python - 如何在一个模型中指定父子关系？

Question

例如我有以下代码:

class FamilyMember(models.Model):
    user = models.OneToOneField(User)

我有以下情况:

a1 = FamilyMember.objects.get(id=1)
a1.first_name = 'John'
a1.last_name = 'Smith'
(a1 is a parent of a2)

a2 = FamilyMember.objects.get(id=2)
a2.first_name = 'Mark'
a2.last_name = 'Smith'
(a2 is a child of a1 and parent of a3 in the same time)

a3 = FamilyMember.objects.get(id=3)
a3.first_name = 'Jason'
a3.last_name = 'Smith'
(a3 is a child of a2)

我怎样才能在一个模型中实现这种关系？

Answer 1

您可以使用一个简单的 ForeignKey to self 来指示父级:

parent = models.ForeignKey('self', blank=True, null=True, related_name='children')

现在您可以执行 a2.parent = a1，并且会自动获得对 a1.children.all() 的访问权限。