First Normal Form (1NF)

It defines the basic requirements for organizing data in a relational database

By Kevin McAleer,    3 Minutes

First Normal Form (1NF) is a fundamental concept in database normalization. It defines the basic requirements for organizing data in a relational database.

In First Normal Form, a table is structured in a way that eliminates repeating groups and ensures that each column contains only atomic values. This means that each cell in the table must hold a single value, and there should be no multiple values or sets of values within a single cell.

To meet the requirements of 1NF, tables should have:

  1. A unique name for each column.
  2. Atomic values in each cell, meaning that each value should be indivisible.
  3. A unique identifier, such as a primary key, to identify each row uniquely.

By organizing data in 1NF, we eliminate data duplication and redundancy, making it easier to manage and update the information. It allows for efficient querying and ensures data integrity.

It’s important to note that achieving 1NF is the foundation for higher levels of normalization, such as Second Normal Form (2NF) and Third Normal Form (3NF). These subsequent normal forms build upon the principles of 1NF to further improve data organization and minimize data redundancy.


Suppose we have a table called “Students” with the following structure:

StudentID StudentName Course1 Course2 Course3
1 Alice Math Science Literature
2 Bob History    
3 Charlie   Music  

In this example, the table violates the principles of 1NF because it contains repeating groups and allows multiple values in a single cell.

To transform this table into 1NF, we need to remove the repeating groups by creating a separate table for courses. Here’s how the transformation can be done:

Table: Students

StudentID StudentName
1 Alice
2 Bob
3 Charlie

Table: Courses

StudentID Course
1 Math
1 Science
1 Literature
2 History
3 Music

In the transformed structure, the “Students” table contains unique student information, with each student having a unique identifier (StudentID). The “Courses” table captures the relationship between students and their courses, with each course associated with the respective student.

By separating the repeating group of courses into a separate table, we eliminate the data redundancy and ensure atomicity of values. Now, each cell in the table contains a single value, adhering to the principles of 1NF.

This transformation enables easier management, querying, and manipulation of the data. It also allows for efficient handling of course-related information for each student.

By transforming the original table into 1NF, we enhance data organization, eliminate data redundancy, and establish a solid foundation for further normalization, such as Second Normal Form (2NF) and beyond.

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