Re: Union quries: INTERSECT, MINUS, etc

From: Nuno Souto <nsouto_at_optusnet.com.au>
Date: Thu, 24 Jul 2003 22:37:27 +1000
Message-Id: <26007.339415@fatcity.com>

Original Message ----- From: "Jonathan Gennick" <jonathan_at_gennick.com>

> I'm doing research for an article on union queries. I'm
> interested in finding examples of problems that were solved
> using UNION, UNION ALL, INTERSECT, or MINUS, with the latter
> two being of special interest because I don't see them used
> very often. If you can think of an interesting problem
> you've solved using one of these keywords, I'd love to hear
> about it.
>

UNION is useful to implement arcs.
INTERSECT I've used very successfully
with two CONNECT BY queries to retrieve all possible paths of travel between two points A and B in a table that implements flight legs. So don't go around saying it isn't used: I need it or the RAAF can't book people to flights. ;)

Cheers
Nuno Souto
nsouto_at_optusnet.com.au Received on Thu Jul 24 2003 - 07:37:27 CDT