Re: Pizza Example
Date: Sun, 04 Apr 2004 12:27:32 +0200
Message-ID: <406fe30f$0$568$e4fe514c_at_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 - 12:27:32 CEST