public function status($order_id, $slug)

{

    if($slug==='2')

    {

        # 发货流程, 先判断是不是优惠券

        if($this->_is_coupon_order($order_id))

        {

            $this->load->model('m_cart', 'cart', true);

            $undiscounted = $this->cart->items($order_id);

            $discounted   = $this->cart->items($order_id, true);

            $merged       = array_merge($undiscounted, $discounted);

            $this->db->where('status', 0)

                     ->where('rule_id', $merged[0]->type_id)

                     ->limit($merged[0]->item_quantity)

                     ->set('user_id', $merged[0]->user_id)

                     ->update('coupon');

        }

        $this->db->where('id', $order_id)->set('status', 2);

    }

    $this->db->update('order');

    return $this->db->affected_rows();

}