Daniel Robbins wrote: > Hi All, > > One of the things that doesn't seem to be covered in the > docs, and that I'm currently trying to figure out, is the > recommended design pattern to use for managing sessions from > declarative methods calls. > > Consider a declarative class "User", where I want to > implement a "FindFriends() method: > > class User(Base): > # declarative fields defined here > > def FindFriends(self): > session = Session() > # it's handy to use the "self" reference in > query methods: > friends = > session.query(Friends).filter_by(friend=self).all() > session.close() > return friends > > Certainly, these types of methods would seem to be useful, > but here's a dilemma - the above code doesn't work. Because > the method uses a new session, which is guaranteed to not be > the same session that was used to retrieve the original User > object, the following code will fail: > > session = session() > me = session.query(User).filter_by(name="Daniel").first() > me.FindFriends() >
See the 'How can I get the Session for a certain object' question at http://www.sqlalchemy.org/docs/session.html#frequently-asked-questions Basically, in your FindFriends method, replace: session = Session() with: session = Session.object_session(self) Hope that helps, Simon -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalch...@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
