<?php

/**
 * @method array getDPromoType4select
 * @method array getProduct4Select
 */
abstract class App_ECommerce_Promo_Abstract_Obj extends Qs_Db_Obj
{
    protected $_tableAlias = 'Promo';

    protected function _getFromColumns()
    {
        $columns = parent::_getFromDbColumns();
        $columns['usageCount'] = '(' . new Zend_Db_Expr($this->_getCountUsageSubselect()) . ')';
        return $columns;
    }

    protected function _getCountUsageSubselect()
    {
        $select = $this->_db->select();
        $select->from($this->_getPair('CartItemPromo'), 'COUNT(*)');
        $select->join(
            $this->_getPair('Cart'),
            '`Cart`.`id` = `CartItemPromo`.`cartId`',
            []
        );
        $select->where('`CartItemPromo`.`promoId` = `' . $this->_tableAlias . '`.`id`');
        $select->where('`Cart`.`transactionId` IS NOT NULL');
        return $select;
    }
}