Normalizing the Data › How To Normalize Data

How To Normalize Data

The primary key for a data entity is used to determine whether the attributes for that entity satisfy the rules of second and third normal form. Sometimes you will need to organize the same list of attributes for an entity in different ways, depending on which attribute(s) is selected as the primary key.

Atomic primary key

The DENTAL CLAIM entity shown below is uniquely identified by an atomic primary key. An atomic primary key is a primary key that consists of a single attribute. The atomic primary key for the DENTAL CLAIM entity shown below is DENTAL CLAIM ID.

          DENTAL CLAIM

             * DENTAL CLAIM ID
               EMP ID
               COVERAGE TYPE
               DATE OF CLAIM
               PATIENT NAME
               RELATION TO EMPLOYEE
               PATIENT SEX
               PATIENT DATE OF BIRTH
               PATIENT ADDRESS
               NUMBER OF DENTAL PROCEDURES
               TOTAL CHARGES
               DENTIST LICENSE NUMBER
               DENTIST NAME
               DENTIST ADDRESS
               PROCEDURE ID
               PROCEDURE DESCRIPTION
               PROCEDURE FEE
               SERVICE DATE

In all the examples that follow, primary key attributes are indicated with a star (*).