Integrity Constraints
Learn about the importance of data integrity and its different types.
We'll cover the following...
In our OnlineStore, what would happen if we tried to ship an order to a customer who doesn’t exist in your system?
Or if you accidentally assigned the same ProductID to two different items, a laptop and a t-shirt? The result would be chaos! Our data would become unreliable, leading to shipping errors, incorrect inventory counts, and frustrated customers.
To prevent such problems, we need a set of rules to ensure the data in our database is accurate and consistent. These rules are called integrity constraints, and they are the guardians of our data’s quality.
By the end of this lesson, we will be able to:
Understand the importance of data integrity.
Define and differentiate between the three main types of integrity constraints: entity, referential, and domain.
Recognize how these constraints are implemented in a relational database schema.
Integrity constraints
Think of a database as a well-organized library. Just as a library has specific rules—each book must have a unique catalog number, belong to a valid section (such as Fiction or Science), and be unavailable for checkout if it does not exist—a database follows defined rules to maintain order and reliability. Integrity constraints are the fundamental rules enforced by the Database Management System (DBMS) to ensure that data remains accurate, consistent, ...