I should add the final version of my file ist at: https://gist.github.com/vfr292/3330037cf5bc621d3d4b should anyone want to reference it.
Thank you again Mr. Bayer! On Monday, November 24, 2014 11:00:06 PM UTC-8, Victor Reichert wrote: > > Thank you! You are not an SQL alchemist, you are a SQL Wizard! Thank you > again! > > For bonus points, an order by is possible on the discriminator like > objects are returned consecutively: > > poly = with_polymorphic( > > AddressAssociation, > > [Customer.assoc_cls, Supplier.assoc_cls], aliased=True) > > > eager_addresses = session.query(Address).options( > > joinedload(Address.association.of_type(poly)).joinedload( > > poly.CustomerAddressAssociation.parent), > > joinedload(Address.association.of_type(poly)).joinedload( > > poly.SupplierAddressAssociation.parent), > > ).order_by(poly.discriminator.desc(), poly.id) > > On Monday, November 24, 2014 4:04:41 PM UTC-8, Michael Bayer wrote: >> >> >> On Nov 24, 2014, at 5:16 PM, Michael Bayer <mik...@zzzcomputing.com> >> wrote: >> >> >> On Nov 24, 2014, at 12:31 PM, Michael Bayer <mik...@zzzcomputing.com> >> wrote: >> >> >> On Nov 24, 2014, at 1:00 AM, Victor Reichert <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.
