<?php
class App_Product_AdminObj extends App_Product_AbstractObj
{
    protected $_hasFilter = true;
    protected $_filterFields = array('name', 'idProductType');
    protected $_insertPlacement = 'APPEND';

    protected function _join(Zend_Db_Select $select = null)
    {
        $select = parent::_join($select);
        $select->join(
            $this->pairProductType,
            '`ProductType`.`id` = `' . $this->_tableAlias . '`.`idProductType`',
            array('productType' => 'title')
        );
        return $select;
    }
}