> On Nov 24, 2014, at 5:16 PM, Michael Bayer <mike...@zzzcomputing.com> wrote: > >> >> On Nov 24, 2014, at 12:31 PM, Michael Bayer <mike...@zzzcomputing.com >> <mailto:mike...@zzzcomputing.com>> wrote: >> >>> >>> On Nov 24, 2014, at 1:00 AM, Victor Reichert <vfr...@gmail.com >>> <mailto:vfr...@gmail.com>> wrote: >>> >>> I've taken another look at trying to eager load the address.parent. Is it >>> possible to do that? >> >> Unfortuntately not really. It should be in theory but I’m not able to >> work out an eager load that goes to both Customer and Supplier in terms of >> AddressAssociation at the same time. I can get the query to render just >> fine but the eager-targeting logic at the moment doesn’t seem to know how to >> be told to go to two separate subclasses of a base class at the same time. >> There’s probably improvements yet to be made in eager loading to support >> this case better, e.g. this is a bug, but I’ve wrestled with it for about an >> hour and I’m out of time on it for now, sorry. Even if it works, the >> query is very unpleasant to look at :) If I get it working later I’ll >> send it out. > > OK here we go, the limitation is that the of_type() modifier is only > recognized along a particular path once. So to get over this we can use a > with_polymorphic():
good news, i whacked that limitation in the latest master for 1.0. so when 1.0 is released (in some months), you can do: eager_addresses = session.query(Address).options( joinedload( Address.association.of_type(Customer.assoc_cls)).joinedload( Customer.assoc_cls.parent), joinedload( Address.association.of_type(Supplier.assoc_cls)).joinedload( Supplier.assoc_cls.parent), ) this will behind the scenes build up that with_polymorphic() thing for you. -- 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.