  
  
  class WorkHour(models.Model):
      datum = models.DateField()
      employee = models.ForeignKey(Employee)
  
  
  class Question(models.Model):
      question = models.CharField(max_length=20)
  
 
</s> remove             question = models.ForeignKey(Question)
 </s> add             question = models.ForeignKey(Question, models.CASCADE) </s> remove             question = models.ForeignKey(Question)
 </s> add             question = models.ForeignKey(Question, models.CASCADE) </s> remove     question = models.ForeignKey(Question, on_delete=models.PROTECT)
 </s> add     question = models.ForeignKey(Question, models.PROTECT) </s> remove     poll = models.ForeignKey(Poll)
 </s> add     poll = models.ForeignKey(Poll, models.CASCADE) </s> remove     owner = models.ForeignKey(User, null=True, blank=True, on_delete=models.SET_NULL)
 </s> add     owner = models.ForeignKey(User, models.SET_NULL, null=True, blank=True)
    employee = models.ForeignKey(Employee, models.CASCADE)
  
  
  class WorkHour(models.Model):
      datum = models.DateField()
    employee = models.ForeignKey(Employee, models.CASCADE)
  
  
  class Question(models.Model):
      question = models.CharField(max_length=20)
  
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