How to work with timestampdiff?

Code:

   function get_TimeDifference($id)

    {

      $this->db->where('id',$id);

      $this->db->select('TIMESTAMPDIFF(HOUR,DateStarted,DateRestored) as OutageDuration',FALSE);

      $query = $this->db->get('network_outage');

      return $query;

    }

Code:

       function update_downtime($id)

          {

            $data['title'] = 'Update Network Downtime';

            $user_id = $this->uri->segment(3);

         





            $data['fetch_single_outage'] = $this->network_model->fetch_single_outage($user_id);

            $data['fecth_downtime'] = $this->network_model->get_outagelist();

            $data['get_ISPStatus'] = $this->network_model->get_ISPStatus();

            $this->load->view('template/header');

            $this->load->view('template/nav');

            $this->load->view('network/update_downtime',$data);

            $this->load->view('template/footer');

          }



          function network_update_form_validation()

          {

            $Outage = $this->report_model->get_TimeDifference($OutageDuration);

              $data  = array(

                'DateRestored' => $this->input->post('date_restored'),

                'Status' => $this->input->post('select_ticket_status'),

                'OutageDuration' => $Outage,

                'PerformedBy' => $this->session->userdata('user_name')

              );



              if($this->input->post('update'))

              {

                  $this->network_model->update_outage($data,$this->input->post('hidden_id'));



                  $this->session->set_flashdata('downtime_updated','Outage has been updated successfully');

                  redirect('network/network_outage');

              }

          }