Get error number with oracle database in Codeigniter
You can use try catch block...
function insertUser($data){$sql = "INSERT INTO USERS VALUES (?, ?, ?, ?, ?, ?, ?, ?)";try{$this->db->trans_start();$query = $this->db->query($sql, array( $data["uname"], $data["nome"], $data["dnuser"], $data["muser"], $data["fruser"], $data["cpuser"], $data["euser"], md5($data["passu"]) ));$this->db->trans_commit();}catch(Exception $ex){$this->db->trans_rollback();echo "Error:".$ex;}} You can check the following article..
http://ellislab.com/codeigniter/user-guide/database/transactions.html