Thanks, both of you. That gives me even more to consider. The problem I'm trying to solve is one of application-specific logic. For example, if the model is used in a Pyramid app, having a __json__() method on each ORM object would be very useful. At the same time, a desktop application won't have much use for a __json__() method. It seems like the JSON serialization rightfully belongs in the Pyramid code where it's actually being used. That's a slightly contrived example, but it gets the flavor.
So my checklist of options seems to be: 1) Each application has it's own model definition, even though they interact with the same database. That means modifying several codebases any time the underlying DB changes. 2) Use one of the above provided methods to subclass the ORM objects in each codebase to provide the added functionality. Alterations tend to be localized, but it may be ugly and "unpythonic". I can see the possibility of brittleness. 3) Monkey patch the needed functionality. I'm not sure why, but this just bugs me. 4) Use reflection. I can't really speak here - I haven't played with reflection much. It still seems like there may be a fair bit of duplicated code between applications, although far less than individual copies of the model. 5) Use a programmatic interface or RPC of some kind between the model and the application. I've considered this several times and keep discarding it. Adding another layer of abstraction just seems like asking for problems. And I'm just moving the application-specific special cases to the middle layer. 6) Some obvious, dumb thing I'm missing. Maybe the design is rotten at the foundation. Thanks again for the ideas. And I'm always open to suggestion. Noah -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
