On Thu, Aug 23, 2018 at 4:51 PM, Tom Lane wrote:
>
> Mark Jeffcoat writes:
> > I would have claimed before seeing this example that it wasn't even
> > grammatical; I thought the only legal place to write the ON clause was
> > immediately after the JOIN. Apparently not.
>
> You read it as
>
> SEL
Mark Jeffcoat writes:
> SELECT *
> FROM relation_a
> LEFT JOIN relation_b
> JOIN relation_c
> ON (relation_c.id_p = relation_b.id_p)
> ON (relation_a.id_c = relation_b.id_c AND relation_a.id_v = relation_b.id_v);
> I would have claimed before seeing this example that it wasn't even
> grammatical;
I'm looking at a query generated by SQLAlchemy. It works; Postgres is
perfectly happy to run it, and it gives answers that make sense to the
guy who wrote it. But I don't understand why it works.
Stripped way down ...
CREATE VIEW relation_a (id_c, id_v)
AS VALUES (1, 20), (2, 21), (3, 22);
CREA
