Question 1
Cutting Edge Incorporated is a company engaged in the development of computer-aided
design (CAD) software packages. The management of Cutting Edge wants to develop a
project tracking system to accumulate and report data on current projects, employees and
departments. System analyst Suriyati Ahmad developed the following initial record
design:
(ProjectNumber,
ProjectName,
StartDate,
ProjectStatus,
(EmployeeNumber,
EmployeeName, DepartmentNumber, DepartmentName, JobTitle, ProjectHours))
Suriyati believes the only system entities are Project, Department and Employee; but
because she is assigned to two other projects, she had no time to consider the
relationships among those system entities or to normalize the record design.
a)
For each of the three entities, identify the likely primary key.
(3 marks)
Answer:
Project – ProjectNuimber
Department – DepartmentNumber
Employee - EmployeeNumber
b)
Draw an initial entity-relationship diagram for the system, using the entities
Suriyati identified. State any assumptions you must make about the Cutting Edge
organization to determine the types of the relationships.
(6 marks)
Answer:
Have
PROJECT
DEPARTMENT
Works
Handle
EMPLOYEE
c)
Convert the record design to third normal form.
(11 marks)
Answer:
1NF
Project (ProjectNumber, ProjectName, StartDate, ProjectStatus)
Employee
(EmployeeNumber,
DepartmentName, JobTitle, ProjectHours)
EmployeeName,
DepartmentNumber,
2NF
ProjectStatus(ProjectNumber, EmployeeNumber, StartDate, ProjectStatus)
Project (ProjectNumber, ProjectName)
Employee
(EmployeeNumber,
DepartmentName, JobTitle, ProjectHours)
EmployeeName,
DepartmentNumber,
3NF
Department ( DepartmentNumber, DepartmentName)
DepartmentProject(DepartmentNumber, ProjectNumber)
Employee ( EmployeeNumber, EmployeeName, JobTitle, ProjectHours)
d)
Draw a final entity-relationship diagram for the system.
(10 marks)
Answer:
PROJECT
PROJECTSTATUS
PROJECTDEPT
DEPARTMENT
EMPLOYEE
Question 2
Do a normalization from First Normal Form (1NF) until Third Normal Form (3NF) and state the
rules for the normalization based on the given CustomerOrder relation. Then draw a complete
Entity-Relationship diagram based on the normalized relation.
CUSTOMERORDER (CustNo, CustName, OrderNo, ProdNo, ProdDesc, Qty, CustAddress,
DateOrdered)
Assumption: A customer can have multiple orders but an order can be for only 1 product.
(20 marks)
Answer:
1NF - remove multivalued dependencies (1 mark)
CUSTOMER (CustNo, CustName, CustAddress) (1 mark)
ORDER (CustNo, OrderNo, ProdNo, ProdDesc, Qty, DateOrdered) (1 mark)
2NF - remove partial dependencies (1 mark)
CUSTOMER (CustNo, CustName, CustAddress) (1 mark)
CUSTOMER ORDER (CustNo, OrderNo) (1 mark)
ORDER (OrderNo, ProdNo, ProdDesc, Qty, DateOrdered) (1 mark)
3NF - remove transitive dependencies (1 mark)
CUSTOMER (CustNo, CustName, CustAddress) (1 mark)
CUSTOMER ORDER (CustNo, OrderNo) (1 mark)
ORDER (OrderNo, ProdNo, Qty, DateOrdered) (1 mark)
PRODUCT (ProdNo, ProdDesc) (1 mark)
Customer
make
1
m
CustomerOrder
m
list
1
Order
m
has
1
Product
(entities = 4 marks, relationship = 3 marks, any 1 cardinality = 1 mark)
Question 3
a)
Write SQL statements based on the following Employee schema relation:
Employee (EmployeeNo, EmployeeName, EmployeeIC, Address, Sex, HandphoneNo, Email,
Salary, Position, Skill, BranchNo)
i)
Identify the foreign key and candidate key in the relation.
(2 marks)
Answer:
Foreign key = BranchNo
Candidate key = EmployeeIC
ii) List all employee who stay in Selangor and works in branch B003.
(3 marks)
Answer:
SELECT *
FROM Staff
WHERE Address = “%Selangor%” AND BranchNo = “B003”;
iii)
List all staff with a salary below 20,000 or above 30,000.
(3 marks)
Answer:
SELECT *
FROM Staff
WHERE salary NOT BETWEEN 20000 AND 30000;
b)
Draw ERD for the following scenario:
“Employee works at a branch. There must be at least 20 employees for each branch. The
branch is managed by a manager. The employee may handle a project or given an
administrative task.”
(12 marks)
Answer: (entities= 4 marks, relationship = 4 marks, cardinalities=4 marks)
Employee
1
Project
manage
work
1
1..1
Branch
1
handle
0..*
1
1..20
handle
0..*
Admin Task
Question 4
Sailors (sid, sname, rating, age);
Boats (bid, bname, colour);
Reserves (sid, bid, day);
Answer the question below based on the above schema.
a)
Create table Sailors.
Create table Sailors
(
sid int Primary key,
sname varchar(50),
rating int,
age int
);
(2 marks)
b)
Find all sailors who are teens (age from 13 to 19)
Select *
From sailors
Where age >= 13
and age <= 19
(2 marks)
c)
Find the names of sailors who have reserved at least two boats
Select distinct s.sname
From sailors s, reserves r1, reserves r2
Where s.sid = r1.sid
and r1.sid = r2.sid
and r1.bid <> r2.bid
(4 marks)
d)
How many boats that has green colour?
Select count(bid)
From boats
Where colour =’green’
(2 marks)
Question 5
Do normalization from First Normal Form (1NF) until Third Normal Form (3NF) and state the
rules for the normalization based on the given CompanyRequest relation.
COMPANYREQUEST (CompNo, CompName, ReqNo, ProdNo, ProdDesc, Qty, CompAddress,
DateRequested)
Assumption: A company can have multiple requests but a request can be for only 1 product.
(10 marks)
Answer:
1NF - remove multivalued dependencies
COMPANY (CompNo, CompName, CompAddress) (1 mark)
REQUEST (CompNo, ReqNo, ProdNo, ProdDesc, Qty, DateRequested) (1 mark)
2NF - remove partial dependencies
COMPANY (CompNo, CompName, CompAddress) (1 mark)
COMPANYREQUEST(CompNo, ReqNo) (1 mark)
REQUEST (ReqNo, ProdNo, ProdDesc, Qty, DateRequested) (1 mark)
3NF - remove transitive dependencies
COMPANY (CompNo, CompName, CompAddress) (1 mark)
COMPANY REQUEST (CompNo, ReqNo) (1 mark)
REQUEST (RequestNo, ProdNo, Qty, DateRequested) (1 mark)
PRODUCT (ProdNo, ProdDesc) (1 mark)
Mark for correct sequence is 1m.