Question

I am currently working on a pyramid system that uses sqlalchemy.

This system will include a model (let’s call it Base) that is stored in a
database table. This model should be extensible by the user on runtime. Basically, the user
should be able to subclass the Base and create a new model (let’s call this one ‘Child’).
Childs should be stored in another database table.

All examples available seem to handle database reflection on a predefined model.
What would be the best way to generate complete model classes via database reflection?

Answer 1

I just solved the problem described above by using the following code snippet:

table = Table('anExistingTable', Base.metadata, autoload=True, autoload_with=Session.bind)
Extension = type('Extension', (BaseClass,), {
    '__table__' : table,
    '__mapper_args__' : {
        'inherits': BaseClass,
        'polymorphic_identity': 'extension'
    }
})

However, I don’t know why the first try didn’t work out…