Tài liệu Activity 7.2: Determining Data Integrity Implementations doc

Activity 7.2: Determining Data Integrity Implementations In this activity, you will evaluate a physical design for the Ferguson and Bardell, Inc.. case study and then determine areas wi

Activity 7.2: Determining Data

Integrity Implementations

In this activity, you will evaluate a physical design for the Ferguson and Bardell, Inc case study and then determine areas within the physical design where data integrity requirements and business rules should be implemented with the methods presented in Module 7, “Implementing Data Integrity.”

Objectives

After completing this activity, you will be able to:

! Identify areas where data integrity should be enforced

! Choose a method for implementing business rules and data integrity requirements

Before You Begin

This activity will take place in small groups, with a class discussion following the activity

Prerequisite

To complete this activity, you will need the:

! Completion of Activity 7.1

Time to complete this activity: 30 minutes

44 Activity 7.2: Determining Data Integrity Implementations

Exercise 1:

Determining Integrity Implementations

In this exercise, you will examine the physical design provided, determine areas

in the design where data integrity should be enforced, and determine how it should be enforced

! Identify areas where data integrity should be enforced

1 Join the group to which the instructor assigned you

2 With your group, study the physical data design on the next page

3 Based on the business rules and data integrity requirements specified in Activity 7.1, identify how the data integrity requirement can be

implemented for each rule in the following table

4 Supply a reason for each answer in the table

Data integrity rule Implementation Description

Timesheet must contain an existing employee, client, job, and task

Contract cannot exist without

a valid employee and client relation

Each job entry must have an associated task assignment

Job cannot be created without

a default task

Valid date must be specified for each timesheet and for each time entry that a consultant makes

All consultants’ expenses must be formatted correctly, and they must be a positive amount

Employee billing rate must be updated

When you have finished, you will discuss your findings with the class

Activity 7.2: Determining Data Integrity Implementations 45

TypeID (FK) (N)Int

FirstName VChar 25

MiddleInitial VChar 2

LastName VChar 25

Address1 VChar 40

Address2 VChar 40

City VChar 30

State VChar 20

Zip VChar 10

SSN VChar 9

E-Mail VChar 50

Salary Currency

BillableRate Currency

EmployeeID (PK) Int

Employee

ClientID (FK) (N)DInt EmployeeID (FK) (N)Int JobID (FK) (N)DInt TaskID(FK) (N)DInt

Expenses Currency TotalHours Float BillableHours Float Description VChar 255

TimesheetID (PK) DInt Timesheet

ClientID (FK) (N)DInt TimesheetID (FK) (N)DInt

Work Description VChar 255

InvoiceID (PK) DInt Invoice

Name VChar 60 Address1 VChar 40 Address2 VChar 40 City VChar 30 State VChar 20 Zip VChar 10

ClientID (PK) DInt Client

EmployeeID (FK) Int

BeginMileage Int

EndMileage Int

VehicleID (PK) Int

Vehicle

Is Issued

1

Completes

1

Is Sent To

1

1

JobDesc VChar 255 JobID (PK) DInt Job

TaskID (FK) DInt JobID (FK) DInt

JobTask_Link Has

Bills Time To

VehicleID (FK) (N)Int MaintenanceCost Currency MaintenanceDesc VChar 255 MaintenanceDate Date MaintenanceMiles Int

MaintID (PK) Int VehicleMaint

Can Have

1

1

TypeDesc VChar 255 TypeID (PK) Int EmployeeType

Is Classified As

1

1

1

ClientID(FK) DInt EmployeeID(FK) Int StartDate Date EndDate Date Description VChar 255

ContractID(PK) DInt Contract

Purchases

1

1

Is Made From Contracts With

TaskDesc VChar 255 TaskID (PK) DInt Task

Has

1

VehicleID (FK) Int

EmployeeID(FK) Int

Vehicle_Link

Can Be Assigned To

1

Bills Time To

1

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