php - can't catch exception in codeIgniter -

sorry english please need have problem when i'm trying catch insert query

i have table employe 3 primary keys (matricule , cin , name)

i want catch exception when add new employe duplicated values

my model

  function insert_employe($donnees){    try{     $this->db->insert('employe',$donnees);     return 'employe enregistré avec succes';    }catch(exception $e)    {        return $e->getmessage();    } } 

my controller

  function nouveau(){     if(!$this->offres->_islogged() || !$this->input->post('ajax')==1){         redirect(base_url().'users');     }     $values = $this->_get_values();     try{     $message = $this->employe->insert_employe($values);     echo $message;     }catch(exception $e){         echo $e->getmessage();     } } 

i can't catch exception

this never throw exception:

$this->db->insert('employe',$donnees); 

so you'll never catch exception that. if insert() method fails generate display custom error if $db['default']['db_debug'] set true on database.config or return false otherwise.

your best bet check errors when doing db operations:

$error = $this->db->_error_message() if(!empty($error)) {   throw new exception('your message'); }