Best way to do this query?
From: Marshall <marshall.spight_at_gmail.com>
Date: 14 Jan 2007 12:10:51 -0800
Message-ID: <1168805451.817253.183270_at_m58g2000cwm.googlegroups.com>
I run in to this kind of query every so often. I wonder if there's a canonical best way to do it?
Date: 14 Jan 2007 12:10:51 -0800
Message-ID: <1168805451.817253.183270_at_m58g2000cwm.googlegroups.com>
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?
Marshall Received on Sun Jan 14 2007 - 21:10:51 CET