Re: using window-functions to get freshest value - how?

SELECT * FROM (SELECT *,row_number() OVER (ORDER BY letztespeicherung
DESC) FROM rfmitzeit) t WHERE row_number=1

On Fri, Nov 20, 2009 at 5:31 AM, Massa, Harald Armin <chef(at)ghum(dot)de> wrote:
>     id_bf,  wert, letztespeicherung:
>>>
>>>   98,  'blue', 2009-11-09
>>>   98,  'red', 2009-11-10
>>>     now I have a select to get the "youngest value" for every id_bf:
>>
>> Not tested:
>>
>> SELECT id_bf,      wert,
>>      max(letztespeicherung) over (partition by id_bf)
>> FROM rfmitzeit
>
> no, that does not work:
> "id_bf";"wert";"max"
> 98;"blue";"2009-11-10 00:00:00"
> 98;"red";"2009-11-10 00:00:00"
>
> result is: I get the date of the youngest value.
>
> My expected result is:
>
> 98;"red"
>
> (that is, the entry of "wert" that is youngest)
>
> thanks for trying,
>
> Harald
>
> --
> GHUM Harald Massa
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> Harald Armin Massa
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