Re: question using aggregate function

From: paul c <toledobythesea_at_oohay.ac>
Date: Wed, 18 Jul 2007 03:31:41 GMT
Message-ID: <xQfni.127957$1i1.94169_at_pd7urf3no>


paul c wrote:
> Bob Badour wrote:
>

>> paul c wrote:
>>
>>> David Portas wrote:
>>>
>>>> "Mia" <nospam_at_cox.net> wrote in message 
>>>> news:WC9ni.3$fK1.2_at_newsfe12.phx...
>>>>
>>>>> I'm having trouble with a query concept.
>>>>>
>>>>> I know that:
>>>>>
>>>>> select max(order_date) from orders;
>>>>>
>>>>> will return the date of the newest order, and that:
>>>>>
>>>>> select supplier_id, max(order_date) from orders group by supplier_id;
>>>>>
>>>>> returns the newest order date from each supplier.  But I'm trying 
>>>>> to write a query that would return only the supplier_id of the most 
>>>>> recently placed order.  How would I do that?  I thought maybe:
>>>>>
>>>>> select supplier_id, max(order_date) from orders group by 
>>>>> supplier_id having max(order_date) = order_date;
>>>>>
>>>>> but it complains that order_date isn't a group by expression in the 
>>>>> having clause.
>>>>>
>>>>> Any ideas how to do this?
>>>>>
>>>>> -Mia
>>>>
>>>>
>>>>
>>>> Have you thought about using a correlated subquery?
>>>
>>>
>>>
>>> No offence to David P who knows much more about SQL than I do and 
>>> plenty else too I think, but somehow I can't imagine Codd talking 
>>> about correlated subqueries.  Don't know if he would have shuddered 
>>> at the term, but I do.  I guess in most fields, lingo eventually 
>>> passes understanding.
>>
>>
>>
>> Are you suggesting he would have found ALL or ANY or EXISTS foreign 
>> concepts?
>> ...

>
>
> i'm pretty sure that was a rhetorical question, but i'll sort-of bite
> anyway. I wonder what the heck do people who learned English as a second
> language think of these terms (which seem fundamental to me, not because
> I'm objective but because I'm used to them, so my thoughts may well be
> distorted by my upbringing and haven't yet learned how to compare them
> to the other themes that Codd involved in his idea, information
> principle and so forth).
>
> p

(I wasn't suggesting that one's first language is the only mental tool, have met people from many other countries who could express the ideas in   a formal notation, but as we see with talk about identity and views, the formal methods usually allow several different human interpretations.)

p Received on Wed Jul 18 2007 - 05:31:41 CEST

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