Emi Lu <[EMAIL PROTECTED]> writes: > Just notice one small thing, and need your information about select
> select col1, col2 > from table1 > left join table2 > using (col1, col2) > ; > This query never complain about ambiguous columns of col1 and col2 in > the select part. That's because you used USING, which merges the similarly-named columns into just one output column. RTFM, or any SQL book. regards, tom lane -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql