SQLite

Check-in [9c19b7ae35]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Update the sqlite3_stmt_readonly() interface so that its output is well-defined for all prepared statements, and so that it gives the correct result for VACUUM.
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 9c19b7ae3542fd1fac692b4471f1839b22685c76
User & Date: drh 2010-12-08 18:30:20.000
Context
2010-12-09
18:55
Mention the SQLITE_DEFAULT_WAL_AUTOCHECKPOINT compile-time option in the documentation for the sqlite3_wal_autocheckpoint() interface. (check-in: 5a52dd59ff user: drh tags: trunk)
2010-12-08
18:30
Update the sqlite3_stmt_readonly() interface so that its output is well-defined for all prepared statements, and so that it gives the correct result for VACUUM. (check-in: 9c19b7ae35 user: drh tags: trunk)
03:28
The command-line shell ignore errors in sqlite3_close() when shutting down. (check-in: 925332c3d7 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/sqlite.h.in.
︙︙
2646
2647
2648
2649
2650
2651
2652
2653
2654









2655


2656
2657


2658




2659
2660


2661
2662
2663
2664
2665
2666
2667

** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
*/
const char *sqlite3_sql(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Determine If An SQL Statement Writes The Database
**
** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
** the [prepared statement] X is [SELECT] statement and false (zero) if









** X is an [INSERT], [UPDATE], [DELETE], CREATE, DROP, [ANALYZE],


** [ALTER], or [REINDEX] statement.
** If X is a NULL pointer or any other kind of statement, including but


** not limited to [ATTACH], [DETACH], [COMMIT], [ROLLBACK], [RELEASE],




** [SAVEPOINT], [PRAGMA], or [VACUUM] the result of sqlite3_stmt_readonly(X) is
** undefined.


*/
int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Dynamically Typed Value Object
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
**








|
|
>
>
>
>
>
>
>
>
>
|
>
>
|
<
>
>
|
>
>
>
>
|
<
>
>








2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667

2668
2669
2670
2671
2672
2673
2674
2675

2676
2677
2678
2679
2680
2681
2682
2683
2684

** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
*/
const char *sqlite3_sql(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Determine If An SQL Statement Writes The Database
**
** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 
** and only if the [prepared statement] X is makes no direct changes to
** the content of the database file.
**
** Note that [application-defined SQL functions] or
** [virtual tables] might change the database indirectly as a side effect.  
** ^(For example, if an application defines a function "eval()" that 
** calls [sqlite3_exec()], then the following SQL statement would
** change the database file through side-effects:
**
** <blockquote><pre>
**    SELECT eval('DELETE FROM t1') FROM t2;
** </pre></blockquote>
**
** But because the [SELECT] statement does not change the database file

** directly, sqlite3_stmt_readonly() would still return true.)^
**
** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
** since the statements themselves do not actually modify the database but
** rather they control the timing of when other statements modify the 
** database.  ^The [ATTACH] and [DETACH] statements also cause
** sqlite3_stmt_readonly() to return true since, while those statements

** change the configuration of a database connection, they do not make 
** changes to the content of the database files on disk.
*/
int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Dynamically Typed Value Object
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
**
︙︙
Changes to src/vdbeaux.c.
︙︙
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418

  p->readOnly = 1;
  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
    u8 opcode = pOp->opcode;

    pOp->opflags = sqlite3OpcodeProperty[opcode];
    if( opcode==OP_Function || opcode==OP_AggStep ){
      if( pOp->p5>nMaxArgs ) nMaxArgs = pOp->p5;
    }else if( opcode==OP_Transaction && pOp->p2!=0 ){
      p->readOnly = 0;
#ifndef SQLITE_OMIT_VIRTUALTABLE
    }else if( opcode==OP_VUpdate ){
      if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
    }else if( opcode==OP_VFilter ){
      int n;
      assert( p->nOp - i >= 3 );








|








404
405
406
407
408
409
410
411
412
413
414
415
416
417
418

  p->readOnly = 1;
  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
    u8 opcode = pOp->opcode;

    pOp->opflags = sqlite3OpcodeProperty[opcode];
    if( opcode==OP_Function || opcode==OP_AggStep ){
      if( pOp->p5>nMaxArgs ) nMaxArgs = pOp->p5;
    }else if( (opcode==OP_Transaction && pOp->p2!=0) || opcode==OP_Vacuum ){
      p->readOnly = 0;
#ifndef SQLITE_OMIT_VIRTUALTABLE
    }else if( opcode==OP_VUpdate ){
      if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
    }else if( opcode==OP_VFilter ){
      int n;
      assert( p->nOp - i >= 3 );
︙︙