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Activity 5.2: Normalizing Data In this activity, you will normalize a set of entities from the Ferguson and Bardell, Inc.. Objectives After completing this activity, you will be able to

Activity 5.2: Normalizing Data

In this activity, you will normalize a set of entities from the Ferguson and Bardell, Inc case study

Objectives

After completing this activity, you will be able to:

• Normalize a logical data design to third normal form

Before You Begin

This activity is completed individually, with a class discussion to follow

Time to complete this activity: 30 minutes

26 Activity 5.2: Normalizing Data

Exercise 1:

Creating a Normalized Data Design

In this exercise, you will evaluate a logical design and then redesign it based on your knowledge of keys and normalization to produce a fully normalized data design

! Normalize the design to third normal form

1 Review the ER diagram on the next page

2 Identify the areas of the ER diagram in which normalization rules are violated as follows:

a Data is duplicated within multiple entities

b Attributes of an entity are not directly associated with that entity

c Each entity does not have attributes that uniquely define each instance

3 On the page opposite the ER diagram, sketch out your own ER diagram with normalization applied to the third normal form

Keep in mind that the data design shown on the next page is not optimized

in any way The keys provided may need to be redesigned as part of the normalization process

Next, you will discuss your answers with the class

Tip

Activity 5.2: Normalizing Data 27

Name

Address

SSN

E-Mail

Type

Salary

BillableRate

EmployeeID(PK)

Employee

ClientID(FK) EmployeeID(FK) JobID(FK) EmployeeFirstName EmployeeLastName ClientName ClientLocation Date

Expenses TotalHours BillableHours Description

TimesheetID(PK) Timesheet

ClientID(FK) TimesheetID(FK) ClientName ClientAddress ClientCity ClientState ClientZip Date Amount Work Description

InvoiceID(PK) Invoice

Name Address City State Zip

ClientID(PK) Client

EmployeeID (FK)

Make

Model

VIN

Year

BeginMileage

EndMileage

MaintenanceCost1

MaintenanceDesc1

MaintenanceDate1

MaintenanceMiles1

MaintenanceCost2

MaintenanceDesc2

MaintenanceDate2

MaintenanceMiles2

MaintenanceCost3

MaintenanceDesc3

MaintenanceDate3

MaintenanceMiles3

VehicleID(PK)

Vehicle

Is Issued

Completes

Is Sent To Contracts With

JobDesc TaskDesc JobID(PK) Job Bills Time To

ClientID(FK) EmployeeID(FK) StartDate EndDate Description

ContractID(PK) Contract

Purchases

1

1 ∞

1

0 ∞

1

1 ∞

0 ∞

1 ∞

1

1 ∞

Is Made From

0 ∞

0 ∞

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