src/legacy.c

   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 ** Main file for the SQLite library.  The routines in this file
  13 ** implement the programmer interface to the library.  Routines in
  14 ** other files are for internal use by SQLite and should not be
  15 ** accessed by users of the library.
  16 */
  17
  18 #include "sqliteInt.h"
  19
  20 /*
  21 ** Execute SQL code.  Return one of the SQLITE_ success/failure
  22 ** codes.  Also write an error message into memory obtained from
  23 ** malloc() and make *pzErrMsg point to that message.
  24 **
  25 ** If the SQL is a query, then for each row in the query result
  26 ** the xCallback() function is called.  pArg becomes the first
  27 ** argument to xCallback().  If xCallback=NULL then no callback
  28 ** is invoked, even for queries.
  29 */
  30 int sqlite3_exec(
  31   sqlite3 *db,                /* The database on which the SQL executes */
  32   const char *zSql,           /* The SQL to be executed */
  33   sqlite3_callback xCallback, /* Invoke this callback routine */
  34   void *pArg,                 /* First argument to xCallback() */
  35   char **pzErrMsg             /* Write error messages here */
  36 ){
  37   int rc = SQLITE_OK;         /* Return code */
  38   const char *zLeftover;      /* Tail of unprocessed SQL */
  39   sqlite3_stmt *pStmt = 0;    /* The current SQL statement */
  40   char **azCols = 0;          /* Names of result columns */
  41   int callbackIsInit;         /* True if callback data is initialized */
  42
  43   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
  44   if( zSql==0 ) zSql = "";
  45
  46   sqlite3_mutex_enter(db->mutex);
  47   sqlite3Error(db, SQLITE_OK);
  48   while( rc==SQLITE_OK && zSql[0] ){
  49     int nCol = 0;
  50     char **azVals = 0;
  51
  52     pStmt = 0;
  53     rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
  54     assert( rc==SQLITE_OK || pStmt==0 );
  55     if( rc!=SQLITE_OK ){
  56       continue;
  57     }
  58     if( !pStmt ){
  59       /* this happens for a comment or white-space */
  60       zSql = zLeftover;
  61       continue;
  62     }
  63     callbackIsInit = 0;
  64
  65     while( 1 ){
  66       int i;
  67       rc = sqlite3_step(pStmt);
  68
  69       /* Invoke the callback function if required */
  70       if( xCallback && (SQLITE_ROW==rc ||
  71           (SQLITE_DONE==rc && !callbackIsInit
  72                            && db->flags&SQLITE_NullCallback)) ){
  73         if( !callbackIsInit ){
  74           nCol = sqlite3_column_count(pStmt);
  75           azCols = sqlite3DbMallocRaw(db, (2*nCol+1)*sizeof(const char*));
  76           if( azCols==0 ){
  77             goto exec_out;
  78           }
  79           for(i=0; i<nCol; i++){
  80             azCols[i] = (char *)sqlite3_column_name(pStmt, i);
  81             /* sqlite3VdbeSetColName() installs column names as UTF8
  82             ** strings so there is no way for sqlite3_column_name() to fail. */
  83             assert( azCols[i]!=0 );
  84           }
  85           callbackIsInit = 1;
  86         }
  87         if( rc==SQLITE_ROW ){
  88           azVals = &azCols[nCol];
  89           for(i=0; i<nCol; i++){
  90             azVals[i] = (char *)sqlite3_column_text(pStmt, i);
  91             if( !azVals[i] && sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
  92               sqlite3OomFault(db);
  93               goto exec_out;
  94             }
  95           }
  96           azVals[i] = 0;
  97         }
  98         if( xCallback(pArg, nCol, azVals, azCols) ){
  99           /* EVIDENCE-OF: R-38229-40159 If the callback function to
 100           ** sqlite3_exec() returns non-zero, then sqlite3_exec() will
 101           ** return SQLITE_ABORT. */
 102           rc = SQLITE_ABORT;
 103           sqlite3VdbeFinalize((Vdbe *)pStmt);
 104           pStmt = 0;
 105           sqlite3Error(db, SQLITE_ABORT);
 106           goto exec_out;
 107         }
 108       }
 109
 110       if( rc!=SQLITE_ROW ){
 111         rc = sqlite3VdbeFinalize((Vdbe *)pStmt);
 112         pStmt = 0;
 113         zSql = zLeftover;
 114         while( sqlite3Isspace(zSql[0]) ) zSql++;
 115         break;
 116       }
 117     }
 118
 119     sqlite3DbFree(db, azCols);
 120     azCols = 0;
 121   }
 122
 123 exec_out:
 124   if( pStmt ) sqlite3VdbeFinalize((Vdbe *)pStmt);
 125   sqlite3DbFree(db, azCols);
 126
 127   rc = sqlite3ApiExit(db, rc);
 128   if( rc!=SQLITE_OK && pzErrMsg ){
 129     *pzErrMsg = sqlite3DbStrDup(0, sqlite3_errmsg(db));
 130     if( *pzErrMsg==0 ){
 131       rc = SQLITE_NOMEM_BKPT;
 132       sqlite3Error(db, SQLITE_NOMEM);
 133     }
 134   }else if( pzErrMsg ){
 135     *pzErrMsg = 0;
 136   }
 137
 138   assert( (rc&db->errMask)==rc );
 139   sqlite3_mutex_leave(db->mutex);
 140   return rc;
 141 }