Michael Bayer wrote: > On Dec 11, 2007, at 10:07 AM, King Simon-NFHD78 wrote: > > > > > I assume the problem is that my date_created column isn't > immediately > > available at the 'after_insert' stage, because it is > generated in the > > SQL INSERT statement, but hasn't been read back from the > database yet. > > Is there a more suitable hook-point than after_insert, where I can > > safely read values like this? > > > > this is a thorny issue, while the immediate issue youre having is > something that can possibly be smoothed over (probably even by > sticking on the _instance_key yourself, not sure if i should > recommend > that though), its not going to work if say you wanted to look at the > foriegn key attributes in an attached collection since they havent > been set up yet. > > also the API youre using with get_history() has changed in > trunk, itll > give you a tuple now of (added, unchanged, deleted). > > there is the notion of SessionExtension which has an after_commit() > hook, not sure if that is a viable option here. I cant go too nuts > with all these extension hooks since they all add latency to > everything (sorta wishing there were a lot less hooks as it is). >
Thanks - I've ignored your warning and stuck on the _instance_key, in the full knowledge that when it breaks it'll be my own silly fault ;-) I'll investigate the SessionExtension as a longer-term fix. If after_commit runs when all attributes are completely up-to-date, and I can still access the previous and new state via get_history, it sounds like the right thing to use. I fully understand your worries about hooks slowing SQLAlchemy down, but I also think that they are one of the features that makes the ORM so flexible, and it would be a great shame to lose them. I wonder if there could be a way of caching all the extension methods so that applying them would be as fast as possible. <checks code> OK, I should have guessed. You've already done that - I see the ExtensionCarrier checks which methods have been overridden when each extension is added. Thanks for your help, Simon --~--~---------~--~----~------------~-------~--~----~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
