On Wed, Oct 5, 2011 at 7:34 PM, Rich Shepard <rshep...@appl-ecosys.com>wrote:
> A table (chemistry) has columns named site_id, sample_date, param, quant, > and str_name (among other columns). I want to find the site_id, > sample_date, > and quant for a specific str_name and param. I cannot get the proper syntax > in the SELECT statement. > > My attempts are variations of, > > SELECT max(quant), param, site_id, sample_date, str_name from chemistry > WHERE param = 'TDS' AND str_name = 'BurrowCrk'; > > which prompts postgres to tell me, > > ERROR: column "chemistry.param" must appear in the GROUP BY clause or be > used in an aggregate function > > I suspect that retrieving these data requires nested SELECT statements, > and I'd appreciate learning how to retrive such data. > > Rich > Based on your subject line, I'm guessing that you want something like this: select quant, param, site_id, sample_date, str_name from chemistry where param = 'TDS' and str_name = 'BurrowCrk' and quant = (select max(quant) from chemistry where param = 'TDS' and str_name = 'BurrowCrk')
