          last_name = models.CharField(max_length=50)
          instrument = models.CharField(max_length=100)
  
      class Album(models.Model):
          artist = models.ForeignKey(Musician)
          name = models.CharField(max_length=100)
          release_date = models.DateField()
          num_stars = models.IntegerField()
  
  Field types
 
</s> remove     band = models.ForeignKey(Band)
 </s> add     band = models.ForeignKey(Band, models.CASCADE) </s> remove             band_ct = models.ForeignKey(ContentType)
 </s> add             band_ct = models.ForeignKey(ContentType, models.CASCADE) </s> remove             band = UnsavedForeignKey(Band)
 </s> add             band = UnsavedForeignKey(Band, models.CASCADE) </s> remove     collection = models.ForeignKey(ProfileCollection, blank=True, null=True)
 </s> add     collection = models.ForeignKey(ProfileCollection, models.SET_NULL, blank=True, null=True) </s> remove     band = models.ForeignKey(Band)
 </s> add     band = models.ForeignKey(Band, models.CASCADE)
        artist = models.ForeignKey(Musician, on_delete=models.CASCADE)
          last_name = models.CharField(max_length=50)
          instrument = models.CharField(max_length=100)
  
      class Album(models.Model):
        artist = models.ForeignKey(Musician, on_delete=models.CASCADE)
          name = models.CharField(max_length=100)
          release_date = models.DateField()
          num_stars = models.IntegerField()
  
  Field types
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
docs/topics/db/models.txt