From: Martijn Tonies
Date: November 14 2008 3:44pm
Subject: Re: normalised designs: customer database
List-Archive: http://lists.mysql.com/mysql/215212
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> >3) create the customer table with a FK for people and a FK for
> >companies, and decide on the customer type in the application based on
> >the presence of that key
> >
> [JS] I'm not sure why you need a foreign key. Surely you won't be entering
> customers using the MySQL CLI client on a routine basis, so your user
> interface could (and should) be responsible for checking the data.

Ehm, no, if it's possible, put the constraints -on the database- ... Never
ever rely on the application alone to enforce data consistency.

> If you really feel the need to constrain the data, define the column as a
> set.

Martijn Tonies
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