Django Sort by backward foreign key

Question

I currently have the following models

class ChatRoom(models.Model):
      creator = models.ForeignKey(\'User\') # points to the initial user

class Message(model         


        

Answer 1

You need to have a additional relation to your last message, otherwise you will not be able to order by them.

class ChatRoom(models.Model):
      creator = models.ForeignKey('User') # points to the initial user
      # you will need to set this in view or with signals.(don't forget to handle delete)
      last_message = models.ForignKey('Message')

And that you can do this

ChatRoom.objects.filter(...).order_by('last_message__date')