db.models.ForeignKey.db_constraint

ForeignKey.db_constraint

Controls whether or not a constraint should be created in the database for this foreign key. The default is True, and that’s almost certainly what you want; setting this to False can be very bad for data integrity. That said, here are some scenarios where you might want to do this:

• You have legacy data that is not valid.
• You’re sharding your database.

If this is set to False, accessing a related object that doesn’t exist will raise its DoesNotExist exception.