Django Unique Together (with foreign keys)

Question

I have a situation where I want to use the Meta options of unique_together to enforce a certain rule, here\'s the intermediary model:

Answer 1

You can't.

The unique_together clause is directly translated to the SQL unique index. And you can only set those on columns of a single table, not a combination of several tables.

You can add validation for it yourself though, simply overwrite the validate_unique method and add this validation to it.

Docs: http://docs.djangoproject.com/en/dev/ref/models/instances/#django.db.models.Model.validate_unique