When is a table in 1NF?

2 years ago
Database Management System

A table is in 1NF when all the key attributes are defined (no repeating groups in the table) and when all remaining attributes are dependent on the primary key. However, a table in 1NF still may contain partial dependencies, i.e., dependencies based on only part of the primary key and/or transitive dependencies that are based on a non-key attribute.

A table is in 1st Normal Form (1NF) when it meets the following criteria:

  1. Each row of the table represents a single, unique entity (i.e. there are no repeating groups of data in a single row)
  2. Each column of the table has a single, atomic (indivisible) value (i.e. no cells contain multiple values)
  3. The table has a primary key, which uniquely identifies each row in the table.
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Bijay Satyal
Bijay Satyal
Oct 23, 2021
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