This query returns “High” and “Low” based on their salary compared to the average salary of all employees.
SELECT employee_id, first_name,
CASE
WHEN Salary>=(SELECT Avg(Salary) From Employees)
THEN ‘High’
ELSE ‘Low’ END As PAY,
Salary From Employees
SELECT employee_id,Last_Name,
(CASE
WHEN Department_Id =
(SELECT Department_ID FROM Departments WHERE
LOCATION_ID=1800)
THEN ‘Canada’ ELSE ‘USA’ END) Locations
FROM Employees