WGU Courses and Certificates Data-Management-Foundations Question # 9 Topic 1 Discussion

TheCHECKconstraint is used in SQL toenforce ruleson a column's values. It ensures that data inserted into a table meets specified conditions, such as range restrictions or logical rules.

Example Usage:

sql

CREATE TABLE Employees (

ID INT PRIMARY KEY,

Name VARCHAR(50),

Salary INT CHECK (Salary BETWEEN 30000 AND 150000)

);

This constraint ensures thatsalary values fall between 30,000 and 150,000.

If an INSERT or UPDATE statement tries to set Salary = 20000, itfailsbecause it does notmeet the CHECK condition.

Why Other Options Are Incorrect:

Option B (FROM) (Incorrect):Used in SELECT statements, not for constraints.

Option C (WHERE) (Incorrect):Filters rows in queries butdoes not enforce constraints.

Option D (SET) (Incorrect):Used for updating records (UPDATE table_name SET column = value) butnot for defining constraints.

Thus,CHECK is the correct answer, as it ensures that column values remain within an expected range.