1NF- First Normal Form, The first step of Normalization

Relational Database Normalization starts with the 1st Normal Form.

This is the first step to prevent redundancy, insertion errors, and deletion errors. 

Requirements for 1st Normal Form

• The table must have a Primary Key/ Index.
• No Repeating Groups
• No mixed data types in a column
• Row order cannot be used for queries.

For Example the table below:

The first column is a unique Primary Key. The key identifies the row. 

The table could be called User_Name.

User John Smith would have a Unique Key 1 making the record unique. 

Each column is a single data type and no repeating groups.