SELECT c.`name` AS catname, c.`safe_name` AS catsname, c.`id` AS catid, f.`name` , f.`safe_name` , f.`id` , t.`id` , t.`title` , t.`updated` , u.`name` AS last_user, t.`date`
FROM `kb_categories` c
RIGHT OUTER JOIN `kb_forums` f ON f.`catid` = c.`id`
LEFT OUTER JOIN `kb_topics` t ON t.`forumid` = f.`id`
LEFT OUTER JOIN `kb_users` u ON t.`userid` = u.`id`
ORDER BY c.`posid` , f.`posid` ASC , t.`updated` DESC