What is the purpose of MySQL constraints?

The role of MySQL constraints is to ensure that the data in the database meets specific conditions or requirements. They are used to maintain data consistency and integrity, preventing invalid, inconsistent, or non-compliant data from entering the database. Constraints can be applied at the column level or table level, specifying data types, uniqueness, primary keys, foreign keys, check conditions, and more. Once constraints are defined, MySQL automatically checks if data insertion, updating, or deleting operations violate the constraint rules and prevents illegal operations. By using constraints, data quality and reliability can be improved, ensuring database consistency.