+ $cgroupby = apply_filters('comment_feed_groupby', '');
+ $cgroupby = ( ! empty( $cgroupby ) ) ? 'GROUP BY ' . $cgroupby : '';
+ $corderby = apply_filters('comment_feed_orderby', 'comment_date_gmt DESC');
+ $corderby = ( ! empty( $corderby ) ) ? 'ORDER BY ' . $corderby : '';
+ $climits = apply_filters('comment_feed_limits', 'LIMIT ' . get_option('posts_per_rss'));
+ $comments_request = "SELECT $wpdb->comments.* FROM $wpdb->comments $cjoin $cwhere $cgroupby $corderby $climits";