WordPress database error: [Unknown column 'comment_date_gmt' in 'field list']
SELECT comment_date_gmt FROM wp_comments WHERE comment_date_gmt <= '2013-05-21 22:36:31' AND comment_approved = '1' ORDER BY comment_date_gmt DESC LIMIT 1

WordPress database error: [Unknown column 'comment_approved' in 'where clause']
SELECT wp_comments.* FROM wp_comments LEFT JOIN wp_posts ON ( wp_comments.comment_post_ID = wp_posts.ID ) WHERE post_status = 'publish' AND comment_approved = '1' ORDER BY comment_date_gmt DESC LIMIT 10