Intermediate SQL Subqueries Exercises

Intermediate-level SQL Subqueries practice exercises with solutions.

Exercise 1

Question: Find employees who earn more than the average salary.

SELECT name, salary
FROM employees
WHERE salary > (SELECT AVG(salary) FROM employees);

A scalar subquery returns a single value and can be used with comparison operators in WHERE clause.

Exercise 2

Question: Find products that have never been ordered.

SELECT name
FROM products
WHERE id NOT IN (SELECT DISTINCT product_id FROM order_items);

Subquery with NOT IN finds values that don't exist in another table's results.