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Re: Normalization, Natural Keys, Surrogate Keys

From: Pablo Sanchez <pablo_at_dev.null>
Date: Sat, 18 May 2002 21:01:30 -0600
Message-ID: <3ce71391$1_9@news.teranews.com>

"Tobin Harris" <comedyharris_at_hotmail.com> wrote in message news:ac5o6i$mh3n1$1_at_ID-135366.news.dfncis.de...
>
> > The reason I like singular is that when you do data model
validation
> > on the cardinality, you speak of an instance/row, not of multiple
> > rows. This is why I wouldn't agree with people who say to use
plural:
> >
> > [order] -----> [order_detail]
> > (0,N) (1,1)
> >
> > "An ORDER may or may not have an ORDER_DETAIL"
> >
> > "An ORDER_DETAIL must have at least one and at most one ORDER"
>
> That's exactly the same reason I use it. It's the cardinality that
> determines whether something is plural or not. For some reason
though, Celko
> (ISO) uses the number of records a table contains. It a table
contains one
> record then it would be singular, otherwise plural, or a collective
noun
> preferably. I'm pretty sure this is how he described it.
>
> I wander if it's better to use singular for logical modelling, then
plural
> for physical modelling? It the mo, I use singular for both, until
someone
> can convince me otherwise.

FWIW, I use singular for both logical and physical. This way the developers (myself included) don't lose information when they code. <g> (yes, that was intentionally full circle!)

--
Pablo Sanchez, High-Performance Database Engineering
mailto:pablo_at_hpdbe.com
http://www.hpdbe.com
Available for short-term and long-term contracts
Received on Sat May 18 2002 - 22:01:30 CDT

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