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Re: Many To Many Relationships

From: David Cressey <cressey73_at_verizon.net>
Date: Tue, 17 Apr 2007 10:28:39 GMT
Message-ID: <rj1Vh.13650$Ln5.11380@trndny06>

"Marshall" <marshall.spight_at_gmail.com> wrote in message news:1176756330.363208.181810_at_o5g2000hsb.googlegroups.com...
> On Apr 16, 1:20 pm, "David Cressey" <cresse..._at_verizon.net> wrote:
> >
> > > Something like that. Requires RVAs and an aggregate union.
> > > Clearly no standard way to do in SQL, but there might be
> > > some hack that lets you do the union as a string operation
> > > which might be sufficient for some applications.
> >
> > OK, but what I offered was not a hack. For once, I was trying to give a
> > serious response to this kind of question.
> >
> > (You may not recognize it as such, but it's the same question that Dawn
has
> > raised a dozen times in the last few years.)
> >
> > Pushing the result of a SQL query through a hierarchical report writer
is
> > really not hacking. It's serious work, albeit without much theoretical
> > merit at all.
>
> Oh, totally. I didn't intend to detract from your answer at all.
> Your answer was practical; mine was almost entirely impractical.
>
>

Then again, I'm thinking that maybe there is a lesson for theoreticians to learn in this exchange.

Turning relational data into hierarchical data is "trivial", in every sense of the word. turning hierarchical data into relational data is, in some cases, non trivial. This suggests that storing database data in relational form is better than storing it in hierarchical form, provided there is some utility in doing so.

Most theoreticians already know this, and know it better than I have verbalized it. But it's worth making it explicit.

> Marshall
>
Received on Tue Apr 17 2007 - 05:28:39 CDT

Original text of this message

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