multiple databases connectivity

To make the alternate database available to multiple models make the property $anotherDb a member of the controller. Set the property in the controller's constructor.

PHP Code:

Class Welcome extends CI_Controller
{
   public $anotherDb;

   function __construct()
   {
       parent::__construct();
       $db_name = $this->session->db_name;
       if(isset($db_name))
       {
            $this->anotherDb = $this->load->database($db_name, TRUE);
        }
        else
        {
              throw new Exception('Second database name not found.');
         }
   }