Re: The..Horror.....The..Horror.

From: Nuno Guerreiro <nuno-v-guerreiro_at_invalid.telecom.pt>
Date: Tue, 12 Jan 1999 16:30:23 GMT
Message-ID: <369b74b5.20996541@news.telecom.pt>

On 12 Jan 1999 03:51:20 GMT, Joe & Anne Buhl <jabuhl_at_worldnet.att.net> wrote:

>Hello,
>
>I just took a new position at a small company. I was not to disturbed
>to find out that they do not utilize referential integrity constraints.
>But to my horror, I found out today that they actually create child
>records with which there is no parent. Sequence numbers are used
>exclusively. They create the foriegn key as a sequence number then when
>they need attributes from the parent they create the parent record.
>
>This violates one of Codds original principals of the relational model.
>I don't have any experience with this type of activity. I don't know
>what kind of problems it causes other than having a bunch of orphan
>records in the table. It seems to me that it is no longer a relational
>database but a database dump.
>
>Can any of you give me some real world examples of the problems this can
>cause.
>
>Please copy me at jbuhl_at_commerce.com for your responses.
>
>Thanks
>
>joe
>

I would advise them to start using database integrity extensively (not only referential) and present its advantages:

If integrity rules are defined on the client side (coded on an application), then:

1.a. there is a lot of (unpleasant) work to be done when the application needs to be created from the ground up on a different programming language, technology, etc.

1.b. When there are several different applications accessing the same database, the same business logic needs to be replicated on every application.

2.. If roles protected by password are not used (and activated by the application on startup), users will be able to go to SQL*Plus (or Access, or whatever) and perform inserts, deletes, etc. as they wish and potentially violate business logic.

3.. When integrity rules are defined on the database, their meaning is far clearer than when they are mixed up with some programming language on the client side. Besides, you can use several tools to get a visual understanding of the relationships between the different objects on the database.

Good Luck,

Nuno Guerreiro

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Walt Whitman Received on Tue Jan 12 1999 - 10:30:23 CST