I am trying to subclass a mapped class from another package for no other reason than to add a utility method. The polymorphic_on condition, if it were defined, would have to be 'True'. Example:
class Mapped(declarative_base()): # columns class Utility(Mapped): def is_something(self): return 'foo' Encouraged by the fact that session.query(Utility).first() works, I proceeded and got an exception. The error is FlushError: Attempting to flush an item of type <Utility> on collection 'Something.mapped', which is not the expected type. Configure mapper 'Mapper|User|user' to load this subtype polymorphically, or set enable_typechecks=False to allow subtypes. Mismatched typeloading may cause bi-directional relationships (backrefs) to not function properly. I'm starting to think I should just monkey patch the original class or just pass the Mapped() into utility()... is that the best way? Thanks! Daniel -- 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.