Hi. I'm using PostgreSQL 7.4.2 under Fedora Core 1. I have two tables with a single varchar(32) column in each. I'm trying to find all the rows from one table that don't exist in the other table. The query that I am using is:
select u.user_name from users u where u.user_name not in (select user_name from iasusers); (Actually, I'm doing something a bit more complex but this illustrates the problem.) It always seems to return 0 rows. As a test, I inserted a row into users that I knew wasn't in iasuses but it didn't make a difference. If I remove the 'not', the query returns the rows that exist in both tables. If I replace the subselect with a list, it seems to work the way that I'd expect, i.e. "not in ('vic', 'joe')" it shows all the rows from users except for vic and joe. Am I doing something wrong or is this a bug? Thanks, -Vic ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly