sqlalchemy many-to-many query examples

sqlalchemy.py

        ## every leader at every church -- OK
        ##
        ##
        ## query = dbsession.query(Leader).join(LeaderChurch).join(Church).filter(LeaderChurch.leader_id == Leader.id and LeaderChurch.church_id == Church.id)


        ## every leader at a particular church -- OK
        ##
        ##
        # query = dbsession.query(Leader). \
        #     join(LeaderChurch). \
        #     join(Church, Church.id == LeaderChurch.church_id). \
        #     filter(Church.uuid == church_uuid.hex)

        ## works but associates sermons with the wrong church
        ## I think because there is a m-2-m church-leader via
        ## the LeaderChurch association table
        
        query = dbsession.query(MediaSermon, Church). \ 
            join(Leader, Leader.id == MediaSermon.leader_id). \
            join(LeaderChurch, LeaderChurch.leader_id == Leader.id). \
            join(Church, Church.id == LeaderChurch.church_id). \
            filter(Church.uuid == church_uuid.hex). \
            order_by(MediaSermon.track_number.asc(), MediaSermon.id)

https://stackoverflow.com/questions/19841877/an-inner-join-with-sqlalchemy