Re: Best way to do this query?

Marshall wrote:

> I run in to this kind of query every so often. I wonder if
> there's a canonical best way to do it?
>
> Consider the following schema:
>
> Invoices:{invoiceid, customerid, date, amount}
>
> Each invoice has an id, the id of the customer who opened the
> invoice, the date of the creation of the invoice, and the amount.
>
> If I want to know the date of every customer's most recent invoice,
> that's easy:
>
> select customerid, max(date) from Invoices group by customerid
>
> But suppose I also want to know the id and amount of that particular
> invoice?

See "quota query"

Your stated problem is a top 1 query, which is very similar to a top 10 query only with fewer tuples. Received on Sun Jan 14 2007 - 21:33:45 CET