Problem with GROUP BY

[Stephen Bennett]

I'm having a little trouble with GROUP BY

I want to return a list of only the most recent invoices for every customer. I've tried

SELECT InvoiceNumber, CustomerID, InvoiceDate
FROM bookings
GROUP BY CustomerID, InvoiceDate DESC;

But this returns every invoice. It does at least have the latest invoice first, but really I want to drop all older invoices.

How do I achieve this?