December 24th, 2002, 03:40 PM
ER Diagram help
Hi, I can anyone solve this question, or at least, attempt it. I have tried it and tried it and I think im wrong .
Any help would be appreciated
A library houses a collection of books, which may be borrowed by or, if unavailable, reserved
by its members. If a copy of a book that has been reserved becomes available, the library will
contact the member reserving the book to notify them of its availability, and hold it for a
period of 5 days. The library will also contact borrowers to notify them when a book that they
have borrowed is overdue. Borrowers of overdue books are not permitted to borrow any more
books until those which are overdue are returned. Books that are overdue by more than 3
months are deemed to be lost and must be paid for by the borrower. Books are categorised
into three classes, depending upon age and subject. The loan period for a particular book
depends on its allocated class and on the status of the borrower. The status of the borrower
also limits the number of books that they are permitted to have on loan simultaneously.
Every book is allocated a unique International Standard Book Number (ISBN) when it is first
published. In addition, when a new book arrives at the library, it is given a class mark by the
Librarian, which determines where it is shelved, and entered into the catalogue.
(i) Develop on E_R model, including attributes, for this UoD. You may draw on your
experience of libraries to make any further assumptions about the UoD that you
need to determine the cardinality and participation of any relationships or the
attributes chosen for the entity sets but you must make them explicit in your
(ii) Generate the logical database design from your ER model, indicating any domain
constraints which may apply.
(iii) Suggest two applications which the database would need to support and verify that
your design is capable of so doing.
December 26th, 2002, 12:09 PM
this sounds like homework to me...at least it isn't really a real life example - so excuse me if i'm wrong...but pls do your homework yourself ;-)