Re: Second Normal Form help.

So Garages should have it's own unique key and then use BuildingID as a foreign key?

"Tom" <Tom_at_webartisan.com> wrote in message news:9a06hm$1u0$1_at_bob.news.rcn.net...
> Sure, Its valid in first normal form. To be in second normal form, all
> non-key attributes need to be functionally dependant on the entire key,
 not
> key combinations.
>
>
> James_one <James_one_at_deja.com> wrote in message
> news:WUMw6.271824$65.1466583_at_news1.rdc1.fl.home.com...
> > Is that not a valid primary key, the combination of BuildingID and
> > GarageNumber?
> >
> >
> > "Tom" <Tom_at_webartisan.com> wrote in message
> > news:9a04n7$nfo$1_at_bob.news.rcn.net...
> > > .... If the BuildingId
> > > was primary and unique throughout ...
> > >
> > > I meant GarageNumber. Sorry.
> > >
> > >
> > > >
> > > > ...thats what you were asking, right?
> > > >
> > > > -tom
> > > >
> > > >
> > > > James_one <James_one_at_deja.com> wrote in message
> > > > news:GoMw6.271821$65.1466316_at_news1.rdc1.fl.home.com...
> > > > > Here is a simplified version of a model I'm working on.
> > > > > Buildings have many garages, and the garages can hold 1 or more
 trucks:
> > > > >
> > > > >
> > > > > CREATE TABLE Buildings (
> > > > > BuildingID int NOT NULL Primary Key ,
> > > > > BuildingName char (20) NOT NULL )
> > > > >
> > > > > CREATE TABLE Garages (
> > > > > BuildingID int NOT NULL REFERENCES Buildings(BuildingID),
> > > > > GarageNumber int NOT NULL ,
> > > > > Width int NOT NULL ,
> > > > > Length int NOT NULL ,
> > > > > Height int NOT NULL,
> > > > > PRIMARY KEY (BuildingID, GarageNumber)
> > > > > )
> > > > >
> > > > > CREATE TABLE Trucks (
> > > > > VIN char (20) NOT NULL Primary Key,
> > > > > TruckCapacity int NOT NULL ,
> > > > > BuildingID int NOT NULL ,
> > > > > GarageNumber int NOT NULL,
> > > > > FOREIGN KEY
> > > > > (BuildingID,GarageNumber)
> > > > > REFERENCES Garages (BuildingID,GarageNumber)
> > > > > )
> > > > >
> > > > >
> > > > > My question is about the garages table. Is it in second normal
 form?
> > > > > I mean do the dimensions(height width and length) of the garage
 depend
 on
> > > > > the whole primary key of garages or just the garage number?
> > > > >
> > > > > Thanks in advance.
> > > > >
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Received on Thu Mar 29 2001 - 22:45:40 CEST