Re: Table design question

"Mike Sherrill" <MSherrillnonono_at_compuserve.com> wrote in message news:qimk1018kh3htkap6gkdif05j1q8705v6v_at_4ax.com...
> On 25 Jan 2004 03:39:33 -0800, andrewst_at_onetel.net.uk (Tony) wrote:
>
> >But it isn't a domain: the domain of user ID numbers would be
> >something like "any 6 digit number between 100000 and 999999" or "a
> >string of between 3 and 30 letters and numbers"; whereas this table
> >represents the list of users who actually exist,
>
> Try thinking about it this way . . .
>
> At the conceptual level, a domain is just a data type, and a type is,
> among other things, a set of all possible values. One way to handle a
> set of values is to store them in a table.

It's the "among other things" that kills you. A variable is not a time invariant set of values and their associated operations. Received on Fri Jan 30 2004 - 18:46:56 CET