MySQL CHECK Constraint

Introduction

The CHECK constraint ensures that values inserted into a column meet a specific condition.

It is used to enforce data validation rules in a table.

Example

CREATE TABLE employees (
id INT,
age INT CHECK (age >= 18)
);

This ensures that employees must be at least 18 years old.

Multiple Conditions

CHECK constraints can include more complex conditions.

Example:

CHECK (salary > 0)

Benefits

• Prevents invalid data entry

• Enforces business rules

• Improves data quality

Key Points

• CHECK validates column values

• Conditions must be satisfied before insertion

• Helps maintain data accuracy