          return self.name
  
  
  class Event(models.Model):
      main_band = models.ForeignKey(Band, limit_choices_to=models.Q(pk__gt=0), related_name='events_main_band_at')
      supporting_bands = models.ManyToManyField(Band, blank=True, related_name='events_supporting_band_at')
      start_date = models.DateField(blank=True, null=True)
      start_time = models.TimeField(blank=True, null=True)
      description = models.TextField(blank=True)
      link = models.URLField(blank=True)
 
</s> remove         parent = models.ForeignKey(RangesModel, blank=True, null=True)
 </s> add         parent = models.ForeignKey(RangesModel, models.SET_NULL, blank=True, null=True) </s> remove     band = models.ForeignKey(Band)
 </s> add     band = models.ForeignKey(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     alfa = models.ForeignKey(Alfa, null=True)
    bravo = models.ForeignKey(Bravo, null=True)
 </s> add     alfa = models.ForeignKey(Alfa, models.SET_NULL, null=True)
    bravo = models.ForeignKey(Bravo, models.SET_NULL, null=True) </s> remove     collection = models.ForeignKey(TitleCollection, blank=True, null=True)
 </s> add     collection = models.ForeignKey(TitleCollection, models.SET_NULL, blank=True, null=True)
    main_band = models.ForeignKey(
        Band,
        models.CASCADE,
        limit_choices_to=models.Q(pk__gt=0),
        related_name='events_main_band_at',
    )
          return self.name
  
  
  class Event(models.Model):
    main_band = models.ForeignKey(
        Band,
        models.CASCADE,
        limit_choices_to=models.Q(pk__gt=0),
        related_name='events_main_band_at',
    )
      supporting_bands = models.ManyToManyField(Band, blank=True, related_name='events_supporting_band_at')
      start_date = models.DateField(blank=True, null=True)
      start_time = models.TimeField(blank=True, null=True)
      description = models.TextField(blank=True)
      link = models.URLField(blank=True)
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/admin_widgets/models.py