  
  @python_2_unicode_compatible
  class Song(models.Model):
      title = models.CharField(max_length=150)
      album = models.ForeignKey(Album)
      original_release = models.DateField(editable=False)
  
      class Meta:
          ordering = ('title',)
  
 
</s> remove     band = models.ForeignKey(Band)
 </s> add     band = models.ForeignKey(Band, models.CASCADE) </s> remove     item = models.ForeignKey(Item)
 </s> add     item = models.ForeignKey(Item, models.CASCADE) </s> remove     title = models.ForeignKey(Title, related_name='attached_%(app_label)s_%(class)s_set')
 </s> add     title = models.ForeignKey(Title, models.CASCADE, related_name='attached_%(app_label)s_%(class)s_set') </s> remove     collector = models.ForeignKey(Collector)
 </s> add     collector = models.ForeignKey(Collector, models.CASCADE) </s> remove     note = models.ForeignKey(Note)
 </s> add     note = models.ForeignKey(Note, models.CASCADE)
    album = models.ForeignKey(Album, models.CASCADE)
  
  @python_2_unicode_compatible
  class Song(models.Model):
      title = models.CharField(max_length=150)
    album = models.ForeignKey(Album, models.CASCADE)
      original_release = models.DateField(editable=False)
  
      class Meta:
          ordering = ('title',)
  
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/admin_checks/models.py