)] function shall replace 1490** busy callback in the [database connection] D with a new 1491** a new busy handler C and application data pointer A. 1492** 1493** {H12312} Newly created [database connections] shall have a busy 1494** handler of NULL. 1495** 1496** {H12314} When two or more [database connections] share a 1497** [sqlite3_enable_shared_cache | common cache], 1498** the busy handler for the database connection currently using 1499** the cache shall be invoked when the cache encounters a lock. 1500** 1501** {H12316} If a busy handler callback returns zero, then the SQLite interface 1502** that provoked the locking event shall return [SQLITE_BUSY]. 1503** 1504** {H12318} SQLite shall invokes the busy handler with two arguments which 1505** are a copy of the pointer supplied by the 3rd parameter to 1506** [sqlite3_busy_handler()] and a count of the number of prior 1507** invocations of the busy handler for the same locking event. 1508** 1509** ASSUMPTIONS: 1510** 1511** {A12319} A busy handler must not close the database connection 1512** or [prepared statement] that invoked the busy handler. 1513*/ 1514int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1515 1516/* 1517** CAPI3REF: Set A Busy Timeout {H12340} 1518** 1519** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1520** for a specified amount of time when a table is locked. The handler 1521** will sleep multiple times until at least "ms" milliseconds of sleeping 1522** have accumulated. {H12343} After "ms" milliseconds of sleeping, 1523** the handler returns 0 which causes [sqlite3_step()] to return 1524** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1525** 1526** Calling this routine with an argument less than or equal to zero 1527** turns off all busy handlers. 1528** 1529** There can only be a single busy handler for a particular 1530** [database connection] any any given moment. If another busy handler 1531** was defined (using [sqlite3_busy_handler()]) prior to calling 1532** this routine, that other busy handler is cleared. 1533** 1534** INVARIANTS: 1535** 1536** {H12341} The [sqlite3_busy_timeout()] function shall override any prior 1537** [sqlite3_busy_timeout()] or [sqlite3_busy_handler()] setting 1538** on the same [database connection]. 1539** 1540** {H12343} If the 2nd parameter to [sqlite3_busy_timeout()] is less than 1541** or equal to zero, then the busy handler shall be cleared so that 1542** all subsequent locking events immediately return [SQLITE_BUSY]. 1543** 1544** {H12344} If the 2nd parameter to [sqlite3_busy_timeout()] is a positive 1545** number N, then a busy handler shall be set that repeatedly calls 1546** the xSleep() method in the [sqlite3_vfs | VFS interface] until 1547** either the lock clears or until the cumulative sleep time 1548** reported back by xSleep() exceeds N milliseconds. 1549*/ 1550int sqlite3_busy_timeout(sqlite3*, int ms); 1551 1552/* 1553** CAPI3REF: Convenience Routines For Running Queries {H12370} 1554** 1555** Definition: A <b>result table</b> is memory data structure created by the 1556** [sqlite3_get_table()] interface. A result table records the 1557** complete query results from one or more queries. 1558** 1559** The table conceptually has a number of rows and columns. But 1560** these numbers are not part of the result table itself. These 1561** numbers are obtained separately. Let N be the number of rows 1562** and M be the number of columns. 1563** 1564** A result table is an array of pointers to zero-terminated UTF-8 strings. 1565** There are (N+1)*M elements in the array. The first M pointers point 1566** to zero-terminated strings that contain the names of the columns. 1567** The remaining entries all point to query results. NULL values result 1568** in NULL pointers. All other values are in their UTF-8 zero-terminated 1569** string representation as returned by [sqlite3_column_text()]. 1570** 1571** A result table might consist of one or more memory allocations. 1572** It is not safe to pass a result table directly to [sqlite3_free()]. 1573** A result table should be deallocated using [sqlite3_free_table()]. 1574** 1575** As an example of the result table format, suppose a query result 1576** is as follows: 1577** 1578** <blockquote><pre> 1579** Name | Age 1580** ----------------------- 1581** Alice | 43 1582** Bob | 28 1583** Cindy | 21 1584** </pre></blockquote> 1585** 1586** There are two column (M==2) and three rows (N==3). Thus the 1587** result table has 8 entries. Suppose the result table is stored 1588** in an array names azResult. Then azResult holds this content: 1589** 1590** <blockquote><pre> 1591** azResult[0] = "Name"; 1592** azResult[1] = "Age"; 1593** azResult[2] = "Alice"; 1594** azResult[3] = "43"; 1595** azResult[4] = "Bob"; 1596** azResult[5] = "28"; 1597** azResult[6] = "Cindy"; 1598** azResult[7] = "21"; 1599** </pre></blockquote> 1600** 1601** The sqlite3_get_table() function evaluates one or more 1602** semicolon-separated SQL statements in the zero-terminated UTF-8 1603** string of its 2nd parameter. It returns a result table to the 1604** pointer given in its 3rd parameter. 1605** 1606** After the calling function has finished using the result, it should 1607** pass the pointer to the result table to sqlite3_free_table() in order to 1608** release the memory that was malloced. Because of the way the 1609** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1610** function must not try to call [sqlite3_free()] directly. Only 1611** [sqlite3_free_table()] is able to release the memory properly and safely. 1612** 1613** The sqlite3_get_table() interface is implemented as a wrapper around 1614** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1615** to any internal data structures of SQLite. It uses only the public 1616** interface defined here. As a consequence, errors that occur in the 1617** wrapper layer outside of the internal [sqlite3_exec()] call are not 1618** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()]. 1619** 1620** INVARIANTS: 1621** 1622** {H12371} If a [sqlite3_get_table()] fails a memory allocation, then 1623** it shall free the result table under construction, abort the 1624** query in process, skip any subsequent queries, set the 1625** *pazResult output pointer to NULL and return [SQLITE_NOMEM]. 1626** 1627** {H12373} If the pnColumn parameter to [sqlite3_get_table()] is not NULL 1628** then a successful invocation of [sqlite3_get_table()] shall 1629** write the number of columns in the 1630** result set of the query into *pnColumn. 1631** 1632** {H12374} If the pnRow parameter to [sqlite3_get_table()] is not NULL 1633** then a successful invocation of [sqlite3_get_table()] shall 1634** writes the number of rows in the 1635** result set of the query into *pnRow. 1636** 1637** {H12376} A successful invocation of [sqlite3_get_table()] that computes 1638** N rows of result with C columns per row shall make *pazResult 1639** point to an array of pointers to (N+1)*C strings where the first 1640** C strings are column names as obtained from 1641** [sqlite3_column_name()] and the rest are column result values 1642** obtained from [sqlite3_column_text()]. 1643** 1644** {H12379} The values in the pazResult array returned by [sqlite3_get_table()] 1645** shall remain valid until cleared by [sqlite3_free_table()]. 1646** 1647** {H12382} When an error occurs during evaluation of [sqlite3_get_table()] 1648** the function shall set *pazResult to NULL, write an error message 1649** into memory obtained from [sqlite3_malloc()], make 1650** **pzErrmsg point to that error message, and return a 1651** appropriate [error code]. 1652*/ 1653int sqlite3_get_table( 1654 sqlite3 *db, /* An open database */ 1655 const char *zSql, /* SQL to be evaluated */ 1656 char ***pazResult, /* Results of the query */ 1657 int *pnRow, /* Number of result rows written here */ 1658 int *pnColumn, /* Number of result columns written here */ 1659 char **pzErrmsg /* Error msg written here */ 1660); 1661void sqlite3_free_table(char **result); 1662 1663/* 1664** CAPI3REF: Formatted String Printing Functions {H17400} 1665** 1666** These routines are workalikes of the "printf()" family of functions 1667** from the standard C library. 1668** 1669** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1670** results into memory obtained from [sqlite3_malloc()]. 1671** The strings returned by these two routines should be 1672** released by [sqlite3_free()]. Both routines return a 1673** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1674** memory to hold the resulting string. 1675** 1676** In sqlite3_snprintf() routine is similar to "snprintf()" from 1677** the standard C library. The result is written into the 1678** buffer supplied as the second parameter whose size is given by 1679** the first parameter. Note that the order of the 1680** first two parameters is reversed from snprintf(). This is an 1681** historical accident that cannot be fixed without breaking 1682** backwards compatibility. Note also that sqlite3_snprintf() 1683** returns a pointer to its buffer instead of the number of 1684** characters actually written into the buffer. We admit that 1685** the number of characters written would be a more useful return 1686** value but we cannot change the implementation of sqlite3_snprintf() 1687** now without breaking compatibility. 1688** 1689** As long as the buffer size is greater than zero, sqlite3_snprintf() 1690** guarantees that the buffer is always zero-terminated. The first 1691** parameter "n" is the total size of the buffer, including space for 1692** the zero terminator. So the longest string that can be completely 1693** written will be n-1 characters. 1694** 1695** These routines all implement some additional formatting 1696** options that are useful for constructing SQL statements. 1697** All of the usual printf() formatting options apply. In addition, there 1698** is are "%q", "%Q", and "%z" options. 1699** 1700** The %q option works like %s in that it substitutes a null-terminated 1701** string from the argument list. But %q also doubles every '\'' character. 1702** %q is designed for use inside a string literal. By doubling each '\'' 1703** character it escapes that character and allows it to be inserted into 1704** the string. 1705** 1706** For example, assume the string variable zText contains text as follows: 1707** 1708** <blockquote><pre> 1709** char *zText = "It's a happy day!"; 1710** </pre></blockquote> 1711** 1712** One can use this text in an SQL statement as follows: 1713** 1714** <blockquote><pre> 1715** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1716** sqlite3_exec(db, zSQL, 0, 0, 0); 1717** sqlite3_free(zSQL); 1718** </pre></blockquote> 1719** 1720** Because the %q format string is used, the '\'' character in zText 1721** is escaped and the SQL generated is as follows: 1722** 1723** <blockquote><pre> 1724** INSERT INTO table1 VALUES('It''s a happy day!') 1725** </pre></blockquote> 1726** 1727** This is correct. Had we used %s instead of %q, the generated SQL 1728** would have looked like this: 1729** 1730** <blockquote><pre> 1731** INSERT INTO table1 VALUES('It's a happy day!'); 1732** </pre></blockquote> 1733** 1734** This second example is an SQL syntax error. As a general rule you should 1735** always use %q instead of %s when inserting text into a string literal. 1736** 1737** The %Q option works like %q except it also adds single quotes around 1738** the outside of the total string. Additionally, if the parameter in the 1739** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 1740** single quotes) in place of the %Q option. So, for example, one could say: 1741** 1742** <blockquote><pre> 1743** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1744** sqlite3_exec(db, zSQL, 0, 0, 0); 1745** sqlite3_free(zSQL); 1746** </pre></blockquote> 1747** 1748** The code above will render a correct SQL statement in the zSQL 1749** variable even if the zText variable is a NULL pointer. 1750** 1751** The "%z" formatting option works exactly like "%s" with the 1752** addition that after the string has been read and copied into 1753** the result, [sqlite3_free()] is called on the input string. {END} 1754** 1755** INVARIANTS: 1756** 1757** {H17403} The [sqlite3_mprintf()] and [sqlite3_vmprintf()] interfaces 1758** return either pointers to zero-terminated UTF-8 strings held in 1759** memory obtained from [sqlite3_malloc()] or NULL pointers if 1760** a call to [sqlite3_malloc()] fails. 1761** 1762** {H17406} The [sqlite3_snprintf()] interface writes a zero-terminated 1763** UTF-8 string into the buffer pointed to by the second parameter 1764** provided that the first parameter is greater than zero. 1765** 1766** {H17407} The [sqlite3_snprintf()] interface does not write slots of 1767** its output buffer (the second parameter) outside the range 1768** of 0 through N-1 (where N is the first parameter) 1769** regardless of the length of the string 1770** requested by the format specification. 1771*/ 1772char *sqlite3_mprintf(const char*,...); 1773char *sqlite3_vmprintf(const char*, va_list); 1774char *sqlite3_snprintf(int,char*,const char*, ...); 1775 1776/* 1777** CAPI3REF: Memory Allocation Subsystem {H17300} 1778** 1779** The SQLite core uses these three routines for all of its own 1780** internal memory allocation needs. "Core" in the previous sentence 1781** does not include operating-system specific VFS implementation. The 1782** Windows VFS uses native malloc() and free() for some operations. 1783** 1784** The sqlite3_malloc() routine returns a pointer to a block 1785** of memory at least N bytes in length, where N is the parameter. 1786** If sqlite3_malloc() is unable to obtain sufficient free 1787** memory, it returns a NULL pointer. If the parameter N to 1788** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 1789** a NULL pointer. 1790** 1791** Calling sqlite3_free() with a pointer previously returned 1792** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 1793** that it might be reused. The sqlite3_free() routine is 1794** a no-op if is called with a NULL pointer. Passing a NULL pointer 1795** to sqlite3_free() is harmless. After being freed, memory 1796** should neither be read nor written. Even reading previously freed 1797** memory might result in a segmentation fault or other severe error. 1798** Memory corruption, a segmentation fault, or other severe error 1799** might result if sqlite3_free() is called with a non-NULL pointer that 1800** was not obtained from sqlite3_malloc() or sqlite3_free(). 1801** 1802** The sqlite3_realloc() interface attempts to resize a 1803** prior memory allocation to be at least N bytes, where N is the 1804** second parameter. The memory allocation to be resized is the first 1805** parameter. If the first parameter to sqlite3_realloc() 1806** is a NULL pointer then its behavior is identical to calling 1807** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 1808** If the second parameter to sqlite3_realloc() is zero or 1809** negative then the behavior is exactly the same as calling 1810** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 1811** sqlite3_realloc() returns a pointer to a memory allocation 1812** of at least N bytes in size or NULL if sufficient memory is unavailable. 1813** If M is the size of the prior allocation, then min(N,M) bytes 1814** of the prior allocation are copied into the beginning of buffer returned 1815** by sqlite3_realloc() and the prior allocation is freed. 1816** If sqlite3_realloc() returns NULL, then the prior allocation 1817** is not freed. 1818** 1819** The memory returned by sqlite3_malloc() and sqlite3_realloc() 1820** is always aligned to at least an 8 byte boundary. {END} 1821** 1822** The default implementation of the memory allocation subsystem uses 1823** the malloc(), realloc() and free() provided by the standard C library. 1824** {H17382} However, if SQLite is compiled with the 1825** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i> 1826** is an integer), then SQLite create a static array of at least 1827** <i>NNN</i> bytes in size and uses that array for all of its dynamic 1828** memory allocation needs. {END} Additional memory allocator options 1829** may be added in future releases. 1830** 1831** In SQLite version 3.5.0 and 3.5.1, it was possible to define 1832** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 1833** implementation of these routines to be omitted. That capability 1834** is no longer provided. Only built-in memory allocators can be used. 1835** 1836** The Windows OS interface layer calls 1837** the system malloc() and free() directly when converting 1838** filenames between the UTF-8 encoding used by SQLite 1839** and whatever filename encoding is used by the particular Windows 1840** installation. Memory allocation errors are detected, but 1841** they are reported back as [SQLITE_CANTOPEN] or 1842** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 1843** 1844** INVARIANTS: 1845** 1846** {H17303} The [sqlite3_malloc(N)] interface returns either a pointer to 1847** a newly checked-out block of at least N bytes of memory 1848** that is 8-byte aligned, or it returns NULL if it is unable 1849** to fulfill the request. 1850** 1851** {H17304} The [sqlite3_malloc(N)] interface returns a NULL pointer if 1852** N is less than or equal to zero. 1853** 1854** {H17305} The [sqlite3_free(P)] interface releases memory previously 1855** returned from [sqlite3_malloc()] or [sqlite3_realloc()], 1856** making it available for reuse. 1857** 1858** {H17306} A call to [sqlite3_free(NULL)] is a harmless no-op. 1859** 1860** {H17310} A call to [sqlite3_realloc(0,N)] is equivalent to a call 1861** to [sqlite3_malloc(N)]. 1862** 1863** {H17312} A call to [sqlite3_realloc(P,0)] is equivalent to a call 1864** to [sqlite3_free(P)]. 1865** 1866** {H17315} The SQLite core uses [sqlite3_malloc()], [sqlite3_realloc()], 1867** and [sqlite3_free()] for all of its memory allocation and 1868** deallocation needs. 1869** 1870** {H17318} The [sqlite3_realloc(P,N)] interface returns either a pointer 1871** to a block of checked-out memory of at least N bytes in size 1872** that is 8-byte aligned, or a NULL pointer. 1873** 1874** {H17321} When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first 1875** copies the first K bytes of content from P into the newly 1876** allocated block, where K is the lesser of N and the size of 1877** the buffer P. 1878** 1879** {H17322} When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first 1880** releases the buffer P. 1881** 1882** {H17323} When [sqlite3_realloc(P,N)] returns NULL, the buffer P is 1883** not modified or released. 1884** 1885** ASSUMPTIONS: 1886** 1887** {A17350} The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 1888** must be either NULL or else pointers obtained from a prior 1889** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 1890** not yet been released. 1891** 1892** {A17351} The application must not read or write any part of 1893** a block of memory after it has been released using 1894** [sqlite3_free()] or [sqlite3_realloc()]. 1895*/ 1896void *sqlite3_malloc(int); 1897void *sqlite3_realloc(void*, int); 1898void sqlite3_free(void*); 1899 1900/* 1901** CAPI3REF: Memory Allocator Statistics {H17370} 1902** 1903** SQLite provides these two interfaces for reporting on the status 1904** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 1905** routines, which form the built-in memory allocation subsystem. 1906** 1907** INVARIANTS: 1908** 1909** {H17371} The [sqlite3_memory_used()] routine returns the number of bytes 1910** of memory currently outstanding (malloced but not freed). 1911** 1912** {H17373} The [sqlite3_memory_highwater()] routine returns the maximum 1913** value of [sqlite3_memory_used()] since the high-water mark 1914** was last reset. 1915** 1916** {H17374} The values returned by [sqlite3_memory_used()] and 1917** [sqlite3_memory_highwater()] include any overhead 1918** added by SQLite in its implementation of [sqlite3_malloc()], 1919** but not overhead added by the any underlying system library 1920** routines that [sqlite3_malloc()] may call. 1921** 1922** {H17375} The memory high-water mark is reset to the current value of 1923** [sqlite3_memory_used()] if and only if the parameter to 1924** [sqlite3_memory_highwater()] is true. The value returned 1925** by [sqlite3_memory_highwater(1)] is the high-water mark 1926** prior to the reset. 1927*/ 1928sqlite3_int64 sqlite3_memory_used(void); 1929sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 1930 1931/* 1932** CAPI3REF: Pseudo-Random Number Generator {H17390} 1933** 1934** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 1935** select random ROWIDs when inserting new records into a table that 1936** already uses the largest possible ROWID. The PRNG is also used for 1937** the build-in random() and randomblob() SQL functions. This interface allows 1938** applications to access the same PRNG for other purposes. 1939** 1940** A call to this routine stores N bytes of randomness into buffer P. 1941** 1942** The first time this routine is invoked (either internally or by 1943** the application) the PRNG is seeded using randomness obtained 1944** from the xRandomness method of the default [sqlite3_vfs] object. 1945** On all subsequent invocations, the pseudo-randomness is generated 1946** internally and without recourse to the [sqlite3_vfs] xRandomness 1947** method. 1948** 1949** INVARIANTS: 1950** 1951** {H17392} The [sqlite3_randomness(N,P)] interface writes N bytes of 1952** high-quality pseudo-randomness into buffer P. 1953*/ 1954void sqlite3_randomness(int N, void *P); 1955 1956/* 1957** CAPI3REF: Compile-Time Authorization Callbacks {H12500} 1958** 1959** This routine registers a authorizer callback with a particular 1960** [database connection], supplied in the first argument. 1961** The authorizer callback is invoked as SQL statements are being compiled 1962** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 1963** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various 1964** points during the compilation process, as logic is being created 1965** to perform various actions, the authorizer callback is invoked to 1966** see if those actions are allowed. The authorizer callback should 1967** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 1968** specific action but allow the SQL statement to continue to be 1969** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 1970** rejected with an error. If the authorizer callback returns 1971** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 1972** then the [sqlite3_prepare_v2()] or equivalent call that triggered 1973** the authorizer will fail with an error message. 1974** 1975** When the callback returns [SQLITE_OK], that means the operation 1976** requested is ok. When the callback returns [SQLITE_DENY], the 1977** [sqlite3_prepare_v2()] or equivalent call that triggered the 1978** authorizer will fail with an error message explaining that 1979** access is denied. If the authorizer code is [SQLITE_READ] 1980** and the callback returns [SQLITE_IGNORE] then the 1981** [prepared statement] statement is constructed to substitute 1982** a NULL value in place of the table column that would have 1983** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 1984** return can be used to deny an untrusted user access to individual 1985** columns of a table. 1986** 1987** The first parameter to the authorizer callback is a copy of the third 1988** parameter to the sqlite3_set_authorizer() interface. The second parameter 1989** to the callback is an integer [SQLITE_COPY | action code] that specifies 1990** the particular action to be authorized. The third through sixth parameters 1991** to the callback are zero-terminated strings that contain additional 1992** details about the action to be authorized. 1993** 1994** An authorizer is used when [sqlite3_prepare | preparing] 1995** SQL statements from an untrusted source, to ensure that the SQL statements 1996** do not try to access data they are not allowed to see, or that they do not 1997** try to execute malicious statements that damage the database. For 1998** example, an application may allow a user to enter arbitrary 1999** SQL queries for evaluation by a database. But the application does 2000** not want the user to be able to make arbitrary changes to the 2001** database. An authorizer could then be put in place while the 2002** user-entered SQL is being [sqlite3_prepare | prepared] that 2003** disallows everything except [SELECT] statements. 2004** 2005** Applications that need to process SQL from untrusted sources 2006** might also consider lowering resource limits using [sqlite3_limit()] 2007** and limiting database size using the [max_page_count] [PRAGMA] 2008** in addition to using an authorizer. 2009** 2010** Only a single authorizer can be in place on a database connection 2011** at a time. Each call to sqlite3_set_authorizer overrides the 2012** previous call. Disable the authorizer by installing a NULL callback. 2013** The authorizer is disabled by default. 2014** 2015** Note that the authorizer callback is invoked only during 2016** [sqlite3_prepare()] or its variants. Authorization is not 2017** performed during statement evaluation in [sqlite3_step()]. 2018** 2019** INVARIANTS: 2020** 2021** {H12501} The [sqlite3_set_authorizer(D,...)] interface registers a 2022** authorizer callback with database connection D. 2023** 2024** {H12502} The authorizer callback is invoked as SQL statements are 2025** being compiled. 2026** 2027** {H12503} If the authorizer callback returns any value other than 2028** [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY], then 2029** the [sqlite3_prepare_v2()] or equivalent call that caused 2030** the authorizer callback to run shall fail with an 2031** [SQLITE_ERROR] error code and an appropriate error message. 2032** 2033** {H12504} When the authorizer callback returns [SQLITE_OK], the operation 2034** described is processed normally. 2035** 2036** {H12505} When the authorizer callback returns [SQLITE_DENY], the 2037** [sqlite3_prepare_v2()] or equivalent call that caused the 2038** authorizer callback to run shall fail 2039** with an [SQLITE_ERROR] error code and an error message 2040** explaining that access is denied. 2041** 2042** {H12506} If the authorizer code (the 2nd parameter to the authorizer 2043** callback) is [SQLITE_READ] and the authorizer callback returns 2044** [SQLITE_IGNORE], then the prepared statement is constructed to 2045** insert a NULL value in place of the table column that would have 2046** been read if [SQLITE_OK] had been returned. 2047** 2048** {H12507} If the authorizer code (the 2nd parameter to the authorizer 2049** callback) is anything other than [SQLITE_READ], then 2050** a return of [SQLITE_IGNORE] has the same effect as [SQLITE_DENY]. 2051** 2052** {H12510} The first parameter to the authorizer callback is a copy of 2053** the third parameter to the [sqlite3_set_authorizer()] interface. 2054** 2055** {H12511} The second parameter to the callback is an integer 2056** [SQLITE_COPY | action code] that specifies the particular action 2057** to be authorized. 2058** 2059** {H12512} The third through sixth parameters to the callback are 2060** zero-terminated strings that contain 2061** additional details about the action to be authorized. 2062** 2063** {H12520} Each call to [sqlite3_set_authorizer()] overrides 2064** any previously installed authorizer. 2065** 2066** {H12521} A NULL authorizer means that no authorization 2067** callback is invoked. 2068** 2069** {H12522} The default authorizer is NULL. 2070*/ 2071int sqlite3_set_authorizer( 2072 sqlite3*, 2073 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2074 void *pUserData 2075); 2076 2077/* 2078** CAPI3REF: Authorizer Return Codes {H12590} 2079** 2080** The [sqlite3_set_authorizer | authorizer callback function] must 2081** return either [SQLITE_OK] or one of these two constants in order 2082** to signal SQLite whether or not the action is permitted. See the 2083** [sqlite3_set_authorizer | authorizer documentation] for additional 2084** information. 2085*/ 2086#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2087#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2088 2089/* 2090** CAPI3REF: Authorizer Action Codes {H12550} 2091** 2092** The [sqlite3_set_authorizer()] interface registers a callback function 2093** that is invoked to authorize certain SQL statement actions. The 2094** second parameter to the callback is an integer code that specifies 2095** what action is being authorized. These are the integer action codes that 2096** the authorizer callback may be passed. 2097** 2098** These action code values signify what kind of operation is to be 2099** authorized. The 3rd and 4th parameters to the authorization 2100** callback function will be parameters or NULL depending on which of these 2101** codes is used as the second parameter. The 5th parameter to the 2102** authorizer callback is the name of the database ("main", "temp", 2103** etc.) if applicable. The 6th parameter to the authorizer callback 2104** is the name of the inner-most trigger or view that is responsible for 2105** the access attempt or NULL if this access attempt is directly from 2106** top-level SQL code. 2107** 2108** INVARIANTS: 2109** 2110** {H12551} The second parameter to an 2111** [sqlite3_set_authorizer | authorizer callback] is always an integer 2112** [SQLITE_COPY | authorizer code] that specifies what action 2113** is being authorized. 2114** 2115** {H12552} The 3rd and 4th parameters to the 2116** [sqlite3_set_authorizer | authorization callback] 2117** will be parameters or NULL depending on which 2118** [SQLITE_COPY | authorizer code] is used as the second parameter. 2119** 2120** {H12553} The 5th parameter to the 2121** [sqlite3_set_authorizer | authorizer callback] is the name 2122** of the database (example: "main", "temp", etc.) if applicable. 2123** 2124** {H12554} The 6th parameter to the 2125** [sqlite3_set_authorizer | authorizer callback] is the name 2126** of the inner-most trigger or view that is responsible for 2127** the access attempt or NULL if this access attempt is directly from 2128** top-level SQL code. 2129*/ 2130/******************************************* 3rd ************ 4th ***********/ 2131#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2132#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2133#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2134#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2135#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2136#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2137#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2138#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2139#define SQLITE_DELETE 9 /* Table Name NULL */ 2140#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2141#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2142#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2143#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2144#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2145#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2146#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2147#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2148#define SQLITE_INSERT 18 /* Table Name NULL */ 2149#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2150#define SQLITE_READ 20 /* Table Name Column Name */ 2151#define SQLITE_SELECT 21 /* NULL NULL */ 2152#define SQLITE_TRANSACTION 22 /* NULL NULL */ 2153#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2154#define SQLITE_ATTACH 24 /* Filename NULL */ 2155#define SQLITE_DETACH 25 /* Database Name NULL */ 2156#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2157#define SQLITE_REINDEX 27 /* Index Name NULL */ 2158#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2159#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2160#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2161#define SQLITE_FUNCTION 31 /* Function Name NULL */ 2162#define SQLITE_COPY 0 /* No longer used */ 2163 2164/* 2165** CAPI3REF: Tracing And Profiling Functions {H12280} 2166** 2167** These routines register callback functions that can be used for 2168** tracing and profiling the execution of SQL statements. 2169** 2170** The callback function registered by sqlite3_trace() is invoked at 2171** various times when an SQL statement is being run by [sqlite3_step()]. 2172** The callback returns a UTF-8 rendering of the SQL statement text 2173** as the statement first begins executing. Additional callbacks occur 2174** as each triggered subprogram is entered. The callbacks for triggers 2175** contain a UTF-8 SQL comment that identifies the trigger. 2176** 2177** The callback function registered by sqlite3_profile() is invoked 2178** as each SQL statement finishes. The profile callback contains 2179** the original statement text and an estimate of wall-clock time 2180** of how long that statement took to run. 2181** 2182** The sqlite3_profile() API is currently considered experimental and 2183** is subject to change or removal in a future release. 2184** 2185** The trigger reporting feature of the trace callback is considered 2186** experimental and is subject to change or removal in future releases. 2187** Future versions of SQLite might also add new trace callback 2188** invocations. 2189** 2190** INVARIANTS: 2191** 2192** {H12281} The callback function registered by [sqlite3_trace()] is 2193** whenever an SQL statement first begins to execute and 2194** whenever a trigger subprogram first begins to run. 2195** 2196** {H12282} Each call to [sqlite3_trace()] overrides the previously 2197** registered trace callback. 2198** 2199** {H12283} A NULL trace callback disables tracing. 2200** 2201** {H12284} The first argument to the trace callback is a copy of 2202** the pointer which was the 3rd argument to [sqlite3_trace()]. 2203** 2204** {H12285} The second argument to the trace callback is a 2205** zero-terminated UTF-8 string containing the original text 2206** of the SQL statement as it was passed into [sqlite3_prepare_v2()] 2207** or the equivalent, or an SQL comment indicating the beginning 2208** of a trigger subprogram. 2209** 2210** {H12287} The callback function registered by [sqlite3_profile()] is invoked 2211** as each SQL statement finishes. 2212** 2213** {H12288} The first parameter to the profile callback is a copy of 2214** the 3rd parameter to [sqlite3_profile()]. 2215** 2216** {H12289} The second parameter to the profile callback is a 2217** zero-terminated UTF-8 string that contains the complete text of 2218** the SQL statement as it was processed by [sqlite3_prepare_v2()] 2219** or the equivalent. 2220** 2221** {H12290} The third parameter to the profile callback is an estimate 2222** of the number of nanoseconds of wall-clock time required to 2223** run the SQL statement from start to finish. 2224*/ 2225void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2226void *sqlite3_profile(sqlite3*, 2227 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2228 2229/* 2230** CAPI3REF: Query Progress Callbacks {H12910} 2231** 2232** This routine configures a callback function - the 2233** progress callback - that is invoked periodically during long 2234** running calls to [sqlite3_exec()], [sqlite3_step()] and 2235** [sqlite3_get_table()]. An example use for this 2236** interface is to keep a GUI updated during a large query. 2237** 2238** If the progress callback returns non-zero, the operation is 2239** interrupted. This feature can be used to implement a 2240** "Cancel" button on a GUI dialog box. 2241** 2242** INVARIANTS: 2243** 2244** {H12911} The callback function registered by sqlite3_progress_handler() 2245** is invoked periodically during long running calls to 2246** [sqlite3_step()]. 2247** 2248** {H12912} The progress callback is invoked once for every N virtual 2249** machine opcodes, where N is the second argument to 2250** the [sqlite3_progress_handler()] call that registered 2251** the callback. If N is less than 1, sqlite3_progress_handler() 2252** acts as if a NULL progress handler had been specified. 2253** 2254** {H12913} The progress callback itself is identified by the third 2255** argument to sqlite3_progress_handler(). 2256** 2257** {H12914} The fourth argument to sqlite3_progress_handler() is a 2258** void pointer passed to the progress callback 2259** function each time it is invoked. 2260** 2261** {H12915} If a call to [sqlite3_step()] results in fewer than N opcodes 2262** being executed, then the progress callback is never invoked. 2263** 2264** {H12916} Every call to [sqlite3_progress_handler()] 2265** overwrites any previously registered progress handler. 2266** 2267** {H12917} If the progress handler callback is NULL then no progress 2268** handler is invoked. 2269** 2270** {H12918} If the progress callback returns a result other than 0, then 2271** the behavior is a if [sqlite3_interrupt()] had been called. 2272*/ 2273void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2274 2275/* 2276** CAPI3REF: Opening A New Database Connection {H12700} 2277** 2278** These routines open an SQLite database file whose name is given by the 2279** filename argument. The filename argument is interpreted as UTF-8 for 2280** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2281** order for sqlite3_open16(). A [database connection] handle is usually 2282** returned in *ppDb, even if an error occurs. The only exception is that 2283** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2284** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2285** object. If the database is opened (and/or created) successfully, then 2286** [SQLITE_OK] is returned. Otherwise an [error code] is returned. The 2287** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2288** an English language description of the error. 2289** 2290** The default encoding for the database will be UTF-8 if 2291** sqlite3_open() or sqlite3_open_v2() is called and 2292** UTF-16 in the native byte order if sqlite3_open16() is used. 2293** 2294** Whether or not an error occurs when it is opened, resources 2295** associated with the [database connection] handle should be released by 2296** passing it to [sqlite3_close()] when it is no longer required. 2297** 2298** The sqlite3_open_v2() interface works like sqlite3_open() 2299** except that it accepts two additional parameters for additional control 2300** over the new database connection. The flags parameter can take one of 2301** the following three values, optionally combined with the 2302** [SQLITE_OPEN_NOMUTEX] flag: 2303** 2304** <dl> 2305** <dt>[SQLITE_OPEN_READONLY]</dt> 2306** <dd>The database is opened in read-only mode. If the database does not 2307** already exist, an error is returned.</dd> 2308** 2309** <dt>[SQLITE_OPEN_READWRITE]</dt> 2310** <dd>The database is opened for reading and writing if possible, or reading 2311** only if the file is write protected by the operating system. In either 2312** case the database must already exist, otherwise an error is returned.</dd> 2313** 2314** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2315** <dd>The database is opened for reading and writing, and is creates it if 2316** it does not already exist. This is the behavior that is always used for 2317** sqlite3_open() and sqlite3_open16().</dd> 2318** </dl> 2319** 2320** If the 3rd parameter to sqlite3_open_v2() is not one of the 2321** combinations shown above or one of the combinations shown above combined 2322** with the [SQLITE_OPEN_NOMUTEX] flag, then the behavior is undefined. 2323** 2324** If the [SQLITE_OPEN_NOMUTEX] flag is set, then mutexes on the 2325** opened [database connection] are disabled and the appliation must 2326** insure that access to the [database connection] and its associated 2327** [prepared statements] is serialized. The [SQLITE_OPEN_NOMUTEX] flag 2328** is the default behavior is SQLite is configured using the 2329** [SQLITE_CONFIG_MULTITHREAD] or [SQLITE_CONFIG_SINGLETHREAD] options 2330** to [sqlite3_config()]. The [SQLITE_OPEN_NOMUTEX] flag only makes a 2331** difference when SQLite is in its default [SQLITE_CONFIG_SERIALIZED] mode. 2332** 2333** If the filename is ":memory:", then a private, temporary in-memory database 2334** is created for the connection. This in-memory database will vanish when 2335** the database connection is closed. Future versions of SQLite might 2336** make use of additional special filenames that begin with the ":" character. 2337** It is recommended that when a database filename actually does begin with 2338** a ":" character you should prefix the filename with a pathname such as 2339** "./" to avoid ambiguity. 2340** 2341** If the filename is an empty string, then a private, temporary 2342** on-disk database will be created. This private database will be 2343** automatically deleted as soon as the database connection is closed. 2344** 2345** The fourth parameter to sqlite3_open_v2() is the name of the 2346** [sqlite3_vfs] object that defines the operating system interface that 2347** the new database connection should use. If the fourth parameter is 2348** a NULL pointer then the default [sqlite3_vfs] object is used. 2349** 2350** <b>Note to Windows users:</b> The encoding used for the filename argument 2351** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2352** codepage is currently defined. Filenames containing international 2353** characters must be converted to UTF-8 prior to passing them into 2354** sqlite3_open() or sqlite3_open_v2(). 2355** 2356** INVARIANTS: 2357** 2358** {H12701} The [sqlite3_open()], [sqlite3_open16()], and 2359** [sqlite3_open_v2()] interfaces create a new 2360** [database connection] associated with 2361** the database file given in their first parameter. 2362** 2363** {H12702} The filename argument is interpreted as UTF-8 2364** for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16 2365** in the native byte order for [sqlite3_open16()]. 2366** 2367** {H12703} A successful invocation of [sqlite3_open()], [sqlite3_open16()], 2368** or [sqlite3_open_v2()] writes a pointer to a new 2369** [database connection] into *ppDb. 2370** 2371** {H12704} The [sqlite3_open()], [sqlite3_open16()], and 2372** [sqlite3_open_v2()] interfaces return [SQLITE_OK] upon success, 2373** or an appropriate [error code] on failure. 2374** 2375** {H12706} The default text encoding for a new database created using 2376** [sqlite3_open()] or [sqlite3_open_v2()] will be UTF-8. 2377** 2378** {H12707} The default text encoding for a new database created using 2379** [sqlite3_open16()] will be UTF-16. 2380** 2381** {H12709} The [sqlite3_open(F,D)] interface is equivalent to 2382** [sqlite3_open_v2(F,D,G,0)] where the G parameter is 2383** [SQLITE_OPEN_READWRITE]|[SQLITE_OPEN_CREATE]. 2384** 2385** {H12711} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the 2386** bit value [SQLITE_OPEN_READONLY] then the database is opened 2387** for reading only. 2388** 2389** {H12712} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the 2390** bit value [SQLITE_OPEN_READWRITE] then the database is opened 2391** reading and writing if possible, or for reading only if the 2392** file is write protected by the operating system. 2393** 2394** {H12713} If the G parameter to [sqlite3_open(v2(F,D,G,V)] omits the 2395** bit value [SQLITE_OPEN_CREATE] and the database does not 2396** previously exist, an error is returned. 2397** 2398** {H12714} If the G parameter to [sqlite3_open(v2(F,D,G,V)] contains the 2399** bit value [SQLITE_OPEN_CREATE] and the database does not 2400** previously exist, then an attempt is made to create and 2401** initialize the database. 2402** 2403** {H12717} If the filename argument to [sqlite3_open()], [sqlite3_open16()], 2404** or [sqlite3_open_v2()] is ":memory:", then an private, 2405** ephemeral, in-memory database is created for the connection. 2406** <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required 2407** in sqlite3_open_v2()?</todo> 2408** 2409** {H12719} If the filename is NULL or an empty string, then a private, 2410** ephemeral on-disk database will be created. 2411** <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required 2412** in sqlite3_open_v2()?</todo> 2413** 2414** {H12721} The [database connection] created by [sqlite3_open_v2(F,D,G,V)] 2415** will use the [sqlite3_vfs] object identified by the V parameter, 2416** or the default [sqlite3_vfs] object if V is a NULL pointer. 2417** 2418** {H12723} Two [database connections] will share a common cache if both were 2419** opened with the same VFS while [shared cache mode] was enabled and 2420** if both filenames compare equal using memcmp() after having been 2421** processed by the [sqlite3_vfs | xFullPathname] method of the VFS. 2422*/ 2423int sqlite3_open( 2424 const char *filename, /* Database filename (UTF-8) */ 2425 sqlite3 **ppDb /* OUT: SQLite db handle */ 2426); 2427int sqlite3_open16( 2428 const void *filename, /* Database filename (UTF-16) */ 2429 sqlite3 **ppDb /* OUT: SQLite db handle */ 2430); 2431int sqlite3_open_v2( 2432 const char *filename, /* Database filename (UTF-8) */ 2433 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2434 int flags, /* Flags */ 2435 const char *zVfs /* Name of VFS module to use */ 2436); 2437 2438/* 2439** CAPI3REF: Error Codes And Messages {H12800} 2440** 2441** The sqlite3_errcode() interface returns the numeric [result code] or 2442** [extended result code] for the most recent failed sqlite3_* API call 2443** associated with a [database connection]. If a prior API call failed 2444** but the most recent API call succeeded, the return value from 2445** sqlite3_errcode() is undefined. 2446** 2447** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2448** text that describes the error, as either UTF-8 or UTF-16 respectively. 2449** Memory to hold the error message string is managed internally. 2450** The application does not need to worry about freeing the result. 2451** However, the error string might be overwritten or deallocated by 2452** subsequent calls to other SQLite interface functions. 2453** 2454** If an interface fails with SQLITE_MISUSE, that means the interface 2455** was invoked incorrectly by the application. In that case, the 2456** error code and message may or may not be set. 2457** 2458** INVARIANTS: 2459** 2460** {H12801} The [sqlite3_errcode(D)] interface returns the numeric 2461** [result code] or [extended result code] for the most recently 2462** failed interface call associated with the [database connection] D. 2463** 2464** {H12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)] 2465** interfaces return English-language text that describes 2466** the error in the mostly recently failed interface call, 2467** encoded as either UTF-8 or UTF-16 respectively. 2468** 2469** {H12807} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()] 2470** are valid until the next SQLite interface call. 2471** 2472** {H12808} Calls to API routines that do not return an error code 2473** (example: [sqlite3_data_count()]) do not 2474** change the error code or message returned by 2475** [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()]. 2476** 2477** {H12809} Interfaces that are not associated with a specific 2478** [database connection] (examples: 2479** [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()] 2480** do not change the values returned by 2481** [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()]. 2482*/ 2483int sqlite3_errcode(sqlite3 *db); 2484const char *sqlite3_errmsg(sqlite3*); 2485const void *sqlite3_errmsg16(sqlite3*); 2486 2487/* 2488** CAPI3REF: SQL Statement Object {H13000} 2489** KEYWORDS: {prepared statement} {prepared statements} 2490** 2491** An instance of this object represents a single SQL statement. 2492** This object is variously known as a "prepared statement" or a 2493** "compiled SQL statement" or simply as a "statement". 2494** 2495** The life of a statement object goes something like this: 2496** 2497** <ol> 2498** <li> Create the object using [sqlite3_prepare_v2()] or a related 2499** function. 2500** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2501** interfaces. 2502** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2503** <li> Reset the statement using [sqlite3_reset()] then go back 2504** to step 2. Do this zero or more times. 2505** <li> Destroy the object using [sqlite3_finalize()]. 2506** </ol> 2507** 2508** Refer to documentation on individual methods above for additional 2509** information. 2510*/ 2511typedef struct sqlite3_stmt sqlite3_stmt; 2512 2513/* 2514** CAPI3REF: Run-time Limits {H12760} 2515** 2516** This interface allows the size of various constructs to be limited 2517** on a connection by connection basis. The first parameter is the 2518** [database connection] whose limit is to be set or queried. The 2519** second parameter is one of the [limit categories] that define a 2520** class of constructs to be size limited. The third parameter is the 2521** new limit for that construct. The function returns the old limit. 2522** 2523** If the new limit is a negative number, the limit is unchanged. 2524** For the limit category of SQLITE_LIMIT_XYZ there is a hard upper 2525** bound set by a compile-time C preprocessor macro named SQLITE_MAX_XYZ. 2526** (The "_LIMIT_" in the name is changed to "_MAX_".) 2527** Attempts to increase a limit above its hard upper bound are 2528** silently truncated to the hard upper limit. 2529** 2530** Run time limits are intended for use in applications that manage 2531** both their own internal database and also databases that are controlled 2532** by untrusted external sources. An example application might be a 2533** webbrowser that has its own databases for storing history and 2534** separate databases controlled by JavaScript applications downloaded 2535** off the Internet. The internal databases can be given the 2536** large, default limits. Databases managed by external sources can 2537** be given much smaller limits designed to prevent a denial of service 2538** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2539** interface to further control untrusted SQL. The size of the database 2540** created by an untrusted script can be contained using the 2541** [max_page_count] [PRAGMA]. 2542** 2543** New run-time limit categories may be added in future releases. 2544** 2545** INVARIANTS: 2546** 2547** {H12762} A successful call to [sqlite3_limit(D,C,V)] where V is 2548** positive changes the limit on the size of construct C in the 2549** [database connection] D to the lesser of V and the hard upper 2550** bound on the size of C that is set at compile-time. 2551** 2552** {H12766} A successful call to [sqlite3_limit(D,C,V)] where V is negative 2553** leaves the state of the [database connection] D unchanged. 2554** 2555** {H12769} A successful call to [sqlite3_limit(D,C,V)] returns the 2556** value of the limit on the size of construct C in the 2557** [database connection] D as it was prior to the call. 2558*/ 2559int sqlite3_limit(sqlite3*, int id, int newVal); 2560 2561/* 2562** CAPI3REF: Run-Time Limit Categories {H12790} 2563** KEYWORDS: {limit category} {limit categories} 2564** 2565** These constants define various aspects of a [database connection] 2566** that can be limited in size by calls to [sqlite3_limit()]. 2567** The meanings of the various limits are as follows: 2568** 2569** <dl> 2570** <dt>SQLITE_LIMIT_LENGTH</dt> 2571** <dd>The maximum size of any string or BLOB or table row.<dd> 2572** 2573** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2574** <dd>The maximum length of an SQL statement.</dd> 2575** 2576** <dt>SQLITE_LIMIT_COLUMN</dt> 2577** <dd>The maximum number of columns in a table definition or in the 2578** result set of a SELECT or the maximum number of columns in an index 2579** or in an ORDER BY or GROUP BY clause.</dd> 2580** 2581** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2582** <dd>The maximum depth of the parse tree on any expression.</dd> 2583** 2584** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2585** <dd>The maximum number of terms in a compound SELECT statement.</dd> 2586** 2587** <dt>SQLITE_LIMIT_VDBE_OP</dt> 2588** <dd>The maximum number of instructions in a virtual machine program 2589** used to implement an SQL statement.</dd> 2590** 2591** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2592** <dd>The maximum number of arguments on a function.</dd> 2593** 2594** <dt>SQLITE_LIMIT_ATTACHED</dt> 2595** <dd>The maximum number of attached databases.</dd> 2596** 2597** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2598** <dd>The maximum length of the pattern argument to the LIKE or 2599** GLOB operators.</dd> 2600** 2601** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2602** <dd>The maximum number of variables in an SQL statement that can 2603** be bound.</dd> 2604** </dl> 2605*/ 2606#define SQLITE_LIMIT_LENGTH 0 2607#define SQLITE_LIMIT_SQL_LENGTH 1 2608#define SQLITE_LIMIT_COLUMN 2 2609#define SQLITE_LIMIT_EXPR_DEPTH 3 2610#define SQLITE_LIMIT_COMPOUND_SELECT 4 2611#define SQLITE_LIMIT_VDBE_OP 5 2612#define SQLITE_LIMIT_FUNCTION_ARG 6 2613#define SQLITE_LIMIT_ATTACHED 7 2614#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2615#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2616 2617/* 2618** CAPI3REF: Compiling An SQL Statement {H13010} 2619** KEYWORDS: {SQL statement compiler} 2620** 2621** To execute an SQL query, it must first be compiled into a byte-code 2622** program using one of these routines. 2623** 2624** The first argument, "db", is a [database connection] obtained from a 2625** prior call to [sqlite3_open()], [sqlite3_open_v2()] or [sqlite3_open16()]. 2626** 2627** The second argument, "zSql", is the statement to be compiled, encoded 2628** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2629** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2630** use UTF-16. 2631** 2632** If the nByte argument is less than zero, then zSql is read up to the 2633** first zero terminator. If nByte is non-negative, then it is the maximum 2634** number of bytes read from zSql. When nByte is non-negative, the 2635** zSql string ends at either the first '\000' or '\u0000' character or 2636** the nByte-th byte, whichever comes first. If the caller knows 2637** that the supplied string is nul-terminated, then there is a small 2638** performance advantage to be gained by passing an nByte parameter that 2639** is equal to the number of bytes in the input string <i>including</i> 2640** the nul-terminator bytes. 2641** 2642** *pzTail is made to point to the first byte past the end of the 2643** first SQL statement in zSql. These routines only compile the first 2644** statement in zSql, so *pzTail is left pointing to what remains 2645** uncompiled. 2646** 2647** *ppStmt is left pointing to a compiled [prepared statement] that can be 2648** executed using [sqlite3_step()]. If there is an error, *ppStmt is set 2649** to NULL. If the input text contains no SQL (if the input is an empty 2650** string or a comment) then *ppStmt is set to NULL. 2651** {A13018} The calling procedure is responsible for deleting the compiled 2652** SQL statement using [sqlite3_finalize()] after it has finished with it. 2653** 2654** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned. 2655** 2656** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2657** recommended for all new programs. The two older interfaces are retained 2658** for backwards compatibility, but their use is discouraged. 2659** In the "v2" interfaces, the prepared statement 2660** that is returned (the [sqlite3_stmt] object) contains a copy of the 2661** original SQL text. This causes the [sqlite3_step()] interface to 2662** behave a differently in two ways: 2663** 2664** <ol> 2665** <li> 2666** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2667** always used to do, [sqlite3_step()] will automatically recompile the SQL 2668** statement and try to run it again. If the schema has changed in 2669** a way that makes the statement no longer valid, [sqlite3_step()] will still 2670** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is 2671** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the 2672** error go away. Note: use [sqlite3_errmsg()] to find the text 2673** of the parsing error that results in an [SQLITE_SCHEMA] return. 2674** </li> 2675** 2676** <li> 2677** When an error occurs, [sqlite3_step()] will return one of the detailed 2678** [error codes] or [extended error codes]. The legacy behavior was that 2679** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2680** and you would have to make a second call to [sqlite3_reset()] in order 2681** to find the underlying cause of the problem. With the "v2" prepare 2682** interfaces, the underlying reason for the error is returned immediately. 2683** </li> 2684** </ol> 2685** 2686** INVARIANTS: 2687** 2688** {H13011} The [sqlite3_prepare(db,zSql,...)] and 2689** [sqlite3_prepare_v2(db,zSql,...)] interfaces interpret the 2690** text in their zSql parameter as UTF-8. 2691** 2692** {H13012} The [sqlite3_prepare16(db,zSql,...)] and 2693** [sqlite3_prepare16_v2(db,zSql,...)] interfaces interpret the 2694** text in their zSql parameter as UTF-16 in the native byte order. 2695** 2696** {H13013} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)] 2697** and its variants is less than zero, the SQL text is 2698** read from zSql is read up to the first zero terminator. 2699** 2700** {H13014} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)] 2701** and its variants is non-negative, then at most nBytes bytes of 2702** SQL text is read from zSql. 2703** 2704** {H13015} In [sqlite3_prepare_v2(db,zSql,N,P,pzTail)] and its variants 2705** if the zSql input text contains more than one SQL statement 2706** and pzTail is not NULL, then *pzTail is made to point to the 2707** first byte past the end of the first SQL statement in zSql. 2708** <todo>What does *pzTail point to if there is one statement?</todo> 2709** 2710** {H13016} A successful call to [sqlite3_prepare_v2(db,zSql,N,ppStmt,...)] 2711** or one of its variants writes into *ppStmt a pointer to a new 2712** [prepared statement] or a pointer to NULL if zSql contains 2713** nothing other than whitespace or comments. 2714** 2715** {H13019} The [sqlite3_prepare_v2()] interface and its variants return 2716** [SQLITE_OK] or an appropriate [error code] upon failure. 2717** 2718** {H13021} Before [sqlite3_prepare(db,zSql,nByte,ppStmt,pzTail)] or its 2719** variants returns an error (any value other than [SQLITE_OK]), 2720** they first set *ppStmt to NULL. 2721*/ 2722int sqlite3_prepare( 2723 sqlite3 *db, /* Database handle */ 2724 const char *zSql, /* SQL statement, UTF-8 encoded */ 2725 int nByte, /* Maximum length of zSql in bytes. */ 2726 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2727 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2728); 2729int sqlite3_prepare_v2( 2730 sqlite3 *db, /* Database handle */ 2731 const char *zSql, /* SQL statement, UTF-8 encoded */ 2732 int nByte, /* Maximum length of zSql in bytes. */ 2733 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2734 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2735); 2736int sqlite3_prepare16( 2737 sqlite3 *db, /* Database handle */ 2738 const void *zSql, /* SQL statement, UTF-16 encoded */ 2739 int nByte, /* Maximum length of zSql in bytes. */ 2740 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2741 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2742); 2743int sqlite3_prepare16_v2( 2744 sqlite3 *db, /* Database handle */ 2745 const void *zSql, /* SQL statement, UTF-16 encoded */ 2746 int nByte, /* Maximum length of zSql in bytes. */ 2747 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2748 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2749); 2750 2751/* 2752** CAPIREF: Retrieving Statement SQL {H13100} 2753** 2754** This interface can be used to retrieve a saved copy of the original 2755** SQL text used to create a [prepared statement] if that statement was 2756** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 2757** 2758** INVARIANTS: 2759** 2760** {H13101} If the [prepared statement] passed as the argument to 2761** [sqlite3_sql()] was compiled using either [sqlite3_prepare_v2()] or 2762** [sqlite3_prepare16_v2()], then [sqlite3_sql()] returns 2763** a pointer to a zero-terminated string containing a UTF-8 rendering 2764** of the original SQL statement. 2765** 2766** {H13102} If the [prepared statement] passed as the argument to 2767** [sqlite3_sql()] was compiled using either [sqlite3_prepare()] or 2768** [sqlite3_prepare16()], then [sqlite3_sql()] returns a NULL pointer. 2769** 2770** {H13103} The string returned by [sqlite3_sql(S)] is valid until the 2771** [prepared statement] S is deleted using [sqlite3_finalize(S)]. 2772*/ 2773const char *sqlite3_sql(sqlite3_stmt *pStmt); 2774 2775/* 2776** CAPI3REF: Dynamically Typed Value Object {H15000} 2777** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2778** 2779** SQLite uses the sqlite3_value object to represent all values 2780** that can be stored in a database table. SQLite uses dynamic typing 2781** for the values it stores. Values stored in sqlite3_value objects 2782** can be integers, floating point values, strings, BLOBs, or NULL. 2783** 2784** An sqlite3_value object may be either "protected" or "unprotected". 2785** Some interfaces require a protected sqlite3_value. Other interfaces 2786** will accept either a protected or an unprotected sqlite3_value. 2787** Every interface that accepts sqlite3_value arguments specifies 2788** whether or not it requires a protected sqlite3_value. 2789** 2790** The terms "protected" and "unprotected" refer to whether or not 2791** a mutex is held. A internal mutex is held for a protected 2792** sqlite3_value object but no mutex is held for an unprotected 2793** sqlite3_value object. If SQLite is compiled to be single-threaded 2794** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 2795** or if SQLite is run in one of reduced mutex modes 2796** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 2797** then there is no distinction between protected and unprotected 2798** sqlite3_value objects and they can be used interchangeably. However, 2799** for maximum code portability it is recommended that applications 2800** still make the distinction between between protected and unprotected 2801** sqlite3_value objects even when not strictly required. 2802** 2803** The sqlite3_value objects that are passed as parameters into the 2804** implementation of [application-defined SQL functions] are protected. 2805** The sqlite3_value object returned by 2806** [sqlite3_column_value()] is unprotected. 2807** Unprotected sqlite3_value objects may only be used with 2808** [sqlite3_result_value()] and [sqlite3_bind_value()]. 2809** The [sqlite3_value_blob | sqlite3_value_type()] family of 2810** interfaces require protected sqlite3_value objects. 2811*/ 2812typedef struct Mem sqlite3_value; 2813 2814/* 2815** CAPI3REF: SQL Function Context Object {H16001} 2816** 2817** The context in which an SQL function executes is stored in an 2818** sqlite3_context object. A pointer to an sqlite3_context object 2819** is always first parameter to [application-defined SQL functions]. 2820** The application-defined SQL function implementation will pass this 2821** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 2822** [sqlite3_aggregate_context()], [sqlite3_user_data()], 2823** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 2824** and/or [sqlite3_set_auxdata()]. 2825*/ 2826typedef struct sqlite3_context sqlite3_context; 2827 2828/* 2829** CAPI3REF: Binding Values To Prepared Statements {H13500} 2830** KEYWORDS: {host parameter} {host parameters} {host parameter name} 2831** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 2832** 2833** In the SQL strings input to [sqlite3_prepare_v2()] and its variants, 2834** literals may be replaced by a parameter in one of these forms: 2835** 2836** <ul> 2837** <li> ? 2838** <li> ?NNN 2839** <li> :VVV 2840** <li> @VVV 2841** <li> $VVV 2842** </ul> 2843** 2844** In the parameter forms shown above NNN is an integer literal, 2845** and VVV is an alpha-numeric parameter name. The values of these 2846** parameters (also called "host parameter names" or "SQL parameters") 2847** can be set using the sqlite3_bind_*() routines defined here. 2848** 2849** The first argument to the sqlite3_bind_*() routines is always 2850** a pointer to the [sqlite3_stmt] object returned from 2851** [sqlite3_prepare_v2()] or its variants. 2852** 2853** The second argument is the index of the SQL parameter to be set. 2854** The leftmost SQL parameter has an index of 1. When the same named 2855** SQL parameter is used more than once, second and subsequent 2856** occurrences have the same index as the first occurrence. 2857** The index for named parameters can be looked up using the 2858** [sqlite3_bind_parameter_index()] API if desired. The index 2859** for "?NNN" parameters is the value of NNN. 2860** The NNN value must be between 1 and the [sqlite3_limit()] 2861** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 2862** 2863** The third argument is the value to bind to the parameter. 2864** 2865** In those routines that have a fourth argument, its value is the 2866** number of bytes in the parameter. To be clear: the value is the 2867** number of <u>bytes</u> in the value, not the number of characters. 2868** If the fourth parameter is negative, the length of the string is 2869** the number of bytes up to the first zero terminator. 2870** 2871** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 2872** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 2873** string after SQLite has finished with it. If the fifth argument is 2874** the special value [SQLITE_STATIC], then SQLite assumes that the 2875** information is in static, unmanaged space and does not need to be freed. 2876** If the fifth argument has the value [SQLITE_TRANSIENT], then 2877** SQLite makes its own private copy of the data immediately, before 2878** the sqlite3_bind_*() routine returns. 2879** 2880** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 2881** is filled with zeroes. A zeroblob uses a fixed amount of memory 2882** (just an integer to hold its size) while it is being processed. 2883** Zeroblobs are intended to serve as placeholders for BLOBs whose 2884** content is later written using 2885** [sqlite3_blob_open | incremental BLOB I/O] routines. 2886** A negative value for the zeroblob results in a zero-length BLOB. 2887** 2888** The sqlite3_bind_*() routines must be called after 2889** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and 2890** before [sqlite3_step()]. 2891** Bindings are not cleared by the [sqlite3_reset()] routine. 2892** Unbound parameters are interpreted as NULL. 2893** 2894** These routines return [SQLITE_OK] on success or an error code if 2895** anything goes wrong. [SQLITE_RANGE] is returned if the parameter 2896** index is out of range. [SQLITE_NOMEM] is returned if malloc() fails. 2897** [SQLITE_MISUSE] might be returned if these routines are called on a 2898** virtual machine that is the wrong state or which has already been finalized. 2899** Detection of misuse is unreliable. Applications should not depend 2900** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a 2901** a logic error in the application. Future versions of SQLite might 2902** panic rather than return SQLITE_MISUSE. 2903** 2904** See also: [sqlite3_bind_parameter_count()], 2905** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 2906** 2907** INVARIANTS: 2908** 2909** {H13506} The [SQL statement compiler] recognizes tokens of the forms 2910** "?", "?NNN", "$VVV", ":VVV", and "@VVV" as SQL parameters, 2911** where NNN is any sequence of one or more digits 2912** and where VVV is any sequence of one or more alphanumeric 2913** characters or "::" optionally followed by a string containing 2914** no spaces and contained within parentheses. 2915** 2916** {H13509} The initial value of an SQL parameter is NULL. 2917** 2918** {H13512} The index of an "?" SQL parameter is one larger than the 2919** largest index of SQL parameter to the left, or 1 if 2920** the "?" is the leftmost SQL parameter. 2921** 2922** {H13515} The index of an "?NNN" SQL parameter is the integer NNN. 2923** 2924** {H13518} The index of an ":VVV", "$VVV", or "@VVV" SQL parameter is 2925** the same as the index of leftmost occurrences of the same 2926** parameter, or one more than the largest index over all 2927** parameters to the left if this is the first occurrence 2928** of this parameter, or 1 if this is the leftmost parameter. 2929** 2930** {H13521} The [SQL statement compiler] fails with an [SQLITE_RANGE] 2931** error if the index of an SQL parameter is less than 1 2932** or greater than the compile-time SQLITE_MAX_VARIABLE_NUMBER 2933** parameter. 2934** 2935** {H13524} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,V,...)] 2936** associate the value V with all SQL parameters having an 2937** index of N in the [prepared statement] S. 2938** 2939** {H13527} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,...)] 2940** override prior calls with the same values of S and N. 2941** 2942** {H13530} Bindings established by [sqlite3_bind_text | sqlite3_bind(S,...)] 2943** persist across calls to [sqlite3_reset(S)]. 2944** 2945** {H13533} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2946** [sqlite3_bind_text(S,N,V,L,D)], or 2947** [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds the first L 2948** bytes of the BLOB or string pointed to by V, when L 2949** is non-negative. 2950** 2951** {H13536} In calls to [sqlite3_bind_text(S,N,V,L,D)] or 2952** [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds characters 2953** from V through the first zero character when L is negative. 2954** 2955** {H13539} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2956** [sqlite3_bind_text(S,N,V,L,D)], or 2957** [sqlite3_bind_text16(S,N,V,L,D)] when D is the special 2958** constant [SQLITE_STATIC], SQLite assumes that the value V 2959** is held in static unmanaged space that will not change 2960** during the lifetime of the binding. 2961** 2962** {H13542} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2963** [sqlite3_bind_text(S,N,V,L,D)], or 2964** [sqlite3_bind_text16(S,N,V,L,D)] when D is the special 2965** constant [SQLITE_TRANSIENT], the routine makes a 2966** private copy of the value V before it returns. 2967** 2968** {H13545} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2969** [sqlite3_bind_text(S,N,V,L,D)], or 2970** [sqlite3_bind_text16(S,N,V,L,D)] when D is a pointer to 2971** a function, SQLite invokes that function to destroy the 2972** value V after it has finished using the value V. 2973** 2974** {H13548} In calls to [sqlite3_bind_zeroblob(S,N,V,L)] the value bound 2975** is a BLOB of L bytes, or a zero-length BLOB if L is negative. 2976** 2977** {H13551} In calls to [sqlite3_bind_value(S,N,V)] the V argument may 2978** be either a [protected sqlite3_value] object or an 2979** [unprotected sqlite3_value] object. 2980*/ 2981int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 2982int sqlite3_bind_double(sqlite3_stmt*, int, double); 2983int sqlite3_bind_int(sqlite3_stmt*, int, int); 2984int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 2985int sqlite3_bind_null(sqlite3_stmt*, int); 2986int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 2987int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 2988int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 2989int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 2990 2991/* 2992** CAPI3REF: Number Of SQL Parameters {H13600} 2993** 2994** This routine can be used to find the number of [SQL parameters] 2995** in a [prepared statement]. SQL parameters are tokens of the 2996** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 2997** placeholders for values that are [sqlite3_bind_blob | bound] 2998** to the parameters at a later time. 2999** 3000** This routine actually returns the index of the largest (rightmost) 3001** parameter. For all forms except ?NNN, this will correspond to the 3002** number of unique parameters. If parameters of the ?NNN are used, 3003** there may be gaps in the list. 3004** 3005** See also: [sqlite3_bind_blob|sqlite3_bind()], 3006** [sqlite3_bind_parameter_name()], and 3007** [sqlite3_bind_parameter_index()]. 3008** 3009** INVARIANTS: 3010** 3011** {H13601} The [sqlite3_bind_parameter_count(S)] interface returns 3012** the largest index of all SQL parameters in the 3013** [prepared statement] S, or 0 if S contains no SQL parameters. 3014*/ 3015int sqlite3_bind_parameter_count(sqlite3_stmt*); 3016 3017/* 3018** CAPI3REF: Name Of A Host Parameter {H13620} 3019** 3020** This routine returns a pointer to the name of the n-th 3021** [SQL parameter] in a [prepared statement]. 3022** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3023** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3024** respectively. 3025** In other words, the initial ":" or "$" or "@" or "?" 3026** is included as part of the name. 3027** Parameters of the form "?" without a following integer have no name 3028** and are also referred to as "anonymous parameters". 3029** 3030** The first host parameter has an index of 1, not 0. 3031** 3032** If the value n is out of range or if the n-th parameter is 3033** nameless, then NULL is returned. The returned string is 3034** always in UTF-8 encoding even if the named parameter was 3035** originally specified as UTF-16 in [sqlite3_prepare16()] or 3036** [sqlite3_prepare16_v2()]. 3037** 3038** See also: [sqlite3_bind_blob|sqlite3_bind()], 3039** [sqlite3_bind_parameter_count()], and 3040** [sqlite3_bind_parameter_index()]. 3041** 3042** INVARIANTS: 3043** 3044** {H13621} The [sqlite3_bind_parameter_name(S,N)] interface returns 3045** a UTF-8 rendering of the name of the SQL parameter in 3046** the [prepared statement] S having index N, or 3047** NULL if there is no SQL parameter with index N or if the 3048** parameter with index N is an anonymous parameter "?". 3049*/ 3050const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3051 3052/* 3053** CAPI3REF: Index Of A Parameter With A Given Name {H13640} 3054** 3055** Return the index of an SQL parameter given its name. The 3056** index value returned is suitable for use as the second 3057** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero 3058** is returned if no matching parameter is found. The parameter 3059** name must be given in UTF-8 even if the original statement 3060** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3061** 3062** See also: [sqlite3_bind_blob|sqlite3_bind()], 3063** [sqlite3_bind_parameter_count()], and 3064** [sqlite3_bind_parameter_index()]. 3065** 3066** INVARIANTS: 3067** 3068** {H13641} The [sqlite3_bind_parameter_index(S,N)] interface returns 3069** the index of SQL parameter in the [prepared statement] 3070** S whose name matches the UTF-8 string N, or 0 if there is 3071** no match. 3072*/ 3073int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3074 3075/* 3076** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} 3077** 3078** Contrary to the intuition of many, [sqlite3_reset()] does not reset 3079** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3080** Use this routine to reset all host parameters to NULL. 3081** 3082** INVARIANTS: 3083** 3084** {H13661} The [sqlite3_clear_bindings(S)] interface resets all SQL 3085** parameter bindings in the [prepared statement] S back to NULL. 3086*/ 3087int sqlite3_clear_bindings(sqlite3_stmt*); 3088 3089/* 3090** CAPI3REF: Number Of Columns In A Result Set {H13710} 3091** 3092** Return the number of columns in the result set returned by the 3093** [prepared statement]. This routine returns 0 if pStmt is an SQL 3094** statement that does not return data (for example an [UPDATE]). 3095** 3096** INVARIANTS: 3097** 3098** {H13711} The [sqlite3_column_count(S)] interface returns the number of 3099** columns in the result set generated by the [prepared statement] S, 3100** or 0 if S does not generate a result set. 3101*/ 3102int sqlite3_column_count(sqlite3_stmt *pStmt); 3103 3104/* 3105** CAPI3REF: Column Names In A Result Set {H13720} 3106** 3107** These routines return the name assigned to a particular column 3108** in the result set of a [SELECT] statement. The sqlite3_column_name() 3109** interface returns a pointer to a zero-terminated UTF-8 string 3110** and sqlite3_column_name16() returns a pointer to a zero-terminated 3111** UTF-16 string. The first parameter is the [prepared statement] 3112** that implements the [SELECT] statement. The second parameter is the 3113** column number. The leftmost column is number 0. 3114** 3115** The returned string pointer is valid until either the [prepared statement] 3116** is destroyed by [sqlite3_finalize()] or until the next call to 3117** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3118** 3119** If sqlite3_malloc() fails during the processing of either routine 3120** (for example during a conversion from UTF-8 to UTF-16) then a 3121** NULL pointer is returned. 3122** 3123** The name of a result column is the value of the "AS" clause for 3124** that column, if there is an AS clause. If there is no AS clause 3125** then the name of the column is unspecified and may change from 3126** one release of SQLite to the next. 3127** 3128** INVARIANTS: 3129** 3130** {H13721} A successful invocation of the [sqlite3_column_name(S,N)] 3131** interface returns the name of the Nth column (where 0 is 3132** the leftmost column) for the result set of the 3133** [prepared statement] S as a zero-terminated UTF-8 string. 3134** 3135** {H13723} A successful invocation of the [sqlite3_column_name16(S,N)] 3136** interface returns the name of the Nth column (where 0 is 3137** the leftmost column) for the result set of the 3138** [prepared statement] S as a zero-terminated UTF-16 string 3139** in the native byte order. 3140** 3141** {H13724} The [sqlite3_column_name()] and [sqlite3_column_name16()] 3142** interfaces return a NULL pointer if they are unable to 3143** allocate memory to hold their normal return strings. 3144** 3145** {H13725} If the N parameter to [sqlite3_column_name(S,N)] or 3146** [sqlite3_column_name16(S,N)] is out of range, then the 3147** interfaces return a NULL pointer. 3148** 3149** {H13726} The strings returned by [sqlite3_column_name(S,N)] and 3150** [sqlite3_column_name16(S,N)] are valid until the next 3151** call to either routine with the same S and N parameters 3152** or until [sqlite3_finalize(S)] is called. 3153** 3154** {H13727} When a result column of a [SELECT] statement contains 3155** an AS clause, the name of that column is the identifier 3156** to the right of the AS keyword. 3157*/ 3158const char *sqlite3_column_name(sqlite3_stmt*, int N); 3159const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3160 3161/* 3162** CAPI3REF: Source Of Data In A Query Result {H13740} 3163** 3164** These routines provide a means to determine what column of what 3165** table in which database a result of a [SELECT] statement comes from. 3166** The name of the database or table or column can be returned as 3167** either a UTF-8 or UTF-16 string. The _database_ routines return 3168** the database name, the _table_ routines return the table name, and 3169** the origin_ routines return the column name. 3170** The returned string is valid until the [prepared statement] is destroyed 3171** using [sqlite3_finalize()] or until the same information is requested 3172** again in a different encoding. 3173** 3174** The names returned are the original un-aliased names of the 3175** database, table, and column. 3176** 3177** The first argument to the following calls is a [prepared statement]. 3178** These functions return information about the Nth column returned by 3179** the statement, where N is the second function argument. 3180** 3181** If the Nth column returned by the statement is an expression or 3182** subquery and is not a column value, then all of these functions return 3183** NULL. These routine might also return NULL if a memory allocation error 3184** occurs. Otherwise, they return the name of the attached database, table 3185** and column that query result column was extracted from. 3186** 3187** As with all other SQLite APIs, those postfixed with "16" return 3188** UTF-16 encoded strings, the other functions return UTF-8. {END} 3189** 3190** These APIs are only available if the library was compiled with the 3191** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 3192** 3193** {A13751} 3194** If two or more threads call one or more of these routines against the same 3195** prepared statement and column at the same time then the results are 3196** undefined. 3197** 3198** INVARIANTS: 3199** 3200** {H13741} The [sqlite3_column_database_name(S,N)] interface returns either 3201** the UTF-8 zero-terminated name of the database from which the 3202** Nth result column of the [prepared statement] S is extracted, 3203** or NULL if the Nth column of S is a general expression 3204** or if unable to allocate memory to store the name. 3205** 3206** {H13742} The [sqlite3_column_database_name16(S,N)] interface returns either 3207** the UTF-16 native byte order zero-terminated name of the database 3208** from which the Nth result column of the [prepared statement] S is 3209** extracted, or NULL if the Nth column of S is a general expression 3210** or if unable to allocate memory to store the name. 3211** 3212** {H13743} The [sqlite3_column_table_name(S,N)] interface returns either 3213** the UTF-8 zero-terminated name of the table from which the 3214** Nth result column of the [prepared statement] S is extracted, 3215** or NULL if the Nth column of S is a general expression 3216** or if unable to allocate memory to store the name. 3217** 3218** {H13744} The [sqlite3_column_table_name16(S,N)] interface returns either 3219** the UTF-16 native byte order zero-terminated name of the table 3220** from which the Nth result column of the [prepared statement] S is 3221** extracted, or NULL if the Nth column of S is a general expression 3222** or if unable to allocate memory to store the name. 3223** 3224** {H13745} The [sqlite3_column_origin_name(S,N)] interface returns either 3225** the UTF-8 zero-terminated name of the table column from which the 3226** Nth result column of the [prepared statement] S is extracted, 3227** or NULL if the Nth column of S is a general expression 3228** or if unable to allocate memory to store the name. 3229** 3230** {H13746} The [sqlite3_column_origin_name16(S,N)] interface returns either 3231** the UTF-16 native byte order zero-terminated name of the table 3232** column from which the Nth result column of the 3233** [prepared statement] S is extracted, or NULL if the Nth column 3234** of S is a general expression or if unable to allocate memory 3235** to store the name. 3236** 3237** {H13748} The return values from 3238** [sqlite3_column_database_name | column metadata interfaces] 3239** are valid for the lifetime of the [prepared statement] 3240** or until the encoding is changed by another metadata 3241** interface call for the same prepared statement and column. 3242** 3243** ASSUMPTIONS: 3244** 3245** {A13751} If two or more threads call one or more 3246** [sqlite3_column_database_name | column metadata interfaces] 3247** for the same [prepared statement] and result column 3248** at the same time then the results are undefined. 3249*/ 3250const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3251const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3252const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3253const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3254const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3255const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3256 3257/* 3258** CAPI3REF: Declared Datatype Of A Query Result {H13760} 3259** 3260** The first parameter is a [prepared statement]. 3261** If this statement is a [SELECT] statement and the Nth column of the 3262** returned result set of that [SELECT] is a table column (not an 3263** expression or subquery) then the declared type of the table 3264** column is returned. If the Nth column of the result set is an 3265** expression or subquery, then a NULL pointer is returned. 3266** The returned string is always UTF-8 encoded. {END} 3267** 3268** For example, given the database schema: 3269** 3270** CREATE TABLE t1(c1 VARIANT); 3271** 3272** and the following statement to be compiled: 3273** 3274** SELECT c1 + 1, c1 FROM t1; 3275** 3276** this routine would return the string "VARIANT" for the second result 3277** column (i==1), and a NULL pointer for the first result column (i==0). 3278** 3279** SQLite uses dynamic run-time typing. So just because a column 3280** is declared to contain a particular type does not mean that the 3281** data stored in that column is of the declared type. SQLite is 3282** strongly typed, but the typing is dynamic not static. Type 3283** is associated with individual values, not with the containers 3284** used to hold those values. 3285** 3286** INVARIANTS: 3287** 3288** {H13761} A successful call to [sqlite3_column_decltype(S,N)] returns a 3289** zero-terminated UTF-8 string containing the declared datatype 3290** of the table column that appears as the Nth column (numbered 3291** from 0) of the result set to the [prepared statement] S. 3292** 3293** {H13762} A successful call to [sqlite3_column_decltype16(S,N)] 3294** returns a zero-terminated UTF-16 native byte order string 3295** containing the declared datatype of the table column that appears 3296** as the Nth column (numbered from 0) of the result set to the 3297** [prepared statement] S. 3298** 3299** {H13763} If N is less than 0 or N is greater than or equal to 3300** the number of columns in the [prepared statement] S, 3301** or if the Nth column of S is an expression or subquery rather 3302** than a table column, or if a memory allocation failure 3303** occurs during encoding conversions, then 3304** calls to [sqlite3_column_decltype(S,N)] or 3305** [sqlite3_column_decltype16(S,N)] return NULL. 3306*/ 3307const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3308const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3309 3310/* 3311** CAPI3REF: Evaluate An SQL Statement {H13200} 3312** 3313** After a [prepared statement] has been prepared using either 3314** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3315** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3316** must be called one or more times to evaluate the statement. 3317** 3318** The details of the behavior of the sqlite3_step() interface depend 3319** on whether the statement was prepared using the newer "v2" interface 3320** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3321** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3322** new "v2" interface is recommended for new applications but the legacy 3323** interface will continue to be supported. 3324** 3325** In the legacy interface, the return value will be either [SQLITE_BUSY], 3326** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3327** With the "v2" interface, any of the other [result codes] or 3328** [extended result codes] might be returned as well. 3329** 3330** [SQLITE_BUSY] means that the database engine was unable to acquire the 3331** database locks it needs to do its job. If the statement is a [COMMIT] 3332** or occurs outside of an explicit transaction, then you can retry the 3333** statement. If the statement is not a [COMMIT] and occurs within a 3334** explicit transaction then you should rollback the transaction before 3335** continuing. 3336** 3337** [SQLITE_DONE] means that the statement has finished executing 3338** successfully. sqlite3_step() should not be called again on this virtual 3339** machine without first calling [sqlite3_reset()] to reset the virtual 3340** machine back to its initial state. 3341** 3342** If the SQL statement being executed returns any data, then [SQLITE_ROW] 3343** is returned each time a new row of data is ready for processing by the 3344** caller. The values may be accessed using the [column access functions]. 3345** sqlite3_step() is called again to retrieve the next row of data. 3346** 3347** [SQLITE_ERROR] means that a run-time error (such as a constraint 3348** violation) has occurred. sqlite3_step() should not be called again on 3349** the VM. More information may be found by calling [sqlite3_errmsg()]. 3350** With the legacy interface, a more specific error code (for example, 3351** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3352** can be obtained by calling [sqlite3_reset()] on the 3353** [prepared statement]. In the "v2" interface, 3354** the more specific error code is returned directly by sqlite3_step(). 3355** 3356** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3357** Perhaps it was called on a [prepared statement] that has 3358** already been [sqlite3_finalize | finalized] or on one that had 3359** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3360** be the case that the same database connection is being used by two or 3361** more threads at the same moment in time. 3362** 3363** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3364** API always returns a generic error code, [SQLITE_ERROR], following any 3365** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3366** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3367** specific [error codes] that better describes the error. 3368** We admit that this is a goofy design. The problem has been fixed 3369** with the "v2" interface. If you prepare all of your SQL statements 3370** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3371** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3372** then the more specific [error codes] are returned directly 3373** by sqlite3_step(). The use of the "v2" interface is recommended. 3374** 3375** INVARIANTS: 3376** 3377** {H13202} If the [prepared statement] S is ready to be run, then 3378** [sqlite3_step(S)] advances that prepared statement until 3379** completion or until it is ready to return another row of the 3380** result set, or until an [sqlite3_interrupt | interrupt] 3381** or a run-time error occurs. 3382** 3383** {H15304} When a call to [sqlite3_step(S)] causes the [prepared statement] 3384** S to run to completion, the function returns [SQLITE_DONE]. 3385** 3386** {H15306} When a call to [sqlite3_step(S)] stops because it is ready to 3387** return another row of the result set, it returns [SQLITE_ROW]. 3388** 3389** {H15308} If a call to [sqlite3_step(S)] encounters an 3390** [sqlite3_interrupt | interrupt] or a run-time error, 3391** it returns an appropriate error code that is not one of 3392** [SQLITE_OK], [SQLITE_ROW], or [SQLITE_DONE]. 3393** 3394** {H15310} If an [sqlite3_interrupt | interrupt] or a run-time error 3395** occurs during a call to [sqlite3_step(S)] 3396** for a [prepared statement] S created using 3397** legacy interfaces [sqlite3_prepare()] or 3398** [sqlite3_prepare16()], then the function returns either 3399** [SQLITE_ERROR], [SQLITE_BUSY], or [SQLITE_MISUSE]. 3400*/ 3401int sqlite3_step(sqlite3_stmt*); 3402 3403/* 3404** CAPI3REF: Number of columns in a result set {H13770} 3405** 3406** Returns the number of values in the current row of the result set. 3407** 3408** INVARIANTS: 3409** 3410** {H13771} After a call to [sqlite3_step(S)] that returns [SQLITE_ROW], 3411** the [sqlite3_data_count(S)] routine will return the same value 3412** as the [sqlite3_column_count(S)] function. 3413** 3414** {H13772} After [sqlite3_step(S)] has returned any value other than 3415** [SQLITE_ROW] or before [sqlite3_step(S)] has been called on the 3416** [prepared statement] for the first time since it was 3417** [sqlite3_prepare | prepared] or [sqlite3_reset | reset], 3418** the [sqlite3_data_count(S)] routine returns zero. 3419*/ 3420int sqlite3_data_count(sqlite3_stmt *pStmt); 3421 3422/* 3423** CAPI3REF: Fundamental Datatypes {H10265} 3424** KEYWORDS: SQLITE_TEXT 3425** 3426** {H10266} Every value in SQLite has one of five fundamental datatypes: 3427** 3428** <ul> 3429** <li> 64-bit signed integer 3430** <li> 64-bit IEEE floating point number 3431** <li> string 3432** <li> BLOB 3433** <li> NULL 3434** </ul> {END} 3435** 3436** These constants are codes for each of those types. 3437** 3438** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3439** for a completely different meaning. Software that links against both 3440** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3441** SQLITE_TEXT. 3442*/ 3443#define SQLITE_INTEGER 1 3444#define SQLITE_FLOAT 2 3445#define SQLITE_BLOB 4 3446#define SQLITE_NULL 5 3447#ifdef SQLITE_TEXT 3448# undef SQLITE_TEXT 3449#else 3450# define SQLITE_TEXT 3 3451#endif 3452#define SQLITE3_TEXT 3 3453 3454/* 3455** CAPI3REF: Result Values From A Query {H13800} 3456** KEYWORDS: {column access functions} 3457** 3458** These routines form the "result set query" interface. 3459** 3460** These routines return information about a single column of the current 3461** result row of a query. In every case the first argument is a pointer 3462** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3463** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3464** and the second argument is the index of the column for which information 3465** should be returned. The leftmost column of the result set has the index 0. 3466** 3467** If the SQL statement does not currently point to a valid row, or if the 3468** column index is out of range, the result is undefined. 3469** These routines may only be called when the most recent call to 3470** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3471** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3472** If any of these routines are called after [sqlite3_reset()] or 3473** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3474** something other than [SQLITE_ROW], the results are undefined. 3475** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3476** are called from a different thread while any of these routines 3477** are pending, then the results are undefined. 3478** 3479** The sqlite3_column_type() routine returns the 3480** [SQLITE_INTEGER | datatype code] for the initial data type 3481** of the result column. The returned value is one of [SQLITE_INTEGER], 3482** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3483** returned by sqlite3_column_type() is only meaningful if no type 3484** conversions have occurred as described below. After a type conversion, 3485** the value returned by sqlite3_column_type() is undefined. Future 3486** versions of SQLite may change the behavior of sqlite3_column_type() 3487** following a type conversion. 3488** 3489** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3490** routine returns the number of bytes in that BLOB or string. 3491** If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3492** the string to UTF-8 and then returns the number of bytes. 3493** If the result is a numeric value then sqlite3_column_bytes() uses 3494** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3495** the number of bytes in that string. 3496** The value returned does not include the zero terminator at the end 3497** of the string. For clarity: the value returned is the number of 3498** bytes in the string, not the number of characters. 3499** 3500** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3501** even empty strings, are always zero terminated. The return 3502** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary 3503** pointer, possibly even a NULL pointer. 3504** 3505** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() 3506** but leaves the result in UTF-16 in native byte order instead of UTF-8. 3507** The zero terminator is not included in this count. 3508** 3509** The object returned by [sqlite3_column_value()] is an 3510** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3511** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3512** If the [unprotected sqlite3_value] object returned by 3513** [sqlite3_column_value()] is used in any other way, including calls 3514** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3515** or [sqlite3_value_bytes()], then the behavior is undefined. 3516** 3517** These routines attempt to convert the value where appropriate. For 3518** example, if the internal representation is FLOAT and a text result 3519** is requested, [sqlite3_snprintf()] is used internally to perform the 3520** conversion automatically. The following table details the conversions 3521** that are applied: 3522** 3523** <blockquote> 3524** <table border="1"> 3525** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3526** 3527** <tr><td> NULL <td> INTEGER <td> Result is 0 3528** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3529** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3530** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3531** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3532** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3533** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3534** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3535** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3536** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3537** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3538** <tr><td> TEXT <td> FLOAT <td> Use atof() 3539** <tr><td> TEXT <td> BLOB <td> No change 3540** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3541** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3542** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3543** </table> 3544** </blockquote> 3545** 3546** The table above makes reference to standard C library functions atoi() 3547** and atof(). SQLite does not really use these functions. It has its 3548** own equivalent internal routines. The atoi() and atof() names are 3549** used in the table for brevity and because they are familiar to most 3550** C programmers. 3551** 3552** Note that when type conversions occur, pointers returned by prior 3553** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3554** sqlite3_column_text16() may be invalidated. 3555** Type conversions and pointer invalidations might occur 3556** in the following cases: 3557** 3558** <ul> 3559** <li> The initial content is a BLOB and sqlite3_column_text() or 3560** sqlite3_column_text16() is called. A zero-terminator might 3561** need to be added to the string.</li> 3562** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3563** sqlite3_column_text16() is called. The content must be converted 3564** to UTF-16.</li> 3565** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3566** sqlite3_column_text() is called. The content must be converted 3567** to UTF-8.</li> 3568** </ul> 3569** 3570** Conversions between UTF-16be and UTF-16le are always done in place and do 3571** not invalidate a prior pointer, though of course the content of the buffer 3572** that the prior pointer points to will have been modified. Other kinds 3573** of conversion are done in place when it is possible, but sometimes they 3574** are not possible and in those cases prior pointers are invalidated. 3575** 3576** The safest and easiest to remember policy is to invoke these routines 3577** in one of the following ways: 3578** 3579** <ul> 3580** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3581** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3582** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3583** </ul> 3584** 3585** In other words, you should call sqlite3_column_text(), 3586** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3587** into the desired format, then invoke sqlite3_column_bytes() or 3588** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3589** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3590** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3591** with calls to sqlite3_column_bytes(). 3592** 3593** The pointers returned are valid until a type conversion occurs as 3594** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3595** [sqlite3_finalize()] is called. The memory space used to hold strings 3596** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3597** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3598** [sqlite3_free()]. 3599** 3600** If a memory allocation error occurs during the evaluation of any 3601** of these routines, a default value is returned. The default value 3602** is either the integer 0, the floating point number 0.0, or a NULL 3603** pointer. Subsequent calls to [sqlite3_errcode()] will return 3604** [SQLITE_NOMEM]. 3605** 3606** INVARIANTS: 3607** 3608** {H13803} The [sqlite3_column_blob(S,N)] interface converts the 3609** Nth column in the current row of the result set for 3610** the [prepared statement] S into a BLOB and then returns a 3611** pointer to the converted value. 3612** 3613** {H13806} The [sqlite3_column_bytes(S,N)] interface returns the 3614** number of bytes in the BLOB or string (exclusive of the 3615** zero terminator on the string) that was returned by the 3616** most recent call to [sqlite3_column_blob(S,N)] or 3617** [sqlite3_column_text(S,N)]. 3618** 3619** {H13809} The [sqlite3_column_bytes16(S,N)] interface returns the 3620** number of bytes in the string (exclusive of the 3621** zero terminator on the string) that was returned by the 3622** most recent call to [sqlite3_column_text16(S,N)]. 3623** 3624** {H13812} The [sqlite3_column_double(S,N)] interface converts the 3625** Nth column in the current row of the result set for the 3626** [prepared statement] S into a floating point value and 3627** returns a copy of that value. 3628** 3629** {H13815} The [sqlite3_column_int(S,N)] interface converts the 3630** Nth column in the current row of the result set for the 3631** [prepared statement] S into a 64-bit signed integer and 3632** returns the lower 32 bits of that integer. 3633** 3634** {H13818} The [sqlite3_column_int64(S,N)] interface converts the 3635** Nth column in the current row of the result set for the 3636** [prepared statement] S into a 64-bit signed integer and 3637** returns a copy of that integer. 3638** 3639** {H13821} The [sqlite3_column_text(S,N)] interface converts the 3640** Nth column in the current row of the result set for 3641** the [prepared statement] S into a zero-terminated UTF-8 3642** string and returns a pointer to that string. 3643** 3644** {H13824} The [sqlite3_column_text16(S,N)] interface converts the 3645** Nth column in the current row of the result set for the 3646** [prepared statement] S into a zero-terminated 2-byte 3647** aligned UTF-16 native byte order string and returns 3648** a pointer to that string. 3649** 3650** {H13827} The [sqlite3_column_type(S,N)] interface returns 3651** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT], 3652** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for 3653** the Nth column in the current row of the result set for 3654** the [prepared statement] S. 3655** 3656** {H13830} The [sqlite3_column_value(S,N)] interface returns a 3657** pointer to an [unprotected sqlite3_value] object for the 3658** Nth column in the current row of the result set for 3659** the [prepared statement] S. 3660*/ 3661const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3662int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3663int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3664double sqlite3_column_double(sqlite3_stmt*, int iCol); 3665int sqlite3_column_int(sqlite3_stmt*, int iCol); 3666sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3667const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3668const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3669int sqlite3_column_type(sqlite3_stmt*, int iCol); 3670sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3671 3672/* 3673** CAPI3REF: Destroy A Prepared Statement Object {H13300} 3674** 3675** The sqlite3_finalize() function is called to delete a [prepared statement]. 3676** If the statement was executed successfully or not executed at all, then 3677** SQLITE_OK is returned. If execution of the statement failed then an 3678** [error code] or [extended error code] is returned. 3679** 3680** This routine can be called at any point during the execution of the 3681** [prepared statement]. If the virtual machine has not 3682** completed execution when this routine is called, that is like 3683** encountering an error or an [sqlite3_interrupt | interrupt]. 3684** Incomplete updates may be rolled back and transactions canceled, 3685** depending on the circumstances, and the 3686** [error code] returned will be [SQLITE_ABORT]. 3687** 3688** INVARIANTS: 3689** 3690** {H11302} The [sqlite3_finalize(S)] interface destroys the 3691** [prepared statement] S and releases all 3692** memory and file resources held by that object. 3693** 3694** {H11304} If the most recent call to [sqlite3_step(S)] for the 3695** [prepared statement] S returned an error, 3696** then [sqlite3_finalize(S)] returns that same error. 3697*/ 3698int sqlite3_finalize(sqlite3_stmt *pStmt); 3699 3700/* 3701** CAPI3REF: Reset A Prepared Statement Object {H13330} 3702** 3703** The sqlite3_reset() function is called to reset a [prepared statement] 3704** object back to its initial state, ready to be re-executed. 3705** Any SQL statement variables that had values bound to them using 3706** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3707** Use [sqlite3_clear_bindings()] to reset the bindings. 3708** 3709** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S 3710** back to the beginning of its program. 3711** 3712** {H11334} If the most recent call to [sqlite3_step(S)] for the 3713** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3714** or if [sqlite3_step(S)] has never before been called on S, 3715** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3716** 3717** {H11336} If the most recent call to [sqlite3_step(S)] for the 3718** [prepared statement] S indicated an error, then 3719** [sqlite3_reset(S)] returns an appropriate [error code]. 3720** 3721** {H11338} The [sqlite3_reset(S)] interface does not change the values 3722** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3723*/ 3724int sqlite3_reset(sqlite3_stmt *pStmt); 3725 3726/* 3727** CAPI3REF: Create Or Redefine SQL Functions {H16100} 3728** KEYWORDS: {function creation routines} 3729** KEYWORDS: {application-defined SQL function} 3730** KEYWORDS: {application-defined SQL functions} 3731** 3732** These two functions (collectively known as "function creation routines") 3733** are used to add SQL functions or aggregates or to redefine the behavior 3734** of existing SQL functions or aggregates. The only difference between the 3735** two is that the second parameter, the name of the (scalar) function or 3736** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16 3737** for sqlite3_create_function16(). 3738** 3739** The first parameter is the [database connection] to which the SQL 3740** function is to be added. If a single program uses more than one database 3741** connection internally, then SQL functions must be added individually to 3742** each database connection. 3743** 3744** The second parameter is the name of the SQL function to be created or 3745** redefined. The length of the name is limited to 255 bytes, exclusive of 3746** the zero-terminator. Note that the name length limit is in bytes, not 3747** characters. Any attempt to create a function with a longer name 3748** will result in [SQLITE_ERROR] being returned. 3749** 3750** The third parameter is the number of arguments that the SQL function or 3751** aggregate takes. If this parameter is negative, then the SQL function or 3752** aggregate may take any number of arguments. 3753** 3754** The fourth parameter, eTextRep, specifies what 3755** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3756** its parameters. Any SQL function implementation should be able to work 3757** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3758** more efficient with one encoding than another. It is allowed to 3759** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3760** times with the same function but with different values of eTextRep. 3761** When multiple implementations of the same function are available, SQLite 3762** will pick the one that involves the least amount of data conversion. 3763** If there is only a single implementation which does not care what text 3764** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3765** 3766** The fifth parameter is an arbitrary pointer. The implementation of the 3767** function can gain access to this pointer using [sqlite3_user_data()]. 3768** 3769** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are 3770** pointers to C-language functions that implement the SQL function or 3771** aggregate. A scalar SQL function requires an implementation of the xFunc 3772** callback only, NULL pointers should be passed as the xStep and xFinal 3773** parameters. An aggregate SQL function requires an implementation of xStep 3774** and xFinal and NULL should be passed for xFunc. To delete an existing 3775** SQL function or aggregate, pass NULL for all three function callbacks. 3776** 3777** It is permitted to register multiple implementations of the same 3778** functions with the same name but with either differing numbers of 3779** arguments or differing preferred text encodings. SQLite will use 3780** the implementation most closely matches the way in which the 3781** SQL function is used. 3782** 3783** INVARIANTS: 3784** 3785** {H16103} The [sqlite3_create_function16()] interface behaves exactly 3786** like [sqlite3_create_function()] in every way except that it 3787** interprets the zFunctionName argument as zero-terminated UTF-16 3788** native byte order instead of as zero-terminated UTF-8. 3789** 3790** {H16106} A successful invocation of 3791** the [sqlite3_create_function(D,X,N,E,...)] interface registers 3792** or replaces callback functions in the [database connection] D 3793** used to implement the SQL function named X with N parameters 3794** and having a preferred text encoding of E. 3795** 3796** {H16109} A successful call to [sqlite3_create_function(D,X,N,E,P,F,S,L)] 3797** replaces the P, F, S, and L values from any prior calls with 3798** the same D, X, N, and E values. 3799** 3800** {H16112} The [sqlite3_create_function(D,X,...)] interface fails with 3801** a return code of [SQLITE_ERROR] if the SQL function name X is 3802** longer than 255 bytes exclusive of the zero terminator. 3803** 3804** {H16118} Either F must be NULL and S and L are non-NULL or else F 3805** is non-NULL and S and L are NULL, otherwise 3806** [sqlite3_create_function(D,X,N,E,P,F,S,L)] returns [SQLITE_ERROR]. 3807** 3808** {H16121} The [sqlite3_create_function(D,...)] interface fails with an 3809** error code of [SQLITE_BUSY] if there exist [prepared statements] 3810** associated with the [database connection] D. 3811** 3812** {H16124} The [sqlite3_create_function(D,X,N,...)] interface fails with an 3813** error code of [SQLITE_ERROR] if parameter N (specifying the number 3814** of arguments to the SQL function being registered) is less 3815** than -1 or greater than 127. 3816** 3817** {H16127} When N is non-negative, the [sqlite3_create_function(D,X,N,...)] 3818** interface causes callbacks to be invoked for the SQL function 3819** named X when the number of arguments to the SQL function is 3820** exactly N. 3821** 3822** {H16130} When N is -1, the [sqlite3_create_function(D,X,N,...)] 3823** interface causes callbacks to be invoked for the SQL function 3824** named X with any number of arguments. 3825** 3826** {H16133} When calls to [sqlite3_create_function(D,X,N,...)] 3827** specify multiple implementations of the same function X 3828** and when one implementation has N>=0 and the other has N=(-1) 3829** the implementation with a non-zero N is preferred. 3830** 3831** {H16136} When calls to [sqlite3_create_function(D,X,N,E,...)] 3832** specify multiple implementations of the same function X with 3833** the same number of arguments N but with different 3834** encodings E, then the implementation where E matches the 3835** database encoding is preferred. 3836** 3837** {H16139} For an aggregate SQL function created using 3838** [sqlite3_create_function(D,X,N,E,P,0,S,L)] the finalizer 3839** function L will always be invoked exactly once if the 3840** step function S is called one or more times. 3841** 3842** {H16142} When SQLite invokes either the xFunc or xStep function of 3843** an application-defined SQL function or aggregate created 3844** by [sqlite3_create_function()] or [sqlite3_create_function16()], 3845** then the array of [sqlite3_value] objects passed as the 3846** third parameter are always [protected sqlite3_value] objects. 3847*/ 3848int sqlite3_create_function( 3849 sqlite3 *db, 3850 const char *zFunctionName, 3851 int nArg, 3852 int eTextRep, 3853 void *pApp, 3854 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3855 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3856 void (*xFinal)(sqlite3_context*) 3857); 3858int sqlite3_create_function16( 3859 sqlite3 *db, 3860 const void *zFunctionName, 3861 int nArg, 3862 int eTextRep, 3863 void *pApp, 3864 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3865 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3866 void (*xFinal)(sqlite3_context*) 3867); 3868 3869/* 3870** CAPI3REF: Text Encodings {H10267} 3871** 3872** These constant define integer codes that represent the various 3873** text encodings supported by SQLite. 3874*/ 3875#define SQLITE_UTF8 1 3876#define SQLITE_UTF16LE 2 3877#define SQLITE_UTF16BE 3 3878#define SQLITE_UTF16 4 /* Use native byte order */ 3879#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3880#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3881 3882/* 3883** CAPI3REF: Obsolete Functions 3884** 3885** These functions are all now obsolete. In order to maintain 3886** backwards compatibility with older code, we continue to support 3887** these functions. However, new development projects should avoid 3888** the use of these functions. To help encourage people to avoid 3889** using these functions, we are not going to tell you want they do. 3890*/ 3891int sqlite3_aggregate_count(sqlite3_context*); 3892int sqlite3_expired(sqlite3_stmt*); 3893int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3894int sqlite3_global_recover(void); 3895void sqlite3_thread_cleanup(void); 3896int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3897 3898/* 3899** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} 3900** 3901** The C-language implementation of SQL functions and aggregates uses 3902** this set of interface routines to access the parameter values on 3903** the function or aggregate. 3904** 3905** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3906** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3907** define callbacks that implement the SQL functions and aggregates. 3908** The 4th parameter to these callbacks is an array of pointers to 3909** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3910** each parameter to the SQL function. These routines are used to 3911** extract values from the [sqlite3_value] objects. 3912** 3913** These routines work only with [protected sqlite3_value] objects. 3914** Any attempt to use these routines on an [unprotected sqlite3_value] 3915** object results in undefined behavior. 3916** 3917** These routines work just like the corresponding [column access functions] 3918** except that these routines take a single [protected sqlite3_value] object 3919** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3920** 3921** The sqlite3_value_text16() interface extracts a UTF-16 string 3922** in the native byte-order of the host machine. The 3923** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3924** extract UTF-16 strings as big-endian and little-endian respectively. 3925** 3926** The sqlite3_value_numeric_type() interface attempts to apply 3927** numeric affinity to the value. This means that an attempt is 3928** made to convert the value to an integer or floating point. If 3929** such a conversion is possible without loss of information (in other 3930** words, if the value is a string that looks like a number) 3931** then the conversion is performed. Otherwise no conversion occurs. 3932** The [SQLITE_INTEGER | datatype] after conversion is returned. 3933** 3934** Please pay particular attention to the fact that the pointer returned 3935** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3936** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3937** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3938** or [sqlite3_value_text16()]. 3939** 3940** These routines must be called from the same thread as 3941** the SQL function that supplied the [sqlite3_value*] parameters. 3942** 3943** INVARIANTS: 3944** 3945** {H15103} The [sqlite3_value_blob(V)] interface converts the 3946** [protected sqlite3_value] object V into a BLOB and then 3947** returns a pointer to the converted value. 3948** 3949** {H15106} The [sqlite3_value_bytes(V)] interface returns the 3950** number of bytes in the BLOB or string (exclusive of the 3951** zero terminator on the string) that was returned by the 3952** most recent call to [sqlite3_value_blob(V)] or 3953** [sqlite3_value_text(V)]. 3954** 3955** {H15109} The [sqlite3_value_bytes16(V)] interface returns the 3956** number of bytes in the string (exclusive of the 3957** zero terminator on the string) that was returned by the 3958** most recent call to [sqlite3_value_text16(V)], 3959** [sqlite3_value_text16be(V)], or [sqlite3_value_text16le(V)]. 3960** 3961** {H15112} The [sqlite3_value_double(V)] interface converts the 3962** [protected sqlite3_value] object V into a floating point value and 3963** returns a copy of that value. 3964** 3965** {H15115} The [sqlite3_value_int(V)] interface converts the 3966** [protected sqlite3_value] object V into a 64-bit signed integer and 3967** returns the lower 32 bits of that integer. 3968** 3969** {H15118} The [sqlite3_value_int64(V)] interface converts the 3970** [protected sqlite3_value] object V into a 64-bit signed integer and 3971** returns a copy of that integer. 3972** 3973** {H15121} The [sqlite3_value_text(V)] interface converts the 3974** [protected sqlite3_value] object V into a zero-terminated UTF-8 3975** string and returns a pointer to that string. 3976** 3977** {H15124} The [sqlite3_value_text16(V)] interface converts the 3978** [protected sqlite3_value] object V into a zero-terminated 2-byte 3979** aligned UTF-16 native byte order 3980** string and returns a pointer to that string. 3981** 3982** {H15127} The [sqlite3_value_text16be(V)] interface converts the 3983** [protected sqlite3_value] object V into a zero-terminated 2-byte 3984** aligned UTF-16 big-endian 3985** string and returns a pointer to that string. 3986** 3987** {H15130} The [sqlite3_value_text16le(V)] interface converts the 3988** [protected sqlite3_value] object V into a zero-terminated 2-byte 3989** aligned UTF-16 little-endian 3990** string and returns a pointer to that string. 3991** 3992** {H15133} The [sqlite3_value_type(V)] interface returns 3993** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT], 3994** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for 3995** the [sqlite3_value] object V. 3996** 3997** {H15136} The [sqlite3_value_numeric_type(V)] interface converts 3998** the [protected sqlite3_value] object V into either an integer or 3999** a floating point value if it can do so without loss of 4000** information, and returns one of [SQLITE_NULL], 4001** [SQLITE_INTEGER], [SQLITE_FLOAT], [SQLITE_TEXT], or 4002** [SQLITE_BLOB] as appropriate for the 4003** [protected sqlite3_value] object V after the conversion attempt. 4004*/ 4005const void *sqlite3_value_blob(sqlite3_value*); 4006int sqlite3_value_bytes(sqlite3_value*); 4007int sqlite3_value_bytes16(sqlite3_value*); 4008double sqlite3_value_double(sqlite3_value*); 4009int sqlite3_value_int(sqlite3_value*); 4010sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4011const unsigned char *sqlite3_value_text(sqlite3_value*); 4012const void *sqlite3_value_text16(sqlite3_value*); 4013const void *sqlite3_value_text16le(sqlite3_value*); 4014const void *sqlite3_value_text16be(sqlite3_value*); 4015int sqlite3_value_type(sqlite3_value*); 4016int sqlite3_value_numeric_type(sqlite3_value*); 4017 4018/* 4019** CAPI3REF: Obtain Aggregate Function Context {H16210} 4020** 4021** The implementation of aggregate SQL functions use this routine to allocate 4022** a structure for storing their state. 4023** 4024** The first time the sqlite3_aggregate_context() routine is called for a 4025** particular aggregate, SQLite allocates nBytes of memory, zeroes out that 4026** memory, and returns a pointer to it. On second and subsequent calls to 4027** sqlite3_aggregate_context() for the same aggregate function index, 4028** the same buffer is returned. The implementation of the aggregate can use 4029** the returned buffer to accumulate data. 4030** 4031** SQLite automatically frees the allocated buffer when the aggregate 4032** query concludes. 4033** 4034** The first parameter should be a copy of the 4035** [sqlite3_context | SQL function context] that is the first parameter 4036** to the callback routine that implements the aggregate function. 4037** 4038** This routine must be called from the same thread in which 4039** the aggregate SQL function is running. 4040** 4041** INVARIANTS: 4042** 4043** {H16211} The first invocation of [sqlite3_aggregate_context(C,N)] for 4044** a particular instance of an aggregate function (for a particular 4045** context C) causes SQLite to allocate N bytes of memory, 4046** zero that memory, and return a pointer to the allocated memory. 4047** 4048** {H16213} If a memory allocation error occurs during 4049** [sqlite3_aggregate_context(C,N)] then the function returns 0. 4050** 4051** {H16215} Second and subsequent invocations of 4052** [sqlite3_aggregate_context(C,N)] for the same context pointer C 4053** ignore the N parameter and return a pointer to the same 4054** block of memory returned by the first invocation. 4055** 4056** {H16217} The memory allocated by [sqlite3_aggregate_context(C,N)] is 4057** automatically freed on the next call to [sqlite3_reset()] 4058** or [sqlite3_finalize()] for the [prepared statement] containing 4059** the aggregate function associated with context C. 4060*/ 4061void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4062 4063/* 4064** CAPI3REF: User Data For Functions {H16240} 4065** 4066** The sqlite3_user_data() interface returns a copy of 4067** the pointer that was the pUserData parameter (the 5th parameter) 4068** of the [sqlite3_create_function()] 4069** and [sqlite3_create_function16()] routines that originally 4070** registered the application defined function. {END} 4071** 4072** This routine must be called from the same thread in which 4073** the application-defined function is running. 4074** 4075** INVARIANTS: 4076** 4077** {H16243} The [sqlite3_user_data(C)] interface returns a copy of the 4078** P pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)] 4079** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that 4080** registered the SQL function associated with [sqlite3_context] C. 4081*/ 4082void *sqlite3_user_data(sqlite3_context*); 4083 4084/* 4085** CAPI3REF: Database Connection For Functions {H16250} 4086** 4087** The sqlite3_context_db_handle() interface returns a copy of 4088** the pointer to the [database connection] (the 1st parameter) 4089** of the [sqlite3_create_function()] 4090** and [sqlite3_create_function16()] routines that originally 4091** registered the application defined function. 4092** 4093** INVARIANTS: 4094** 4095** {H16253} The [sqlite3_context_db_handle(C)] interface returns a copy of the 4096** D pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)] 4097** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that 4098** registered the SQL function associated with [sqlite3_context] C. 4099*/ 4100sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4101 4102/* 4103** CAPI3REF: Function Auxiliary Data {H16270} 4104** 4105** The following two functions may be used by scalar SQL functions to 4106** associate metadata with argument values. If the same value is passed to 4107** multiple invocations of the same SQL function during query execution, under 4108** some circumstances the associated metadata may be preserved. This may 4109** be used, for example, to add a regular-expression matching scalar 4110** function. The compiled version of the regular expression is stored as 4111** metadata associated with the SQL value passed as the regular expression 4112** pattern. The compiled regular expression can be reused on multiple 4113** invocations of the same function so that the original pattern string 4114** does not need to be recompiled on each invocation. 4115** 4116** The sqlite3_get_auxdata() interface returns a pointer to the metadata 4117** associated by the sqlite3_set_auxdata() function with the Nth argument 4118** value to the application-defined function. If no metadata has been ever 4119** been set for the Nth argument of the function, or if the corresponding 4120** function parameter has changed since the meta-data was set, 4121** then sqlite3_get_auxdata() returns a NULL pointer. 4122** 4123** The sqlite3_set_auxdata() interface saves the metadata 4124** pointed to by its 3rd parameter as the metadata for the N-th 4125** argument of the application-defined function. Subsequent 4126** calls to sqlite3_get_auxdata() might return this data, if it has 4127** not been destroyed. 4128** If it is not NULL, SQLite will invoke the destructor 4129** function given by the 4th parameter to sqlite3_set_auxdata() on 4130** the metadata when the corresponding function parameter changes 4131** or when the SQL statement completes, whichever comes first. 4132** 4133** SQLite is free to call the destructor and drop metadata on any 4134** parameter of any function at any time. The only guarantee is that 4135** the destructor will be called before the metadata is dropped. 4136** 4137** In practice, metadata is preserved between function calls for 4138** expressions that are constant at compile time. This includes literal 4139** values and SQL variables. 4140** 4141** These routines must be called from the same thread in which 4142** the SQL function is running. 4143** 4144** INVARIANTS: 4145** 4146** {H16272} The [sqlite3_get_auxdata(C,N)] interface returns a pointer 4147** to metadata associated with the Nth parameter of the SQL function 4148** whose context is C, or NULL if there is no metadata associated 4149** with that parameter. 4150** 4151** {H16274} The [sqlite3_set_auxdata(C,N,P,D)] interface assigns a metadata 4152** pointer P to the Nth parameter of the SQL function with context C. 4153** 4154** {H16276} SQLite will invoke the destructor D with a single argument 4155** which is the metadata pointer P following a call to 4156** [sqlite3_set_auxdata(C,N,P,D)] when SQLite ceases to hold 4157** the metadata. 4158** 4159** {H16277} SQLite ceases to hold metadata for an SQL function parameter 4160** when the value of that parameter changes. 4161** 4162** {H16278} When [sqlite3_set_auxdata(C,N,P,D)] is invoked, the destructor 4163** is called for any prior metadata associated with the same function 4164** context C and parameter N. 4165** 4166** {H16279} SQLite will call destructors for any metadata it is holding 4167** in a particular [prepared statement] S when either 4168** [sqlite3_reset(S)] or [sqlite3_finalize(S)] is called. 4169*/ 4170void *sqlite3_get_auxdata(sqlite3_context*, int N); 4171void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4172 4173 4174/* 4175** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} 4176** 4177** These are special values for the destructor that is passed in as the 4178** final argument to routines like [sqlite3_result_blob()]. If the destructor 4179** argument is SQLITE_STATIC, it means that the content pointer is constant 4180** and will never change. It does not need to be destroyed. The 4181** SQLITE_TRANSIENT value means that the content will likely change in 4182** the near future and that SQLite should make its own private copy of 4183** the content before returning. 4184** 4185** The typedef is necessary to work around problems in certain 4186** C++ compilers. See ticket #2191. 4187*/ 4188typedef void (*sqlite3_destructor_type)(void*); 4189#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4190#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4191 4192/* 4193** CAPI3REF: Setting The Result Of An SQL Function {H16400} 4194** 4195** These routines are used by the xFunc or xFinal callbacks that 4196** implement SQL functions and aggregates. See 4197** [sqlite3_create_function()] and [sqlite3_create_function16()] 4198** for additional information. 4199** 4200** These functions work very much like the [parameter binding] family of 4201** functions used to bind values to host parameters in prepared statements. 4202** Refer to the [SQL parameter] documentation for additional information. 4203** 4204** The sqlite3_result_blob() interface sets the result from 4205** an application-defined function to be the BLOB whose content is pointed 4206** to by the second parameter and which is N bytes long where N is the 4207** third parameter. 4208** 4209** The sqlite3_result_zeroblob() interfaces set the result of 4210** the application-defined function to be a BLOB containing all zero 4211** bytes and N bytes in size, where N is the value of the 2nd parameter. 4212** 4213** The sqlite3_result_double() interface sets the result from 4214** an application-defined function to be a floating point value specified 4215** by its 2nd argument. 4216** 4217** The sqlite3_result_error() and sqlite3_result_error16() functions 4218** cause the implemented SQL function to throw an exception. 4219** SQLite uses the string pointed to by the 4220** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4221** as the text of an error message. SQLite interprets the error 4222** message string from sqlite3_result_error() as UTF-8. SQLite 4223** interprets the string from sqlite3_result_error16() as UTF-16 in native 4224** byte order. If the third parameter to sqlite3_result_error() 4225** or sqlite3_result_error16() is negative then SQLite takes as the error 4226** message all text up through the first zero character. 4227** If the third parameter to sqlite3_result_error() or 4228** sqlite3_result_error16() is non-negative then SQLite takes that many 4229** bytes (not characters) from the 2nd parameter as the error message. 4230** The sqlite3_result_error() and sqlite3_result_error16() 4231** routines make a private copy of the error message text before 4232** they return. Hence, the calling function can deallocate or 4233** modify the text after they return without harm. 4234** The sqlite3_result_error_code() function changes the error code 4235** returned by SQLite as a result of an error in a function. By default, 4236** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() 4237** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4238** 4239** The sqlite3_result_toobig() interface causes SQLite to throw an error 4240** indicating that a string or BLOB is to long to represent. 4241** 4242** The sqlite3_result_nomem() interface causes SQLite to throw an error 4243** indicating that a memory allocation failed. 4244** 4245** The sqlite3_result_int() interface sets the return value 4246** of the application-defined function to be the 32-bit signed integer 4247** value given in the 2nd argument. 4248** The sqlite3_result_int64() interface sets the return value 4249** of the application-defined function to be the 64-bit signed integer 4250** value given in the 2nd argument. 4251** 4252** The sqlite3_result_null() interface sets the return value 4253** of the application-defined function to be NULL. 4254** 4255** The sqlite3_result_text(), sqlite3_result_text16(), 4256** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4257** set the return value of the application-defined function to be 4258** a text string which is represented as UTF-8, UTF-16 native byte order, 4259** UTF-16 little endian, or UTF-16 big endian, respectively. 4260** SQLite takes the text result from the application from 4261** the 2nd parameter of the sqlite3_result_text* interfaces. 4262** If the 3rd parameter to the sqlite3_result_text* interfaces 4263** is negative, then SQLite takes result text from the 2nd parameter 4264** through the first zero character. 4265** If the 3rd parameter to the sqlite3_result_text* interfaces 4266** is non-negative, then as many bytes (not characters) of the text 4267** pointed to by the 2nd parameter are taken as the application-defined 4268** function result. 4269** If the 4th parameter to the sqlite3_result_text* interfaces 4270** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4271** function as the destructor on the text or BLOB result when it has 4272** finished using that result. 4273** If the 4th parameter to the sqlite3_result_text* interfaces or 4274** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4275** assumes that the text or BLOB result is in constant space and does not 4276** copy the it or call a destructor when it has finished using that result. 4277** If the 4th parameter to the sqlite3_result_text* interfaces 4278** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4279** then SQLite makes a copy of the result into space obtained from 4280** from [sqlite3_malloc()] before it returns. 4281** 4282** The sqlite3_result_value() interface sets the result of 4283** the application-defined function to be a copy the 4284** [unprotected sqlite3_value] object specified by the 2nd parameter. The 4285** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4286** so that the [sqlite3_value] specified in the parameter may change or 4287** be deallocated after sqlite3_result_value() returns without harm. 4288** A [protected sqlite3_value] object may always be used where an 4289** [unprotected sqlite3_value] object is required, so either 4290** kind of [sqlite3_value] object can be used with this interface. 4291** 4292** If these routines are called from within the different thread 4293** than the one containing the application-defined function that received 4294** the [sqlite3_context] pointer, the results are undefined. 4295** 4296** INVARIANTS: 4297** 4298** {H16403} The default return value from any SQL function is NULL. 4299** 4300** {H16406} The [sqlite3_result_blob(C,V,N,D)] interface changes the 4301** return value of function C to be a BLOB that is N bytes 4302** in length and with content pointed to by V. 4303** 4304** {H16409} The [sqlite3_result_double(C,V)] interface changes the 4305** return value of function C to be the floating point value V. 4306** 4307** {H16412} The [sqlite3_result_error(C,V,N)] interface changes the return 4308** value of function C to be an exception with error code 4309** [SQLITE_ERROR] and a UTF-8 error message copied from V up to the 4310** first zero byte or until N bytes are read if N is positive. 4311** 4312** {H16415} The [sqlite3_result_error16(C,V,N)] interface changes the return 4313** value of function C to be an exception with error code 4314** [SQLITE_ERROR] and a UTF-16 native byte order error message 4315** copied from V up to the first zero terminator or until N bytes 4316** are read if N is positive. 4317** 4318** {H16418} The [sqlite3_result_error_toobig(C)] interface changes the return 4319** value of the function C to be an exception with error code 4320** [SQLITE_TOOBIG] and an appropriate error message. 4321** 4322** {H16421} The [sqlite3_result_error_nomem(C)] interface changes the return 4323** value of the function C to be an exception with error code 4324** [SQLITE_NOMEM] and an appropriate error message. 4325** 4326** {H16424} The [sqlite3_result_error_code(C,E)] interface changes the return 4327** value of the function C to be an exception with error code E. 4328** The error message text is unchanged. 4329** 4330** {H16427} The [sqlite3_result_int(C,V)] interface changes the 4331** return value of function C to be the 32-bit integer value V. 4332** 4333** {H16430} The [sqlite3_result_int64(C,V)] interface changes the 4334** return value of function C to be the 64-bit integer value V. 4335** 4336** {H16433} The [sqlite3_result_null(C)] interface changes the 4337** return value of function C to be NULL. 4338** 4339** {H16436} The [sqlite3_result_text(C,V,N,D)] interface changes the 4340** return value of function C to be the UTF-8 string 4341** V up to the first zero if N is negative 4342** or the first N bytes of V if N is non-negative. 4343** 4344** {H16439} The [sqlite3_result_text16(C,V,N,D)] interface changes the 4345** return value of function C to be the UTF-16 native byte order 4346** string V up to the first zero if N is negative 4347** or the first N bytes of V if N is non-negative. 4348** 4349** {H16442} The [sqlite3_result_text16be(C,V,N,D)] interface changes the 4350** return value of function C to be the UTF-16 big-endian 4351** string V up to the first zero if N is negative 4352** or the first N bytes or V if N is non-negative. 4353** 4354** {H16445} The [sqlite3_result_text16le(C,V,N,D)] interface changes the 4355** return value of function C to be the UTF-16 little-endian 4356** string V up to the first zero if N is negative 4357** or the first N bytes of V if N is non-negative. 4358** 4359** {H16448} The [sqlite3_result_value(C,V)] interface changes the 4360** return value of function C to be the [unprotected sqlite3_value] 4361** object V. 4362** 4363** {H16451} The [sqlite3_result_zeroblob(C,N)] interface changes the 4364** return value of function C to be an N-byte BLOB of all zeros. 4365** 4366** {H16454} The [sqlite3_result_error()] and [sqlite3_result_error16()] 4367** interfaces make a copy of their error message strings before 4368** returning. 4369** 4370** {H16457} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)], 4371** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)], 4372** [sqlite3_result_text16be(C,V,N,D)], or 4373** [sqlite3_result_text16le(C,V,N,D)] is the constant [SQLITE_STATIC] 4374** then no destructor is ever called on the pointer V and SQLite 4375** assumes that V is immutable. 4376** 4377** {H16460} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)], 4378** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)], 4379** [sqlite3_result_text16be(C,V,N,D)], or 4380** [sqlite3_result_text16le(C,V,N,D)] is the constant 4381** [SQLITE_TRANSIENT] then the interfaces makes a copy of the 4382** content of V and retains the copy. 4383** 4384** {H16463} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)], 4385** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)], 4386** [sqlite3_result_text16be(C,V,N,D)], or 4387** [sqlite3_result_text16le(C,V,N,D)] is some value other than 4388** the constants [SQLITE_STATIC] and [SQLITE_TRANSIENT] then 4389** SQLite will invoke the destructor D with V as its only argument 4390** when it has finished with the V value. 4391*/ 4392void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4393void sqlite3_result_double(sqlite3_context*, double); 4394void sqlite3_result_error(sqlite3_context*, const char*, int); 4395void sqlite3_result_error16(sqlite3_context*, const void*, int); 4396void sqlite3_result_error_toobig(sqlite3_context*); 4397void sqlite3_result_error_nomem(sqlite3_context*); 4398void sqlite3_result_error_code(sqlite3_context*, int); 4399void sqlite3_result_int(sqlite3_context*, int); 4400void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4401void sqlite3_result_null(sqlite3_context*); 4402void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4403void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4404void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4405void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4406void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4407void sqlite3_result_zeroblob(sqlite3_context*, int n); 4408 4409/* 4410** CAPI3REF: Define New Collating Sequences {H16600} 4411** 4412** These functions are used to add new collation sequences to the 4413** [database connection] specified as the first argument. 4414** 4415** The name of the new collation sequence is specified as a UTF-8 string 4416** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4417** and a UTF-16 string for sqlite3_create_collation16(). In all cases 4418** the name is passed as the second function argument. 4419** 4420** The third argument may be one of the constants [SQLITE_UTF8], 4421** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied 4422** routine expects to be passed pointers to strings encoded using UTF-8, 4423** UTF-16 little-endian, or UTF-16 big-endian, respectively. The 4424** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that 4425** the routine expects pointers to 16-bit word aligned strings 4426** of UTF-16 in the native byte order of the host computer. 4427** 4428** A pointer to the user supplied routine must be passed as the fifth 4429** argument. If it is NULL, this is the same as deleting the collation 4430** sequence (so that SQLite cannot call it anymore). 4431** Each time the application supplied function is invoked, it is passed 4432** as its first parameter a copy of the void* passed as the fourth argument 4433** to sqlite3_create_collation() or sqlite3_create_collation16(). 4434** 4435** The remaining arguments to the application-supplied routine are two strings, 4436** each represented by a (length, data) pair and encoded in the encoding 4437** that was passed as the third argument when the collation sequence was 4438** registered. {END} The application defined collation routine should 4439** return negative, zero or positive if the first string is less than, 4440** equal to, or greater than the second string. i.e. (STRING1 - STRING2). 4441** 4442** The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4443** except that it takes an extra argument which is a destructor for 4444** the collation. The destructor is called when the collation is 4445** destroyed and is passed a copy of the fourth parameter void* pointer 4446** of the sqlite3_create_collation_v2(). 4447** Collations are destroyed when they are overridden by later calls to the 4448** collation creation functions or when the [database connection] is closed 4449** using [sqlite3_close()]. 4450** 4451** INVARIANTS: 4452** 4453** {H16603} A successful call to the 4454** [sqlite3_create_collation_v2(B,X,E,P,F,D)] interface 4455** registers function F as the comparison function used to 4456** implement collation X on the [database connection] B for 4457** databases having encoding E. 4458** 4459** {H16604} SQLite understands the X parameter to 4460** [sqlite3_create_collation_v2(B,X,E,P,F,D)] as a zero-terminated 4461** UTF-8 string in which case is ignored for ASCII characters and 4462** is significant for non-ASCII characters. 4463** 4464** {H16606} Successive calls to [sqlite3_create_collation_v2(B,X,E,P,F,D)] 4465** with the same values for B, X, and E, override prior values 4466** of P, F, and D. 4467** 4468** {H16609} If the destructor D in [sqlite3_create_collation_v2(B,X,E,P,F,D)] 4469** is not NULL then it is called with argument P when the 4470** collating function is dropped by SQLite. 4471** 4472** {H16612} A collating function is dropped when it is overloaded. 4473** 4474** {H16615} A collating function is dropped when the database connection 4475** is closed using [sqlite3_close()]. 4476** 4477** {H16618} The pointer P in [sqlite3_create_collation_v2(B,X,E,P,F,D)] 4478** is passed through as the first parameter to the comparison 4479** function F for all subsequent invocations of F. 4480** 4481** {H16621} A call to [sqlite3_create_collation(B,X,E,P,F)] is exactly 4482** the same as a call to [sqlite3_create_collation_v2()] with 4483** the same parameters and a NULL destructor. 4484** 4485** {H16624} Following a [sqlite3_create_collation_v2(B,X,E,P,F,D)], 4486** SQLite uses the comparison function F for all text comparison 4487** operations on the [database connection] B on text values that 4488** use the collating sequence named X. 4489** 4490** {H16627} The [sqlite3_create_collation16(B,X,E,P,F)] works the same 4491** as [sqlite3_create_collation(B,X,E,P,F)] except that the 4492** collation name X is understood as UTF-16 in native byte order 4493** instead of UTF-8. 4494** 4495** {H16630} When multiple comparison functions are available for the same 4496** collating sequence, SQLite chooses the one whose text encoding 4497** requires the least amount of conversion from the default 4498** text encoding of the database. 4499*/ 4500int sqlite3_create_collation( 4501 sqlite3*, 4502 const char *zName, 4503 int eTextRep, 4504 void*, 4505 int(*xCompare)(void*,int,const void*,int,const void*) 4506); 4507int sqlite3_create_collation_v2( 4508 sqlite3*, 4509 const char *zName, 4510 int eTextRep, 4511 void*, 4512 int(*xCompare)(void*,int,const void*,int,const void*), 4513 void(*xDestroy)(void*) 4514); 4515int sqlite3_create_collation16( 4516 sqlite3*, 4517 const void *zName, 4518 int eTextRep, 4519 void*, 4520 int(*xCompare)(void*,int,const void*,int,const void*) 4521); 4522 4523/* 4524** CAPI3REF: Collation Needed Callbacks {H16700} 4525** 4526** To avoid having to register all collation sequences before a database 4527** can be used, a single callback function may be registered with the 4528** [database connection] to be called whenever an undefined collation 4529** sequence is required. 4530** 4531** If the function is registered using the sqlite3_collation_needed() API, 4532** then it is passed the names of undefined collation sequences as strings 4533** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used, 4534** the names are passed as UTF-16 in machine native byte order. 4535** A call to either function replaces any existing callback. 4536** 4537** When the callback is invoked, the first argument passed is a copy 4538** of the second argument to sqlite3_collation_needed() or 4539** sqlite3_collation_needed16(). The second argument is the database 4540** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4541** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4542** sequence function required. The fourth parameter is the name of the 4543** required collation sequence. 4544** 4545** The callback function should register the desired collation using 4546** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4547** [sqlite3_create_collation_v2()]. 4548** 4549** INVARIANTS: 4550** 4551** {H16702} A successful call to [sqlite3_collation_needed(D,P,F)] 4552** or [sqlite3_collation_needed16(D,P,F)] causes 4553** the [database connection] D to invoke callback F with first 4554** parameter P whenever it needs a comparison function for a 4555** collating sequence that it does not know about. 4556** 4557** {H16704} Each successful call to [sqlite3_collation_needed()] or 4558** [sqlite3_collation_needed16()] overrides the callback registered 4559** on the same [database connection] by prior calls to either 4560** interface. 4561** 4562** {H16706} The name of the requested collating function passed in the 4563** 4th parameter to the callback is in UTF-8 if the callback 4564** was registered using [sqlite3_collation_needed()] and 4565** is in UTF-16 native byte order if the callback was 4566** registered using [sqlite3_collation_needed16()]. 4567*/ 4568int sqlite3_collation_needed( 4569 sqlite3*, 4570 void*, 4571 void(*)(void*,sqlite3*,int eTextRep,const char*) 4572); 4573int sqlite3_collation_needed16( 4574 sqlite3*, 4575 void*, 4576 void(*)(void*,sqlite3*,int eTextRep,const void*) 4577); 4578 4579/* 4580** Specify the key for an encrypted database. This routine should be 4581** called right after sqlite3_open(). 4582** 4583** The code to implement this API is not available in the public release 4584** of SQLite. 4585*/ 4586int sqlite3_key( 4587 sqlite3 *db, /* Database to be rekeyed */ 4588 const void *pKey, int nKey /* The key */ 4589); 4590 4591/* 4592** Change the key on an open database. If the current database is not 4593** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4594** database is decrypted. 4595** 4596** The code to implement this API is not available in the public release 4597** of SQLite. 4598*/ 4599int sqlite3_rekey( 4600 sqlite3 *db, /* Database to be rekeyed */ 4601 const void *pKey, int nKey /* The new key */ 4602); 4603 4604/* 4605** CAPI3REF: Suspend Execution For A Short Time {H10530} 4606** 4607** The sqlite3_sleep() function causes the current thread to suspend execution 4608** for at least a number of milliseconds specified in its parameter. 4609** 4610** If the operating system does not support sleep requests with 4611** millisecond time resolution, then the time will be rounded up to 4612** the nearest second. The number of milliseconds of sleep actually 4613** requested from the operating system is returned. 4614** 4615** SQLite implements this interface by calling the xSleep() 4616** method of the default [sqlite3_vfs] object. 4617** 4618** INVARIANTS: 4619** 4620** {H10533} The [sqlite3_sleep(M)] interface invokes the xSleep 4621** method of the default [sqlite3_vfs|VFS] in order to 4622** suspend execution of the current thread for at least 4623** M milliseconds. 4624** 4625** {H10536} The [sqlite3_sleep(M)] interface returns the number of 4626** milliseconds of sleep actually requested of the operating 4627** system, which might be larger than the parameter M. 4628*/ 4629int sqlite3_sleep(int); 4630 4631/* 4632** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} 4633** 4634** If this global variable is made to point to a string which is 4635** the name of a folder (a.k.a. directory), then all temporary files 4636** created by SQLite will be placed in that directory. If this variable 4637** is a NULL pointer, then SQLite performs a search for an appropriate 4638** temporary file directory. 4639** 4640** It is not safe to modify this variable once a [database connection] 4641** has been opened. It is intended that this variable be set once 4642** as part of process initialization and before any SQLite interface 4643** routines have been call and remain unchanged thereafter. 4644*/ 4645SQLITE_EXTERN char *sqlite3_temp_directory; 4646 4647/* 4648** CAPI3REF: Test To See If The Database Is In Auto-Commit Mode {H12930} 4649** KEYWORDS: {autocommit mode} 4650** 4651** The sqlite3_get_autocommit() interface returns non-zero or 4652** zero if the given database connection is or is not in autocommit mode, 4653** respectively. Autocommit mode is on by default. 4654** Autocommit mode is disabled by a [BEGIN] statement. 4655** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4656** 4657** If certain kinds of errors occur on a statement within a multi-statement 4658** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4659** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4660** transaction might be rolled back automatically. The only way to 4661** find out whether SQLite automatically rolled back the transaction after 4662** an error is to use this function. 4663** 4664** INVARIANTS: 4665** 4666** {H12931} The [sqlite3_get_autocommit(D)] interface returns non-zero or 4667** zero if the [database connection] D is or is not in autocommit 4668** mode, respectively. 4669** 4670** {H12932} Autocommit mode is on by default. 4671** 4672** {H12933} Autocommit mode is disabled by a successful [BEGIN] statement. 4673** 4674** {H12934} Autocommit mode is enabled by a successful [COMMIT] or [ROLLBACK] 4675** statement. 4676** 4677** ASSUMPTIONS: 4678** 4679** {A12936} If another thread changes the autocommit status of the database 4680** connection while this routine is running, then the return value 4681** is undefined. 4682*/ 4683int sqlite3_get_autocommit(sqlite3*); 4684 4685/* 4686** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} 4687** 4688** The sqlite3_db_handle interface returns the [database connection] handle 4689** to which a [prepared statement] belongs. The database handle returned by 4690** sqlite3_db_handle is the same database handle that was the first argument 4691** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4692** create the statement in the first place. 4693** 4694** INVARIANTS: 4695** 4696** {H13123} The [sqlite3_db_handle(S)] interface returns a pointer 4697** to the [database connection] associated with the 4698** [prepared statement] S. 4699*/ 4700sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4701 4702/* 4703** CAPI3REF: Find the next prepared statement {H13140} 4704** 4705** This interface returns a pointer to the next [prepared statement] after 4706** pStmt associated with the [database connection] pDb. If pStmt is NULL 4707** then this interface returns a pointer to the first prepared statement 4708** associated with the database connection pDb. If no prepared statement 4709** satisfies the conditions of this routine, it returns NULL. 4710** 4711** INVARIANTS: 4712** 4713** {H13143} If D is a [database connection] that holds one or more 4714** unfinalized [prepared statements] and S is a NULL pointer, 4715** then [sqlite3_next_stmt(D, S)] routine shall return a pointer 4716** to one of the prepared statements associated with D. 4717** 4718** {H13146} If D is a [database connection] that holds no unfinalized 4719** [prepared statements] and S is a NULL pointer, then 4720** [sqlite3_next_stmt(D, S)] routine shall return a NULL pointer. 4721** 4722** {H13149} If S is a [prepared statement] in the [database connection] D 4723** and S is not the last prepared statement in D, then 4724** [sqlite3_next_stmt(D, S)] routine shall return a pointer 4725** to the next prepared statement in D after S. 4726** 4727** {H13152} If S is the last [prepared statement] in the 4728** [database connection] D then the [sqlite3_next_stmt(D, S)] 4729** routine shall return a NULL pointer. 4730*/ 4731sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4732 4733/* 4734** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} 4735** 4736** The sqlite3_commit_hook() interface registers a callback 4737** function to be invoked whenever a transaction is committed. 4738** Any callback set by a previous call to sqlite3_commit_hook() 4739** for the same database connection is overridden. 4740** The sqlite3_rollback_hook() interface registers a callback 4741** function to be invoked whenever a transaction is committed. 4742** Any callback set by a previous call to sqlite3_commit_hook() 4743** for the same database connection is overridden. 4744** The pArg argument is passed through to the callback. 4745** If the callback on a commit hook function returns non-zero, 4746** then the commit is converted into a rollback. 4747** 4748** If another function was previously registered, its 4749** pArg value is returned. Otherwise NULL is returned. 4750** 4751** Registering a NULL function disables the callback. 4752** 4753** For the purposes of this API, a transaction is said to have been 4754** rolled back if an explicit "ROLLBACK" statement is executed, or 4755** an error or constraint causes an implicit rollback to occur. 4756** The rollback callback is not invoked if a transaction is 4757** automatically rolled back because the database connection is closed. 4758** The rollback callback is not invoked if a transaction is 4759** rolled back because a commit callback returned non-zero. 4760** <todo> Check on this </todo> 4761** 4762** INVARIANTS: 4763** 4764** {H12951} The [sqlite3_commit_hook(D,F,P)] interface registers the 4765** callback function F to be invoked with argument P whenever 4766** a transaction commits on the [database connection] D. 4767** 4768** {H12952} The [sqlite3_commit_hook(D,F,P)] interface returns the P argument 4769** from the previous call with the same [database connection] D, 4770** or NULL on the first call for a particular database connection D. 4771** 4772** {H12953} Each call to [sqlite3_commit_hook()] overwrites the callback 4773** registered by prior calls. 4774** 4775** {H12954} If the F argument to [sqlite3_commit_hook(D,F,P)] is NULL 4776** then the commit hook callback is canceled and no callback 4777** is invoked when a transaction commits. 4778** 4779** {H12955} If the commit callback returns non-zero then the commit is 4780** converted into a rollback. 4781** 4782** {H12961} The [sqlite3_rollback_hook(D,F,P)] interface registers the 4783** callback function F to be invoked with argument P whenever 4784** a transaction rolls back on the [database connection] D. 4785** 4786** {H12962} The [sqlite3_rollback_hook(D,F,P)] interface returns the P 4787** argument from the previous call with the same 4788** [database connection] D, or NULL on the first call 4789** for a particular database connection D. 4790** 4791** {H12963} Each call to [sqlite3_rollback_hook()] overwrites the callback 4792** registered by prior calls. 4793** 4794** {H12964} If the F argument to [sqlite3_rollback_hook(D,F,P)] is NULL 4795** then the rollback hook callback is canceled and no callback 4796** is invoked when a transaction rolls back. 4797*/ 4798void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4799void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4800 4801/* 4802** CAPI3REF: Data Change Notification Callbacks {H12970} 4803** 4804** The sqlite3_update_hook() interface registers a callback function 4805** with the [database connection] identified by the first argument 4806** to be invoked whenever a row is updated, inserted or deleted. 4807** Any callback set by a previous call to this function 4808** for the same database connection is overridden. 4809** 4810** The second argument is a pointer to the function to invoke when a 4811** row is updated, inserted or deleted. 4812** The first argument to the callback is a copy of the third argument 4813** to sqlite3_update_hook(). 4814** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4815** or [SQLITE_UPDATE], depending on the operation that caused the callback 4816** to be invoked. 4817** The third and fourth arguments to the callback contain pointers to the 4818** database and table name containing the affected row. 4819** The final callback parameter is the rowid of the row. In the case of 4820** an update, this is the rowid after the update takes place. 4821** 4822** The update hook is not invoked when internal system tables are 4823** modified (i.e. sqlite_master and sqlite_sequence). 4824** 4825** If another function was previously registered, its pArg value 4826** is returned. Otherwise NULL is returned. 4827** 4828** INVARIANTS: 4829** 4830** {H12971} The [sqlite3_update_hook(D,F,P)] interface causes the callback 4831** function F to be invoked with first parameter P whenever 4832** a table row is modified, inserted, or deleted on 4833** the [database connection] D. 4834** 4835** {H12973} The [sqlite3_update_hook(D,F,P)] interface returns the value 4836** of P for the previous call on the same [database connection] D, 4837** or NULL for the first call. 4838** 4839** {H12975} If the update hook callback F in [sqlite3_update_hook(D,F,P)] 4840** is NULL then the no update callbacks are made. 4841** 4842** {H12977} Each call to [sqlite3_update_hook(D,F,P)] overrides prior calls 4843** to the same interface on the same [database connection] D. 4844** 4845** {H12979} The update hook callback is not invoked when internal system 4846** tables such as sqlite_master and sqlite_sequence are modified. 4847** 4848** {H12981} The second parameter to the update callback 4849** is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 4850** depending on the operation that caused the callback to be invoked. 4851** 4852** {H12983} The third and fourth arguments to the callback contain pointers 4853** to zero-terminated UTF-8 strings which are the names of the 4854** database and table that is being updated. 4855 4856** {H12985} The final callback parameter is the rowid of the row after 4857** the change occurs. 4858*/ 4859void *sqlite3_update_hook( 4860 sqlite3*, 4861 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4862 void* 4863); 4864 4865/* 4866** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} 4867** KEYWORDS: {shared cache} {shared cache mode} 4868** 4869** This routine enables or disables the sharing of the database cache 4870** and schema data structures between [database connection | connections] 4871** to the same database. Sharing is enabled if the argument is true 4872** and disabled if the argument is false. 4873** 4874** Cache sharing is enabled and disabled for an entire process. {END} 4875** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4876** sharing was enabled or disabled for each thread separately. 4877** 4878** The cache sharing mode set by this interface effects all subsequent 4879** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4880** Existing database connections continue use the sharing mode 4881** that was in effect at the time they were opened. 4882** 4883** Virtual tables cannot be used with a shared cache. When shared 4884** cache is enabled, the [sqlite3_create_module()] API used to register 4885** virtual tables will always return an error. 4886** 4887** This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4888** successfully. An [error code] is returned otherwise. 4889** 4890** Shared cache is disabled by default. But this might change in 4891** future releases of SQLite. Applications that care about shared 4892** cache setting should set it explicitly. 4893** 4894** INVARIANTS: 4895** 4896** {H10331} A successful invocation of [sqlite3_enable_shared_cache(B)] 4897** will enable or disable shared cache mode for any subsequently 4898** created [database connection] in the same process. 4899** 4900** {H10336} When shared cache is enabled, the [sqlite3_create_module()] 4901** interface will always return an error. 4902** 4903** {H10337} The [sqlite3_enable_shared_cache(B)] interface returns 4904** [SQLITE_OK] if shared cache was enabled or disabled successfully. 4905** 4906** {H10339} Shared cache is disabled by default. 4907*/ 4908int sqlite3_enable_shared_cache(int); 4909 4910/* 4911** CAPI3REF: Attempt To Free Heap Memory {H17340} 4912** 4913** The sqlite3_release_memory() interface attempts to free N bytes 4914** of heap memory by deallocating non-essential memory allocations 4915** held by the database library. {END} Memory used to cache database 4916** pages to improve performance is an example of non-essential memory. 4917** sqlite3_release_memory() returns the number of bytes actually freed, 4918** which might be more or less than the amount requested. 4919** 4920** INVARIANTS: 4921** 4922** {H17341} The [sqlite3_release_memory(N)] interface attempts to 4923** free N bytes of heap memory by deallocating non-essential 4924** memory allocations held by the database library. 4925** 4926** {H16342} The [sqlite3_release_memory(N)] returns the number 4927** of bytes actually freed, which might be more or less 4928** than the amount requested. 4929*/ 4930int sqlite3_release_memory(int); 4931 4932/* 4933** CAPI3REF: Impose A Limit On Heap Size {H17350} 4934** 4935** The sqlite3_soft_heap_limit() interface places a "soft" limit 4936** on the amount of heap memory that may be allocated by SQLite. 4937** If an internal allocation is requested that would exceed the 4938** soft heap limit, [sqlite3_release_memory()] is invoked one or 4939** more times to free up some space before the allocation is performed. 4940** 4941** The limit is called "soft", because if [sqlite3_release_memory()] 4942** cannot free sufficient memory to prevent the limit from being exceeded, 4943** the memory is allocated anyway and the current operation proceeds. 4944** 4945** A negative or zero value for N means that there is no soft heap limit and 4946** [sqlite3_release_memory()] will only be called when memory is exhausted. 4947** The default value for the soft heap limit is zero. 4948** 4949** SQLite makes a best effort to honor the soft heap limit. 4950** But if the soft heap limit cannot be honored, execution will 4951** continue without error or notification. This is why the limit is 4952** called a "soft" limit. It is advisory only. 4953** 4954** Prior to SQLite version 3.5.0, this routine only constrained the memory 4955** allocated by a single thread - the same thread in which this routine 4956** runs. Beginning with SQLite version 3.5.0, the soft heap limit is 4957** applied to all threads. The value specified for the soft heap limit 4958** is an upper bound on the total memory allocation for all threads. In 4959** version 3.5.0 there is no mechanism for limiting the heap usage for 4960** individual threads. 4961** 4962** INVARIANTS: 4963** 4964** {H16351} The [sqlite3_soft_heap_limit(N)] interface places a soft limit 4965** of N bytes on the amount of heap memory that may be allocated 4966** using [sqlite3_malloc()] or [sqlite3_realloc()] at any point 4967** in time. 4968** 4969** {H16352} If a call to [sqlite3_malloc()] or [sqlite3_realloc()] would 4970** cause the total amount of allocated memory to exceed the 4971** soft heap limit, then [sqlite3_release_memory()] is invoked 4972** in an attempt to reduce the memory usage prior to proceeding 4973** with the memory allocation attempt. 4974** 4975** {H16353} Calls to [sqlite3_malloc()] or [sqlite3_realloc()] that trigger 4976** attempts to reduce memory usage through the soft heap limit 4977** mechanism continue even if the attempt to reduce memory 4978** usage is unsuccessful. 4979** 4980** {H16354} A negative or zero value for N in a call to 4981** [sqlite3_soft_heap_limit(N)] means that there is no soft 4982** heap limit and [sqlite3_release_memory()] will only be 4983** called when memory is completely exhausted. 4984** 4985** {H16355} The default value for the soft heap limit is zero. 4986** 4987** {H16358} Each call to [sqlite3_soft_heap_limit(N)] overrides the 4988** values set by all prior calls. 4989*/ 4990void sqlite3_soft_heap_limit(int); 4991 4992/* 4993** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} 4994** 4995** This routine returns metadata about a specific column of a specific 4996** database table accessible using the [database connection] handle 4997** passed as the first function argument. 4998** 4999** The column is identified by the second, third and fourth parameters to 5000** this function. The second parameter is either the name of the database 5001** (i.e. "main", "temp" or an attached database) containing the specified 5002** table or NULL. If it is NULL, then all attached databases are searched 5003** for the table using the same algorithm used by the database engine to 5004** resolve unqualified table references. 5005** 5006** The third and fourth parameters to this function are the table and column 5007** name of the desired column, respectively. Neither of these parameters 5008** may be NULL. 5009** 5010** Metadata is returned by writing to the memory locations passed as the 5th 5011** and subsequent parameters to this function. Any of these arguments may be 5012** NULL, in which case the corresponding element of metadata is omitted. 5013** 5014** <blockquote> 5015** <table border="1"> 5016** <tr><th> Parameter <th> Output<br>Type <th> Description 5017** 5018** <tr><td> 5th <td> const char* <td> Data type 5019** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5020** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5021** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5022** <tr><td> 9th <td> int <td> True if column is AUTOINCREMENT 5023** </table> 5024** </blockquote> 5025** 5026** The memory pointed to by the character pointers returned for the 5027** declaration type and collation sequence is valid only until the next 5028** call to any SQLite API function. 5029** 5030** If the specified table is actually a view, an [error code] is returned. 5031** 5032** If the specified column is "rowid", "oid" or "_rowid_" and an 5033** INTEGER PRIMARY KEY column has been explicitly declared, then the output 5034** parameters are set for the explicitly declared column. If there is no 5035** explicitly declared INTEGER PRIMARY KEY column, then the output 5036** parameters are set as follows: 5037** 5038** <pre> 5039** data type: "INTEGER" 5040** collation sequence: "BINARY" 5041** not null: 0 5042** primary key: 1 5043** auto increment: 0 5044** </pre> 5045** 5046** This function may load one or more schemas from database files. If an 5047** error occurs during this process, or if the requested table or column 5048** cannot be found, an [error code] is returned and an error message left 5049** in the [database connection] (to be retrieved using sqlite3_errmsg()). 5050** 5051** This API is only available if the library was compiled with the 5052** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 5053*/ 5054int sqlite3_table_column_metadata( 5055 sqlite3 *db, /* Connection handle */ 5056 const char *zDbName, /* Database name or NULL */ 5057 const char *zTableName, /* Table name */ 5058 const char *zColumnName, /* Column name */ 5059 char const **pzDataType, /* OUTPUT: Declared data type */ 5060 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5061 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5062 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5063 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5064); 5065 5066/* 5067** CAPI3REF: Load An Extension {H12600} 5068** 5069** This interface loads an SQLite extension library from the named file. 5070** 5071** {H12601} The sqlite3_load_extension() interface attempts to load an 5072** SQLite extension library contained in the file zFile. 5073** 5074** {H12602} The entry point is zProc. 5075** 5076** {H12603} zProc may be 0, in which case the name of the entry point 5077** defaults to "sqlite3_extension_init". 5078** 5079** {H12604} The sqlite3_load_extension() interface shall return 5080** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5081** 5082** {H12605} If an error occurs and pzErrMsg is not 0, then the 5083** [sqlite3_load_extension()] interface shall attempt to 5084** fill *pzErrMsg with error message text stored in memory 5085** obtained from [sqlite3_malloc()]. {END} The calling function 5086** should free this memory by calling [sqlite3_free()]. 5087** 5088** {H12606} Extension loading must be enabled using 5089** [sqlite3_enable_load_extension()] prior to calling this API, 5090** otherwise an error will be returned. 5091*/ 5092int sqlite3_load_extension( 5093 sqlite3 *db, /* Load the extension into this database connection */ 5094 const char *zFile, /* Name of the shared library containing extension */ 5095 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5096 char **pzErrMsg /* Put error message here if not 0 */ 5097); 5098 5099/* 5100** CAPI3REF: Enable Or Disable Extension Loading {H12620} 5101** 5102** So as not to open security holes in older applications that are 5103** unprepared to deal with extension loading, and as a means of disabling 5104** extension loading while evaluating user-entered SQL, the following API 5105** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5106** 5107** Extension loading is off by default. See ticket #1863. 5108** 5109** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1 5110** to turn extension loading on and call it with onoff==0 to turn 5111** it back off again. 5112** 5113** {H12622} Extension loading is off by default. 5114*/ 5115int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5116 5117/* 5118** CAPI3REF: Make Arrangements To Automatically Load An Extension {H12640} 5119** 5120** This API can be invoked at program startup in order to register 5121** one or more statically linked extensions that will be available 5122** to all new [database connections]. {END} 5123** 5124** This routine stores a pointer to the extension in an array that is 5125** obtained from [sqlite3_malloc()]. If you run a memory leak checker 5126** on your program and it reports a leak because of this array, invoke 5127** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory. 5128** 5129** {H12641} This function registers an extension entry point that is 5130** automatically invoked whenever a new [database connection] 5131** is opened using [sqlite3_open()], [sqlite3_open16()], 5132** or [sqlite3_open_v2()]. 5133** 5134** {H12642} Duplicate extensions are detected so calling this routine 5135** multiple times with the same extension is harmless. 5136** 5137** {H12643} This routine stores a pointer to the extension in an array 5138** that is obtained from [sqlite3_malloc()]. 5139** 5140** {H12644} Automatic extensions apply across all threads. 5141*/ 5142int sqlite3_auto_extension(void *xEntryPoint); 5143 5144/* 5145** CAPI3REF: Reset Automatic Extension Loading {H12660} 5146** 5147** This function disables all previously registered automatic 5148** extensions. {END} It undoes the effect of all prior 5149** [sqlite3_auto_extension()] calls. 5150** 5151** {H12661} This function disables all previously registered 5152** automatic extensions. 5153** 5154** {H12662} This function disables automatic extensions in all threads. 5155*/ 5156void sqlite3_reset_auto_extension(void); 5157 5158/* 5159****** EXPERIMENTAL - subject to change without notice ************** 5160** 5161** The interface to the virtual-table mechanism is currently considered 5162** to be experimental. The interface might change in incompatible ways. 5163** If this is a problem for you, do not use the interface at this time. 5164** 5165** When the virtual-table mechanism stabilizes, we will declare the 5166** interface fixed, support it indefinitely, and remove this comment. 5167*/ 5168 5169/* 5170** Structures used by the virtual table interface 5171*/ 5172typedef struct sqlite3_vtab sqlite3_vtab; 5173typedef struct sqlite3_index_info sqlite3_index_info; 5174typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5175typedef struct sqlite3_module sqlite3_module; 5176 5177/* 5178** CAPI3REF: Virtual Table Object {H18000} 5179** KEYWORDS: sqlite3_module 5180** 5181** A module is a class of virtual tables. Each module is defined 5182** by an instance of the following structure. This structure consists 5183** mostly of methods for the module. 5184** 5185** This interface is experimental and is subject to change or 5186** removal in future releases of SQLite. 5187*/ 5188struct sqlite3_module { 5189 int iVersion; 5190 int (*xCreate)(sqlite3*, void *pAux, 5191 int argc, const char *const*argv, 5192 sqlite3_vtab **ppVTab, char**); 5193 int (*xConnect)(sqlite3*, void *pAux, 5194 int argc, const char *const*argv, 5195 sqlite3_vtab **ppVTab, char**); 5196 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5197 int (*xDisconnect)(sqlite3_vtab *pVTab); 5198 int (*xDestroy)(sqlite3_vtab *pVTab); 5199 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5200 int (*xClose)(sqlite3_vtab_cursor*); 5201 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5202 int argc, sqlite3_value **argv); 5203 int (*xNext)(sqlite3_vtab_cursor*); 5204 int (*xEof)(sqlite3_vtab_cursor*); 5205 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5206 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5207 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5208 int (*xBegin)(sqlite3_vtab *pVTab); 5209 int (*xSync)(sqlite3_vtab *pVTab); 5210 int (*xCommit)(sqlite3_vtab *pVTab); 5211 int (*xRollback)(sqlite3_vtab *pVTab); 5212 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5213 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5214 void **ppArg); 5215 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5216}; 5217 5218/* 5219** CAPI3REF: Virtual Table Indexing Information {H18100} 5220** KEYWORDS: sqlite3_index_info 5221** 5222** The sqlite3_index_info structure and its substructures is used to 5223** pass information into and receive the reply from the xBestIndex 5224** method of an sqlite3_module. The fields under **Inputs** are the 5225** inputs to xBestIndex and are read-only. xBestIndex inserts its 5226** results into the **Outputs** fields. 5227** 5228** The aConstraint[] array records WHERE clause constraints of the form: 5229** 5230** <pre>column OP expr</pre> 5231** 5232** where OP is =, <, <=, >, or >=. The particular operator is 5233** stored in aConstraint[].op. The index of the column is stored in 5234** aConstraint[].iColumn. aConstraint[].usable is TRUE if the 5235** expr on the right-hand side can be evaluated (and thus the constraint 5236** is usable) and false if it cannot. 5237** 5238** The optimizer automatically inverts terms of the form "expr OP column" 5239** and makes other simplifications to the WHERE clause in an attempt to 5240** get as many WHERE clause terms into the form shown above as possible. 5241** The aConstraint[] array only reports WHERE clause terms in the correct 5242** form that refer to the particular virtual table being queried. 5243** 5244** Information about the ORDER BY clause is stored in aOrderBy[]. 5245** Each term of aOrderBy records a column of the ORDER BY clause. 5246** 5247** The xBestIndex method must fill aConstraintUsage[] with information 5248** about what parameters to pass to xFilter. If argvIndex>0 then 5249** the right-hand side of the corresponding aConstraint[] is evaluated 5250** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit 5251** is true, then the constraint is assumed to be fully handled by the 5252** virtual table and is not checked again by SQLite. 5253** 5254** The idxNum and idxPtr values are recorded and passed into xFilter. 5255** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true. 5256** 5257** The orderByConsumed means that output from xFilter will occur in 5258** the correct order to satisfy the ORDER BY clause so that no separate 5259** sorting step is required. 5260** 5261** The estimatedCost value is an estimate of the cost of doing the 5262** particular lookup. A full scan of a table with N entries should have 5263** a cost of N. A binary search of a table of N entries should have a 5264** cost of approximately log(N). 5265** 5266** This interface is experimental and is subject to change or 5267** removal in future releases of SQLite. 5268*/ 5269struct sqlite3_index_info { 5270 /* Inputs */ 5271 int nConstraint; /* Number of entries in aConstraint */ 5272 struct sqlite3_index_constraint { 5273 int iColumn; /* Column on left-hand side of constraint */ 5274 unsigned char op; /* Constraint operator */ 5275 unsigned char usable; /* True if this constraint is usable */ 5276 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5277 } *aConstraint; /* Table of WHERE clause constraints */ 5278 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5279 struct sqlite3_index_orderby { 5280 int iColumn; /* Column number */ 5281 unsigned char desc; /* True for DESC. False for ASC. */ 5282 } *aOrderBy; /* The ORDER BY clause */ 5283 /* Outputs */ 5284 struct sqlite3_index_constraint_usage { 5285 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5286 unsigned char omit; /* Do not code a test for this constraint */ 5287 } *aConstraintUsage; 5288 int idxNum; /* Number used to identify the index */ 5289 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5290 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5291 int orderByConsumed; /* True if output is already ordered */ 5292 double estimatedCost; /* Estimated cost of using this index */ 5293}; 5294#define SQLITE_INDEX_CONSTRAINT_EQ 2 5295#define SQLITE_INDEX_CONSTRAINT_GT 4 5296#define SQLITE_INDEX_CONSTRAINT_LE 8 5297#define SQLITE_INDEX_CONSTRAINT_LT 16 5298#define SQLITE_INDEX_CONSTRAINT_GE 32 5299#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5300 5301/* 5302** CAPI3REF: Register A Virtual Table Implementation {H18200} 5303** 5304** This routine is used to register a new module name with a 5305** [database connection]. Module names must be registered before 5306** creating new virtual tables on the module, or before using 5307** preexisting virtual tables of the module. 5308** 5309** This interface is experimental and is subject to change or 5310** removal in future releases of SQLite. 5311*/ 5312int sqlite3_create_module( 5313 sqlite3 *db, /* SQLite connection to register module with */ 5314 const char *zName, /* Name of the module */ 5315 const sqlite3_module *, /* Methods for the module */ 5316 void * /* Client data for xCreate/xConnect */ 5317); 5318 5319/* 5320** CAPI3REF: Register A Virtual Table Implementation {H18210} 5321** 5322** This routine is identical to the [sqlite3_create_module()] method above, 5323** except that it allows a destructor function to be specified. It is 5324** even more experimental than the rest of the virtual tables API. 5325*/ 5326int sqlite3_create_module_v2( 5327 sqlite3 *db, /* SQLite connection to register module with */ 5328 const char *zName, /* Name of the module */ 5329 const sqlite3_module *, /* Methods for the module */ 5330 void *, /* Client data for xCreate/xConnect */ 5331 void(*xDestroy)(void*) /* Module destructor function */ 5332); 5333 5334/* 5335** CAPI3REF: Virtual Table Instance Object {H18010} 5336** KEYWORDS: sqlite3_vtab 5337** 5338** Every module implementation uses a subclass of the following structure 5339** to describe a particular instance of the module. Each subclass will 5340** be tailored to the specific needs of the module implementation. 5341** The purpose of this superclass is to define certain fields that are 5342** common to all module implementations. 5343** 5344** Virtual tables methods can set an error message by assigning a 5345** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5346** take care that any prior string is freed by a call to [sqlite3_free()] 5347** prior to assigning a new string to zErrMsg. After the error message 5348** is delivered up to the client application, the string will be automatically 5349** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note 5350** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field 5351** since virtual tables are commonly implemented in loadable extensions which 5352** do not have access to sqlite3MPrintf() or sqlite3Free(). 5353** 5354** This interface is experimental and is subject to change or 5355** removal in future releases of SQLite. 5356*/ 5357struct sqlite3_vtab { 5358 const sqlite3_module *pModule; /* The module for this virtual table */ 5359 int nRef; /* Used internally */ 5360 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5361 /* Virtual table implementations will typically add additional fields */ 5362}; 5363 5364/* 5365** CAPI3REF: Virtual Table Cursor Object {H18020} 5366** KEYWORDS: sqlite3_vtab_cursor 5367** 5368** Every module implementation uses a subclass of the following structure 5369** to describe cursors that point into the virtual table and are used 5370** to loop through the virtual table. Cursors are created using the 5371** xOpen method of the module. Each module implementation will define 5372** the content of a cursor structure to suit its own needs. 5373** 5374** This superclass exists in order to define fields of the cursor that 5375** are common to all implementations. 5376** 5377** This interface is experimental and is subject to change or 5378** removal in future releases of SQLite. 5379*/ 5380struct sqlite3_vtab_cursor { 5381 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5382 /* Virtual table implementations will typically add additional fields */ 5383}; 5384 5385/* 5386** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} 5387** 5388** The xCreate and xConnect methods of a module use the following API 5389** to declare the format (the names and datatypes of the columns) of 5390** the virtual tables they implement. 5391** 5392** This interface is experimental and is subject to change or 5393** removal in future releases of SQLite. 5394*/ 5395int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable); 5396 5397/* 5398** CAPI3REF: Overload A Function For A Virtual Table {H18300} 5399** 5400** Virtual tables can provide alternative implementations of functions 5401** using the xFindFunction method. But global versions of those functions 5402** must exist in order to be overloaded. 5403** 5404** This API makes sure a global version of a function with a particular 5405** name and number of parameters exists. If no such function exists 5406** before this API is called, a new function is created. The implementation 5407** of the new function always causes an exception to be thrown. So 5408** the new function is not good for anything by itself. Its only 5409** purpose is to be a placeholder function that can be overloaded 5410** by virtual tables. 5411** 5412** This API should be considered part of the virtual table interface, 5413** which is experimental and subject to change. 5414*/ 5415int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5416 5417/* 5418** The interface to the virtual-table mechanism defined above (back up 5419** to a comment remarkably similar to this one) is currently considered 5420** to be experimental. The interface might change in incompatible ways. 5421** If this is a problem for you, do not use the interface at this time. 5422** 5423** When the virtual-table mechanism stabilizes, we will declare the 5424** interface fixed, support it indefinitely, and remove this comment. 5425** 5426****** EXPERIMENTAL - subject to change without notice ************** 5427*/ 5428 5429/* 5430** CAPI3REF: A Handle To An Open BLOB {H17800} 5431** KEYWORDS: {BLOB handle} {BLOB handles} 5432** 5433** An instance of this object represents an open BLOB on which 5434** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5435** Objects of this type are created by [sqlite3_blob_open()] 5436** and destroyed by [sqlite3_blob_close()]. 5437** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5438** can be used to read or write small subsections of the BLOB. 5439** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5440*/ 5441typedef struct sqlite3_blob sqlite3_blob; 5442 5443/* 5444** CAPI3REF: Open A BLOB For Incremental I/O {H17810} 5445** 5446** This interfaces opens a [BLOB handle | handle] to the BLOB located 5447** in row iRow, column zColumn, table zTable in database zDb; 5448** in other words, the same BLOB that would be selected by: 5449** 5450** <pre> 5451** SELECT zColumn FROM zDb.zTable WHERE rowid = iRow; 5452** </pre> {END} 5453** 5454** If the flags parameter is non-zero, the the BLOB is opened for read 5455** and write access. If it is zero, the BLOB is opened for read access. 5456** 5457** Note that the database name is not the filename that contains 5458** the database but rather the symbolic name of the database that 5459** is assigned when the database is connected using [ATTACH]. 5460** For the main database file, the database name is "main". 5461** For TEMP tables, the database name is "temp". 5462** 5463** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5464** to *ppBlob. Otherwise an [error code] is returned and any value written 5465** to *ppBlob should not be used by the caller. 5466** This function sets the [database connection] error code and message 5467** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()]. 5468** 5469** If the row that a BLOB handle points to is modified by an 5470** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5471** then the BLOB handle is marked as "expired". 5472** This is true if any column of the row is changed, even a column 5473** other than the one the BLOB handle is open on. 5474** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5475** a expired BLOB handle fail with an return code of [SQLITE_ABORT]. 5476** Changes written into a BLOB prior to the BLOB expiring are not 5477** rollback by the expiration of the BLOB. Such changes will eventually 5478** commit if the transaction continues to completion. 5479** 5480** INVARIANTS: 5481** 5482** {H17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)] 5483** interface shall open an [sqlite3_blob] object P on the BLOB 5484** in column C of the table T in the database B on 5485** the [database connection] D. 5486** 5487** {H17814} A successful invocation of [sqlite3_blob_open(D,...)] shall start 5488** a new transaction on the [database connection] D if that 5489** connection is not already in a transaction. 5490** 5491** {H17816} The [sqlite3_blob_open(D,B,T,C,R,F,P)] interface shall open 5492** the BLOB for read and write access if and only if the F 5493** parameter is non-zero. 5494** 5495** {H17819} The [sqlite3_blob_open()] interface shall return [SQLITE_OK] on 5496** success and an appropriate [error code] on failure. 5497** 5498** {H17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)] 5499** then subsequent calls to [sqlite3_errcode(D)], 5500** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return 5501** information appropriate for that error. 5502** 5503** {H17824} If any column in the row that a [sqlite3_blob] has open is 5504** changed by a separate [UPDATE] or [DELETE] statement or by 5505** an [ON CONFLICT] side effect, then the [sqlite3_blob] shall 5506** be marked as invalid. 5507*/ 5508int sqlite3_blob_open( 5509 sqlite3*, 5510 const char *zDb, 5511 const char *zTable, 5512 const char *zColumn, 5513 sqlite3_int64 iRow, 5514 int flags, 5515 sqlite3_blob **ppBlob 5516); 5517 5518/* 5519** CAPI3REF: Close A BLOB Handle {H17830} 5520** 5521** Closes an open [BLOB handle]. 5522** 5523** Closing a BLOB shall cause the current transaction to commit 5524** if there are no other BLOBs, no pending prepared statements, and the 5525** database connection is in [autocommit mode]. 5526** If any writes were made to the BLOB, they might be held in cache 5527** until the close operation if they will fit. {END} 5528** 5529** Closing the BLOB often forces the changes 5530** out to disk and so if any I/O errors occur, they will likely occur 5531** at the time when the BLOB is closed. {H17833} Any errors that occur during 5532** closing are reported as a non-zero return value. 5533** 5534** The BLOB is closed unconditionally. Even if this routine returns 5535** an error code, the BLOB is still closed. 5536** 5537** INVARIANTS: 5538** 5539** {H17833} The [sqlite3_blob_close(P)] interface closes an [sqlite3_blob] 5540** object P previously opened using [sqlite3_blob_open()]. 5541** 5542** {H17836} Closing an [sqlite3_blob] object using 5543** [sqlite3_blob_close()] shall cause the current transaction to 5544** commit if there are no other open [sqlite3_blob] objects 5545** or [prepared statements] on the same [database connection] and 5546** the database connection is in [autocommit mode]. 5547** 5548** {H17839} The [sqlite3_blob_close(P)] interfaces shall close the 5549** [sqlite3_blob] object P unconditionally, even if 5550** [sqlite3_blob_close(P)] returns something other than [SQLITE_OK]. 5551*/ 5552int sqlite3_blob_close(sqlite3_blob *); 5553 5554/* 5555** CAPI3REF: Return The Size Of An Open BLOB {H17840} 5556** 5557** Returns the size in bytes of the BLOB accessible via the open 5558** []BLOB handle] in its only argument. 5559** 5560** INVARIANTS: 5561** 5562** {H17843} The [sqlite3_blob_bytes(P)] interface returns the size 5563** in bytes of the BLOB that the [sqlite3_blob] object P 5564** refers to. 5565*/ 5566int sqlite3_blob_bytes(sqlite3_blob *); 5567 5568/* 5569** CAPI3REF: Read Data From A BLOB Incrementally {H17850} 5570** 5571** This function is used to read data from an open [BLOB handle] into a 5572** caller-supplied buffer. N bytes of data are copied into buffer Z 5573** from the open BLOB, starting at offset iOffset. 5574** 5575** If offset iOffset is less than N bytes from the end of the BLOB, 5576** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is 5577** less than zero, [SQLITE_ERROR] is returned and no data is read. 5578** 5579** An attempt to read from an expired [BLOB handle] fails with an 5580** error code of [SQLITE_ABORT]. 5581** 5582** On success, SQLITE_OK is returned. 5583** Otherwise, an [error code] or an [extended error code] is returned. 5584** 5585** INVARIANTS: 5586** 5587** {H17853} A successful invocation of [sqlite3_blob_read(P,Z,N,X)] 5588** shall reads N bytes of data out of the BLOB referenced by 5589** [BLOB handle] P beginning at offset X and store those bytes 5590** into buffer Z. 5591** 5592** {H17856} In [sqlite3_blob_read(P,Z,N,X)] if the size of the BLOB 5593** is less than N+X bytes, then the function shall leave the 5594** Z buffer unchanged and return [SQLITE_ERROR]. 5595** 5596** {H17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero 5597** then the function shall leave the Z buffer unchanged 5598** and return [SQLITE_ERROR]. 5599** 5600** {H17862} The [sqlite3_blob_read(P,Z,N,X)] interface shall return [SQLITE_OK] 5601** if N bytes are successfully read into buffer Z. 5602** 5603** {H17863} If the [BLOB handle] P is expired and X and N are within bounds 5604** then [sqlite3_blob_read(P,Z,N,X)] shall leave the Z buffer 5605** unchanged and return [SQLITE_ABORT]. 5606** 5607** {H17865} If the requested read could not be completed, 5608** the [sqlite3_blob_read(P,Z,N,X)] interface shall return an 5609** appropriate [error code] or [extended error code]. 5610** 5611** {H17868} If an error occurs during evaluation of [sqlite3_blob_read(P,...)] 5612** then subsequent calls to [sqlite3_errcode(D)], 5613** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return 5614** information appropriate for that error, where D is the 5615** [database connection] that was used to open the [BLOB handle] P. 5616*/ 5617int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5618 5619/* 5620** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} 5621** 5622** This function is used to write data into an open [BLOB handle] from a 5623** caller-supplied buffer. N bytes of data are copied from the buffer Z 5624** into the open BLOB, starting at offset iOffset. 5625** 5626** If the [BLOB handle] passed as the first argument was not opened for 5627** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5628** this function returns [SQLITE_READONLY]. 5629** 5630** This function may only modify the contents of the BLOB; it is 5631** not possible to increase the size of a BLOB using this API. 5632** If offset iOffset is less than N bytes from the end of the BLOB, 5633** [SQLITE_ERROR] is returned and no data is written. If N is 5634** less than zero [SQLITE_ERROR] is returned and no data is written. 5635** 5636** An attempt to write to an expired [BLOB handle] fails with an 5637** error code of [SQLITE_ABORT]. Writes to the BLOB that occurred 5638** before the [BLOB handle] expired are not rolled back by the 5639** expiration of the handle, though of course those changes might 5640** have been overwritten by the statement that expired the BLOB handle 5641** or by other independent statements. 5642** 5643** On success, SQLITE_OK is returned. 5644** Otherwise, an [error code] or an [extended error code] is returned. 5645** 5646** INVARIANTS: 5647** 5648** {H17873} A successful invocation of [sqlite3_blob_write(P,Z,N,X)] 5649** shall write N bytes of data from buffer Z into the BLOB 5650** referenced by [BLOB handle] P beginning at offset X into 5651** the BLOB. 5652** 5653** {H17874} In the absence of other overridding changes, the changes 5654** written to a BLOB by [sqlite3_blob_write()] shall 5655** remain in effect after the associated [BLOB handle] expires. 5656** 5657** {H17875} If the [BLOB handle] P was opened for reading only then 5658** an invocation of [sqlite3_blob_write(P,Z,N,X)] shall leave 5659** the referenced BLOB unchanged and return [SQLITE_READONLY]. 5660** 5661** {H17876} If the size of the BLOB referenced by [BLOB handle] P is 5662** less than N+X bytes then [sqlite3_blob_write(P,Z,N,X)] shall 5663** leave the BLOB unchanged and return [SQLITE_ERROR]. 5664** 5665** {H17877} If the [BLOB handle] P is expired and X and N are within bounds 5666** then [sqlite3_blob_read(P,Z,N,X)] shall leave the BLOB 5667** unchanged and return [SQLITE_ABORT]. 5668** 5669** {H17879} If X or N are less than zero then [sqlite3_blob_write(P,Z,N,X)] 5670** shall leave the BLOB referenced by [BLOB handle] P unchanged 5671** and return [SQLITE_ERROR]. 5672** 5673** {H17882} The [sqlite3_blob_write(P,Z,N,X)] interface shall return 5674** [SQLITE_OK] if N bytes where successfully written into the BLOB. 5675** 5676** {H17885} If the requested write could not be completed, 5677** the [sqlite3_blob_write(P,Z,N,X)] interface shall return an 5678** appropriate [error code] or [extended error code]. 5679** 5680** {H17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)] 5681** then subsequent calls to [sqlite3_errcode(D)], 5682** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return 5683** information appropriate for that error. 5684*/ 5685int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5686 5687/* 5688** CAPI3REF: Virtual File System Objects {H11200} 5689** 5690** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5691** that SQLite uses to interact 5692** with the underlying operating system. Most SQLite builds come with a 5693** single default VFS that is appropriate for the host computer. 5694** New VFSes can be registered and existing VFSes can be unregistered. 5695** The following interfaces are provided. 5696** 5697** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5698** Names are case sensitive. 5699** Names are zero-terminated UTF-8 strings. 5700** If there is no match, a NULL pointer is returned. 5701** If zVfsName is NULL then the default VFS is returned. 5702** 5703** New VFSes are registered with sqlite3_vfs_register(). 5704** Each new VFS becomes the default VFS if the makeDflt flag is set. 5705** The same VFS can be registered multiple times without injury. 5706** To make an existing VFS into the default VFS, register it again 5707** with the makeDflt flag set. If two different VFSes with the 5708** same name are registered, the behavior is undefined. If a 5709** VFS is registered with a name that is NULL or an empty string, 5710** then the behavior is undefined. 5711** 5712** Unregister a VFS with the sqlite3_vfs_unregister() interface. 5713** If the default VFS is unregistered, another VFS is chosen as 5714** the default. The choice for the new VFS is arbitrary. 5715** 5716** INVARIANTS: 5717** 5718** {H11203} The [sqlite3_vfs_find(N)] interface returns a pointer to the 5719** registered [sqlite3_vfs] object whose name exactly matches 5720** the zero-terminated UTF-8 string N, or it returns NULL if 5721** there is no match. 5722** 5723** {H11206} If the N parameter to [sqlite3_vfs_find(N)] is NULL then 5724** the function returns a pointer to the default [sqlite3_vfs] 5725** object if there is one, or NULL if there is no default 5726** [sqlite3_vfs] object. 5727** 5728** {H11209} The [sqlite3_vfs_register(P,F)] interface registers the 5729** well-formed [sqlite3_vfs] object P using the name given 5730** by the zName field of the object. 5731** 5732** {H11212} Using the [sqlite3_vfs_register(P,F)] interface to register 5733** the same [sqlite3_vfs] object multiple times is a harmless no-op. 5734** 5735** {H11215} The [sqlite3_vfs_register(P,F)] interface makes the [sqlite3_vfs] 5736** object P the default [sqlite3_vfs] object if F is non-zero. 5737** 5738** {H11218} The [sqlite3_vfs_unregister(P)] interface unregisters the 5739** [sqlite3_vfs] object P so that it is no longer returned by 5740** subsequent calls to [sqlite3_vfs_find()]. 5741*/ 5742sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5743int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5744int sqlite3_vfs_unregister(sqlite3_vfs*); 5745 5746/* 5747** CAPI3REF: Mutexes {H17000} 5748** 5749** The SQLite core uses these routines for thread 5750** synchronization. Though they are intended for internal 5751** use by SQLite, code that links against SQLite is 5752** permitted to use any of these routines. 5753** 5754** The SQLite source code contains multiple implementations 5755** of these mutex routines. An appropriate implementation 5756** is selected automatically at compile-time. The following 5757** implementations are available in the SQLite core: 5758** 5759** <ul> 5760** <li> SQLITE_MUTEX_OS2 5761** <li> SQLITE_MUTEX_PTHREAD 5762** <li> SQLITE_MUTEX_W32 5763** <li> SQLITE_MUTEX_NOOP 5764** </ul> 5765** 5766** The SQLITE_MUTEX_NOOP implementation is a set of routines 5767** that does no real locking and is appropriate for use in 5768** a single-threaded application. The SQLITE_MUTEX_OS2, 5769** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 5770** are appropriate for use on OS/2, Unix, and Windows. 5771** 5772** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5773** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5774** implementation is included with the library. In this case the 5775** application must supply a custom mutex implementation using the 5776** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5777** before calling sqlite3_initialize() or any other public sqlite3_ 5778** function that calls sqlite3_initialize(). 5779** 5780** {H17011} The sqlite3_mutex_alloc() routine allocates a new 5781** mutex and returns a pointer to it. {H17012} If it returns NULL 5782** that means that a mutex could not be allocated. {H17013} SQLite 5783** will unwind its stack and return an error. {H17014} The argument 5784** to sqlite3_mutex_alloc() is one of these integer constants: 5785** 5786** <ul> 5787** <li> SQLITE_MUTEX_FAST 5788** <li> SQLITE_MUTEX_RECURSIVE 5789** <li> SQLITE_MUTEX_STATIC_MASTER 5790** <li> SQLITE_MUTEX_STATIC_MEM 5791** <li> SQLITE_MUTEX_STATIC_MEM2 5792** <li> SQLITE_MUTEX_STATIC_PRNG 5793** <li> SQLITE_MUTEX_STATIC_LRU 5794** <li> SQLITE_MUTEX_STATIC_LRU2 5795** </ul> 5796** 5797** {H17015} The first two constants cause sqlite3_mutex_alloc() to create 5798** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5799** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} 5800** The mutex implementation does not need to make a distinction 5801** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5802** not want to. {H17016} But SQLite will only request a recursive mutex in 5803** cases where it really needs one. {END} If a faster non-recursive mutex 5804** implementation is available on the host platform, the mutex subsystem 5805** might return such a mutex in response to SQLITE_MUTEX_FAST. 5806** 5807** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return 5808** a pointer to a static preexisting mutex. {END} Four static mutexes are 5809** used by the current version of SQLite. Future versions of SQLite 5810** may add additional static mutexes. Static mutexes are for internal 5811** use by SQLite only. Applications that use SQLite mutexes should 5812** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5813** SQLITE_MUTEX_RECURSIVE. 5814** 5815** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5816** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5817** returns a different mutex on every call. {H17034} But for the static 5818** mutex types, the same mutex is returned on every call that has 5819** the same type number. 5820** 5821** {H17019} The sqlite3_mutex_free() routine deallocates a previously 5822** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every 5823** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in 5824** use when they are deallocated. {A17022} Attempting to deallocate a static 5825** mutex results in undefined behavior. {H17023} SQLite never deallocates 5826** a static mutex. {END} 5827** 5828** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5829** to enter a mutex. {H17024} If another thread is already within the mutex, 5830** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5831** SQLITE_BUSY. {H17025} The sqlite3_mutex_try() interface returns [SQLITE_OK] 5832** upon successful entry. {H17026} Mutexes created using 5833** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5834** {H17027} In such cases the, 5835** mutex must be exited an equal number of times before another thread 5836** can enter. {A17028} If the same thread tries to enter any other 5837** kind of mutex more than once, the behavior is undefined. 5838** {H17029} SQLite will never exhibit 5839** such behavior in its own use of mutexes. 5840** 5841** Some systems (for example, Windows 95) do not support the operation 5842** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5843** will always return SQLITE_BUSY. {H17030} The SQLite core only ever uses 5844** sqlite3_mutex_try() as an optimization so this is acceptable behavior. 5845** 5846** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was 5847** previously entered by the same thread. {A17032} The behavior 5848** is undefined if the mutex is not currently entered by the 5849** calling thread or is not currently allocated. {H17033} SQLite will 5850** never do either. {END} 5851** 5852** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5853** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5854** behave as no-ops. 5855** 5856** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5857*/ 5858sqlite3_mutex *sqlite3_mutex_alloc(int); 5859void sqlite3_mutex_free(sqlite3_mutex*); 5860void sqlite3_mutex_enter(sqlite3_mutex*); 5861int sqlite3_mutex_try(sqlite3_mutex*); 5862void sqlite3_mutex_leave(sqlite3_mutex*); 5863 5864/* 5865** CAPI3REF: Mutex Methods Object {H17120} 5866** 5867** An instance of this structure defines the low-level routines 5868** used to allocate and use mutexes. 5869** 5870** Usually, the default mutex implementations provided by SQLite are 5871** sufficient, however the user has the option of substituting a custom 5872** implementation for specialized deployments or systems for which SQLite 5873** does not provide a suitable implementation. In this case, the user 5874** creates and populates an instance of this structure to pass 5875** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5876** Additionally, an instance of this structure can be used as an 5877** output variable when querying the system for the current mutex 5878** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5879** 5880** The xMutexInit method defined by this structure is invoked as 5881** part of system initialization by the sqlite3_initialize() function. 5882** {H17001} The xMutexInit routine shall be called by SQLite once for each 5883** effective call to [sqlite3_initialize()]. 5884** 5885** The xMutexEnd method defined by this structure is invoked as 5886** part of system shutdown by the sqlite3_shutdown() function. The 5887** implementation of this method is expected to release all outstanding 5888** resources obtained by the mutex methods implementation, especially 5889** those obtained by the xMutexInit method. {H17003} The xMutexEnd() 5890** interface shall be invoked once for each call to [sqlite3_shutdown()]. 5891** 5892** The remaining seven methods defined by this structure (xMutexAlloc, 5893** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5894** xMutexNotheld) implement the following interfaces (respectively): 5895** 5896** <ul> 5897** <li> [sqlite3_mutex_alloc()] </li> 5898** <li> [sqlite3_mutex_free()] </li> 5899** <li> [sqlite3_mutex_enter()] </li> 5900** <li> [sqlite3_mutex_try()] </li> 5901** <li> [sqlite3_mutex_leave()] </li> 5902** <li> [sqlite3_mutex_held()] </li> 5903** <li> [sqlite3_mutex_notheld()] </li> 5904** </ul> 5905** 5906** The only difference is that the public sqlite3_XXX functions enumerated 5907** above silently ignore any invocations that pass a NULL pointer instead 5908** of a valid mutex handle. The implementations of the methods defined 5909** by this structure are not required to handle this case, the results 5910** of passing a NULL pointer instead of a valid mutex handle are undefined 5911** (i.e. it is acceptable to provide an implementation that segfaults if 5912** it is passed a NULL pointer). 5913*/ 5914typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5915struct sqlite3_mutex_methods { 5916 int (*xMutexInit)(void); 5917 int (*xMutexEnd)(void); 5918 sqlite3_mutex *(*xMutexAlloc)(int); 5919 void (*xMutexFree)(sqlite3_mutex *); 5920 void (*xMutexEnter)(sqlite3_mutex *); 5921 int (*xMutexTry)(sqlite3_mutex *); 5922 void (*xMutexLeave)(sqlite3_mutex *); 5923 int (*xMutexHeld)(sqlite3_mutex *); 5924 int (*xMutexNotheld)(sqlite3_mutex *); 5925}; 5926 5927/* 5928** CAPI3REF: Mutex Verification Routines {H17080} 5929** 5930** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5931** are intended for use inside assert() statements. {H17081} The SQLite core 5932** never uses these routines except inside an assert() and applications 5933** are advised to follow the lead of the core. {H17082} The core only 5934** provides implementations for these routines when it is compiled 5935** with the SQLITE_DEBUG flag. {A17087} External mutex implementations 5936** are only required to provide these routines if SQLITE_DEBUG is 5937** defined and if NDEBUG is not defined. 5938** 5939** {H17083} These routines should return true if the mutex in their argument 5940** is held or not held, respectively, by the calling thread. 5941** 5942** {X17084} The implementation is not required to provided versions of these 5943** routines that actually work. If the implementation does not provide working 5944** versions of these routines, it should at least provide stubs that always 5945** return true so that one does not get spurious assertion failures. 5946** 5947** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then 5948** the routine should return 1. {END} This seems counter-intuitive since 5949** clearly the mutex cannot be held if it does not exist. But the 5950** the reason the mutex does not exist is because the build is not 5951** using mutexes. And we do not want the assert() containing the 5952** call to sqlite3_mutex_held() to fail, so a non-zero return is 5953** the appropriate thing to do. {H17086} The sqlite3_mutex_notheld() 5954** interface should also return 1 when given a NULL pointer. 5955*/ 5956int sqlite3_mutex_held(sqlite3_mutex*); 5957int sqlite3_mutex_notheld(sqlite3_mutex*); 5958 5959/* 5960** CAPI3REF: Mutex Types {H17001} 5961** 5962** {H17002} The [sqlite3_mutex_alloc()] interface takes a single argument 5963** which is one of these integer constants. 5964*/ 5965#define SQLITE_MUTEX_FAST 0 5966#define SQLITE_MUTEX_RECURSIVE 1 5967#define SQLITE_MUTEX_STATIC_MASTER 2 5968#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5969#define SQLITE_MUTEX_STATIC_MEM2 4 /* sqlite3_release_memory() */ 5970#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5971#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5972#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ 5973 5974/* 5975** CAPI3REF: Low-Level Control Of Database Files {H11300} 5976** 5977** {H11301} The [sqlite3_file_control()] interface makes a direct call to the 5978** xFileControl method for the [sqlite3_io_methods] object associated 5979** with a particular database identified by the second argument. {H11302} The 5980** name of the database is the name assigned to the database by the 5981** <a href="lang_attach.html">ATTACH</a> SQL command that opened the 5982** database. {H11303} To control the main database file, use the name "main" 5983** or a NULL pointer. {H11304} The third and fourth parameters to this routine 5984** are passed directly through to the second and third parameters of 5985** the xFileControl method. {H11305} The return value of the xFileControl 5986** method becomes the return value of this routine. 5987** 5988** {H11306} If the second parameter (zDbName) does not match the name of any 5989** open database file, then SQLITE_ERROR is returned. {H11307} This error 5990** code is not remembered and will not be recalled by [sqlite3_errcode()] 5991** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might 5992** also return SQLITE_ERROR. {A11309} There is no way to distinguish between 5993** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5994** xFileControl method. {END} 5995** 5996** See also: [SQLITE_FCNTL_LOCKSTATE] 5997*/ 5998int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5999 6000/* 6001** CAPI3REF: Testing Interface {H11400} 6002** 6003** The sqlite3_test_control() interface is used to read out internal 6004** state of SQLite and to inject faults into SQLite for testing 6005** purposes. The first parameter is an operation code that determines 6006** the number, meaning, and operation of all subsequent parameters. 6007** 6008** This interface is not for use by applications. It exists solely 6009** for verifying the correct operation of the SQLite library. Depending 6010** on how the SQLite library is compiled, this interface might not exist. 6011** 6012** The details of the operation codes, their meanings, the parameters 6013** they take, and what they do are all subject to change without notice. 6014** Unlike most of the SQLite API, this function is not guaranteed to 6015** operate consistently from one release to the next. 6016*/ 6017int sqlite3_test_control(int op, ...); 6018 6019/* 6020** CAPI3REF: Testing Interface Operation Codes {H11410} 6021** 6022** These constants are the valid operation code parameters used 6023** as the first argument to [sqlite3_test_control()]. 6024** 6025** These parameters and their meanings are subject to change 6026** without notice. These values are for testing purposes only. 6027** Applications should not use any of these parameters or the 6028** [sqlite3_test_control()] interface. 6029*/ 6030#define SQLITE_TESTCTRL_PRNG_SAVE 5 6031#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6032#define SQLITE_TESTCTRL_PRNG_RESET 7 6033#define SQLITE_TESTCTRL_BITVEC_TEST 8 6034#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6035#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6036 6037/* 6038** CAPI3REF: SQLite Runtime Status {H17200} 6039** 6040** This interface is used to retrieve runtime status information 6041** about the preformance of SQLite, and optionally to reset various 6042** highwater marks. The first argument is an integer code for 6043** the specific parameter to measure. Recognized integer codes 6044** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...]. 6045** The current value of the parameter is returned into *pCurrent. 6046** The highest recorded value is returned in *pHighwater. If the 6047** resetFlag is true, then the highest record value is reset after 6048** *pHighwater is written. Some parameters do not record the highest 6049** value. For those parameters 6050** nothing is written into *pHighwater and the resetFlag is ignored. 6051** Other parameters record only the highwater mark and not the current 6052** value. For these latter parameters nothing is written into *pCurrent. 6053** 6054** This routine returns SQLITE_OK on success and a non-zero 6055** [error code] on failure. 6056** 6057** This routine is threadsafe but is not atomic. This routine can 6058** called while other threads are running the same or different SQLite 6059** interfaces. However the values returned in *pCurrent and 6060** *pHighwater reflect the status of SQLite at different points in time 6061** and it is possible that another thread might change the parameter 6062** in between the times when *pCurrent and *pHighwater are written. 6063** 6064** This interface is experimental and is subject to change or 6065** removal in future releases of SQLite. 6066*/ 6067int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6068 6069/* 6070** CAPI3REF: Status Parameters {H17250} 6071** 6072** These integer constants designate various run-time status parameters 6073** that can be returned by [sqlite3_status()]. 6074** 6075** <dl> 6076** <dt>SQLITE_STATUS_MEMORY_USED</dt> 6077** <dd>This parameter is the current amount of memory checked out 6078** using [sqlite3_malloc()], either directly or indirectly. The 6079** figure includes calls made to [sqlite3_malloc()] by the application 6080** and internal memory usage by the SQLite library. Scratch memory 6081** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6082** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6083** this parameter. The amount returned is the sum of the allocation 6084** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd> 6085** 6086** <dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6087** <dd>This parameter returns the number of pages used out of the 6088** page cache buffer configured using [SQLITE_CONFIG_PAGECACHE]. The 6089** value returned is in pages, not in bytes.</dd> 6090** 6091** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6092** <dd>This parameter returns the number of bytes of page cache 6093** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE] 6094** buffer and where forced to overflow to [sqlite3_malloc()].</dd> 6095** 6096** <dt>SQLITE_STATUS_SCRATCH_USED</dt> 6097** <dd>This parameter returns the number of allocations used out of the 6098** scratch allocation lookaside buffer configured using 6099** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6100** in bytes. Since a single thread may only have one allocation 6101** outstanding at time, this parameter also reports the number of threads 6102** using scratch memory at the same time.</dd> 6103** 6104** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6105** <dd>This parameter returns the number of bytes of scratch memory 6106** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH] 6107** buffer and where forced to overflow to [sqlite3_malloc()].</dd> 6108** 6109** <dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6110** <dd>This parameter records the largest memory allocation request 6111** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6112** internal equivalents). The value of interest is return in the 6113** *pHighwater parameter to [sqlite3_status()]. The value written 6114** into the *pCurrent parameter is undefined.</dd> 6115** </dl> 6116** 6117** New status parameters may be added from time to time. 6118*/ 6119#define SQLITE_STATUS_MEMORY_USED 0 6120#define SQLITE_STATUS_PAGECACHE_USED 1 6121#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6122#define SQLITE_STATUS_SCRATCH_USED 3 6123#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6124#define SQLITE_STATUS_MALLOC_SIZE 5 6125 6126 6127/* 6128** Undo the hack that converts floating point types to integer for 6129** builds on processors without floating point support. 6130*/ 6131#ifdef SQLITE_OMIT_FLOATING_POINT 6132# undef double 6133#endif 6134 6135#ifdef __cplusplus 6136} /* End of the 'extern "C"' block */ 6137#endif 6138#endif 6139