1.1 - Relational database conceptsmetalab.uniten.edu.my/~alancheah/CISB314/Lab 1/Lab 1...Chapter 4: Relational database design (optional) Supporting reading material •Overview •Information

Relational Database Concepts

1 © 2011 IBMCorporation

IBM Information Management Cloud Computing Center of Competence IBM Canada Labs

• Overview

• Information and Data Models

• The relational model

• Entity-Relationship diagrams

• Types of relationships

• Mapping entities to tables

• Relational model concepts

• Relational model constraints

• Normalization


Agenda

• Reading materials

• Database Fundamentals eBook


•

•

•

•

Chapter 1: Databases and information models

Chapter 2: The relational data model

Chapter 3: The conceptual data model (optional)

Chapter 4: Relational database design (optional)

Supporting reading material

• Overview








• Normalization

Agenda


Data vs. Information

• Data: Collection of letters, numbers or facts

• Information: Processed data that provides value


Databases and DBMS


• Databases

• A repository of data

• DBMS (Database management system)

• Software system that manages databases

• The terms “Database”, “DBMS”, “data server”, “database

server” often used interchangeably to refer to a DBMS

• Why a DBMS?

• Security

• Can handle many users with good performance

• Allows for concurrency while keeping data consistent

• Protects from disaster

• Overview








• Normalization

Agenda


Information and Data Models

Relationship between an Information Model and a Data Model


Data Models


• Network

• Hierarchical

• Relational

• Entity-Relationship

• Extended relational

• Semantic

• Object-oriented

• Object-relational

• Semi-structured

• Overview








• Normalization

Agenda


Relational Model


Entity-Relationship Diagrams

• Building Blocks

• Entities

• Attributes

Entity

Attribute


Entity and Attributes


ER diagram

Book

Title

ISBN

Editon

Year

PricePages


Aisle

Description

Exercise: Identify entities and attributes


House

ComputerSocial Security Number

Height Order #

Product

Date

Phone #

Did you get them right?

House

Date

ComputerSocial Security Number

Height Order #

Product

Phone #


• Overview

• Entity-relationship diagrams







• Normalization

Agenda


Relationships

• Building Blocks

– Entity sets

– Relationship sets

– Crows Foot notations


ERD of Book

Book

Title

ISBN

Editon

Year

PricePages


Aisle

Description

ERD of Author

Author

Author_Id

City

Lastname

Firstname

Email

Country


Example 1


Example 2


One-to-one Relationship

Book Authored By Author

Types of Relationships


One-to-many Relationships

Book AuthorAuthored By

Types of Relationships (Continued)


Many-to-many Relationships

Book AuthorAuthored By

Types of Relationships (Continued)


• Overview








• Normalization

Agenda


ERD revisited

Book

Title

ISBN

Editon

Year

PricePages


Aisle

Description

Mapping entity to a table

Entity

Table

Book

Title

ISBN

Editon

Year

PricePages

Aisle

Description

Attributes

Columns


Mapping entity to a table (Continued)


Title Edition Year Price ISBN Pages Aisle Description

Database 1 2010 24.99 978-0- 300 DB- Teaches you

Fundamentals 98662 A02 the

83-1-1 fundamentals

of databases

Getting started 1 2010 24.99 978-0- 280 DB- Teaches you

with DB2 98662 A01 the essentials

Express-C 83-5-1 of DB2 using

DB2 Express-

C, the free

version of

DB2

Table: Book

Mapping entity to a table (Continued)


Author_ID Lastname Firstname Email City Country

A1 Chong Raul [email protected] Toronto CA

A2 Ahuja Rav [email protected] Toronto CA

A3 Hakes Ian [email protected] Toronto CA

A4 Sharma Neeraj [email protected] Chennai IN

A5 Perniu Liviu [email protected] Transilva nia

RO

Table: Author

mailto:[email protected]





• Overview








• Normalization

Agenda


Relational Model Concepts


• Building Blocks

• Relation

• Sets

Dr. E.F. Codd of IBM in 1970:

“A Relational Model for Large Shared Data Banks”

A Relational Database


• RelationalDatabase

• Relation

• Relation Schema

• Relation Instance

A Relation

TUPLES

Author_ ID

Lastname Firstna me

Email City Country





A5 Perniu Liviu [email protected] Transilvania RO

ATTRIBUTES

DEGREE=6

CARDINALITY=5

AUTHOR(Author_ID: char, lastname: varchar, firstname: varchar,

email: varchar, city: varchar, country: char)


Relation

Schema

Relation Instance

A DOMAIN is the set of all possible values for a specific attribute







• Overview








• Normalization

Agenda


Relational Model Constraints

Business Rules


Referencing

Data Integrity


ERD representation of a Relational Data Model

Primary Key

Foreign Key

Parent Table

Dependant Table


Constraints


• Entity Integrity Constraint

• Referential Integrity Constraint

• Semantic Integrity Constraint

• Domain Constraint

• Null Constraint

• Check Constraint

Entity Integrity Constraint


Author_ID

[PK]Lastname Firstname Email City Country






AUTHOR







Author_ID







AUTHOR








A1

AUTHOR

Author_ID


NULL Chong Raul [email protected] Toronto CA












A1

A4

AUTHOR

Author_ID


NULL Chong Raul [email protected] Toronto CA



NULL Sharma Neeraj [email protected] Chennai IN








Referential Integrity Constraint


Referencing


Semantic Integrity Constraint


Author_ID







AUTHOR






Semantic Integrity Constraint

Toronto

Author_ID


A1 Chong Raul [email protected] 12(*)&^23 CA






AUTHOR






Domain Constraint








AUTHOR







Domain Constraint

CA

CA

CA


A1 Chong Raul [email protected] Toronto 34

A2 Ahuja Rav [email protected] Toronto 34

A3 Hakes Ian [email protected] Toronto 34



AUTHOR








NULL Constraint








AUTHOR






NULL Constraint

Raul

Hakes


A1 Chong NULL [email protected] Toronto CA


A3 NULL Ian [email protected] Toronto CA




AUTHOR






Check Constraint





83-1-1 fundamentals

of databases

Getting started 1 2010 24.99 978-0- 280 DB- Teaches you

with DB2 98662 A01 the essentials


DB2 Express-

C, the free

version of

DB2

BOOK

Check Constraint

2010




83-1-1 fundamentals

of databases

Getting started with DB2

1 2015 24.99 978-0-

98662280 DB-

A01Teaches you the essentials


DB2 Express-

C, the free

version of

DB2


BOOK

• Overview








• Normalization

Agenda


Normalization

■ Process in database design to remove redundancies

■ Example:

Consider the following table listing all the tasks of an employee:

Problem:

If John moves to a new city, all entries related to John must be updated


Normalization (continued)

No redundancy, no anomalies, no loss of information



Thank you!

Documents

1.1 - Relational database conceptsmetalab.uniten.edu.my/~alancheah/CISB314/Lab 1/Lab 1...Chapter 4: Relational database design (optional) Supporting reading material •Overview •Information