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      |

+----------+

查找表中员工工资比经理工资高的数据

• 员工的数据是有ManagerId的，可以使用连接查询，e1是查的员工的数据，e2是查的经理的数据,然后条件是e1中的salary字段要比e2中的大。

select 
 e1.name as Employee 
from 
 Employee e1
inner join 
 Employee e2
on e1.managerId = e2.id
and e1.salary > e2.salary