Z556: Session 8

Data Modeling Entity-Relationship Diagram (ER).

Unified Modeling Language (UML). 1

Modeling

2

Cultural Model

Flow Model

Physical Model

Artifact Model

Sequence Model

E-R Diagram

What is Data Modeling?

A process for identifying, documenting & organizing

data elements based on specified requirements.

3

3

What is Data Modeling?

A design activity that is not limited to data analysis.

(Be Creative…)

4

4

What is Data Modeling?

Can be presented in many different ways.

5

E.g., Tables Entity-Relationship diagramClass diagramActivity diagram

5

Why Data Modeling?

To identify essential data elements and understand their role in supporting

business processes.

6

6

A Little Incentive to Pay Attention

Annual Mean Salary by Job Financial specialist $74,270

Information and Record Clerks $32,320

Loan officer $71,800

Network & Computer Systems administrator

$77,910

Paralegals $51,170

Database administrator $80,740

Advertising Sales Agents $57,440

Actuaries $107,7407

Bureau of Labor Statistics http://www.bls.gov/oes/current/oes_nat.htm

Data Modeling Language

Entity-Relationship (ER) Diagram

Object-Oriented (OO) Design

Unified Modeling Language (UML)

8

8

Case Study: KCCI Training Center

• KCCI training center organizes training programs for customers in three different areas: Investment, Real-Estate, & Human-Resources.

• For each program to run, there is a required minimum number of attendees.

• To enroll in a program or more, a customer fills a registration form and send it to the center.

• A training coordinator keeps track of the number of registered customers. When the minimum number is reached before the start date of the program, the coordinator contacts a trainer to run the program and then sends confirmation/invoice letters to the customers.

• If no trainer is available or the minimum number is not reached, cancelation letters are sent to the customers. 9

Case Study: KCCI Training Center

Problems: Ineffective paper-based system that fails to

meet the growing trends of the center.

Difficulty to track programs and participants.

Difficulty to locate misplaced or lost files.

Difficulty to share and access information.

Underutilized data for future planning.

10

Case Study: KCCI Training CenterSolution:

Develop a new information system for managing, storing, retrieving, and

analyzing all information related to training programs.

Purpose of data modeling: To identify essential data elements and

understand their role in supporting work processes. 11

Relationship Attribute

ER Diagram

12

o The principle data objects about which information is to be collected. E.g., person, place, document, etc.

o Entity instance: a particular occurrence of an entity.

University•Indiana University Bloomington•University of Indianapolis•University of Phoenix

Entity name

Instances

Entity

Attribute

ER Diagram

13

Entity

Real-word association among entities.

Entity Relationship Entity

Manager Manages Department

Relationship

Attribute

ER Diagram

14

Entity

o Connectivity of a relationship :Describes the constraints on the connection of the associated instance in the relationship.

Entity Relationship Entity

Entity Relationship Entity

Entity Relationship Entity1 1

1 *

**

Relationship

ER Diagram

15

Entity Relationship Attribute

o Provides descriptive detail about entities and relationships.

o An attribute value: a particular occurrence of an attribute within an entity or relationship.

Student enroll

ID

Classname

dateSection

Title

KCCI ER Diagram

16

Customeris

given by

Program Trainer

Coordinator

enrolls

is-contacted-

bycontacts

Manages

1

*

1

1*

* * **

Name

NameName CustID

Phone

CoID

TrnIDTitle

ProgID

Area

AddressDate

1

KCCI ER Diagram

17

Customeris

given by

Program Trainer

Coordinator

enrolls

is-contacted-

bycontacts

Manage

1

*

1

1*

* * **

Name

NameName CustID

Phone

CoID

TrnIDTitle

ProgID

Area

AddressDate

1

KCCI ER Diagram

18

Customeris

given by

Program Trainer

Coordinatoris-

contacted-by

contacts

Manage

1

*

1

1*

* * **

Name

NameName CustID

Phone

CoID

TrnIDTitle

ProgID

Area

AddressDate

1

Registration Form

11

Implementing

19

Entity (Customer)

Cust# Name Address Phone #

100 Peter Alex 335 10th 555-4444

Implementing

20

Attribute (address)

Entity

data instance

Cust# Name Address Phone #

100 Peter Alex 335 10th 555-4444

Many-to-Many Relationship

Cust_id F_name L_name address

1234 Mary Gray 456 Oak street

1235 Bill Dodds 789 Woodburn street

1236 Justin Moore 903 College avenue

Class_id

Price Date Class name

135 100 Oct-1-2013 Customer Service 101

136 200 Nov-1-2013 Types of Investment

137 100 Oct-31-2013 Property Evaluation

21

Registration

Many-to-Many Relationship

Registration_id Cust_id Class_id0088 1234 136

Cust_id F_name L_name Address

Class_id Price Date Class name22

CUSTOMER

REGISTRATION

PRODUCT

Generalization Hierarchy Diagram

Entities with common attributes can be generalized into a higher entity type

(Superset entity).

Subsets entities can be either disjoint (d) or overlapping (o).

23

23

Hierarchy Diagram

24

Customer TrainerCoordinator

PerID

Person

o

Name Phone

Email

Real-EstateHuman-

ResourcesInvestment

ProgID

Program

d

StartDate

EndDate

Disjoint (d) Generalization Overlap (o) Generalization

Object-Oriented (OO) Design

Objects are the basic unit which the organization must keep track of or that participate in a business process.

A system is a set of objects that collaborate and interact with each other.

UML is a widely accepted standard incorporating OO concepts, and provides terminology and diagram

conventions.

25

25

Object-Oriented Design

26

• Properties attached to each object.

Attributes:

• Functions that could change the value of object’s attribute.

Operations :

• Procedure used to carry on the operations.

Methods:26

OO Concepts• Classes:

Categories to which an object belong to and share the same operation, methods, and attributes.

27

Class Name

Attribute 1Attribute 2Attribute 3Operation 1 ()Operation 2 ()Operation 3 ()

Customer

CustomerIDNameAddressSearchProgram()Enroll ()Pay () 27

Class Relationships in UML

Generalization: A relationship between a more general class and a more specific class.

Association: Objects in one class linked to objects in the other class.Multiplicities: 1 to 1 , 1 to * , * to *

28

Real-Estate Human-ResourcesInvestment

Program

Coordinator Program28

Class Relationships in UMLAggregation:

Relationship between a whole and its parts.

Composition: An aggregation relation in which the part belong to only one whole at a time.

29

Trainer Program

ProgramDescripton Program

PurposeTargetAudience 29

Trainer

<pk>TrainerIDNamePlaceOfWorkPhoneFaxEmailNote

Program

<pk>ProgramIDTitleTrainingAreaLocationStartDateEndDateStartTimeEndTimeCostMinAttendeesCoordinatorStatusNote

Customer

<pk>CustomerIDTitleNamePhoneFaxEmailWorkNote

Coordinator

<pk>CoordinatorIDNamePhoneEmailNote

RegistrationForm

<pk>RegFormIDDate<pk>CustomerID<pk>ProgramIDNote

Invoice

<pk>InvoiceIDDateRegistrationFormCostNote

UML Class Diagram (Attributes)

30

1..* 1..*1..*1..1

1..*

1..1

1..1

1..1Association Class

1..11..1

Trainer

AddTrainer()RemoveTrainer()isAvailable(:Boolean)

Program

AddProg ()ConfirmProg ()CancelProg()

Customer

NewCust()SignIn()FindProgram()Enroll(in enrl: Program)SendRegForm()Payment()

Coordinator

ProgStatus ()ConfirmLetter ()CanelLetter ()ContactTrainer()

RegistrationForm

AddProgram()RemoveProgram()AddCustomer()RemoveCustomer()

Invoice

Total (amnt: Dollar)

UML Class Diagram (Operation)

31

1..* 1..*1..*1..1

1..*

1..1

1..1

1..1

1..11..1

SummaryData modeling help identify essential data elements and

understand their role in supporting business processes. Data modeling simplifies communication between system

developers and end users.Data modeling supports the development of information

systems.

32

32

Develop a Data Model for Choosing a Job?

• What are the entities/classes?• What are the attributes? • What are the relationships?

33

33

Develop a Data Model for Choosing a Job?

34

ContactPerson

<pk>CP_IDNamePhoneFaxEmailNote

Job

<pk>JobID<pk>CP_ID<pk>OrgIDTitleSalaryResponsibilitiesRequirementsStartDateLocationNote

Organization

<pk>OrgIDNamePhoneFaxEmailWebsiteTypeNote

1..* 1..11..*1..1

34

The 7 Habits of Highly Effective Data Modelers

(Moody, 1996)

35

Knowledge

SkillMotivation

Habit

Moody, D. (1996) The seven habits of highly effective data modelers. Database Programming & Design, 9, 10, 57-64.

The 7 Habits of Highly Effective Data Modelers (Moody, 1996)

• See for yourself (observation—Method school of data modeling)

• Generate alternatives• Keep it simple (generalization)• Test the model (prototyping/scenario)• Know when to stop• Remember the big picture• Following through

• Contextual Inquiry 36

Object-Orientation

• Objects• An object has attributes and operations

ILS

Z5

56

37

Attributes: Color; Size

Object-Orientation

• Objects• An object has attributes and operations

ILS

Z5

56

38

Operations: Make a call

Object-Orientation

• A class is a category to which an object belongs• E.g., Smartphone is a class for Nexus and iPhone; both

share the same attributes and operations

ILS

Z5

56

39

Object-Orientation• Window is a class

that has:• Attributes of: size,

location, background color, etc. IL

S Z

556

40

Object-Orientation• Window is a class

that has:• Operations of:

open, close, resize, etc.

ILS

Z5

56

41

UML and ER

• UML class diagrams =~ ER diagrams• Classes =~ Entities

Class Name

Attribute 1Attribute 2

Operation 1()Operation 2()

42

Entity Name

Attribute 1

UML and ER

• UML class diagrams =~ ER diagrams• Classes =~ Entities

Class Name

Attribute 1Attribute 2

Operation 1()Operation 2()

Customer

<pk>Customer_id: stringCustomer_name: stringAddress: string

creditRating ()43

Example

UML and ER

• UML class diagrams =~ ER diagrams• Classes =~ Entities

Class Name

Attribute 1Attribute 2

Operation 1()Operation 2()

Customer

<pk>Customer_id: stringCustomer_name: stringAddress: string

creditRating ()44

Example

CreateReadUpdateDelete

UML: Class Diagram

45

Customer Order

Payment

Credit Cash Check

OrderDetail

nameaddress

datestatus

amount

calcTaxcalcTotalcalcTotalWeight

numbertypeexpDate

authorized

cashTendered namebankID

authorized

quantitytaxStatus

calcSubTotalcalcWeight

1 0..*

1

1..*

1..*

1

specialization

association

aggregation

line item

http://edn.embarcadero.com/article/images/31863/classdiagramno3d.gif