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;