查询部门最高工资的员工
Employee 表包含所有员工信息，每个员工有其对应的 Id, salary 和 department Id。
Department 表包含公司所有部门的信息。
编写一个 SQL 查询，找出每个部门工资最高的员工。
第一版sql：
select Department.name as Department,Employee.Name as Employee,max(Salary) as Salary from Employee left join Department on Department.Id = Employee.DepartmentId group by DepartmentId
输出结果：
发现最高薪资查出来了，但是名字和薪资对不上
第二版sql:
select d.name as Department,e.name as Employee,Salary from Employee e inner join Department d on e.DepartmentId=d.id where e.Salary>=(select max(Salary) as Salary from Employee where DepartmentId = d.id )
输出结果正确。
第三版：
先查出部门最高工资的思路
select d.name as department,e.name,e.salary from employee e left JOIN (select id,max(salary) as salary,departmentid from employee GROUP by departmentid)c on e.DepartmentId=c.DepartmentId left JOIN department d on e.departmentid= d.id where e.departmentid = c.departmentid and e.salary = c.salary
执行结果
结果正确。
参考：https://blog.csdn.net/qq_43048011/article/details/82193952
