Rich Shepard <rshepard@xxxxxxxxxxxxxxx> writes: > What I need to do are three things: > 1.) Find the date and site for the maximum value of a specified constituent > on a named stream. > 2.) Find the values of that same constituent at other sites on the named > stream on that same date. > 3.) Find the date of the maximum value of a constituent for all sites on > the named stream. You can do that type of thing using subqueries, eg select ... from mytab where col = (select max(col) from mytab where ...) or if you don't mind a nonstandard construct, consider SELECT DISTINCT ON. There's an example of how to use that in the SELECT reference page (look for the weather-reports example). In any case you're going to have to consider what you want to have happen when there are multiple occurrences of the maximum value. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
