On Monday 06 April 2009 18:26:06 Marcin Krol wrote: > Hello everyone, > > I've got this query: > > selectexpr = session.query(Host, Architecture, OS_Kind, OS_version, > Virtualization, Project, Reservation) > > ... > > selectexpr = selectexpr.filter(or_(Host.earliest_reservation_id == > None, and_(Host.earliest_reservation_id == Reservation.id, > Reservation.start_date < sd))) > > The problem with this query is that SQLA/Postgres does a join on > Host.earliest_reservation_id == None (producing each combination of > every Reservation and every host with Host.earliest_reservation_id > = NULL). > > Now I could make a second query like session.query(Host, > Architecture, OS_Kind, OS_version, Virtualization, Project), but do > I have to? > > Is there some way to account for condition > Host.earliest_reservation_id == None and produce None / NULL as > Reservation in resulting row tuple as result of a single query? left outer join?
--~--~---------~--~----~------------~-------~--~----~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
