Hi, This probably reflects my confusion with how self joins work.
Suppose we have this table: =# SELECT * FROM tmp; a | b ---+--- 1 | 2 2 | 3 4 | 5 (3 rows) If I want to get a table with records where none of the values in column b are found in column a, I thought this should do it: =# SELECT * FROM tmp t1, tmp t2 WHERE t2.b <> t1.a; a | b | a | b ---+---+---+--- 1 | 2 | 1 | 2 1 | 2 | 2 | 3 1 | 2 | 4 | 5 2 | 3 | 2 | 3 2 | 3 | 4 | 5 4 | 5 | 1 | 2 4 | 5 | 2 | 3 4 | 5 | 4 | 5 (8 rows) I need to get: a | b | a | b ---+---+---+--- 1 | 2 | 1 | 2 4 | 5 | 4 | 5 Or just: a | b ---+--- 1 | 2 4 | 5 -- Seb -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
