Tricky SQL query

[eluser]ehicks727[/eluser]
[quote author="uptime" date="1219782902"]Why are you using two different tables?

You could have them all under one table with a parent_id field. if parent_id = 0 it would be considered as a new thread. Otherwise set parent_id to the thread's ID. I think it would make your life a little easier. Unless you have another reason, do you?[/quote]

Because that wouldn't be a properly normalized table. Actually, it's not normalized right now because the userid is in both tables, but that's not that big of a deal.

If you threw this all in one table, you'd most likely be painting yourself into a corner. It'll bite you in the butt later when you need to perform more complex manipulations or reporting on the data. As much normalization as is reasonable is always a best practice.