[FIXED] How can redefine attribute in abstract model?

Issue

Hello I have two models

class A(models.Model):
    slug = models.SlugField()

     class Meta:
        abstract = True


class B(A):
    slug = models.CharField()

    class Meta:
        abstract = True

I get error AttributeError: Manager isn't available; B is abstract

How do can to redefine attribute in abstract class? class A cannot be changedю

Solution

Abstract models don't have a manager on them because they don't map to a database table. They are used to define reusable mixins that you can compose into concrete models. To make B a concrete model remove the abstract flag and then it will have an objects attribute defined on its instances.

class A(models.Model):
    slug = models.SlugField()

    class Meta:
        abstract = True


class B(A):
    slug = models.CharField()

As an aside, as things stand with your models this is a pointless hierarchy because the slug field on B overrides the slug field that is being inherited from A and therefore there is currently zero shared custom functionality between the two definitions. You may as well just have B inherit from models.Model directly.

Answered By - jhrr