The Employee table holds all employees. Every employee has an Id, a salary, and there is also a column for the department Id.
+----+-------+--------+--------------+
| Id | Name | Salary | DepartmentId |
+----+-------+--------+--------------+
| 1 | Joe | 70000 | 1 |
| 2 | Henry | 80000 | 2 |
| 3 | Sam | 60000 | 2 |
| 4 | Max | 90000 | 1 |
+----+-------+--------+--------------+The Department table holds all departments of the company.
+----+----------+
| Id | Name |
+----+----------+
| 1 | IT |
| 2 | Sales |
+----+----------+Write a SQL query to find employees who have the highest salary in each of the departments. For the above
tables, Max has the highest salary in the IT department and Henry has the highest salary in the Sales
department.
+------------+----------+--------+
| Department | Employee | Salary |
+------------+----------+--------+
| IT | Max | 90000 |
| Sales | Henry | 80000 |
+------------+----------+--------+解决方式1
SELECT
d.Name AS Department, e.Name AS Employee, e.Salary
FROM
Employee e,
Department d
WHERE
e.DepartmentId = d.id
AND e.Salary = (SELECT
MAX(Salary)
FROM
Employee e2
WHERE
e2.DepartmentId = d.id)