On Fri, Jan 20, 2006 at 01:58:16PM +0000, Richard Huxton wrote:
> Aside:
> Even if not using name+address as a primary key, a separate record
> should be kept of these details *at the time of the invoice* otherwise
> you'll never be able to match up a printed invoice with its digital
> source. Usually of course this is by inv_name, inv_address columns in
> the invoice header, but it could be by some fancy temporal versioning on
> client details.
Aside: Using name+address is terrible way for customers to identify
themselves. After you have a couple of experiences of ex-spouses trying
to hijack accounts you get fairly strict about what they have to know.
Bill identifiers, account identifiers, other surrogate keys are fine
but information that's reasonably general knowledge is nice, but not
enough.
Have a nice day,
--
Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.