gnumed-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Gnumed-devel] Questions re database schema:street:address:urb:count


From: Horst Herb
Subject: Re: [Gnumed-devel] Questions re database schema:street:address:urb:country
Date: Tue, 31 Aug 2004 00:23:43 +1000
User-agent: KMail/1.6.2

On Mon, 30 Aug 2004 08:22, Richard Terry wrote:
> a) Table: public.street
>          id serial NOT NULL,
>           id_urb int4 NOT NULL,
>           name text NOT NULL,
>           postcode varchar(12),
>
> I take it that public.street  is an attempt to normalise street names, if
> so, why is _urb and postcode included in this.

Because there may be an XYZ street in urb A, and another XYZ street in urb B, 
and they are *not* identical, hence need different entries in a normalized 
database system.
Because, one day, urb A migth decide to rename street XYZ into street ZXY, and 
if I change the name of XYZ(A) it must not affect XYZ(B)

Horst




reply via email to

[Prev in Thread] Current Thread [Next in Thread]