Select all threads and order by the latest one

Question

Now that I got the Select all forums and get latest post too.. how? question answered, I am trying to write a query to select all threads in one particular

Answer 1

Forget the distinct on:

SELECT t.id, u.username, p.updated_at, t.title
FROM   forum_threads             t
LEFT   JOIN forum_posts   p ON p.thread_id = t.id
LEFT   JOIN users         u ON u.id = p.user_id
WHERE t.forum_id = 3
ORDER  BY p.updated_at DESC;