contrib.auth on seperate db in multi-db setup fails

[dhageman]

contrib.auth will break if you put it onto a database by itself. There is a hard coded SQL statement in contrib.auth.backends at line 27 (get_group_permissions) that joins the auth tables with django_content_type. This will obviously cause an error if the django_ tables are not in the same database with the auth_ tables.

[Jacob]

We're probably not going to tackle the "django_* tables on a different db from the auth_* tables" this time around. That requires figuring out foreign keys across databases, which probably is never going to work (think constraints), and hence is the topic of a *much* bigger problem.

For the purposes of this ticket, let's just tackle the fact that the ModelBackend hardcodes the default connection.

[Russell Keith-Magee]

(In [12509]) Fixed #12729 -- Replaced a hard-coded SQL statement with an ORM query so that the contrib.auth ModelBackend will work on a routed multi-db setup. Thanks to dhageman for the report.

Historical note: The SQL that was removed predates Django being open sourced.

[Jacob]

Milestone 1.2 deleted