You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'slide.attr( 'data-thumb' ) '' ORDER BY `order` ASC LIMIT 1' at line 3 on: `SELECT * FROM `gull20_pages` p
LEFT JOIN `gull20_pages_text` t ON p.`page_id` = t.`page_id`
WHERE lang='dutch' AND t.`clean_title` = '' slide.attr( 'data-thumb' ) '' ORDER BY `order` ASC LIMIT 1`.