Database error: query() - invalid SQL query

Original query:
 SELECT id, title_pt, subtitle_pt, bodytext_pt , link, externo, date_object, youtube, youtube_embebbed, youtube_thumb, video, photo, photo_cropped, photo_w, photo_h, cropped_w, cropped_h, show_title FROM highlights_ml WHERE visible='true' AND ( ( !date_start && !date_end ) OR ( '2019-09-20 19:32:27' BETWEEN date_start AND date_end ) OR ( '2019-09-20 19:32:27'<=date_end && !date_start ) OR ( '2019-09-20 19:32:27'>=date_start && !date_end )) AND tipo =  AND destaque_principal='true'


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 'AND destaque_principal='true'' at line 1