Thanks again, Michael. I guess for now I will be using a view as a
workaround, yet using your core (brilliant) ideas for the issue.
Thanks a lot for all your great work.
Sqlalchemy changed my life :-)
Adolfo
On Tuesday, August 21, 2012 11:09:05 PM UTC-5, Michael Bayer wrote:
>
>
> On Aug 21, 2012, at 4:34 PM, adolfo wrote:
>
> > Hi Michael and all....
> >
> > I successfully built a "all nodes" relationship following your
> guidelines.
> >
> > As:
> >
> >
> subq1=select([caso_vinculo.c.caso_1_id.label('id1'),caso_vinculo.c.caso_2_id.label('id2')]).union(select([caso_vinculo.c.caso_2_id,
>
> caso_vinculo.c.caso_1_id]))
> > subq2=aliased(subq1)
> >
> > CasoMapper = mapper(Caso, caso, properties=
> > {
> > 'LinkedNodes':relation(Caso, secondary=subq2,
> > primaryjoin=caso.c.id ==
> subq2.c.id1,
> > secondaryjoin=subq2.c.id2==
> caso.c.id),
> > So with this property I can get both left and right linked nodes.
> >
> >
> > with:
> > CasoAlias=aliased(Caso)
> > q1=session.query(Caso.id).outerjoin(CasoAlias.LinkedNodes)
> > q1.all()
> > works fine
> > and once I add a new column from the aliased entity (CasoAlias)
> > q2=q1.add_column(CasoAlias.id)
> > it compiles fine
> >
> > SELECT caso.id AS caso_id, caso_1.id AS caso_1_id
> > FROM caso AS caso_1 LEFT OUTER JOIN (SELECT caso_vinculo.caso_1_id AS
> id1, caso_vinculo.caso_2_id AS id2
> > FROM caso_vinculo UNION SELECT caso_vinculo.caso_2_id AS caso_2_id,
> caso_vinculo.caso_1_id AS caso_1_id
> > FROM caso_vinculo) AS anon_1 ON caso_1.id = anon_1.id1 LEFT OUTER JOIN
> caso ON anon_1.id2 = caso.id
>
> there's a bug in SQLAlchemy here which I'll have fixed soon, it is
> somewhat hilarious though, the unusual naming scheme you're using for
> caso_vinculo's columns is conflicting with the labels SQLAlchemy is
> assigning. Note in the query, "caso_1.id AS caso_1_id" at the top.
> Later on, when it renders "caso_vinculo.caso_1_id" in the subquery, it's
> erroneously stepping on the internal column record for the "caso_1_id"
> symbol and breaking things.
>
> If you use different names on the caso_vinculo table for now it should be
> fine.
>
>
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