Django subclass model gives "duplicate key value violates unique constraint" on save

I have a class with many fields:

class Parent(models.Model):      id = models.AutoField(primary_key=True)      ... many more fields  

and I create a subclass

class Child(Parent):      other_field = models.CharField(max_length=512, blank=True, null=True)      date_featured = models.DateField()  

After I migrate and create a Child object in the admin I get

duplicate key value violates unique constraint "parent_pkey"  DETAIL:  Key (id)=(5) already exists.  

I've seen some similar questions that suggest that you modify the database but I can't easily do that. Do I need to change the id of the subclass?

https://stackoverflow.com/questions/67377032/django-subclass-model-gives-duplicate-key-value-violates-unique-constraint-on May 04, 2021 at 07:38AM