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Re: 4NF and 5NF

From: Neo <neo55592_at_hotmail.com>
Date: 5 Jan 2005 07:54:48 -0800
Message-ID: <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 - 16:54:48 CET












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