$this->form_validation->set_rules('order_no', 'Order no', 'required|callback_check_order_no');

function check_unique_order_no($id = '', $order_no) { $this->db->where('order_no', $order_no); $this->db->where('status', "A"); if($id) { $this->db->where_not_in('id', $id); } return $this->db->get('delivery_order')->num_rows(); }

function check_order_no($order_no) { if($this->input->post('id')) $id = $this->input->post('id'); else $id = ''; $result = $this->Data_model->check_unique_order_no($id, $order_no); if($result == 0) $response = true; else { $this->form_validation->set_message('check_order_no', 'Order no already exist'); $response = false; } return $response; }