Employee 表包含所有员工，他们的经理也属于员工。每个员工都有一个 Id，此外还有一列对应员工的经理的 Id。
| Id | Name | Salary | ManagerId |
|---|---|---|---|
| 1 | Joe | 70000 | 3 |
| 2 | Henry | 80000 | 4 |
| 3 | Sam | 60000 | NULL |
| 4 | Max | 90000 | NULL |
给定 Employee 表，编写一个 SQL 查询，该查询可以获取收入超过他们经理的员工的姓名。在上面的表格中，Joe 是唯一一个收入超过他的经理的员工。
| Employee |
|---|
| Joe |
题解:
内连接
# Write your MySQL query statement below
select e1.name as Employee
from
Employee e1 join Employee e2
on
e1.ManagerId=e2.Id and e1.Salary > e2.Salary;
左连接
select e1.name as Employee
from
Employee e1 left join Employee e2
on
e1.ManagerId=e2.Id
where e1.Salary > e2.Salary;
不连接
select e1.name as Employee
from
Employee as e1, Employee as e2
where e1.Salary > e2.Salary and e1.managerid=e2.id;
