タイトル
Employeeテーブルには、それぞれがその対応する従業員ID、給与および部門IDを持っている、すべての従業員に関する情報が含まれています。
Departmentテーブルには、会社のすべてのセクターに関する情報が含まれています。
各部門の従業員の最も高い賃金を見つけるために、SQLクエリを記述します。例えば、上記の表によると、マックスは、IT部門の最高賃金を持っていた、ヘンリーは、営業部門で最も高い賃金を持っていました。
分析
-- 查看员工表
SELECT
*
FROM
employee;
-- 查看部门表
SELECT
*
FROM
department;
-- 每个部门的最大薪水
SELECT
DepartmentId,
MAX( Salary )
FROM
Employee
GROUP BY
DepartmentId;
![在这里插入图片描述](https://img-blog.csdnimg.cn/20200225113606400.png)
-- 连接员工表和部门表
SELECT
*
FROM
Employee
JOIN department ON Employee.DepartmentId = Department.Id;
-- 加上前面那个部门薪水最高的表过滤一下
SELECT
*
FROM
Employee
JOIN
Department ON Employee.DepartmentId = Department.Id
WHERE
(Employee.DepartmentId , Employee.Salary) IN
( SELECT
DepartmentId, MAX(Salary)
FROM
Employee
GROUP BY DepartmentId
)
;
-- 列名
SELECT
Department.Name as Department,
Employee.Name as Employee,
Salary
FROM
Employee
JOIN
Department ON Employee.DepartmentId = Department.Id
WHERE
(Employee.DepartmentId , Employee.Salary) IN
( SELECT
DepartmentId, MAX(Salary)
FROM
Employee
GROUP BY DepartmentId
)
;
答え
-- 查看员工表
SELECT
*
FROM
employee;
-- 查看部门表
SELECT
*
FROM
department;
-- 每个部门的最大薪水
SELECT
DepartmentId,
MAX( Salary )
FROM
Employee
GROUP BY
DepartmentId;
-- 连接员工表和部门表
SELECT
*
FROM
Employee
JOIN department ON Employee.DepartmentId = Department.Id;
-- 加上前面那个部门薪水最高的表过滤一下
SELECT
*
FROM
Employee
JOIN
Department ON Employee.DepartmentId = Department.Id
WHERE
(Employee.DepartmentId , Employee.Salary) IN
( SELECT
DepartmentId, MAX(Salary)
FROM
Employee
GROUP BY DepartmentId
)
;
-- 列名
SELECT
Department.Name as Department,
Employee.Name as Employee,
Salary
FROM
Employee
JOIN
Department ON Employee.DepartmentId = Department.Id
WHERE
(Employee.DepartmentId , Employee.Salary) IN
( SELECT
DepartmentId, MAX(Salary)
FROM
Employee
GROUP BY DepartmentId
)
;