How can I eagerly load an answers latest revision?

I have a Q&A site and it allows answers to be changed while storing a revision of each change, much like here on Stackoverflow. When selecting some answers, I'd like it to include the most recent(but not all) revision as a property of each answer, so that I can avoid doing n+1 queries on my page.

class Answer(开发者_StackOverflow社区models.Model):
    user = models.ForeignKey(User)
    problem = models.ForeignKey(Problem)

class AnswerRevision(models.Model):
    answer = models.ForeignKey(Answer, related_name='revisions')
    text = models.TextField()
    timestamp = models.DateTimeField()


Answer.objects.filter(problem=p)

I'd suggest the following structure:

class Answer(models.Model):
    user = models.ForeignKey(User)
    revision = models.ForeignKey(AnswerRevision)
    problem = models.ForeignKey(Problem)

class AnswerRevision(models.Model):
    answer = models.ForeignKey(Answer, related_name='revisions')
    text = models.TextField()
    timestamp = models.DateTimeField()

The only difference is that I added a revision property to the answer. When a new revision is made, just change the FK to point to the new revision.