          ordering = ['y']
  
  
  class LoopY(models.Model):
      x = models.ForeignKey(LoopX)
  
      class Meta:
          ordering = ['x']
  
  
 
</s> remove     z = models.ForeignKey('self')
 </s> add     z = models.ForeignKey('self', models.CASCADE) </s> remove     y = models.ForeignKey('LoopY')
 </s> add     y = models.ForeignKey('LoopY', models.CASCADE) </s> remove     b = models.ForeignKey(B)
 </s> add     b = models.ForeignKey(B, models.CASCADE) </s> remove     b = models.ForeignKey(B, null=True)
 </s> add     b = models.ForeignKey(B, models.SET_NULL, null=True) </s> remove             parent = models.ForeignKey(Parent)
 </s> add             parent = models.ForeignKey(Parent, models.CASCADE)
    x = models.ForeignKey(LoopX, models.CASCADE)
          ordering = ['y']
  
  
  class LoopY(models.Model):
    x = models.ForeignKey(LoopX, models.CASCADE)
  
      class Meta:
          ordering = ['x']
  
  
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