Check after mysql_store_result propery

fixes #51

_mysql.c

@@ -408,7 +408,7 @@ _mysql_ResultObject_Initialize(
 	self->result = result;
 	Py_END_ALLOW_THREADS ;
 	if (!result) {
-		if (mysql_field_count(&(conn->connection)) > 0) {
+		if (mysql_errno(&(conn->connection))) {
 		    _mysql_Exception(conn);
 		    return -1;
 		}