Re: How to do a difference on two sets from same table?
Date: Tue, 31 Aug 2004 14:24:55 -0400
"Dan" <dan_at_nospam.com> wrote in message
> On 8/31/2004 12:02 PM, Alan wrote:
> > "Laconic2" <laconic2_at_comcast.net> wrote in message
> > news:2IadnZOYKbBuEancRVn-rw_at_comcast.com...
> >>"Alan" <not.me_at_uhuh.rcn.com> wrote in message
> >>>FROM same_place
> >>>WHERE other_condition
> >>As usual, your comments are excellent.
> >>I do have a quibble with you on this one. The "FROM same_place" is
> >>misleading. You don't always have
> >>to draw the second set from the same source as the first, just as you
> > don't
> >>necessarily have to draw both sets
> >>from the same source in UNION.
> >>When the sets are both drawn from the same source, it's possbile to
> > express
> >>the result without a MINUS,
> >>by just saying WHERE some_condition AND NOT other_condition. This
> >>the learner in a quandary about
> >>why the MINUS had to be added to the already complex bag of things to be
> >>learned. The MINUS is more useful,
> >>and sometimes necessary, when the two sets are drawn from different
> >>sources. The same comment applies to UNION.
> > I agree- I was debating whether or not to get into it- but I decided
> > give a very simple (unintimidating) example. I am surprised that Brio
> > doesn't offer MINUS. It could be that there is an end-user version and a
> > developer's version. I've seen this with several other tools.
> Maybe it is the DataDirect odbc driver I am using with Brio to access ms
> sql server. UNION works but EXCEPT (both from a list) errors out.
That's possible. I try in this order:
- Native connection (if supplied by the report tool vendor)
- Report tool vendor ODBC driver.
- RDBMS ODBC driver.
Sounds like you are using #2. Received on Tue Aug 31 2004 - 20:24:55 CEST