On 11/7/07, Paul McNett <[EMAIL PROTECTED]> wrote: > > I guess the simplest way to say why it is bad is that you now have a row > with a different meaning from the rest, and we all know that different > meanings really belong in different datasets. >
Good explanation. And to expand a bit: it looks easy enough in the simple case, but most of my SQLs turn out to have four or five joins, and an outer join, and a subquery; those all have to be written twice, once for the top query, and once for the bottom query, and kept in sync, along with the field lists. Change one without changing the other and you get column mismatches or worse, the wrong totals without any warning. You've denormalized your SQL and violated the DRY (Don't Repeat Yourself) principle. Not that I haven't tried to get away with it on occasion, but you need to be wary of the many ways this can bite you. -- Ted Roche Ted Roche & Associates, LLC http://www.tedroche.com _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/profox OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/[EMAIL PROTECTED] ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
