超过经理收入的员工 表的自JOIN
https://leetcode-cn.com/problems/employees-earning-more-than-their-managers/description/
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 | +----------+
SELECT e.Name AS Employee FROM Employee e LEFT JOIN Employee eb ON e.ManagerId=eb.Id WHERE e.ManagerId IS NOT NULL AND e.Salary>eb.Salary;