Re: practice test question...

thank you Jan,

I'm going to put some time into this today. You've given me some solid direction, which is exactly what I was hoping for!

**thanks**

Pat.

Jan Hidders <hidders_at_REMOVE.THIS.win.tue.nl> wrote in message news:98krg9$eua$1_at_news.tue.nl...
> MadG wrote:
> >
> > I have a test Friday in my Database Systems class. The prof gave us
> > a practise test with this question. He's not taking anything up and
> > I'm really stuck. I've gotten as far as what's included, but
> > everytime I try to expand the answer it looks wrong.
> >
> > Could you help?
>
> Yes, but I am only going to tell you what I think your teacher would
> have said if he was in a more helpful mood. :-)
>
> > ---- Entites
> > TEXTBOOK (ISBN[PRIMARY KEY], BOOKNAME, AUTHOR, AFF_NUM[FORIEGN KEY
> > --A.TABLE], YEAR. COST (SUPPLEMENT)[REPEATING GROUP])
> >
> > PUBLISHER (PUB_NUM[PRIMARY KEY], PUB_NAME, CONTACT, WEBSITE,
 LAST_CONTACT)
> >
> > AFFILIATE (AFF_NUM[PRIMARY KEY], PUB_NUM[FOREIGN KEY -P.TABLE],
 AFF_NAME)
> >
> > ----
> >
> > Keep track of textbook features to be evaluated (content coverage,
> > ease of reading, exercises, cost), the weights (1-3) associated with
> > each of these features and the evaluation number (1-10) scored for
> > each feature of a particular textbook.
>
> Think of the entity 'Evaluation'.
>
> Important questions: What attributes belong to an Evaluation? What
> identifies an Evaluation? Is the relationship between Evaluation and
> Textbook a one-to-one, one-to-many, many-to-one, or a many-to-many
> relationship?
>
> > There is a requirement to identify the textbooks being evaluated for
> > different subject areas (example: systems analysis and design;
> > database systems; C++ programming)
>
> Think of the entity 'Subject area' and ask the same questions. What
> attributes are there? How is a subject area identified. What type of
> relationship does it have with Book?
>
> > I don not know how to take care of the repeating group. I had
> > thought that perhaps I should create an entity SUPPLEMENT but from
> > there I get stuck as to what to include.
>
> You have to include of course the information in the repeating group
> itself, but also something that relates these records to the original
> records that they belonged to. What foreign key could do that?
>
> Good luck,
>
> --
> Jan Hidders
Received on Tue Mar 13 2001 - 13:26:42 CET