地址:https://leetcode-cn.com/problems/employees-earning-more-than-their-managers/
## 编写一个 SQL查询,交换所有的 f 和 m 值(例如,将所有 f 值更改为 m,反之亦然 示例: 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 | +----------+ `解题思路` 1 使用where `select a.Name as Employee from Employee as a, Employee as b where a.ManagerId =b.id and a.Salary>b.Salary; ` 2 使用join `select b.Name as Employee from Employee as a join Employee as b on a.id =b.ManagerId and a.Salary<b.Salary`