Question:

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      |

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

Analysis:

Employee表格包含公司里所有的员工，包括他们的经理。每个员工都有一个员工ID和一个经理ID。

给出Employee表格，写一个SQL语句，找出工资比他的经理还高的员工。例如在上面的例子中，只有Joe满足该情况。

最后给出什么则select后面接什么，如果遇到比较的，则应该选择使用两个表格。

Answer：

select e1.Name from Employee e1, Employee e2

where e2.Id = e1.ManagerId and e1.Salary > e2.Salary