Store the DB used in the state before calling Model._save_table()

[Joseph Kahn]

I was trying to figure out why when calling .using before .create the self._state.db was not available. I happen to want the result of that to use in the pk value, so right now I have to re fetch that information. As it turns out, the cause can be narrowed down to a single line. However, I'm not sure if it was ordered that way for a reason but here:
​https://github.com/django/django/blob/d2a26c1a90e837777dabdf3d67ceec4d2a70fb86/django/db/models/base.py#L831-L836

Since not every function call gets the using param passed to it, but most get the instance like when it wants to get a pk value prior to saving.

I was wondering if it's possible to move that self._state.db = using up.

[Tim Graham]

Does the test suite pass with the change?

[Tim Graham]

The proposed change doesn't seem to work, at least multiple_database.tests.RouterTestCase.test_deferred_models fails. Feel free to reopen if you have a working patch.

[Joseph Kahn]

I created a PR with a change that doesn't break that test but fixes it for a lot of the edge cases I run into with multiple databases.

​https://github.com/django/django/pull/7841

[Tim Graham]

Tentatively accepting, although I haven't analyzed this in detail. Perhaps adding a test to the pull request will clarify the use case.

[Ingo Klöcker]

The pull request has been withdrawn.