Lesson Notes By Weeks and Term - Senior Secondary 2

Normal form IV

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Term: 1st Term

Week: 9

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 2 periods each

Date:       

Subject:      Data Processing

Topic:-       Normal Form IV

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

  1. Define key, primary key
  2. Discuss the concept of foreign key
  3. State the characteristics of a suitable relation

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 normal forms

Students pay attention

STEP 2

EXPLANATION

He explains the meaning of key with regards to database. He further discusses the concept of primary key and foreign key

 

Students pay attention and participates

STEP 3

DEMONSTRATION

He further the characteristics of a suitable relation

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

KEY

A key is an attribute or field that can be used to identify a record in a database table or file.

The primary Key is a unique attribute that can be used to identify a record in a database table. For Example, in the student database table above, the attribute that is unique to identify each record is the Student-ID or RegNo.

CONCEPTS OF FOREIGN KEY

A foreign key is a field in a relational table that matches a candidate key of another table. A foreign key (FK) is a column or combination of columns that is used to establish and enforce a link between the data in two tables. You can create a foreign key by defining a FOREIGN KEY constraint when you create or modify a table. The foreign key can be used to cross-reference table. The foreign key identifies a column or set of columns in one (referencing or child) table that refers to a column or set of column in another (referenced or parent) table. The columns in the child table must reference the columns of the primary key or other super key in the parent table.            

 

DETERMINATION OF NORMAL FORM

Normalization is a technique for producing a set of suitable relations that support the data requirements of an enterprise. Characteristics of a suitable set of relations include:

  1. The minimal number of attributes necessary to support the data requirements of the enterprise
    1. Attributes with a close logical relationship are found in the same relation.
    2. Minimal redundancy with each attribute represented only once with the important exception of attributes that form all or part of foreign keys.

EVALUATION:   1. Define Key as regards to database.

  1. Differentiate between primary key and foreign key
  2. Discuss the characteristics of a suitable relation

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively