Database Systems: Design and Online

Joanna Loveday

School of Engineering and Information Science

Coursework 2 – Further SQL and PLSQL

This is an INDIVIDUAL coursework.

Before you start this coursework you should have completed the SQL exercises on the Bus/Drivers/Depots Database. If you need

to revise this topic, see Text book Chapters 5 & 6.

Important note – check that you have not, in previous modules, created tables with the same names as in this exercise. If any

of these table names already exist in your area within Oracle then you must either delete them (using ‘drop table xyz cascade

constraints’) or use different names for tables in the coursework database. There may also be problems if constraint primary

key and foreign key names are the same so it is advisable to delete all tables created in previous modules. After creating

and loading tables check that all data is present.

Use Oracle SQL*PLUS to answer the following queries. It is recommended that you either use Notepad or similar (not Word) to

initially create the queries.

The Children’s Library Database

This scenario relates to a database which is to be set up for a library which lends books to children:

A Children’s Library keeps information on books held, borrowers who borrow these books and the loans of these books, which

the borrowers make. In addition information is held about the authors and publishers of these books.

The information is to be held in a Relational database and implemented using Oracle. Two files are available on OasisPlus for

you to create the relations and to load the relations with sample data. The tables in the database are shown below. The

identifier attribute(s) are underlined, foreign keys are asterisked *.

Table Attributes
Borrower borId, borName, borAddress, borMaxbooks

BookTitle isbn, btName, datePublished, pubId*, ageLower ageUpper, value

BookCopy bcId, isbn*, dateAcquired, dateDestroyed

Loan borId*, bcId*, dateOut, dateDue, dateBack

Publisher pubId, pubName, pubAddress

Author authorId, authorName

Authorship authorId*, isbn*

Note that the BookCopy table holds information on the physical books stored in the library whereas the BookTitle table holds

information on a particular publication of a book. For example, there are two copies of ‘Winnie the Pooh’, with bcId of 101

and 102 with an ISBN (International Standard Book Number) of 10: 0786843411. The BookTitle table hold information about the

recommended age range for each book (ageLower and ageUpper). A book may have a number of authors and this is indicated in the

Authorship table.

The attribute borMaxbooks indicates the maximum number of books that a borrower can borrow at a time. Also, a book, which is

still out on loan, will have a blank dateBack field in the loan table.

As copies of books become old, damaged and dirty the books are removed from the library and destroyed. Destroyed book copies

have a date to indicate this otherwise the date is null.

It is essential that you draw an Entity-Relationship diagram mapped to a relational database, showing the entities and

relationships involved. Assume that attributes with the same name are based on the same domain. Do not hand in this diagram –

it is not assessed.

Coursework 2 – Further SQL

Use join conditions to answer the queries in this questions 1 and 2
Q1 Find borrowers (by name) who have ever borrowed a book written by Phillip Pullman.

Q2 Find borrowers (by name) who have currently on loan a book written by Phillip Pullman

Q3 Give the ISBN and title of each book and the number of copies currently on loan listing most popular first.

Q4 Display the names of borrowers who have never borrowed books published by the publisher Mammoth.

Q5 Give the titles of books which have the same value as ‘Northern Lights’. Do not include Northern Lights in your output.

Q6 List all book titles and the total value of the book copies for a particular title which are currently on loan where the

total value is greater than or equal to £20.

Q7 List the borrowers (by number and name, once only), who have currently on loan a book which has the same title as a book

that Jenny Wren has borrowed. Do not include Jenny Wren in the output.

Q8 Give the name of any borrower who has ever borrowed all the book copies in the library. It is possible that no-one has

borrowed all the copies. (Hint: this is an example of relational algebra divide).
Continued/

Q9 Run the Create View statement and the query below and show the results. Give the English meaning of the query (as in

questions 1-7 above):

Create view borrowedBooks
As Select l.borId, bc.isbn, bc.bcId
From Loan l, bookCopy bc
Where l.bcId = bc.bcId;

Select b.borName
From Borrower b
Where not exists
(select *
from bookTitle bt, Publisher p
where bt.pubId=p.pubId
and pubName=’Puffin’
and not exists
(select *
from borrowedBooks bb
where bb.borId = b.borId
and bb.isbn = bt.isbn));

Q10 Run the query below and show the results. Give the English meaning of the query (as in questions 1-7 above):

Select distinct b.borName
From Borrower b, Loan l, Book_copy bc,
Author a1, Author a2,
Authorship ash1, Authorship ash2
Where b.borId = l.borId
And l.bcId = bc.bcId
And bc.isbn = ash1.isbn
And bc.isbn = ash2.isbn
And ash1.authorId = a1.authorId
And ash2.authorId = a2.authorId
And a1.authorName = ‘Janet Ahlberg’
And a2.authorName = ‘Allan Ahlberg’;

Coursework 2 PL/SQL – Triggers and stored procedures

Don’t forget to type the command ‘set serveroutput on’ before executing the code in this section. If you are forced out of

SQL*PLUS don’t forget to retype this command.

Again it is recommended that you either use Notepad or similar to initially create the code.

Before you start this coursework you should have completed the PL/SQL exercises on the Bus/Drivers/Depots Database. If you

need to revise this topic, see text book Chapter 6.

I have put some PLSQL code examples (from the text book) on OasisPlus to use as templates to help you with this part of the

coursework.

1. Write a PL/SQL block which includes a procedure getTotalLoans which accepts a ISBN and returns the title and number

of copies currently on loan for that book. (See Question 3 of the SQL queries part of the coursework.) The main block should

call the procedure with an ISBN of 4 and output the book title and number of copies.

2. Write a PL/SQL block, which displays for all book titles held in the library (not those destroyed). You should

include the ISBN, the book title, publisher name and the number of copies of each held (whether on loan or not). Use a cursor

to do this question.

3. Write a stored function called getPublisher. This function takes as input an ISBN for a book and returns the

publisher name.

Call the function from within an SQL statement to display the publisher for book title ‘The Twits’

4. Create a trigger ‘checkRecommendedAge’ to enforce the (harsh) constraint that children are only allowed to borrow

books deemed suitable for their age. The trigger fires whenever there is a new loan and outputs an error message whenever an

attempt is made to borrow a book where the borrower’s actual age is not within the lower to upper age range for the book.

Ignore the fact that some of the data already in the database may violate the constraint.

Show what happens when you try to insert following records into the Loan table using the following statements:

Insert into Loan values (001,144,’29-aug-2008′,’18-sep-2008′,”);
Insert into Loan values (001,101,’29-aug-2008′,’18-sep-2008′,”);
Insert into Loan values (001,120,’29-aug-2008′,’18-sep-2008′,”);

For testing purposes the following commands (which set the database back to its original state) might be useful:

delete from Loan where borId=001 and bcId=144 and dateOut=’29-aug-2008′;
delete from Loan where borId=001 and bcId=101 and dateOut=’29-aug-2008′;
delete from Loan where borId=001 and bcId=120 and dateOut=’29-aug-2008′;

Note well: read following page before handing in your coursework

Your submission should consist of an Oracle SQL print-out of the SQL code which is your solution to the problems above. All

code must be visible to receive the marks. Note that marks will be awarded for SQL and PLSQL code which is easy to read and

hence easy to debug. Each answer should consist of the following:

o For SQL coding, indication of the question a particular solution refers to, written as a comment e.g. /* Question 1

List the borrowers……*/

o For PLSQL coding the question number is required only.

o The SQL and PLSQL code in its entirety, formatted with indentations so it is easy to read (see code in text book).

Please use a reasonable size of font. All code must be present to receive the marks.

o SQL*Plus Screen print to verify that you have executed the code

o The resulting table created from the SQL execution or results from your PLSQL execution. You should copy the results

from SQL*Plus. If the output is very long, hand in the first page only. Note that the correct solutions generate small

tables. Do not print/hand in unnecessary paper- save trees!

o No cds or similar to be handed in

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