On Sat, Mar 04, 2006 at 03:35:02 +1100,
Alex <alex@meerkatsoft.com> wrote:
> Hi,
> i want to calculate the price difference, change% of 2 price records. Is
> there an easy way to do that within one query, rather than writing a
> function?
You can use a self join to do this. It won't be spectaculatly fast though.
The idea is too join each record to the record with the largest date less
than the date of the current record. Note that on record won't have a match.