/*** 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.***************************************************************************** This file contains the sqlite3_get_table() and sqlite3_free_table()** interface routines.  These are just wrappers around the main** interface routine of sqlite3_exec().**** These routines are in a separate files so that they will not be linked** if they are not used.*/#include <stdlib.h>#include <string.h>#include "sqliteInt.h"/*** This structure is used to pass data from sqlite3_get_table() through** to the callback function is uses to build the result.*/typedef struct TabResult {  char **azResult;  char *zErrMsg;  int nResult;  int nAlloc;  int nRow;  int nColumn;  int nData;  int rc;} TabResult;/*** This routine is called once for each row in the result table.  Its job** is to fill in the TabResult structure appropriately, allocating new** memory as necessary.*/static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){  TabResult *p = (TabResult*)pArg;  int need;  int i;  char *z;  /* Make sure there is enough space in p->azResult to hold everything  ** we need to remember from this invocation of the callback.  */  if( p->nRow==0 && argv!=0 ){    need = nCol*2;  }else{    need = nCol;  }  if( p->nData + need >= p->nAlloc ){    char **azNew;    p->nAlloc = p->nAlloc*2 + need + 1;    azNew = realloc( p->azResult, sizeof(char*)*p->nAlloc );    if( azNew==0 ) goto malloc_failed;    p->azResult = azNew;  }  /* If this is the first row, then generate an extra row containing  ** the names of all columns.  */  if( p->nRow==0 ){    p->nColumn = nCol;    for(i=0; i<nCol; i++){      if( colv[i]==0 ){        z = 0;      }else{        z = malloc( strlen(colv[i])+1 );        if( z==0 ) goto malloc_failed;        strcpy(z, colv[i]);      }      p->azResult[p->nData++] = z;    }  }else if( p->nColumn!=nCol ){    sqlite3SetString(&p->zErrMsg,       "sqlite3_get_table() called with two or more incompatible queries",       (char*)0);    p->rc = SQLITE_ERROR;    return 1;  }  /* Copy over the row data  */  if( argv!=0 ){    for(i=0; i<nCol; i++){      if( argv[i]==0 ){        z = 0;      }else{        z = malloc( strlen(argv[i])+1 );        if( z==0 ) goto malloc_failed;        strcpy(z, argv[i]);      }      p->azResult[p->nData++] = z;    }    p->nRow++;  }  return 0;malloc_failed:  p->rc = SQLITE_NOMEM;  return 1;}/*** Query the database.  But instead of invoking a callback for each row,** malloc() for space to hold the result and return the entire results** at the conclusion of the call.**** The result that is written to ***pazResult is held in memory obtained** from malloc().  But the caller cannot free this memory directly.  ** Instead, the entire table should be passed to sqlite3_free_table() when** the calling procedure is finished using it.*/int sqlite3_get_table(  sqlite3 *db,                /* The database on which the SQL executes */  const char *zSql,           /* The SQL to be executed */  char ***pazResult,          /* Write the result table here */  int *pnRow,                 /* Write the number of rows in the result here */  int *pnColumn,              /* Write the number of columns of result here */  char **pzErrMsg             /* Write error messages here */){  int rc;  TabResult res;  if( pazResult==0 ){ return SQLITE_ERROR; }  *pazResult = 0;  if( pnColumn ) *pnColumn = 0;  if( pnRow ) *pnRow = 0;  res.zErrMsg = 0;  res.nResult = 0;  res.nRow = 0;  res.nColumn = 0;  res.nData = 1;  res.nAlloc = 20;  res.rc = SQLITE_OK;  res.azResult = malloc( sizeof(char*)*res.nAlloc );  if( res.azResult==0 ) return SQLITE_NOMEM;  res.azResult[0] = 0;  rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);  if( res.azResult ){    res.azResult[0] = (char*)res.nData;  }  if( rc==SQLITE_ABORT ){    sqlite3_free_table(&res.azResult[1]);    if( res.zErrMsg ){      if( pzErrMsg ){        free(*pzErrMsg);        *pzErrMsg = sqlite3_mprintf("%s",res.zErrMsg);      }      sqliteFree(res.zErrMsg);    }    db->errCode = res.rc;    return res.rc;  }  sqliteFree(res.zErrMsg);  if( rc!=SQLITE_OK ){    sqlite3_free_table(&res.azResult[1]);    return rc;  }  if( res.nAlloc>res.nData ){    char **azNew;    azNew = realloc( res.azResult, sizeof(char*)*(res.nData+1) );    if( azNew==0 ){      sqlite3_free_table(&res.azResult[1]);      return SQLITE_NOMEM;    }    res.nAlloc = res.nData+1;    res.azResult = azNew;  }  *pazResult = &res.azResult[1];  if( pnColumn ) *pnColumn = res.nColumn;  if( pnRow ) *pnRow = res.nRow;  return rc;}/*** This routine frees the space the sqlite3_get_table() malloced.*/void sqlite3_free_table(  char **azResult            /* Result returned from from sqlite3_get_table() */){  if( azResult ){    int i, n;    azResult--;    if( azResult==0 ) return;    n = (int)azResult[0];    for(i=1; i<n; i++){ if( azResult[i] ) free(azResult[i]); }    free(azResult);  }}