On Wed, Jan 19, 2011 at 03:37:58PM -0500, Aram Fingal wrote: > Suppose I'm doing a group by query like the following: > > SELECT drug1, drug2, AVG(response) > FROM data > GROUP BY drug1, drug2 > > The problem is that the same drug may appear sometimes as drug1 and > sometimes as drug2. So, for example, the combination "aspirin, > acetaminophen" may also appear as "acetaminophen, aspirin" and I want > these grouped together in the query. Is there a simple way to do > this? instead of drug1 write: least(drug1, drug2) and instead of drug2 write: greatest(drug1, drug2) - both in select and group by. Best regards, depesz -- Linkedin: http://www.linkedin.com/in/depesz / blog: http://www.depesz.com/ jid/gtalk: depesz@xxxxxxxxxx / aim:depeszhdl / skype:depesz_hdl / gg:6749007 -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general