On Wednesday, January 12, 2011 2:16:00 PM UTC-5, Michael Bayer wrote: > see expire_on_commit=False as well as Session.commit() for further detail: > http://www.sqlalchemy.org/docs/orm/session.html#committing > > http://www.sqlalchemy.org/docs/orm/session.html#sqlalchemy.orm.session.Session.commit > To reassociate detached objects with a session, use Session.add() or > Session.merge(). Detachment is described at > http://www.sqlalchemy.org/docs/orm/session.html#quickie-intro-to-object-states > . > I think I'm in a catch-22 situation I'm not sure how to get out of (short of copying my object to an unmapped one, which seems wasteful)...
I have N objects in a scoped session and I want to commit the changes on them all. After this is done, I want to keep just one of them around in a cache as a simple detached object that won't ever result in emitted SQL. The business rules are such that for this object there is no way the object will differ from what is in the DB (and even if the DB was changed behind the scenes I want the values at time of commit). The issue seems to be that on commit(), everything is expired, and the comment in the docs that says "They are still functional in the detached state *if the user has ensured that their state has not been expired before detachment*" indicates that I can't have a cleanly detached object after a commit because of this expiration. At least not without setting expire_on_commit = False... but that applies to all objects in the session. I only want one object to be severed from the database linkage. Is there any clean way to set expire_on_commit behaviour at a per-object level? It seems to be all or nothing at the moment. I dug into the code that seems to do the expiry (session._remove_snapshot through to InstanceState.expire_attributes) and nothing is leaping out at me. Can I force an "un-expire" after the commit without legitimately reflecting the persistent state? Russ > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@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.
