Problem
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 |
Solution
select e.Name as "Employee" from Employee e
join Employee m
on (e.ManagerId = m.Id)
where e.Salary > m.Salary; 
