Hello,
maybe some Hibernate Pro can help me with a HQL query. I'm sorry if this is not the right forum.

I am developing a Forum software. In a Forum there can be many Messages (threads). A message can have multiple responses, which are also messages.

The basic structure for a Message is:

Message properties:
-> Forum (forum object it belongs to)
-> responseTo (is null if is first message in a Thread or points to the message it responds, conforming a thread)
Date
Subject
Body


I'd like to get a list of threads (messages with null responseTo value) but sorted by the Date field of the last response to its thread. (A very old message having a recent response in its thread chain would be the first in the resultList)

Thanks for any help on this,
Ignacio