Re: Primary Key Theory Question

In news:9aie60p88f5p07u0osaud08km55aq03cri_at_4ax.com, Bob Hairgrove <wouldnt_you_like_at_to_know.com> typed:
: On Sun, 28 Mar 2004 18:56:03 GMT, Ben <BenNOSPAM_at_NOSPAMknieff2.com>
: wrote:
:
[Snipped...]
:: Example 2 - I see a person as an entity. SSN is a good candidate key
:: for a person, but in my situation, that information will frequently
:: be unknown. I see no other candidate keys. Yet if it is poor
:: practice to 'manufacture' a key, what approach should be taken?
:
: SSN is also not a good choice ... it can change, it is often unknown
: (foreigners to the USA and children don't have SSN), and it is not
: guaranteed to be unique in all cases (don't ask me for the source on
: this ... Joe will have a much better answer<g>)
[...Snipped]

SSN is *not* a good *primary* key in large personnel databases, working in the industrial temporary services industry, I can tell you have duplicate SSN's (ya know, the same guys sells the fake SSN cards to multiple people). Just a perspective from the employment end. Received on Mon Mar 29 2004 - 17:30:40 CEST