On Sep 26, 2008, at 9:02 PM, adolfo wrote:
> Hello, and sorry if this issue is already covered. > I have a table which makes foreign references to other table, and I > need to make a filter against that table multiple times. > > so I have: > > q1=session.query(Fuente).outerjoin(Fuente.PPersona, > aliased=True).outerjoin(Fuente.PPersona_como_fuente, aliased=True) > > i.e. Fuente makes more than one reference to table Persona, thru the > properties PPersona and PPersona_como_fuente. > > until here, it works fine. > > Now if I need to construct a filter against Persona, how do I make > explicit that I want to make a condition to a field of Persona > as, for example, Fuente.PPersona.sexo and not > Fuente.PPersona_como_fuente.sexo ? when you're dealing with the aliased=True approach, this is a "shortcut" approach that apples the *most recent* alias to subsequent filter expressions, such as: q1=session.query(Fuente).outerjoin(Fuente.PPersona, aliased = True ).filter(Persona.foo=='bar').outerjoin(Fuente.PPersona_como_fuente, aliased=True).filter(Persona.bar=='foo') the first filter is against Fuente.PPersona, the second against Fuenty.PPersona_como_fuente. Now, the "explicit" approach is to use aliases. In 0.5, its like this: p1 = aliased(Persona) p2 = aliased(Persona) q1=session.query(Fuente).outerjoin((p1, Fuente.PPersona)).outerjoin((p2, Fuente.PPersona_como_fuente)) you then filter using p1 or p2: q.filter(p1.foo=='bar').filter(p2.bar=='foo') 0.4 doesn't have an ORM-level "aliased" construct, so this approach requires using Table objects (using the Table.alias() method, constructing the joins with the expression language and using query.select_from(thejoin)) when working with 0.4. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
