SQLAlchemy many-to-many orphan deletion

Question

I\'m trying to use SQLAlchemy to implement a basic users-groups model where users can have multiple groups and groups can have multiple users.

When a group becomes empty

Answer 1

I had the same problem about 3 months ago, i have a Post/Tags relation and wanted to delete unused Tags. I asked on irc and SA's author told me that cascades on many-to-many relations are not supported, which kind of makes sense since there is no "parent" in many-to-many.

But extending SA is easy, you can probably use a AttributeExtension to check if the group became empty when is removed from a User and delete it from there.