In firebird-support@yahoogroups.com, "Rick Debay" <rdebay@r...>
wrote:

> I know of two ways to get records from set A that don't exist in
> set B.


> The first is to do a left join, and filter where B.nonNullValue
> is null. The other way would be to not do a join, and filter
> where there are no results based on a query similar to the
> previous join statement.

I may have completely misunderstood here, but I thought that
the MINUS set operator was specifically designed for
that purpose. I see other people have answered this
who know a lot more about SQL than I do and haven't mentioned
it. Would somebody care to explain why?


Paul...

> Rick DeBay