181. Employees Earning More Than Their Managers(Lettcode)

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      |+----------+

大意是找出比Manager工资高的Employee，首先想到的是自连接，可博主大概是头疼脑热。。写了个子查询的代码

还为此纠结了半天，写此博文来警醒自己。下面贴代码

select e1.Name as Employee from Employee e1,Employee e2 where e1.ManagerId = e2.Id and e1.Salary > e2.Salary;

或者内连接也可以

select e1.Name as Employee from Employee e1 inner join Employee e2 on e1.ManagerId = e2.Id and e1.Salary > e2.Salary;