php - Error when checking if a cookie is set -

i using in controller check if cookie set. if not, set it.

function x(){     if(!isset($_cookie['sg'])){         $this->load->model('generate_model');         $val=$this->generate_model->random();         setcookie('sg',$val, time()+3600*24*30*12*3,"/", "" );     }     $this->load->model('model');     $data['cod']=$cod;     $this->model->select($cod);     $this->load->view('templates/header');     redirect('home','refresh'); } 

if cookie not set, 2 errors:

a php error encountered

severity: notice

message: undefined index: sg

filename: models/select_gift_model.php

line number: 12

a database error occurred

error number: 1048

column 'uid' cannot null

insert id ( uid, cod) values ( null, '35a5v0mogc')

filename: c:\wamp\www\ci\system\database\db_driver.php

line number: 330

the cookie set, , if press , call again, function works normally.

how can check if cookie set , make function work properly?

in docs of php:

once cookies have been set, can accessed on next page load $_cookie or $http_cookie_vars arrays. note, superglobals such $_cookie became available in php 4.1.0. cookie values exist in $_request.

source: http://php.net/manual/en/function.setcookie.php

the best way make in current connection available folling:

setcookie('sg',$val, time()+3600*24*30*12*3,"/", "" ); $_cookie = $val;