when deleting users with schedule_files I got this:
IntegrityError at /admin/auth/user/166/delete/ (1451, 'Cannot delete or update a parent row: a foreign key constraint fails (
vacation
.vacations_schedulefile
, CONSTRAINTvacations_schedulefile_user_id_e85fa52f_fk_auth_user_id
FOREIGN KEY (user_id
) REFERENCESauth_user
(id
))')
My models are:
class ScheduleFile(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
added = models.DateTimeField(default=django.utils.timezone.now)
def __str__(self):
return '[User ID: {}] {}'.format(str(self.user.id), self.user.username)
And
class VacationEvent(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
schedule_type = models.CharField(choices=SCHEDULE_TYPES, default=STRICT_TIME, max_length=3)
exclude_fba_from_chatzos = models.BooleanField(default=False)
schedule_file = models.ForeignKey(ScheduleFile, on_delete=models.CASCADE, null=True)
status = models.CharField(verbose_name="status event", choices=EVENT_STATUSES, max_length=3, default=CREATED)
And User(AbstractUser) I decided to create pre_delete signal and delete relative objects of schedule model:
@receiver(pre_delete, dispatch_uid='User')
def user_del(sender, instance, **kwargs):
i = instance
events = VacationEvent.objects.filter(user_id=166)
schedule = prefetch_related_objects(events, 'schedule_file__user')
schedule.delete()
# instance.user.schedulefile_set.clear()
# qs = VacationEvent.objects.filter(user_id=166).prefetch_related_('schedule_file')
# qs.delete()
# b = ScheduleFile.objects.filter(user_id=166)
# e = VacationEvent.objects.filter(user_id=166)
# e.schedule_file.remove(b)
But it returns 'NoneType' object has no attribute 'delete'. How can I do it right? Thanks for any help.