An entity is said to be in the second normal form (2NF) if it is already in 1NF and all non-identifying attributes are dependent on the entity's entire unique identifier.

If any attribute is not dependent entirely upon the entity's unique identifier, that attribute has been misplaced and must be removed.

Normalize these attributes either by finding the entity where it belongs or by creating an additional entity where the attribute should be placed.

The data model with a new entity