Question

A user is the database administrator for a company. the user has been asked to implement an integrity rule that states every table ​must have a primary key and that the column or columns chosen to be the primary key must be unique and not null. which integrity requirement is the user implementing?

Answer 1

In the given scenario, the user is implementing the ‘Entity Integrity’ rule.

Entity integrity emphasizes on the following points:

• A table must have one or more columns that has a unique entity to identify each row.
• Primary key is not NULL.
• Each primary key must be different and unique.
• Primary key retrieves each row in the table separately.