A Database Error Occurred

Error Number: 1054

Unknown column 'comments' in 'order clause'

SELECT * FROM (`object_assoc_videos`) JOIN `videos` ON object_assoc_videos.object_id = videos.id WHERE (video_type = 'user' AND visible_to = 'everyone' ) AND (object_assoc_videos.assoc = 'domain' AND object_assoc_videos.assoc_id = '3') ORDER BY `comments` DESC LIMIT 20