beginnersbook.com

  • Home
  • All Tutorials
    • Learn Servlet
    • Learn JSP
    • Learn JSTL
    • Learn C
    • Learn C++
    • Learn MongoDB
    • Learn XML
    • Learn Python
    • Learn Perl
    • Learn Kotlin
    • Learn jQuery
  • Core Java
  • OOPs
  • Collections
  • Java I/O
  • JSON
  • DBMS

DBMS – First Normal Form (1NF)

By Chaitanya Singh | Filed Under: DBMS

A relation is said to be in 1NF (first normal form), if it doesn’t contain any multi-valued attribute. In other words you can say that a relation is in 1NF if each attribute contains only atomic(single) value only. We have already covered brief of each of the normal forms in our Normalization in DBMS tutorial, here we will discuss the 1NF in detail with the help of few examples.

Example: Multi-valued attribute to 1NF

In the following example, we have a relation with multi-valued attribute. Since this relation is not in 1NF, let’s convert this relation to First Normal Form 1NF.

NOT in 1NF: This relation is not in 1NF because it contains a multi-valued attribute EMPLOYEE_MOBILE, in this example Employee “Hari” has more than one mobile numbers.

EMPLOYEE_IDEMPLOYEE_NAMEEMPLOYEE_MOBILEEMPLOYEE_COUNTRY
168284Ajeet9521750388INDIA
168285Hari9787777009,
9787778881
INDIA
168286Chaitanya9976543298INDIA

Converting the above relation in 1NF: Let’s convert the above relation into First normal form (1NF). To do this, we simply have to have a separate row for each multi-valued attribute as shown below.

EMPLOYEE_IDEMPLOYEE_NAMEEMPLOYEE_MOBILEEMPLOYEE_COUNTRY
168284Ajeet9521750388INDIA
168285Hari9787777009INDIA
168285Hari9787778881INDIA
168286Chaitanya9976543298INDIA

❮ DBMS Normalization

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

DBMS Tutorial

Basics

  • DBMS Tutorial
  • DBMS Introduction
  • Database Applications
  • DBMS vs File System
  • DBMS Architecture
  • Three-level DBMS architecture
  • View in DBMS
  • Abstraction
  • Instance & Schema
  • DBMS languages

Data Models

  • Data Models
  • ER Diagram
  • ER Design issues
  • Convert ER to table
  • DBMS Generalization
  • DBMS Specialization
  • DBMS Aggregration
  • Relational Model
  • Hierarchical Model
  • Constraints
  • Cardinality

Relational Database

  • RDBMS concepts
  • Relational Algebra
  • Relational Calculus
  • Keys Index
  • Primary Key
  • Super Key
  • Candidate Key
  • Foreign Key
  • Composite Key
  • Alternate Key

Normalization

  • Normalization
  • Functional dependency

Transaction Management

  • Transaction Management
  • ACID properties
  • Transaction States
  • DBMS Schedules
  • Serializability
  • Conflict Serializability
  • View Serializability
  • Deadlock

Concurrency Control

  • Concurrency Control

Recently Added..

  • JSON Tutorial
  • Java Regular Expressions Tutorial
  • Java Enum Tutorial
  • Java Annotations Tutorial

Copyright © 2012 – 2022 BeginnersBook . Privacy Policy . Sitemap