Re: question using aggregate function

"Bob Badour" <bbadour_at_pei.sympatico.ca> wrote in message news:469e049b$0$8865$9a566e8b_at_news.aliant.net...
> paul c wrote:
> > paul c wrote:
> >
> >> Bob Badour wrote:
> >>
> >>> paul c wrote:
> >>>
> >>>> David Portas wrote:
> >>>>
> >>>>> "Mia" <nospam_at_cox.net> wrote in message
> >>>>> news:WC9ni.3$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.)
>
> English pollutes a lot of mathematics.

More so than German or Swahili? Received on Wed Jul 18 2007 - 17:01:00 CEST