Re: Modeling Address using Relational Theory

From: dawn <dawnwolthuis_at_gmail.com>
Date: 31 Aug 2005 19:17:02 -0700
Message-ID: <1125541022.387943.240990_at_f14g2000cwb.googlegroups.com>


Marshall Spight wrote:
> dawn wrote:
> >
> > Absolutely agreed. However, the student with a Major1 of Biology and a
> > Major2 of Theater is likely to walk at graduation with the Theater
> > majors while if the order is reversed, they will walk with the Biology
> > majors (this is, of course, dependent on the business rules of the
> > institution, but the fact is that business rules might be set based on
> > this ordering whose value is embedded in an attribute name).
>
> Well, I actually have two majors, and I can tell you that there
> was no ordering between them in the "business rules" of the
> university that I attended.

I've worked with several colleges and universities and sometimes there is a (slight) difference and often there is not. But in the cases where there is a difference, Major1 is the major major. That might only mean that in instances where they need to have mutually disjoint sets of majors for students showing up somewhere at a given time, the "first major" is the one the student is directed to. In some cases that might be the one first in alpha order. In cases where there is no difference, then we are talking about a set and not a list.

>
> > Yes and that is one of my points. I was completely unaware that it was
> > considered proper relational modeling to place ordering data in
> > attribute names,
>
> It isn't. And that's not what's happening with addresses, either.

Can you explain to me what the difference is between addressLine2 & addressLine3 as far as what the values can be and/or what they mean other than that one is placed in order before the other? What could they be named that doesn't have ordering information in the attribute names? Sorry to be dense -- I just want to understand this one as I started explaining something very small and got caught on the address.

Thanks. --dawn

>
> Marshall
Received on Thu Sep 01 2005 - 04:17:02 CEST

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