MySQL题目练习正在更新中

目录

• 练习环境
• 第一题

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
;