Re: pgsql aggregate: conditional max

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От Weimao Ke
Тема Re: pgsql aggregate: conditional max
Дата
Msg-id 44145265.6030100@indiana.edu
обсуждение исходный текст
Ответ на Re: pgsql aggregate: conditional max  (Michael Fuhr <mike@fuhr.org>)
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Michael Fuhr wrote:

>On Sun, Mar 12, 2006 at 12:34:57AM -0500, Jeffrey Melloy wrote:
>  
>
>>Should be able to do this with a standard max() aggregate.
>>
>>select aid, cat, max(weight)
>>from table
>>group by aid, cat;
>>    
>>
>
>That query returns the maximum weight for each (aid, cat) pair.
>Against the example data it returns the entire table, not the
>(aid, cat) pair with the max weight for a given aid.
>
>  
>
Michael is right. This query does not solve the problem...

-- 
All best, 

Weimao

Weimao Ke
Indiana University Bloomington
School of Library and Information Science
http://ella.slis.indiana.edu/~wke



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