2012/11/27 ssylla <stefansy...@gmx.de>: > assuming I have the following n:n relationship: > > intermediary table: > t3 > id_project|id_product > 1|1 > 1|2 > 2|1 > > How can I create an output like this: > id_project|id_product1|id_product2 > 1|1|2 > 2|1|NULL
I'd said the sample is too simplified — not clear which id_product should be picked if there're more then 2 exists. I assumed the ones with smallest IDs. -- this is just a sample source generator WITH t3(id_project, id_product) AS (VALUES (1,1),(1,2),(2,1)) -- this is the query SELECT l.id_project, min(l.id_product) id_product1, min(r.id_product) id_product2 FROM t3 l LEFT JOIN t3 r ON l.id_project=r.id_project AND l.id_product < r.id_product GROUP BY l.id_project; -- Victor Y. Yegorov -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
