Chapter 15 Methodology – Logical database
design for relational model
(ER – Relation Mapping)
Tutorial
1. Represent the entity and relationship types shown in the ER diagrams below as
relations.
Employee
empNo {PK}
name
address
Project
projectNo {PK}
pName
description
WorksOn
1 * 1 *
Employee
empNo {PK}
name
address
Holds
1 1 1 1
Employment
Contract
contractNo {PK}
position
date
salary
Vehicle
regNo {PK}
make

cAddress
cTelNo
cFaxNo
Operates
1 1
1 *
Department
dNo {PK}
dName
dLoc
Employs
1 1
Employee
empNo {PK}
name
fName
lName
address
Has
0 *
1 1
Employment
History
compOrganName
(PPK}
address
position
sDate
fDate
1 *

creditLimit
Places
1 *
1 1
Order
ordeNo (PK}
status
dateDue
/totalPrice
1 1
3. Present a relational schema for the ER diagram shown below.
Dependent
dName {PPK}
relationship
sex
birthDate
Project
number {PK}
name {AK}
location
RelatedTo
0 *
1 1
Employee
SSN {PK}
name
fName
mI
lName
address