Tài liệu Activity 7.1: Identifying Data Integrity Requirements pdf

Activity 7.1: Identifying Data Integrity Requirements In this activity, you will evaluate a set of data requirements from the Ferguson and Bardell, Inc.. You will then formulate a set o

Activity 7.1: Identifying Data Integrity Requirements

In this activity, you will evaluate a set of data requirements from the Ferguson and Bardell, Inc case study to determine areas where possible data integrity issues might arise You will then formulate a set of data integrity requirements that must be followed by the development team for the Ferguson and Bardell, Inc solution

Objectives

After completing this activity, you will be able to:

! Identify areas where data integrity and validity are required

! Specify data integrity requirements as they relate to data requirements

Before You Begin

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

Prerequisites

To complete this activity, you will need the:

! Data requirements generated in Activity 3.1

! Existence and relationship requirements generated in Activity 4.2

Time to complete this activity: 25 minutes

Exercise 1:

Determining Data Validity Requirements

In this exercise, you will identify data validity requirements for the Ferguson and Bardell, Inc case study

! Identify data validity requirements

1 Join the group to which you have been assigned by the instructor

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

3 Consider the data requirements specified in Activity 3.1

4 Look for areas in the solution that depend upon data being in a certain format or within a range of values

These areas are data validity requirements Your group should attempt to find five to seven data validity requirements

5 Document each data validity requirement and its reason in the following table

There may be more rows in the table below than data validity requirements Only fill in information that you find

Data validity requirement Description Timesheet must report positive billable

hours Because a timesheet is a revenue- generating document, it must report a

positive dollar amount

Invoice cannot bill for negative amount Ferguson and Bardell, Inc cannot

generate invoices that lead the client to expect revenue from Ferguson and Bardell, Inc

Customer address and postal code must

be verifiable

All addresses within the Ferguson and Bardell, Inc system must have valid state and postal codes

Contract end date must be later than start date

For a contract to be valid, it must be for

a length of traceable time

Vehicle identification number (VIN) must be traceable through government records

The VIN must be in a format that is specified by the federal government and automobile manufacturers

Note

Employee billing rate cannot be zero All employees must bill at a positive

billing rate

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

Bitmap found in v06_1609a_act61-answer.vsd or bmp

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 Date Date Expenses Currency TotalHours Float BillableHours Float Description VChar 255

TimesheetID (PK) DInt Timesheet

ClientID (FK) (N)DInt TimesheetID (FK) (N)DInt Date Date Amount Currency 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

Make VChar 100

Model VChar 100

VIN VChar 30

Year Date

BeginMileage Int

EndMileage Int

VehicleID (PK) Int

Vehicle

Is Issued

1

Completes

1

1 ∞

Is Sent To

1

0 ∞

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

0 ∞

1

1

1 ∞

TypeDesc VChar 255 TypeID (PK) Int EmployeeType

Is Classified As

1

1

1 ∞

1

1 ∞

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

ContractID(PK) DInt Contract

Purchases

1

1

0 ∞

Is Made From Contracts With

TaskDesc VChar 255 TaskID (PK) DInt Task

Has

1 ∞

1

0 ∞

VehicleID (FK) Int

EmployeeID(FK) Int

Vehicle_Link

Can Be Assigned To

0 ∞

1

Bills Time To

1 ∞

1

Exercise 2:

Determining Data Integrity Requirements

In this exercise, you will determine the data integrity requirements for the Ferguson and Bardell, Inc solution

! Determine data integrity requirements

1 Refer to the physical data design on the previous page

2 Consider the existence and relationship requirements specified in Activity 4.2

3 Look for areas in the data design where relationships require integrity or where the existence of entities will cause integrity issues These areas are the relational integrity requirements

4 Document each data integrity requirement and its reason in the following table

There may be more rows in the table below than data integrity requirements Only fill in information that you find

Data integrity requirement Relationship requirement Timesheet must contain an existing

employee, client, job, and task Timesheet entity must have foreign keys for employee, client, job, and task

entities

Contract cannot exist without a valid employee and customer relationship Contract entity must have foreign keys for employee and customer entities

Task must be tied to a specific job Unique foreign key in job entity is

primary key of task entity

Invoice cannot be generated without a timesheet

Invoice entity must have foreign key for timesheet entity

Maintenance on a vehicle cannot exist without a vehicle Vehicle maintenance entity cannot have null foreign key for vehicle entity

Job cannot be created without a default task

Timesheet entity cannot have null foreign key for job or task entities

Note

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