ИНТЕРНЕТ-МАГАЗИН / Сортировка товаров со скидкой

$Shop_Controller_Show->addCacheSignature('sorting=' . $sorting);

        if(intval(Core_Array::getGet('filter')) && intval(Core_Array::getGet('is_sale'))) {
          $current_date = date('Y-m-d H:i:s');
        $Shop_Controller_Show->shopItems()
           ->queryBuilder()
        ->join('shop_item_discounts', 'shop_items.id', '=', 'shop_item_discounts.shop_item_id')
            ->join('shop_discounts', 'shop_item_discounts.shop_discount_id', '=', 'shop_discounts.id', array(
                array('AND (' => array('shop_discounts.end_datetime', '>=', $current_date)),
                array('OR' => array('shop_discounts.end_datetime', '=', '0000-00-00 00:00:00')),
               array('AND' => array('shop_discounts.start_datetime', '<=', $current_date)),
             array(')' => NULL)
              ));
        }