protected function getSelectAccessControlEntryIdSql($classId, $oid, $field, $order)
    {
        return sprintf(
            'SELECT id FROM %s WHERE class_id = %d AND %s AND %s AND ace_order = %d',
            $this->options['entry_table_name'],
            $classId,
            null === $oid ?
                $this->connection->getDatabasePlatform()->getIsNullExpression('object_identity_id')
                : 'object_identity_id = '.(int) $oid,
            null === $field ?
                $this->connection->getDatabasePlatform()->getIsNullExpression('field_name')
                : 'field_name = '.$this->connection->quote($field),
            $order
        );
    }