MySQL Constraints and Constraint Management

Create a Table with Multiple Constraints

Design and create a MySQL table named 'Products' with columns for ProductID, ProductName, Price, and CategoryID. Apply appropriate constraints including PRIMARY KEY, NOT NULL, UNIQUE, and FOREIGN KEY.

Expected output: A Products table with enforced constraints ensuring data integrity.

Hint: Use CREATE TABLE with constraint definitions and reference an existing Categories table for the foreign key.

Modify an Existing Table to Add a CHECK Constraint

Add a CHECK constraint to the 'Employees' table to ensure that the 'Salary' column is greater than zero.

Expected output: The Employees table enforces that Salary values must be positive.

Hint: Use ALTER TABLE with ADD CONSTRAINT and CHECK syntax.

A PRIMARY KEY uniquely identifies each record in a table and ensures that the key column(s) cannot contain NULL values.

FOREIGN KEY constraints enforce referential integrity by ensuring that a value in one table corresponds to a valid record in another related table.

Yes, you can add constraints using the ALTER TABLE statement with ADD CONSTRAINT syntax.