On Mar 29, 2012, at 9:50 AM, lars van gemerden wrote: > I have found that this specific behaviour (re-initialization of the > InstrumentedList) does not happen if "expire_on_commit = False" is set > on the sesssion. However this leads to other errors in my code. > > I guess I don't quite understand why expire would be called after a > commit; shouldn't the commit result in the session being perfectly > synchronized with the DB?
It does. The expire of the attributes doesn't cause any SQL to be emitted until you access the attributes, in which case a new transaction is begun (note the DBAPI's default mode of operation is to always be in a transaction, and SQLAlchemy does not challenge this). In between your commit() and the start of a new transaction, any amount of state within the database may have been changed by other transactions. If expire_on_commit=False is leading to errors, that would imply that this is actually happening in your case. -- 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.
