As far as I can tell, neither this article nor Alex Gaynor's slides mention another big problem with Django's ORM: lack of support for composite primary keys an

As far as I can tell, neither this article nor Alex Gaynor's slides mention another big problem with Django's ORM: lack of support for composite primary keys and composite foreign keys. We were layering some web stuff on top of a database that worked flawlessly with SQLAlchemy and ended up changing our data model to accommodate Django's weaknesses.