Employees Earning More Than Their Managers

Question

The Employee table holds all employees including their managers. Every employee has an Id, and there is also a column for the manager Id.

+----+-------+--------+-----------+
| Id | Name  | Salary | ManagerId |
+----+-------+--------+-----------+
| 1  | Joe   | 70000  | 3         |
| 2  | Henry | 80000  | 4         |
| 3  | Sam   | 60000  | NULL      |
| 4  | Max   | 90000  | NULL      |
+----+-------+--------+-----------+

Given the Employee table, write a SQL query that finds out employees who earn more than their managers. For the above table, Joe is the only employee who earns more than his manager.

+----------+
| Employee |
+----------+
| Joe      |
+----------+

Tags

• SQL

Thought

Two ways to solve this:

1. Use WHERE clause to compare the salary between the employee and the corresponding manager
2. Use JOIN clause to compare the salary.

The implementations of these two approaches are all below.

Code

-- Write your MySQL query statement below

-- Use WHERE
SELECT e.Name AS Employee
FROM Employee e
WHERE e.Salary > (
    SELECT m.Salary
    FROM Employee m
    WHERE e.ManagerId = m.Id
);


-- Use JOIN
SELECT e.Name AS Employee
FROM Employee e
JOIN Employee m ON e.ManagerId = m.Id AND e.Salary > m.Salary;