          poll_date = models.DateField()
          objects = PollManager()
  
      class Response(models.Model):
          poll = models.ForeignKey(OpinionPoll)
          person_name = models.CharField(max_length=50)
          response = models.TextField()
  
  With this example, you'd use ``OpinionPoll.objects.with_counts()`` to return
  that list of ``OpinionPoll`` objects with ``num_responses`` attributes.
 
</s> remove     related = models.ForeignKey(RelatedModel)
 </s> add     related = models.ForeignKey(RelatedModel, models.CASCADE) </s> remove     related = models.OneToOneField(RelatedModel)
 </s> add     related = models.OneToOneField(RelatedModel, models.CASCADE) </s> remove     reporter = models.ForeignKey(ProxyTrackerUser)
    associated_bug = models.ForeignKey(ProxyProxyBug)
 </s> add     reporter = models.ForeignKey(ProxyTrackerUser, models.CASCADE)
    associated_bug = models.ForeignKey(ProxyProxyBug, models.CASCADE) </s> remove     person = models.OneToOneField(Member, primary_key=True)
    parent = models.ForeignKey(Member, related_name="children")
 </s> add     person = models.OneToOneField(Member, models.CASCADE, primary_key=True)
    parent = models.ForeignKey(Member, models.CASCADE, related_name="children") </s> remove     details = models.OneToOneField(Detail, primary_key=True)
 </s> add     details = models.OneToOneField(Detail, models.CASCADE, primary_key=True)
        poll = models.ForeignKey(OpinionPoll, on_delete=models.CASCADE)
          poll_date = models.DateField()
          objects = PollManager()
  
      class Response(models.Model):
        poll = models.ForeignKey(OpinionPoll, on_delete=models.CASCADE)
          person_name = models.CharField(max_length=50)
          response = models.TextField()
  
  With this example, you'd use ``OpinionPoll.objects.with_counts()`` to return
  that list of ``OpinionPoll`` objects with ``num_responses`` attributes.
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
docs/topics/db/managers.txt