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 ** $Id: legacy.c,v 1.15 2006/06/26 21:35:45 drh Exp $

    18 */

    19 

    20 #include "sqliteInt.h"

    21 #include "os.h"

    22 #include <ctype.h>

    23 

    24 /*

    25 ** Execute SQL code.  Return one of the SQLITE_ success/failure

    26 ** codes.  Also write an error message into memory obtained from

    27 ** malloc() and make *pzErrMsg point to that message.

    28 **

    29 ** If the SQL is a query, then for each row in the query result

    30 ** the xCallback() function is called.  pArg becomes the first

    31 ** argument to xCallback().  If xCallback=NULL then no callback

    32 ** is invoked, even for queries.

    33 */

    34 int sqlite3_exec(

    35   sqlite3 *db,                /* The database on which the SQL executes */

    36   const char *zSql,           /* The SQL to be executed */

    37   sqlite3_callback xCallback, /* Invoke this callback routine */

    38   void *pArg,                 /* First argument to xCallback() */

    39   char **pzErrMsg             /* Write error messages here */

    40 ){

    41   int rc = SQLITE_OK;

    42   const char *zLeftover;

    43   sqlite3_stmt *pStmt = 0;

    44   char **azCols = 0;

    45 

    46   int nRetry = 0;

    47   int nChange = 0;

    48   int nCallback;

    49 

    50   if( zSql==0 ) return SQLITE_OK;

    51   while( (rc==SQLITE_OK || (rc==SQLITE_SCHEMA && (++nRetry)<2)) && zSql[0] ){

    52     int nCol;

    53     char **azVals = 0;

    54 

    55     pStmt = 0;

    56     rc = sqlite3_prepare(db, zSql, -1, &pStmt, &zLeftover);

    57     assert( rc==SQLITE_OK || pStmt==0 );

    58     if( rc!=SQLITE_OK ){

    59       continue;

    60     }

    61     if( !pStmt ){

    62       /* this happens for a comment or white-space */

    63       zSql = zLeftover;

    64       continue;

    65     }

    66 

    67     db->nChange += nChange;

    68     nCallback = 0;

    69 

    70     nCol = sqlite3_column_count(pStmt);

    71     azCols = sqliteMalloc(2*nCol*sizeof(const char *) + 1);

    72     if( azCols==0 ){

    73       goto exec_out;

    74     }

    75 

    76     while( 1 ){

    77       int i;

    78       rc = sqlite3_step(pStmt);

    79 

    80       /* Invoke the callback function if required */

    81       if( xCallback && (SQLITE_ROW==rc || 

    82           (SQLITE_DONE==rc && !nCallback && db->flags&SQLITE_NullCallback)) ){

    83         if( 0==nCallback ){

    84           for(i=0; i<nCol; i++){

    85             azCols[i] = (char *)sqlite3_column_name(pStmt, i);

    86           }

    87           nCallback++;

    88         }

    89         if( rc==SQLITE_ROW ){

    90           azVals = &azCols[nCol];

    91           for(i=0; i<nCol; i++){

    92             azVals[i] = (char *)sqlite3_column_text(pStmt, i);

    93           }

    94         }

    95         if( xCallback(pArg, nCol, azVals, azCols) ){

    96           rc = SQLITE_ABORT;

    97           goto exec_out;

    98         }

    99       }

   100 

   101       if( rc!=SQLITE_ROW ){

   102         rc = sqlite3_finalize(pStmt);

   103         pStmt = 0;

   104         if( db->pVdbe==0 ){

   105           nChange = db->nChange;

   106         }

   107         if( rc!=SQLITE_SCHEMA ){

   108           nRetry = 0;

   109           zSql = zLeftover;

   110           while( isspace((unsigned char)zSql[0]) ) zSql++;

   111         }

   112         break;

   113       }

   114     }

   115 

   116     sqliteFree(azCols);

   117     azCols = 0;

   118   }

   119 

   120 exec_out:

   121   if( pStmt ) sqlite3_finalize(pStmt);

   122   if( azCols ) sqliteFree(azCols);

   123 

   124   rc = sqlite3ApiExit(0, rc);

   125   if( rc!=SQLITE_OK && rc==sqlite3_errcode(db) && pzErrMsg ){

   126     *pzErrMsg = sqlite3_malloc(1+strlen(sqlite3_errmsg(db)));

   127     if( *pzErrMsg ){

   128       strcpy(*pzErrMsg, sqlite3_errmsg(db));

   129     }

   130   }else if( pzErrMsg ){

   131     *pzErrMsg = 0;

   132   }

   133 

   134   return rc;

   135 }