Re: Help finding natural keys

Jan Hidders wrote:
>In article <3E2808A5.29237234_at_nll.ibmm.com>,
>Anton Versteeg <av_at_nll.ibmm.com> wrote:
>>Jan Hidders wrote:
>>>
>>> The only requirement for a key is that *at every moment* there are no two
>>> entities (tuples) for which these values are the same. Since the firm
>>> name will be unique before the change and after the change it is
>>> therefore a good key.
>>
>>Sorry, I disagree: names are IMO not good for primary keys. Often they are
>>not unique and it is easy to enter wrong names (typo's etc) and thus wrong
>>keys.
>
>Well, if they are not unique then they are obviously not a key by
>definition. :-) The point was that if they are unique then you could use
>them as primary key.

         ^^^^^^^

That should have read "candidate". Whether they are suitable as primary keys is a different discussion.

• Jan Hidders