  
  @python_2_unicode_compatible
  class Annotation(models.Model):
      name = models.CharField(max_length=10)
      tag = models.ForeignKey(Tag)
      notes = models.ManyToManyField(Note)
  
      def __str__(self):
          return self.name
  
 
</s> remove     tag = models.ForeignKey(Tag)
 </s> add     tag = models.ForeignKey(Tag, models.CASCADE) </s> remove     creator = models.ForeignKey(Author, to_field='num', null=True)
 </s> add     creator = models.ForeignKey(Author, models.SET_NULL, to_field='num', null=True) </s> remove     child = models.ForeignKey(Child)
    second_child = models.ForeignKey(Child, related_name="other", null=True)
 </s> add     child = models.ForeignKey(Child, models.CASCADE)
    second_child = models.ForeignKey(Child, models.SET_NULL, related_name="other", null=True) </s> remove     extra = models.ForeignKey(ExtraInfo)
 </s> add     extra = models.ForeignKey(ExtraInfo, models.CASCADE) </s> remove     poet = models.ForeignKey(Poet)
 </s> add     poet = models.ForeignKey(Poet, models.CASCADE)
    tag = models.ForeignKey(Tag, models.CASCADE)
  
  @python_2_unicode_compatible
  class Annotation(models.Model):
      name = models.CharField(max_length=10)
    tag = models.ForeignKey(Tag, models.CASCADE)
      notes = models.ManyToManyField(Note)
  
      def __str__(self):
          return self.name
  
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/queries/models.py