supports_mars attribute error when using multiple databases.

[ScottBarkman]

Ran into an issue when I was attempting to use this with multiple databases (MS sql server & postgresql) Whenever I would run a query on the sql server, followed by one on postgres - the postgresql one would fail with DatabaseWrapper has no attribute supports_mars

I traced this back to a method (_cursor_iter) inside of pyodbc/compile.py which appeared to be running on each database connection, including the postgresql one.

Adding a simple @ line 84:

if not hasattr(cursor.db, "supports_mars"):
    cursor.db.supports_mars = False;

solves the issue.

[jmelloy]

I've been having this exact issue.

[michiya]

Thank you for reporting and sorry for inconvenience. I have made the fix for this and pushed it to PyPI. Let me know if you still see the same error after upgrading django-pyodbc-azure to the latest version.

[ScottBarkman]

No worries, thanks for the fix. I wasn't that confident with always assuming it doesn't support mars or I would have submitted a pull request.

Thanks again - works great installed from pypi