          ordering = ('release_date',)  # overridden in PodcastAdmin
  
  
  class Vodcast(Media):
      media = models.OneToOneField(Media, primary_key=True, parent_link=True)
      released = models.BooleanField(default=False)
  
  
  class Parent(models.Model):
      name = models.CharField(max_length=128)
 
</s> remove     parent = models.OneToOneField(Place, parent_link=True)
 </s> add     parent = models.OneToOneField(Place, models.CASCADE, parent_link=True) </s> remove             parent = models.ForeignKey(Parent)
 </s> add             parent = models.ForeignKey(Parent, models.CASCADE) </s> remove     author = models.OneToOneField(Author, parent_link=True)
 </s> add     author = models.OneToOneField(Author, models.CASCADE, parent_link=True) </s> remove     parent = models.OneToOneField(Place, parent_link=True)
 </s> add     parent = models.OneToOneField(Place, models.CASCADE, parent_link=True) </s> remove     book = models.OneToOneField(Book, parent_link=True)
 </s> add     book = models.OneToOneField(Book, models.CASCADE, parent_link=True)
    media = models.OneToOneField(Media, models.CASCADE, primary_key=True, parent_link=True)
          ordering = ('release_date',)  # overridden in PodcastAdmin
  
  
  class Vodcast(Media):
    media = models.OneToOneField(Media, models.CASCADE, primary_key=True, parent_link=True)
      released = models.BooleanField(default=False)
  
  
  class Parent(models.Model):
      name = models.CharField(max_length=128)
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/admin_views/models.py