Annotation of embedaddon/sqlite3/src/table.c, revision 1.1
1.1 ! misho 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: ** This file contains the sqlite3_get_table() and sqlite3_free_table()
! 13: ** interface routines. These are just wrappers around the main
! 14: ** interface routine of sqlite3_exec().
! 15: **
! 16: ** These routines are in a separate files so that they will not be linked
! 17: ** if they are not used.
! 18: */
! 19: #include "sqliteInt.h"
! 20: #include <stdlib.h>
! 21: #include <string.h>
! 22:
! 23: #ifndef SQLITE_OMIT_GET_TABLE
! 24:
! 25: /*
! 26: ** This structure is used to pass data from sqlite3_get_table() through
! 27: ** to the callback function is uses to build the result.
! 28: */
! 29: typedef struct TabResult {
! 30: char **azResult; /* Accumulated output */
! 31: char *zErrMsg; /* Error message text, if an error occurs */
! 32: int nAlloc; /* Slots allocated for azResult[] */
! 33: int nRow; /* Number of rows in the result */
! 34: int nColumn; /* Number of columns in the result */
! 35: int nData; /* Slots used in azResult[]. (nRow+1)*nColumn */
! 36: int rc; /* Return code from sqlite3_exec() */
! 37: } TabResult;
! 38:
! 39: /*
! 40: ** This routine is called once for each row in the result table. Its job
! 41: ** is to fill in the TabResult structure appropriately, allocating new
! 42: ** memory as necessary.
! 43: */
! 44: static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
! 45: TabResult *p = (TabResult*)pArg; /* Result accumulator */
! 46: int need; /* Slots needed in p->azResult[] */
! 47: int i; /* Loop counter */
! 48: char *z; /* A single column of result */
! 49:
! 50: /* Make sure there is enough space in p->azResult to hold everything
! 51: ** we need to remember from this invocation of the callback.
! 52: */
! 53: if( p->nRow==0 && argv!=0 ){
! 54: need = nCol*2;
! 55: }else{
! 56: need = nCol;
! 57: }
! 58: if( p->nData + need > p->nAlloc ){
! 59: char **azNew;
! 60: p->nAlloc = p->nAlloc*2 + need;
! 61: azNew = sqlite3_realloc( p->azResult, sizeof(char*)*p->nAlloc );
! 62: if( azNew==0 ) goto malloc_failed;
! 63: p->azResult = azNew;
! 64: }
! 65:
! 66: /* If this is the first row, then generate an extra row containing
! 67: ** the names of all columns.
! 68: */
! 69: if( p->nRow==0 ){
! 70: p->nColumn = nCol;
! 71: for(i=0; i<nCol; i++){
! 72: z = sqlite3_mprintf("%s", colv[i]);
! 73: if( z==0 ) goto malloc_failed;
! 74: p->azResult[p->nData++] = z;
! 75: }
! 76: }else if( p->nColumn!=nCol ){
! 77: sqlite3_free(p->zErrMsg);
! 78: p->zErrMsg = sqlite3_mprintf(
! 79: "sqlite3_get_table() called with two or more incompatible queries"
! 80: );
! 81: p->rc = SQLITE_ERROR;
! 82: return 1;
! 83: }
! 84:
! 85: /* Copy over the row data
! 86: */
! 87: if( argv!=0 ){
! 88: for(i=0; i<nCol; i++){
! 89: if( argv[i]==0 ){
! 90: z = 0;
! 91: }else{
! 92: int n = sqlite3Strlen30(argv[i])+1;
! 93: z = sqlite3_malloc( n );
! 94: if( z==0 ) goto malloc_failed;
! 95: memcpy(z, argv[i], n);
! 96: }
! 97: p->azResult[p->nData++] = z;
! 98: }
! 99: p->nRow++;
! 100: }
! 101: return 0;
! 102:
! 103: malloc_failed:
! 104: p->rc = SQLITE_NOMEM;
! 105: return 1;
! 106: }
! 107:
! 108: /*
! 109: ** Query the database. But instead of invoking a callback for each row,
! 110: ** malloc() for space to hold the result and return the entire results
! 111: ** at the conclusion of the call.
! 112: **
! 113: ** The result that is written to ***pazResult is held in memory obtained
! 114: ** from malloc(). But the caller cannot free this memory directly.
! 115: ** Instead, the entire table should be passed to sqlite3_free_table() when
! 116: ** the calling procedure is finished using it.
! 117: */
! 118: int sqlite3_get_table(
! 119: sqlite3 *db, /* The database on which the SQL executes */
! 120: const char *zSql, /* The SQL to be executed */
! 121: char ***pazResult, /* Write the result table here */
! 122: int *pnRow, /* Write the number of rows in the result here */
! 123: int *pnColumn, /* Write the number of columns of result here */
! 124: char **pzErrMsg /* Write error messages here */
! 125: ){
! 126: int rc;
! 127: TabResult res;
! 128:
! 129: *pazResult = 0;
! 130: if( pnColumn ) *pnColumn = 0;
! 131: if( pnRow ) *pnRow = 0;
! 132: if( pzErrMsg ) *pzErrMsg = 0;
! 133: res.zErrMsg = 0;
! 134: res.nRow = 0;
! 135: res.nColumn = 0;
! 136: res.nData = 1;
! 137: res.nAlloc = 20;
! 138: res.rc = SQLITE_OK;
! 139: res.azResult = sqlite3_malloc(sizeof(char*)*res.nAlloc );
! 140: if( res.azResult==0 ){
! 141: db->errCode = SQLITE_NOMEM;
! 142: return SQLITE_NOMEM;
! 143: }
! 144: res.azResult[0] = 0;
! 145: rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);
! 146: assert( sizeof(res.azResult[0])>= sizeof(res.nData) );
! 147: res.azResult[0] = SQLITE_INT_TO_PTR(res.nData);
! 148: if( (rc&0xff)==SQLITE_ABORT ){
! 149: sqlite3_free_table(&res.azResult[1]);
! 150: if( res.zErrMsg ){
! 151: if( pzErrMsg ){
! 152: sqlite3_free(*pzErrMsg);
! 153: *pzErrMsg = sqlite3_mprintf("%s",res.zErrMsg);
! 154: }
! 155: sqlite3_free(res.zErrMsg);
! 156: }
! 157: db->errCode = res.rc; /* Assume 32-bit assignment is atomic */
! 158: return res.rc;
! 159: }
! 160: sqlite3_free(res.zErrMsg);
! 161: if( rc!=SQLITE_OK ){
! 162: sqlite3_free_table(&res.azResult[1]);
! 163: return rc;
! 164: }
! 165: if( res.nAlloc>res.nData ){
! 166: char **azNew;
! 167: azNew = sqlite3_realloc( res.azResult, sizeof(char*)*res.nData );
! 168: if( azNew==0 ){
! 169: sqlite3_free_table(&res.azResult[1]);
! 170: db->errCode = SQLITE_NOMEM;
! 171: return SQLITE_NOMEM;
! 172: }
! 173: res.azResult = azNew;
! 174: }
! 175: *pazResult = &res.azResult[1];
! 176: if( pnColumn ) *pnColumn = res.nColumn;
! 177: if( pnRow ) *pnRow = res.nRow;
! 178: return rc;
! 179: }
! 180:
! 181: /*
! 182: ** This routine frees the space the sqlite3_get_table() malloced.
! 183: */
! 184: void sqlite3_free_table(
! 185: char **azResult /* Result returned from from sqlite3_get_table() */
! 186: ){
! 187: if( azResult ){
! 188: int i, n;
! 189: azResult--;
! 190: assert( azResult!=0 );
! 191: n = SQLITE_PTR_TO_INT(azResult[0]);
! 192: for(i=1; i<n; i++){ if( azResult[i] ) sqlite3_free(azResult[i]); }
! 193: sqlite3_free(azResult);
! 194: }
! 195: }
! 196:
! 197: #endif /* SQLITE_OMIT_GET_TABLE */
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