Re: SELECT statement not working as intended

On Mon, Oct 10, 2011 at 6:14 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote:
> On Mon, Oct 10, 2011 at 4:17 PM, Rich Shepard <rshepard@appl-ecosys.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.

Correction.

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 order by 4 desc limit 1;