Subquery in WHERE
SELECT name FROM employees WHERE salary > (SELECT AVG(salary) FROM employees);Subquery in FROM
SELECT dept, avg_salary FROM (SELECT dept, AVG(salary) as avg_salary FROM employees GROUP BY dept) AS dept_avg;SELECT name FROM employees WHERE salary > (SELECT AVG(salary) FROM employees);SELECT dept, avg_salary FROM (SELECT dept, AVG(salary) as avg_salary FROM employees GROUP BY dept) AS dept_avg;