Constraint trouble with concrete base models after migrating Django from MySQL to PostgreSQL

Question

I'm attempting a migration from MySQL to PostgreSQL, and now I'm having trouble with concrete base classes. I have code similar to this:

class BaseKlass(models.Model):
    name = CharField(max_length = 64)

class SomeKlass(BaseKlass):
    value = IntegerField()

Whenever I create an instance of SomeKlass, I get an error like this:

IntegrityError: null value in column "baseklass_ptr_id" violates not-null constraint

I looked at the SQL being executed, and indeed the value for baseklass_ptr_id was null.

Any idea?

As you have discovered, Postgres is a lot more strict than MySQL. +1 because it looks like you answered your own question. — Peter Rowell
– Peter Rowell, Commented Dec 29, 2012 at 23:52

Salvatore Iovene · Accepted Answer · 2012-12-29 18:25:49Z

2

Setting an owner for the id sequence solved the problem:

ALTER SEQUENCE myapp_baseklass_id_seq OWNED BY myapp_baseklass.id;

answered Dec 29, 2012 at 18:25

Salvatore Iovene

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