Data Modeling and Database Design Using ERwin

Data Modeling and Database Design Using ERwin

PRACTICAL DATA MODELING and DATABASE DESIGN USING ERWIN • ERWIN and Its Main Features • Data Modeling Using ERWIN • Before Database Design • Transforming Data Model To Database Design • Reverse Engineering • ERWIN Reports • Samples

Assoc.Prof.Dr.B.G.Çetiner 2000

ERWIN and Its Main Features



Erwin*; A Data Modeling and Database Design Application CASE Tool working on Windows

What is ERWIN?

* CopyRighted by Logic Works and Platinum Inc. Assoc.Prof.Dr.B.G.Çetiner 2000



ERWIN and Its Main Features Main Features: Supported DBMSs

Main Features Forward Engineering: Transforming Data Model into Database Reverse Engineering: Obtaining Design Info and Data Model From a Relational Database

Relational Data Model Forward Engineering

Reverse Engineering

Relational Database Assoc.Prof.Dr.B.G.Çetiner 2000


1



Main Features: ORACLE Designer Data Modeling Tool

Main Features: Importing Entities from BPwin

ORACLE Designer 2000 Compatible

BPWin is an activity (process) modeling, and data flow diagramming tool





Main Features: BPWin ve ERWin

Main Features: Working Levels

STRATEGY ANALYSIS

BPWin Analysis Program

DESIGN

ERWin Data Modeling and Database Design Tool

IMPLEMENTATION

1. Logical (Conceptual) Level (Data Modeling) 2. Physical Level

DOCUMENTATION

TEST FEEDBACK

System Development Life Cycle




Main Features: Working Levels (for Version 3.5.2) 1. Logical Level (Data Modeling)

Exclusive Sub-Category

Adding Entity


Main Features: Working Levels

(For Version 4 )

1. Logical Level (Data Modeling)

Adding Text

Adding Entity

Exclusive Sub-Category

Non-identifying Relationship

Selection Non-identifying Relationship

Changing Attributes

Identifying relationship

Selection

Identifying relationship

many-to-many relationship

many-to-many relationship Assoc.Prof.Dr.B.G.Çetiner 2000


2



Working Levels

Working Levels

2. Physical Level

(Version 3.5.2)

View

Independent Table

Adding Text

2. Physical Level

Independent Table

(Version 4)

View

Selection Non-identifying Relationship

Changing Columns

Identifying Relationship

View Relationship

Selection

Identifying Relationship

View Relationship





Data Modeling Using ERWIN

Modeling and Design Stages for ERwin

Representing Entities and Attributes (Logical Level)

PRODUCE DATA MODEL

Logical Level

DESCRIBE DATA TYPES

Physical Level

ENTITY NAME Unique Identifier Attributes SETTINGS FOR ACCESSING DATABASE

Native or ODBC

Other Attributes VIA SQL SCRIPTS

BY CONNECTING TO DATABASE

REVERSE ENGINEERING

Foreign KeyAttribute

Forward Engineering





Representing Entities and Attributes (Logical Level) Composite Unique Identifiers Entity Name Key Area Composite Unique Identifier Non-Key Area


Other Attributes


3



Optionality in Attributes

Representing Foreign Key Attributes

Click twice on any entity to open it in attribute editor

Required attribute

Child Entity

Master Entity

There are two different relationships between Entity 1 and Entity 2. 1. Identifying Relationships 2. Non-Identifying Relationships





Data Modeling Using ERWIN Many-to-many Relationships


Non-Identifying Relationships Crow foot

Identifying Relationship In both relationships, Unique Identifier in master entity goes to the second (child) entity as foreign key.

Identifying Relationship (Unique Identifier of Entity 1 becomes the part of unique identifier in entity 2. It is placed in key area of second entity)





Representing Foreign Key Attributes Use Different names for the attributes in key area (unique identifier)

Optionality Overwrites the attribute

Non-Identifying Relationship (Unique Identifier of Entity 1 becomes new attribute in entity 2. It is placed in non-key area of second entity) Assoc.Prof.Dr.B.G.Çetiner 2000


4



Use Different names for the attributes in key area (unique identifier)

Tables and Columns (Physical Representation) Table Name Unique Identifier Column Other Columns




Data Modeling Using ERWIN Tables and Columns (Physical Representation)

Tables and Columns (Physical Representation)

Changing default data types for Physical level Note: All Attributes are assigned as char(18) (or any default value defined) when the level is changed to physical one. Assoc.Prof.Dr.B.G.Çetiner 2000




Adding Icons to Entities and Attributes

Adding Icons to Entities and Attributes



5



Establishing Non-identifying Relationship

Establishing Identifying Relationship

1. Choose Non-identifying Relationship

1. Choose Identifying Relationship

2. Click the master entity (DEPARTMENT in this case) 3. Click the child entity (EMPLOYEE)

2. Click the master entity (EMPLOYEE in this case) 3. Click the child entity (EMPLOYEE CHILD)

DEPARTMEN ID in DEPARTMENT comes as foreign key to the non-key area of EMPLOYEE

EMPLOYEE ID in EMPLOYEE comes as foreign key to the key area of EMPLOYEE CHILD





Representing ORACLE Designer Notations under ERwin


1. Many-to-one (One-to-many) Relationships (Mandatory) Child Entity

assigned to EMPLOYEE

DEPARTMENT made up of

2. Many-to-one (One-to-many) Relationships (Optional)

Parent Entity ORACLE

Child Entity


DEPARTMENT made up of

ERWin

ERWin



Assoc.Prof.Dr.B.G.Çetiner

2000






3. One-to-one Relationships (Optional) Child Entity

4. One-to-one Relationships (Mandatory)

containing CAR

installed in


ENGINE


Child Entity

containing CAR

installed in

ENGINE

ERWin Non-identifying Relationship

The entity covering the other entity is defined as child entity in one-to-one relationship.



ERWin Non-identifying Relationship

The entity covering the other entity is defined as child entity in one-to-one relationship.


6





5. Many-to-many Relationships


1. Choose many-to-many relationship in Logical Level 2. Click on both entities


DEPARTMENT

ORACLE

staffing

Note: First, you have to resolve many-to-many relationships 3. If you have chosen auto-transform, then an intersection entity will be added automatically. Assoc.Prof.Dr.B.G.Çetiner 2000








Intersection Entity Added Automatically

It becomes identifiying relationship







6. Obtaining Uniqueness via Relationships ACCOUNT #* Account No * Type

opened in opening

ORACLE Designer

7. Recursive Relationships ORACLE Designer

BANK #* Bank ID * Name

ERwin

EMPLOYEE #* employee ID * name * surname o job

ERwin

managed by

manager for Represented as identifying relationship Assoc.Prof.Dr.B.G.Çetiner 2000

Modeled as Non-identifying Relationship as in one-to-many relationship Assoc.Prof.Dr.B.G.Çetiner 2000

7





7. Recursive Relationships


1. First, identify the entity and its unique identifier

1. First, identify the entity and its unique identifier 2. Choose non-identifying relationship from toolbox









1. First, identify the entity and its unique identifier 2. Choose non-identifying relationhip from toolbox 3. Click twice on the same entity (EMPLOYEE)

1. First, identify the entity and its unique identifier 2. Choose non-identifying relationhip from toolbox 3. Click twice on the same entity (EMPLOYEE) 4. EMPLOYEE ID has not come as Foreign Key









1. First, identify the entity and its unique identifier 2. Choose non-identifying relationhip from toolbox 3. Click twice on the same entity (EMPLOYEE) 4. EMPLOYEE ID has not come yet as Foreign Key 5. Click twice on the relationship to identify rolename Assoc.Prof.Dr.B.G.Çetiner 2000

MANAGER ID comes as Foreign key.


8





8. Exclusive Relationships


assigned as d ne sig as

an entity under

WORKER o hourly rate o overtime rate

EMPLOYEE # * employee id * name * lastname o job



an entity under


as

as

y tit en er an und

y tit en er an und

STAFF o title

Transferred to ERwin for each pair of relationships

STAFF o title

Transferred to ERwin for each pair of relationships








9. Supertypes and Subtypes

as

y tit en er an und

STAFF o title

Transferred to ERwin for each pair of relationships Assoc.Prof.Dr.B.G.Çetiner 2000


EMPLOYEE # * employee id * name * surname WORKER * hourly rate * overtime rate

STAFF * title

member for

assigned to deploying DEPARTMENT

made up of UNION

Modeled as Identifying Relationship

ip ION nsh latio and UN y re man RKER -toO One een W betw

an entity under


One betw -to-ma n and een EM y relat io DE PAR PLOY nship E TM ENT E




Transforming Data Model To Database Design


Choosing Target Database Management System

9. Supertypes and Subtypes

Database/Choose Database for selecting target database management system

EMPLOYEE # * employee id * name * surname STAFF * title

WORKER * hourly rate * overtime rate

NOTE: You have to be level under

Modeled as Identifying Relationship



9


Before Transforming Data Model

Choosing Target Database Management System

You can also access to the DBMSs not listed here via ODBC/Generic

Desktop SQL Dataase Management Systems DBMS

Supported Database Management Systems 1. IBM DB2 2. IBM AS/400 3. ORACLE 4. MS SQL Server 5. InterBase 6. SYBASE 7. PROGRESS 8. INFORMIX 9. Ingres 10. Red Brick 11. SQLBase 12. Rdb 13. WATCOM/SQL Anywhere 14. Teradata 15. Clipper 16. FoxPro 17. dBase 18. Access 19. Paradox


Before Transforming Data Model

Making Connection Settings for Target Database Management System ODBC Settings For connecting to DBMS

You can directly invoke ODBC Administrator from Run Dialog:

odbcad32



Making Connection Settings for Target Database Management System

Example; Settings for connecting to Oracle DBMS through ODBC

For adding new connection For connecting to Oracle DBMS


Transforming Data Model To Database Design Example; Settings for connecting to Oracle DBMS through ODBC

Connection name to connect (You can reach under ERWin ODBC Connection)


Transforming Data Model To Database Design Example; MS SQL Server Connections

Connection Name for SQL Server

Service name Optional Description Username AI1 is the server name

ODBC Settings for each DBMS is different (like printer drivers) Assoc.Prof.Dr.B.G.Çetiner 2000


10


Transforming Data Model To Database Design Forward Engineering Choose Forward Engineer Under Tools

Forward Engineering Applying the principles of Systems Development Life Cycle (SDLC) (Going from the top to bottom in Waterfall model)

Producing the Relational Database Objects via the use of Data Models





Forward Engineering: Settings

Forward Engineering

1. Press

Options

2. Give required security information and press Connect button.

Filtering model Preview Print objects SQL Script SQL Script

ODBC Connection

Write SQL Script to a File


Native Connection

Generate Database Objects

Transforming Data Model To Database Design Produce the database objects from data model directly


Transforming Data Model To Database Design Produce the database objects from data model using SQL Script

1. Press

button

SQL Script filename

2.



11



Produce the database objects from data model using SQL Script

Produce the database objects from data model using SQL Script Just run the SQL Script File using tools under the DBMSs Examples Oracle SQL*Plus for Oracle DBMS Query Analyzer for MS SQL Server

Name of Script File Oracle SQL*Plus for Oracle DBMS Assoc.Prof.Dr.B.G.Çetiner 2000




Just run the SQL Script File using tools under the DBMSs Examples Oracle SQL*Plus for Oracle DBMS Query Analyzer for MS SQL Server

Query Analyzer for MS SQL Server Assoc.Prof.Dr.B.G.Çetiner 2000

Reverse Engineering

Interactive SQL for Interbase DBMS


Reverse Engineering

Reverse Engineering

Reverse Engineering

Applying the principles of Systems Development Life Cycle (SDLC) in reverse order (Going from the bottom to top in Waterfall model)

Select Reverse Engineer under Tools Menu

Inferring the Data Model from Database Objects



12

Reverse Engineering

Reverse Engineering Reverse Engineering

Reverse Engineering: Settings As in forward engineering, connections are achieved via the native or ODBC type of connection

Choose the Target DBMS to reverse engineer the database


Reverse Engineering


Reverse Engineering

Reverse Engineering

Reverse Engineering

Data model can be obtained from; 1. DBMS by direct connection 2. SQL Script Files If the database is not relational then you can infere primary keys and relationships from Indexes and the column names in tables Assoc.Prof.Dr.B.G.Çetiner 2000

Reengineering


ERwin Reports

Other Functions

Report Generation

Reengineering: Compares the data model and physical database. You can update the data model via the database or database via the data model 

Assoc.Prof.Dr.B.G.Çetiner 2000

For report generation Assoc.Prof.Dr.B.G.Çetiner 2000

13

ERwin Reports

ERwin Reports

Reports

Reports: Example; Table/Physical Properties


ERwin Reports


ERwin Reports

Reports: Reports are generated Using Report Templates and Output type (such as HTML)

Reports: Reports are generated Using Report Templates and Output type (such as HTML)


A typical data model using ERwin


Sample data model using Oracle Designer



14

Sample data model using ERwin


15