compare id of Site object with SITE_ID before updating (in create_test_db)

[kallous@…]

MSSQL Server cannot update identity columns, but 1.3.1 introduced a change in django.db.backends.creation at line 385 which ensures the Site object instance id matches the SITE_ID in <project>.settings. This is just a recommendation to test the value before updating it to prevent unnecessary complications.

[Michael Manfre]

#15573 was the breaking change (Oracle test support was fixed at the expense of MSSQL).

[Aymeric Augustin]

See also #17415.

[Aymeric Augustin]

Given the history that led to the current code (around 10 tickets), this isn't really an easy picking.

[Michael Manfre]

I added a temporary fix to django-mssql (​https://code.google.com/p/django-mssql/source/detail?r=08bba3453814d7f00ee93e2c8077a82a060265b7), which overrides create_test_db and removes the offending update. The change to django-mssql is a temporary solution to allow running unit tests and does not remove the need to fix this in django.

[Aymeric Augustin]

Currently, Django allows forcing the primary key of an object — that's what #17415 is about — so, even if we rollback the offending code, it's a limitation of django-mssql.

I'm marking this as a release blocker, because it is a regression from the previous version, and it's a blocker for your (legitimate) use case.

But I really can't say what's the best solution. We're stuck by SITE_ID, a mandatory setting.

[Aymeric Augustin]

Sorry, I was confused in my previous comments. Like I said, there's a lot of history :)

The code you're suggesting to patch was removed at r16868 in trunk and at r16869 in 1.3.X. Django now ensures that the id of the default site object is 1 without updating the primary key; it creates the object directly with the proper id. If I understand correctly, that should fix your problem.

I just edited that code, here's what it looks like now on trunk and on 1.3.X.

Thanks for the report, and feel free to reopen this ticket if the issue persists! (I don't have access to a MSSQL database to validate the current code.)