Re: Oracle NULL vs '' revisited

Tony Rogerson wrote:

> Then why say this "Natural keys can not change. If it can change IT IS
> NOT A KEY it is just a value.".
>
> You seem to be under the impression that "Natural keys can not change".

If it CAN change it is NOT a key. That is the definition. Let me give you an example.

 From the standpoint of my bank and my bank account number ... they can never change. I may close an account ... I may open an account. But each account is uniquely defined by that account number.

If you need additional help with the concept please ask.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu (replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org