First Normal Form(1NF)

DBMS Tutorial

First Normal Form(1NF) : Introduction

  • The First Normal Form(1NF) is the basic normal form, at-least which a database must follow and if it not, that database can be termed as an example of bad design.
  • The First Normal Form(1NF) works on the concept of “Atomicity” in values of every individual tuple of tables present in the database. It means, a relation is said to be in "1NF" if, every attribute in a relation is has “Single Valued” tuple.
  • Also, the domain of the attributes must remain same throughout the table. For example : E_ID attribute should contain only Employee ID and not any other value.

NOTE : Atomic values are those which cannot be decomposed further.

 

First Normal Form(1NF) : Example

  • Consider the table consist of details of professors of a college along with their domain specialization.

 

This image describes the example of first normal form supporting its concept of atomic values.

Example : First Normal Form

 

  • Now using the concept of "1NF", the number of tuples in the table gets increased along with redundancy in attributes. But, the tuples in combine have different values.
  • Also, "1NF" Normal Form is a lot of theoretical and less of practical/conceptual topic. But, one must know this, as it is used in other normal forms such as Second Normal Form(2NF).