Lesson Notes By Weeks and Term - Senior Secondary 2

Entity-relationship model

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Term: 1st Term

Week: 10

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 2 periods each

Date:       

Subject:      Data Processing

Topic:-       Entity-relationship model

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

  1. Define entity relationship model
  2. Highlight the uses of entity-relationship diagrams
  3. State and explain the components of the entity-relationship model

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, pictures, Data Processing for senior Secondary Education by Hiit Plc, WAPB Computer Studies for Senior Secondary I by Adekunle et al, On-line Materials.

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION

TEACHER’S ACTIVITY

STUDENT’S ACTIVITY

STEP 1

INTRODUCTION

The teacher reviews the previous lesson on the concept of primary and foreign key in database

Students pay attention

STEP 2

EXPLANATION

He explains the meaning of the entity-relationship model and highlights its uses.

 

Students pay attention and participates

STEP 3

DEMONSTRATION

He lists and explains the components of the entity-relationship model

Students pay attention and participate

STEP 4

NOTE TAKING

The teacher writes a summarized note on the board

The students copy the note in their books

 

NOTE

ENTITY-RELATIONSHIP MODEL

Entity-Relationship is a graphical representation of entities and their relationships to each other.

Entity relationship diagrams (ERDs) illustrate the logical structure of database. Diagrams created to design these entities and relationships are called entity-relationship diagrams or ER diagram.

 

Uses of Entity Relationship Diagram

  1. The Entity-Relationship Diagram is used to identify the data that must be captured, stored and retrieved in order to support the business.
  2. The Entity-Relationship Diagram is also used to identify the data required to derive and generate report on the performance measures that an organization should be monitoring.

 

Components of Entity-Relationship

Entity- Relationship diagrams have three different components;

  • Entities
  • Attributes
  • Relationships

Entities: Entities are objects or concepts within the data model. Each entity is represented by a box with in the ERD.  An entity might be considered a container that holds all of the instances of a particular thing in a system.

Attributes: a key attribute is the unique, distinguishing characteristics of the entity. Primary key is always the attribute of ER. Entities are further described by their attributes (sometimes called data element). These are the smallest units of data that can be described in a meaningful manner.

Relationship: A relationship is an association among the instances of one or more entity types that is of interest to the organization. A relationship is the association between entities or entity occurrence

EVALUATION:   1. Define entity-relationship model

  1. Highlight the uses of the entity-relationship diagram
  2. State and explain the components of the entity-relationship model

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively