Re: SELECT statement not working as intended

On Mon, Oct 10, 2011 at 5:17 PM, Rich Shepard <rshepard(at)appl-ecosys(dot)com> wrote:
>  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.

remove the sample_date the group by and the select list. by having it
in there you are asking for the max for each specific sample date.

merlin