Question

Which of the following best describes the purpose of a primary key?

A) To ensure that each row in the table is unique
B) To create the relationship between two tables
C) To provide business information, but are not required to build a database
D) To support business processes across the organization

Answer 1

The primary key's main purpose is to ensure that each row in a table is unique, thus maintaining data integrity and preventing record duplication.

Step-by-step explanation:

The purpose of a primary key in a database is A) To ensure that each row in the table is unique. A primary key is an attribute or a set of attributes that uniquely identifies a row in a table. No two rows can have the same value for the primary key attribute(s), which ensures that each entry in the table can be distinctly referenced. This is essential because it maintains the integrity of the data within the database and helps prevent duplication of records.

While a primary key can be used as part of the mechanism to create relationships between tables (foreign keys), its main purpose is not B) To create the relationship between two tables. Options C and D are also incorrect as the primary key's role is neither to provide business information nor to support business processes across the organization directly; it serves as a fundamental aspect of database organization and design.