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;
  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
  64     callbackIsInit = 0;
  65     nCol = sqlite3_column_count(pStmt);
  66
  67     while( 1 ){
  68       int i;
  69       rc = sqlite3_step(pStmt);
  70
  71       /* Invoke the callback function if required */
  72       if( xCallback && (SQLITE_ROW==rc ||
  73           (SQLITE_DONE==rc && !callbackIsInit
  74                            && db->flags&SQLITE_NullCallback)) ){
  75         if( !callbackIsInit ){
  76           azCols = sqlite3DbMallocRaw(db, (2*nCol+1)*sizeof(const char*));
  77           if( azCols==0 ){
  78             goto exec_out;
  79           }
  80           for(i=0; i<nCol; i++){
  81             azCols[i] = (char *)sqlite3_column_name(pStmt, i);
  82             /* sqlite3VdbeSetColName() installs column names as UTF8
  83             ** strings so there is no way for sqlite3_column_name() to fail. */
  84             assert( azCols[i]!=0 );
  85           }
  86           callbackIsInit = 1;
  87         }
  88         if( rc==SQLITE_ROW ){
  89           azVals = &azCols[nCol];
  90           for(i=0; i<nCol; i++){
  91             azVals[i] = (char *)sqlite3_column_text(pStmt, i);
  92             if( !azVals[i] && sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
  93               sqlite3OomFault(db);
  94               goto exec_out;
  95             }
  96           }
  97           azVals[i] = 0;
  98         }
  99         if( xCallback(pArg, nCol, azVals, azCols) ){
 100           /* EVIDENCE-OF: R-38229-40159 If the callback function to
 101           ** sqlite3_exec() returns non-zero, then sqlite3_exec() will
 102           ** return SQLITE_ABORT. */
 103           rc = SQLITE_ABORT;
 104           sqlite3VdbeFinalize((Vdbe *)pStmt);
 105           pStmt = 0;
 106           sqlite3Error(db, SQLITE_ABORT);
 107           goto exec_out;
 108         }
 109       }
 110
 111       if( rc!=SQLITE_ROW ){
 112         rc = sqlite3VdbeFinalize((Vdbe *)pStmt);
 113         pStmt = 0;
 114         zSql = zLeftover;
 115         while( sqlite3Isspace(zSql[0]) ) zSql++;
 116         break;
 117       }
 118     }
 119
 120     sqlite3DbFree(db, azCols);
 121     azCols = 0;
 122   }
 123
 124 exec_out:
 125   if( pStmt ) sqlite3VdbeFinalize((Vdbe *)pStmt);
 126   sqlite3DbFree(db, azCols);
 127
 128   rc = sqlite3ApiExit(db, rc);
 129   if( rc!=SQLITE_OK && pzErrMsg ){
 130     *pzErrMsg = sqlite3DbStrDup(0, sqlite3_errmsg(db));
 131     if( *pzErrMsg==0 ){
 132       rc = SQLITE_NOMEM_BKPT;
 133       sqlite3Error(db, SQLITE_NOMEM);
 134     }
 135   }else if( pzErrMsg ){
 136     *pzErrMsg = 0;
 137   }
 138
 139   assert( (rc&db->errMask)==rc );
 140   sqlite3_mutex_leave(db->mutex);
 141   return rc;
 142 }