I'm working on a custom forum system and I'm trying to figure out how to put a thread on the top of the list if a user posts in it. I've got this for my query SELECT user_threads.threadID, user_threads.title, user_threads.uid, user_threads.postDate, thread_messages.posted FROM user_threads, thread_messages WHERE parent = :parent GROUP BY user_threads.title ORDER BY thread_messages.posted DESC Which doesn't appear to be working. if I post in a new thread, it remains where it is on the list.