hi all,

I need to construct an ER diagram involving a student. The student has
the usual attributes including student number, name, telephone etc.

In addition I am told that he is in a CLASS, freshman, sophomore, etc

and that he may be part of major or minor DEPARTMENTS,

and DEGREE PROGRAM (B.A., B.S., ..., Ph.D.).

How do i treat class, departments and degree?

Can they be attributes of student, or something else..?

thanks

Shannon

shannon <shannon (AT) nolunchmeat (DOT) com> wrote:
department - entity with relationship to degree
(student) degree - entity with relationship to student

Read your textbook. No one here will do your homework for you.


"shannon" <shannon (AT) nolunchmeat (DOT) com> wrote

whats up, I am just tryin to learn DB,

if you can't help then thats okay,

Alan wrote:

shannon> whats up, I am just tryin to learn DB, if you can't help then thats
shannon> okay,

shannon> Alan wrote:

What Alan (I guess) meant is that books tell, that it depends. If you have no
other information of the degree but its name, then it is an attribute. If you
have lots of information, like how many points (we use term study week) it
lasts, when the degree was given etc., then it is an entity.

I guess one approach is to make all things entitites, and then collect those
together you can. Another is to make a one big entity (or universal relation
in relation system), and split it to smaller ones.

But as Alan said, read your textbook.

--
Arto V. Viitanen av (AT) cs (DOT) uta.fi
University of Tampere, Department of Computer Sciences
Tampere, Finland http://www.cs.uta.fi/~av/

As all insist I should read my text book, then I guess its time to buy one,

I am doing online tutorials but there is not enough content in them to
make the complex stuff understandable,

the two textbooks that I see most mentioned are,

Fundamentals of Database systems
(Ramez Elmasri, Shamkant Navathe)

An Introduction to Database Systems
(C.J.Date)


Fundamentals is vastly more expensive than the other, Is it worth it?

Are there acceptable alternatives?

Greetings

Shannon

Any good public library system should have both even if perhaps not the
latest edition.

"shannon" <shannon (AT) nolunchmeat (DOT) com> wrote

Elmasri is a very good book, and is a standard text in many colleges. If you
are not mathematically minded, you can skip the algebraic gobbildy-gook that
permeates the book. Most of it is not necessary, but is helpful if you are
thus inclined.

"shannon" <shannon (AT) nolunchmeat (DOT) com> wrote

shannon <shannon (AT) nolunchmeat (DOT) com> wrote

and then creating one that meets your requirements.

This the approach that I would suggest which will help you in
constructing an ER diagram that culd be used to design a Database for
an operational system :-
1) Start by looking at the Student-related Models on this page of
the Database Answers web site :-
http://www.databaseanswers.com/data_models/index.htm
2) Identify the Data Model(s) that most closely match your
requirements.
3) Choose the Entities that you need (a valuable learning
experience)
4) Assemble the corresponding Business Rules
5) Modify the Rules as appropriate.
6) Assemble some Test Data - just 10 or 20 records.
7) Define a typical User Scenario based on the test data.
8) Put 4 pieces of paper on a desk or table -
i) Data MOdels
ii) Business Rules
iii) User Scenarios
iv) Test Data
9) Reflect on them while driving, in the shower, on the bus/train,
out walking and so on.
10) Prepare a presentation to show the requirements,(Rules), and the
logic of
your solution.
11) Let me know how it goes !

Good luck.

Barry Williams

shannon wrote:
A book that I would strongly recommend is

Lewis, Bernstein and Kifer: Databases and Transaction Processing - An
Application Oriented Approach

It is well worth the money, and touches more subjects as far as I can tell.