On 08/25/2015 09:40 AM, Melvin Davidson wrote:
> Adrian,
>
> Stop being so technical. When we/I speak of natural keys, we are
> talking about the column
> that would NATURALly lend itself as the primary key.
> No one ever said a number is not natural. just that there is no need
> to duplicate uniqueness
> with a separate number.
>
> IOW: If we have an account table, then the account_id or account_no
> would be the primary key. There is no need to have a separate
> serial id as the primary key.
If I'm following correctly, you're saying that if the definition of the
entity contains and arbitrary unique value then use that. Fine. I guess
I quibble with the notion of VIN as a "natural" attribute of car. (I
have no firsthand experience with VINs but I would bet there's
information tucked inside them, which would make me sceptical of using
them :) )