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Re: Pizza Example

From: mAsterdam <mAsterdam_at_vrijdag.org>
Date: Sun, 04 Apr 2004 12:27:32 +0200
Message-ID: <406fe30f$0$568$e4fe514c@news.xs4all.nl>


Dawn M. Wolthuis wrote:

> In trying to get a better handle on relational database design compared to
> XML or PICK database design, I'm writing up the example below and got stuck
> on just how a relational theorist would likely design this.

Will the true relational theorist please stand up ;-)

One swampy area where one may get stuck in is in the use of constrained lists: the fields Cheese and Toppings have listvalues, with a constraint on
the individual items (every individual value has to be present in a vocabulary).
 From earlier back and forth on that it looks like a sensitive issue. There are choices here, some of which depend on what we want, some depend on the DBMS, maybe some on both. When reverse engineering/refactoring it helps to know something about the target(s).

Where *did* you get stuck?

> ... Function/File: VALIDATIONS
>
> Purpose: This file maps a validation list name to the set of valid entries
> and their descriptions

>...

Maybe it also helps to know someting about the source: could you show how/where this constraint is/should be enforced? Received on Sun Apr 04 2004 - 05:27:32 CDT

Original text of this message

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