protected function createSelectQuery()
    {
        $query = $this->handler->createSelectQuery();
        $query->select(
            $this->handler->quoteColumn(self::COLUMN_ID),
            $this->handler->quoteColumn(self::COLUMN_URL),
            $this->handler->quoteColumn(self::COLUMN_ORIGINAL_URL_MD5),
            $this->handler->quoteColumn(self::COLUMN_IS_VALID),
            $this->handler->quoteColumn(self::COLUMN_LAST_CHECKED),
            $this->handler->quoteColumn(self::COLUMN_CREATED),
            $this->handler->quoteColumn(self::COLUMN_MODIFIED)
        )->from(
            $this->handler->quoteTable(self::URL_TABLE)
        );

        return $query;
    }