Re: 4NF and 5NF

Thanks. I'm sort of missing your point. Perhaps you could explain what this all means.

Cheers, Mike

"Neo" <neo55592_at_hotmail.com> wrote in message news:1104940488.918072.284480_at_c13g2000cwb.googlegroups.com...
>> HouseNotes
>> buyer seller lender
>> ==================================
>> Smith Jones National Bank
>> Smith Wilson Home Bank
>> Nelson Jones Home Bank
>
> Script below shows an alternate solution using an eXperimental Db:
>
> // Create persons
> CREATE *person.item ~in = dir;
> CREATE *smith.cls = person;
> CREATE *nelson.cls = person;
> CREATE *jones.cls = person;
> CREATE *wilson.cls = person;
>
> // Create buyers
> CREATE *buyer.item ~in = dir;
> CREATE smith.cls = buyer;
> CREATE nelson.cls = buyer;
>
> // Create sellers
> CREATE *seller.item ~in = dir;
> CREATE jones.cls = seller;
> CREATE wilson.cls = seller;
>
> // Create banks
> CREATE *bank.item ~in = dir;
> CREATE *national bank.cls = bank;
> CREATE *home bank.cls = bank;
>
> // Create lenders
> CREATE *lender.item ~in = dir;
> CREATE national bank.cls = lender;
> CREATE home bank.cls = lender;
>
> // Create house notes
> CREATE *house note.item ~in = dir;
>
> // Create 1st note
> CREATE *;
> CREATE it.cls = house note;
> CREATE it.buyer = smith;
> CREATE it.seller = jones;
> CREATE it.lender = national bank;
>
> // Create 2nd note
> CREATE *;
> CREATE it.cls = house note;
> CREATE it.buyer = smith;
> CREATE it.seller = wilson;
> CREATE it.lender = home bank;
>
> // Create 3rd note
> CREATE *;
> CREATE it.cls = (%.name=house note & %.item~in=dir);
> CREATE it.buyer = (%.name=nelson & %.cls=buyer);
> CREATE it.seller = (%.name=jones & %.cls=seller);
> CREATE it.lender = (%.name=home bank & %.cls=lender);
>
> // Find a note where buyer is smith,
> // seller is wilson and lender is home bank.
> // Finds 2nd house note.
> SELECT %.cls=house note & %.buyer=smith & %.seller=wilson &
> %.lender=home bank;
>
Received on Wed Jan 05 2005 - 18:26:17 CET