Re: Dreaming About Redesigning SQL

"Marshall Spight" <mspight_at_dnai.com> wrote in message news:<yZQmb.35715$HS4.125895_at_attbi_s01>...
> Okay, I'm not 100% sure I understand, because your notation is
> new to me. But if I read it correctly, you have a list (multivalue?)
> of phone numbers for each person and a list of persons for each
> phone number, is that correct?

Well yes - except that we would call each list a multivalued attribute.

>
> If it is correct, then there is a potential problem, illustrated by
> this dataset:
>
> File: Persons
> ID: Marshall
> PhoneNumbers: 123-4567, 234-5678
> ID: Mike
> PhoneNumbers: 222-2222
>
> File: PhoneNumbers
> ID: 222-2222
> Persons: Marshall
>
> See? The cross-table ids don't match. In the Persons file, 222-2222
> belong to Mike; in the PhoneNumbers file, it belong to Marshall.
>
> Is this possble in Pick, and if so, what, if anything, can be done
> about it? (If it's not possible, what did I get wrong?)
>

You *could* do this - although it's unlikely you'd want to. Could you not do it in SQL-relational? Received on Mon Oct 27 2003 - 06:47:44 CET