I'm trying to query the table to extract the single highest value of a chemical by location and date. This statement gives me all the values per stream, site, and date:
SELECT str_name, site_id, sample_date, max(quant) FROM chemistry WHERE hydro = 'Humboldt' group by str_name, sample_date, site_id order by str_name, site_id; I'm not seeing why this doesn't work; the top few lines of output are: CalifCrk | CalCrk | 1996-10-18 | 188 CalifCrk | CalCrk | 1996-08-23 | 183 CalifCrk | CalCrk | 1996-07-29 | 201 CalifCrk | CalCrk | 1996-09-27 | 185 when what I want is only the third line. A clue to the correct syntax is solicited. I'm sure it's something simple that I'm just not seeing. Rich -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
