目录
练习环境
MySQL版本为5.6
使用的软件 navicate
第一题
题目：统计每个部门中薪酬最高的员工
知识点：分组排序，多表查询
解题思路：
插入数据
CREATE TABLE `EMPLOYEE` (
`ID` varchar(255),
`Name` varchar(255),
`Salary` varchar(255),
`DepartmentID` varchar(255)
);
INSERT INTO `EMPLOYEE` VALUES ('1', 'Joe', '70000', '1');
INSERT INTO `EMPLOYEE` VALUES ('2', 'Henry', '80000', '2');
INSERT INTO `EMPLOYEE` VALUES ('3', 'Jane', '60000', '2');
INSERT INTO `EMPLOYEE` VALUES ('4', 'Ben', '90000', '1');
CREATE TABLE `DEPARTMENT` (
`ID` varchar(255),
`DEPARTMENT` varchar(255)
);
INSERT INTO `DEPARTMENT` VALUES ('1', 'IT');
INSERT INTO `DEPARTMENT` VALUES ('2', 'Sales');
点击查看答案
# 方法一
SELECT
`Name`,
Salary,
DEPARTMENT
FROM
( EMPLOYEE INNER JOIN DEPARTMENT ON EMPLOYEE.DepartmentID = DEPARTMENT.ID )
INNER JOIN ( SELECT DepartmentID, MAX( Salary ) AS MAX_Salary FROM EMPLOYEE GROUP BY DepartmentID ) AS T ON EMPLOYEE.DepartmentID = T.DepartmentID
AND EMPLOYEE.Salary = T.MAX_Salary;
# 方法二
SELECT
*
FROM
(SELECT
`Name` ,Salary,DEPARTMENT as D
FROM
EMPLOYEE INNER JOIN DEPARTMENT
ON
EMPLOYEE.DepartmentID = DEPARTMENT.ID
ORDER BY
D,Salary DESC
) as t
GROUP BY
D
;
原创文章，作者：dweifng，如若转载，请注明出处：https://blog.ytso.com/277620.html