On Sunday 22 June 2008 19:48:55 Michael Bayer wrote: > On Jun 22, 2008, at 12:51 PM, [EMAIL PROTECTED] wrote: > > On Sunday 22 June 2008 18:51:44 Michael Bayer wrote: > >> On Jun 22, 2008, at 8:27 AM, [EMAIL PROTECTED] wrote: > >>> hi > >>> i want to fetch/eagerload just one column off a related object. > >>> e.g. if > >>> A.b pointing to B and B having x,y,z, i want to get all As and > >>> the A.b.x, and nothing else from B. > >>> it even doesnot actualy matter if it will be really A.b.x or > >>> just some A.new_bx made-up column/attribute. > >>> > >>> can? > >> > >> you can: > >> > >> query(A, B.x).join(A.bs).all() > > > > how do i alias those as they are all similar (e.g. B.x and C.x > > etc) > > > > i do (pseudocode): > > r = query(A)... > > extra_name = ... #the above 'x' present in all B,C,D,... > > for selector,selklas in dict(b=B,c=C,d=D).items(): > > r = r.add_column( getattr( selklas, extra_attrname) ) > > r = r.outerjoin( selector) > > > > the error is: > > Ambiguous join for entity 'B.x'; specify id=<someid> to > > query.join()/query.add_column(), or use the aliased() function to > > use explicit class aliases. > > Balias = aliased(B) > Calias = aliased(C) > > query(A, Balias.x, Calias.x), ....
this in 0.4 doesnot handle inherited attributes - which i just hacked, the sql it generates isnt much smaller than eagerloading all them things, but the worst is the query now yields nothing.. with or without joins, all the same. okay, i'll go eagerloading for now. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
