Zend选择问题

我在 zend 数据库表库方面遇到了问题;

抱歉，我修复了上一个问题，但在功能上得到了另一个问题

Message: Method "fetchAll" does not exist and was not trapped in __call()

这是我正在使用的脚本

 //setIntegrityCheck to false to allow joins
        $roomModel = new self();
        $select = $roomModel->select(Zend_Db_Table::SELECT_WITH_FROM_PART)
                ->setIntegrityCheck(FALSE);
        //performs join aliasing table room_type to t
        $select->join(array('t' => 'room_types'), 't.room_type_id = room.room_type_id AND num_beds> '.$number_beds);
        ////performs join aliasing table room_status to s
        $select->join(array('s' => 'room_statuses'), 's.room_status_id = room.room_status_id');
        $select->join(array('chin' => 'checkin'), 'chin.checkin_date IS NOT BETWEEN `'.$checkin.'` AND `'.$checkout.'`');
        $select->join(array('chout' => 'checkout'), 'chout.checkout_date IS NOT BETWEEN `'.$checkin.'` AND `'.$checkout.'`');
        $result = $this->fetchAll($select);
        return $result;