Database Normalization

First Normalization Form (1NF)

In the first article, I describe normalization and why we need normalization. In this article, I explain the first normalization. Consider the following Employee table.

Table-1: Employee

To satisfy the first normal form following facts must be satisfied.

• There must be atomic values in the table. That means each cell of the table can not have multiple values.
• There should be a unique name for each column.

Employee table, there are several phone numbers in the emp_phone column. So it is not in its first normal form.

So Employee table must be re-organized to meet the first normal form.

Re-organized employee table.

Emp_id is unique for each record. So it is known as the primary key in the table. (Prime attribute). Records in the columns (non-prime attributes) depend on each primary key. This relationship is known as functional dependencies.