Tom Lane wrote: > Bruce Momjian <[EMAIL PROTECTED]> writes: > > Well, it can be an expression _if_ the expression _matches_ an existing > > UNION column. > > You're mistaken. It has to be *an output column name*. Not anything else.
Yea, I was thinking of this: SELECT *, state IS NULL AS state_is_null FROM income_tax_rate_us UNION SELECT *, state IS NULL AS state_is_null FROM income_tax_rate_us ORDER BY state_is_null Here the column result is an expression, and you reference that. Updated wording: test=> select * from test union select * from test order by x is null; ERROR: A UNION/INTERSECT/EXCEPT ORDER BY cannot use expressions or functions, only result column names -- Bruce Momjian [EMAIL PROTECTED] EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq