Employee 表包含所有員工信息浆兰，每個員工有其對應(yīng)的 Id, salary 和 department Id
+----+-------+--------+--------------+
| Id | Name | Salary | DepartmentId |
+----+-------+--------+--------------+
| 1 | Joe | 70000 | 1 |
| 2 | Henry | 80000 | 2 |
| 3 | Sam | 60000 | 2 |
| 4 | Max | 90000 | 1 |
+----+-------+--------+--------------+
Department 表包含公司所有部門的信息珊豹。
+----+----------+
| Id | Name |
+----+----------+
| 1 | IT |
| 2 | Sales |
+----+----------+
編寫一個 SQL 查詢，找出每個部門工資最高的員工店茶。例如，根據(jù)上述給定的表格贩幻，Max 在 IT 部門有最高工資两嘴，Henry 在 Sales 部門有最高工資。
+------------+----------+--------+
| Department | Employee | Salary |
+------------+----------+--------+
| IT | Max | 90000 |
| Sales | Henry | 80000 |
+------------+----------+--------+
解析：
把兩個匹配的行內(nèi)關(guān)聯(lián)起來憔辫。
答案:
select b.name Department , a.Name Employee, a.Salary Salary
from Employee a inner join Department b
on a.DepartmentId = b.Id
where a.Salary =
(select max(Salary) from Employee where DepartmentId = b.id);
