from __future__ import unicode_literals from django.db import models from django.utils.encoding import python_2_unicode_compatible @python_2_unicode_compatible class R(models.Model): is_default = models.BooleanField(default=False) def __str__(self): return "%s" % self.pk def get_default_r(): return R.objects.get_or_create(is_default=True)[0] class S(models.Model): r = models.ForeignKey(R) class T(models.Model): s = models.ForeignKey(S) class U(models.Model): t = models.ForeignKey(T) class RChild(R): pass class A(models.Model): name = models.CharField(max_length=30) auto = models.ForeignKey(R, related_name="auto_set") auto_nullable = models.ForeignKey(R, null=True, related_name='auto_nullable_set') setvalue = models.ForeignKey(R, on_delete=models.SET(get_default_r), related_name='setvalue') setnull = models.ForeignKey(R, on_delete=models.SET_NULL, null=True, related_name='setnull_set') setdefault = models.ForeignKey(R, on_delete=models.SET_DEFAULT, default=get_default_r, related_name='setdefault_set') setdefault_none = models.ForeignKey(R, on_delete=models.SET_DEFAULT, default=None, null=True, related_name='setnull_nullable_set') cascade = models.ForeignKey(R, on_delete=models.CASCADE, related_name='cascade_set') cascade_nullable = models.ForeignKey(R, on_delete=models.CASCADE, null=True, related_name='cascade_nullable_set') protect = models.ForeignKey(R, on_delete=models.PROTECT, null=True) donothing = models.ForeignKey(R, on_delete=models.DO_NOTHING, null=True, related_name='donothing_set') child = models.ForeignKey(RChild, related_name="child") child_setnull = models.ForeignKey(RChild, on_delete=models.SET_NULL, null=True, related_name="child_setnull") # A OneToOneField is just a ForeignKey unique=True, so we don't duplicate # all the tests; just one smoke test to ensure on_delete works for it as # well. o2o_setnull = models.ForeignKey(R, null=True, on_delete=models.SET_NULL, related_name="o2o_nullable_set") def create_a(name): a = A(name=name) for name in ('auto', 'auto_nullable', 'setvalue', 'setnull', 'setdefault', 'setdefault_none', 'cascade', 'cascade_nullable', 'protect', 'donothing', 'o2o_setnull'): r = R.objects.create() setattr(a, name, r) a.child = RChild.objects.create() a.child_setnull = RChild.objects.create() a.save() return a class M(models.Model): m2m = models.ManyToManyField(R, related_name="m_set") m2m_through = models.ManyToManyField(R, through="MR", related_name="m_through_set") m2m_through_null = models.ManyToManyField(R, through="MRNull", related_name="m_through_null_set") class MR(models.Model): m = models.ForeignKey(M) r = models.ForeignKey(R) class MRNull(models.Model): m = models.ForeignKey(M) r = models.ForeignKey(R, null=True, on_delete=models.SET_NULL) class Avatar(models.Model): desc = models.TextField(null=True) class User(models.Model): avatar = models.ForeignKey(Avatar, null=True) class HiddenUser(models.Model): r = models.ForeignKey(R, related_name="+") class HiddenUserProfile(models.Model): user = models.ForeignKey(HiddenUser) class M2MTo(models.Model): pass class M2MFrom(models.Model): m2m = models.ManyToManyField(M2MTo) class Parent(models.Model): pass class Child(Parent): pass class Base(models.Model): pass class RelToBase(models.Model): base = models.ForeignKey(Base, on_delete=models.DO_NOTHING)