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 | +----------+
The Employee table holds all employees including their managers. Every employee has an Id, and there is also a column for the manager Id. 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.
select b.Name as `Employee` from Employee a, Employee b where b.ManagerId = a.Id and a.Salary < b.Salary or select b.Name as `Employee` from Employee a left join Employee b on b.ManagerId = a.Id where a.Salary < b.Salary
