How to use ForeignKey with abstract base class in django?

Question

Django

I want this:

class A(models.Model):
    class Meta: 
        abstract = True

class B(A):
    pass

class C(A):
    pass

class D(models.Model):
    a = models.ForeignKey(A)

    def is_b(self):
        return if isinstance(self.a, b):

But when creating migrations, jang complains that it cannot create a ForeignKey for an abstract class. How is it solved?

Answer 1

Don't make the class abstract.

Answer 2

The abstract class does not create a table, how do you think it should work at the database level?