Introduction

Why we need integrity constraints

In order to detect non-admissible and inconsistent data, and to prevent such data from being added to an application’s database, we need to define suitable integrity constraints. These constraints can be used by the application’s data validation mechanisms to catch cases of flawed data. Integrity constraints are logical conditions that must be satisfied by the data entered by a user and stored in the application’s database.

For instance, if an application is managing data about persons including their birth dates ...