Oracle backend regex lookup broken if Oracle backend is not default

[Jirka Vejrazka]

I hit a bug with django-pyodbc that was related to multi-db and realized that Oracle backend has the same problem. The problem lies [browser:django/trunk/django/db/backends/oracle/base.py?rev=15299#L260 here]. This will break if the Oracle backend is not the default one.

I have not figured out a good way to get the right connection in this portion of code. I did monkeypatch my copy of code (the django-pyodbc one) in ​the following way, but have no idea what a good solution might be.

[Erin Kelly]

This point was also raised in #9405, which was closed wontfix at the time. This is something that we do need to fix one way or another, though.

[Ramiro Morales]

The technique of passing the connection to the DatabaseOperations instance is already being used in the PostgreSQL backends (most surely a change introduced after Malcolm added his comment to #9045 opposing to such an API change). The inconsistency of these two backends with django.db.backends.BaseDatabaseOperations and the rest of the DB backends we ship is reported in #13630. Once we fix it we'll hopefully be able t use that instance variable to solve this issue.

[Ramiro Morales]

Replying to ramiro:

The technique of passing the connection to the DatabaseOperations instance is already being used in the PostgreSQL backends (most surely a change introduced after Malcolm added his comment to #9405 opposing to such an API change).

The change was introduced when the multi-db branch got merged in with trunk, in revision 11952.

[Erin Kelly]

In [16041]:

Fixed #15534: Made the Oracle runtime test for regex capabilities use the DatabaseOperations connection instead of grabbing the default connection.