      name = models.CharField(max_length=128)
  
  
  class Child(models.Model):
      parent = models.ForeignKey(Parent, editable=False, null=True)
      name = models.CharField(max_length=30, blank=True)
      age = models.IntegerField(null=True, blank=True)
  
  
  class Genre(models.Model):
 
</s> remove     parent = models.ForeignKey(Parent, editable=False)
 </s> add     parent = models.ForeignKey(Parent, models.CASCADE, editable=False) </s> remove             parent = models.ForeignKey(Parent)
 </s> add             parent = models.ForeignKey(Parent, models.CASCADE) </s> remove     mother = models.ForeignKey(Parent, related_name='mothers_children')
    father = models.ForeignKey(Parent, related_name='fathers_children')
    school = models.ForeignKey(School)
 </s> add     mother = models.ForeignKey(Parent, models.CASCADE, related_name='mothers_children')
    father = models.ForeignKey(Parent, models.CASCADE, related_name='fathers_children')
    school = models.ForeignKey(School, models.CASCADE) </s> remove     parent = models.ForeignKey('self', null=True, blank=True)
 </s> add     parent = models.ForeignKey('self', models.SET_NULL, null=True, blank=True) </s> remove     chef = models.ForeignKey(Chef, null=True, blank=True)
 </s> add     chef = models.ForeignKey(Chef, models.SET_NULL, null=True, blank=True)
    parent = models.ForeignKey(Parent, models.SET_NULL, editable=False, null=True)
      name = models.CharField(max_length=128)
  
  
  class Child(models.Model):
    parent = models.ForeignKey(Parent, models.SET_NULL, editable=False, null=True)
      name = models.CharField(max_length=30, blank=True)
      age = models.IntegerField(null=True, blank=True)
  
  
  class Genre(models.Model):
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/admin_changelist/models.py