Re: Newbie question
Date: Tue, 21 Jun 2005 21:02:47 +0100
> Jon Heggland wrote:
>>Why is that? Just to avoid a lookup on the key value?
> I guess it's a practical consideration so that simple typos can be
> trapped by the client, to save hitting the database server. In some
> scenarios this could be useful.
Primarily it is required to prevent simple typos (or misread handwriting, or misheard phone calls) from picking up another (but wrong ) entity.
Think of a telephone mail order system -- if the card number is misheard we want a nice simple "computer says no" rather than the wrong credit card being debited.
Misha Received on Tue Jun 21 2005 - 22:02:47 CEST