个人网站
首发于公众号小肖学数据分析
描述
有一个员工表dept_emp简况如下:
有一个薪水表salaries简况如下:
获取每个部门中当前员工薪水最高的相关信息，给出dept_no, emp_no以及其对应的salary，按照部门编号dept_no升序排列，以上例子输出如下:
解题思路：
1、获取每个部门最高薪水的员工
2、对部门的薪水进行排序，利用rank() over() ，对薪水降序排列，取第一条
3、部门编号dept_no升序排列
-- 创建测试数据drop table if exists `dept_emp` ;drop table if exists `salaries` ;CREATE TABLE `dept_emp` (`emp_no` int(11) NOT NULL,`dept_no` char(4) NOT NULL,`from_date` date NOT NULL,`to_date` date NOT NULL,PRIMARY KEY (`emp_no`,`dept_no`));CREATE TABLE `salaries` (`emp_no` int(11) NOT NULL,`salary` int(11) NOT NULL,`from_date` date NOT NULL,`to_date` date NOT NULL,PRIMARY KEY (`emp_no`,`from_date`));INSERT INTO dept_emp VALUES(10001,'d001','1986-06-26','9999-01-01');INSERT INTO dept_emp VALUES(10002,'d001','1996-08-03','9999-01-01');INSERT INTO dept_emp VALUES(10003,'d002','1996-08-03','9999-01-01');INSERT INTO dept_emp VALUES(10004,'d002','1996-08-03','9999-01-01');INSERT INTO dept_emp VALUES(10005,'d002','1996-08-03','9999-01-01');INSERT INTO salaries VALUES(10001,88958,'2002-06-22','9999-01-01');INSERT INTO salaries VALUES(10002,72527,'2001-08-02','9999-01-01');INSERT INTO salaries VALUES(10003,92527,'2001-08-02','9999-01-01');INSERT INTO salaries VALUES(10004,92527,'2001-08-02','9999-01-01');INSERT INTO salaries VALUES(10005,52342,'2001-08-02','9999-01-01');查询脚本
SELECTdept_no,emp_no,salaryFROM(SELECTb.dept_no,b.emp_no,a.salary,rank() over ( PARTITION BY b.dept_no ORDER BY a.salary DESC ) rtFROMsalaries aINNER JOIN dept_emp b ON a.emp_no = b.emp_no) aWHERErt = 1order by dept_no公众号回复加油即可获取PDF版本
