You can create your custom 404 page with these steps. Please follow these steps one by one.

• You have to update your own created CONTROLLER's class with $route['404_override'] = 'Controller_Class_Name';. You have to update this in your application/config/routes.php
• Please create your new controller "Controller_Class_Name" file in your controllers directory application/controllers/.
• Please put this code in your Controller_Class_Name.php
  
  class Controller_Class_Name extends CI_Controller {
       public function __construct() {
            parent::__construct();
       }
  
      public function index() {
           $this->output->set_status_header('404');
           $this->LOAD->VIEW('error_page_404');
      }
  }
• Now create your "error_page_404" view file.

You can use $this->db->insert(); to insert data in your database in Codeigniter.

If you want to insert this in your "Admin Table".

$dataArray = array(
       'name'=>'bestinterviewquestion.com',
       'phone'=>'9971083635',
       'email'=>'[email protected]'
);

$this->db->insert('Admin',$dataArray);

// Here "Admin" is My TableName