javascript - Jquery Ajax Shows error 500 when ever sql returns error -

i working on codeigniter , getting problem while inserting values in database via ajax. problem occur when sql query throws error. controller code:-

public function register_data() {     $data = array(         'user_name'=>$this->input->post('name'),         'user_email'=>$this->input->post('emailid'),         'user_pwd'=>$this->input->post('pwd'),         'user_pno'=>$this->input->post('pno'),         'user_gender'=>$this->input->post('gender'),         'user_age'=>$this->input->post('age'),         'dor'=>date('y-m-d h:i:s'),);     $this->load->model('register');     $this->register->insert_content($data);     $output = array(); //creating output array json response ajax     $output['result'] = $this->register->getstatus();    echo $output['result'].'---';     $output['message'] = $this->register->getmessage();  echo $output['message'];     echo json_encode($output); } 

my model code :-

class register extends ci_model{ var $message; var $status; public function __construct()  {     parent::__construct();     $this->load->database(); } public function insert_content($da) {        if ($this->db->insert('user',$da))//checking if mysql query successful     {         $this->status = true;         $this->message = "data inserted";     }     else     {         $this->status = false;         $this->message = $this->db->error_message();                 } } public function getstatus() {     return $this->status; } public function getmessage() {     return $this->message; }} 

and ajax call:-

$.ajax({     url: "<?php echo site_url('home_controller/register_data');?>",     data: $("#frm").serialize(),     type: 'post',     success: function (data) {         alert(data);         var resp = $.parsejson(data);         if (resp.result) {             window.location.href = "<?php echo site_url('home_controller');?>";         } else {             $("#msgs").html(resp.message);         }     },     error: function (error) {         $("#msgs").html(json.stringify(error)); //this returned when model condition inserting data throws error.     } }); 

and please note datas getting inserted. hence there no problem while inserting. have used json return response ajax. problem occurs when inserting goes wrong. example:- have kept email unique in database hence when insert duplicate in db mysql throws error says duplication error, u can see code in model have made insert code in if condition , when insert query gets failed status , msg stored in variable. how used in core php. have no idea how handle in codeigniter. kindly provide solutions. appreciated.

codeigniter has included error() function display db error. db->error_message() problem hear