Question

I have two models, one a vanilla Django model, another an unmanaged model wrapping a view.

class A(models.Model):
    name = models.CharField(max_length=255)

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

    class Meta:
        managed = False
        db_table = 'myview'

Everything works well, unless I try to delete a row from A, which gives me an error like:

django.db.utils.DatabaseError: cannot delete from view "myview"
HINT:  You need an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.

Apparently, Django is assuming the unmanaged model is a table, and is therefore trying to delete the dependent rows, and since it’s a readonly view, my PostgreSQL backend is throwing this error.

Is there any way around this?

I found this bug report outlining the issue, but none of the stopgap hacks seem to work for me, and the bug itself was marked a duplicate of another slightly different yet unresolved bug…

Answer 1

have you tried on_delete=models.SET_NULL as a workaround?