Don't know why this is not posted ... -----Original Message----- From: John Liu [mailto:johnl@emrx.com] Sent: Wednesday, March 31, 2004 11:50 AM To: 'pgsql-general@postgresql.org' Subject: select distinct w/order by I know this is an old topic, but it's not easy to find a way around it, so when we migrate SQL from other database to PostgreSQL, it causes a huge headache. Here's an extremely simple example - The original simple SQL - select distinct atcode from TMP order by torder; (it'll error out in PostgreSQL, although SQL92 extension may allow it; there's time you just can't do "select distinct atcode,torder from TMP order by torder"!!) My desire result - HGB HCT WBC RBC MCV MCH MCHC RDW RDWSD PLT DIFF | TYPE SEGS LYMPHS MONOS EOS BASOS I tried to rewrite the above simple query in PostgreSQL as - select distinct atcode from (select atcode,torder from TMP order by torder) t; But the return results are not what I want - BASOS DIFF | TYPE EOS HCT HGB LYMPHS MCH MCHC MCV MONOS PLT RBC RDW RDWSD SEGS WBC Can anybody provide a real/general solution to the above practical problem? (Tom?) This causes postgreSQL users too much time and headache. Thanks. johnl ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
