/*** 2001 September 15**** The author disclaims copyright to this source code.  In place of** a legal notice, here is a blessing:****    May you do good and not evil.**    May you find forgiveness for yourself and forgive others.**    May you share freely, never taking more than you give.***************************************************************************** Main file for the SQLite library.  The routines in this file** implement the programmer interface to the library.  Routines in** other files are for internal use by SQLite and should not be** accessed by users of the library.**** $Id: legacy.c,v 1.7 2004/09/06 17:34:13 drh Exp $*/#include "sqliteInt.h"#include "os.h"#include <ctype.h>/*** Execute SQL code.  Return one of the SQLITE_ success/failure** codes.  Also write an error message into memory obtained from** malloc() and make *pzErrMsg point to that message.**** If the SQL is a query, then for each row in the query result** the xCallback() function is called.  pArg becomes the first** argument to xCallback().  If xCallback=NULL then no callback** is invoked, even for queries.*/int sqlite3_exec(  sqlite3 *db,                /* The database on which the SQL executes */  const char *zSql,           /* The SQL to be executed */  sqlite3_callback xCallback, /* Invoke this callback routine */  void *pArg,                 /* First argument to xCallback() */  char **pzErrMsg             /* Write error messages here */){  int rc = SQLITE_OK;  const char *zLeftover;  sqlite3_stmt *pStmt = 0;  char **azCols = 0;  int nRetry = 0;  int nChange = 0;  int nCallback;  if( zSql==0 ) return SQLITE_OK;  while( (rc==SQLITE_OK || (rc==SQLITE_SCHEMA && (++nRetry)<2)) && zSql[0] ){    int nCol;    char **azVals = 0;    pStmt = 0;    rc = sqlite3_prepare(db, zSql, -1, &pStmt, &zLeftover);    if( rc!=SQLITE_OK ){      if( pStmt ) sqlite3_finalize(pStmt);      continue;    }    if( !pStmt ){      /* this happens for a comment or white-space */      zSql = zLeftover;      continue;    }    db->nChange += nChange;    nCallback = 0;    nCol = sqlite3_column_count(pStmt);    azCols = sqliteMalloc(2*nCol*sizeof(const char *));    if( nCol && !azCols ){      rc = SQLITE_NOMEM;      goto exec_out;    }    while( 1 ){      int i;      rc = sqlite3_step(pStmt);      /* Invoke the callback function if required */      if( xCallback && (SQLITE_ROW==rc ||           (SQLITE_DONE==rc && !nCallback && db->flags&SQLITE_NullCallback)) ){        if( 0==nCallback ){          for(i=0; i<nCol; i++){            azCols[i] = (char *)sqlite3_column_name(pStmt, i);          }          nCallback++;        }        if( rc==SQLITE_ROW ){          azVals = &azCols[nCol];          for(i=0; i<nCol; i++){            azVals[i] = (char *)sqlite3_column_text(pStmt, i);          }        }        if( xCallback(pArg, nCol, azVals, azCols) ){          rc = SQLITE_ABORT;          goto exec_out;        }      }      if( rc!=SQLITE_ROW ){        rc = sqlite3_finalize(pStmt);        pStmt = 0;        if( db->pVdbe==0 ){          nChange = db->nChange;        }        if( rc!=SQLITE_SCHEMA ){          nRetry = 0;          zSql = zLeftover;          while( isspace((unsigned char)zSql[0]) ) zSql++;        }        break;      }    }    sqliteFree(azCols);    azCols = 0;  }exec_out:  if( pStmt ) sqlite3_finalize(pStmt);  if( azCols ) sqliteFree(azCols);  if( sqlite3_malloc_failed ){    rc = SQLITE_NOMEM;  }  if( rc!=SQLITE_OK && rc==sqlite3_errcode(db) && pzErrMsg ){    *pzErrMsg = malloc(1+strlen(sqlite3_errmsg(db)));    if( *pzErrMsg ){      strcpy(*pzErrMsg, sqlite3_errmsg(db));    }  }else if( pzErrMsg ){    *pzErrMsg = 0;  }  return rc;}