Okay, I fled SQL courses like the plague in school (if you had told me then I’d be spending all of my time writing MySQL queries… well, let’s say I wouldn’t have lived to taste Coke Zero) but I think I would still be choking on this one if I hadn’t.

So, let’s say I’ve got a table of comments; each comment is associated with a post ID, obviously. If I want to know how many comments there are per post, I can write:

But what if I want to know that count plus some contents from the last comment on each post? Is there a way to do that without making one query per post?

(Actually, even if I didn’t want to get COUNT(*), I still wouldn’t know how to do that in just one query.)