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
SELECT
dept_no,
emp_no,
salary
FROM
(
SELECT
b.dept_no,
b.emp_no,
a.salary,
rank() over ( PARTITION BY b.dept_no ORDER BY a.salary DESC ) rt
FROM
salaries a
INNER JOIN dept_emp b ON a.emp_no = b.emp_no
) a
WHERE
rt = 1
order by dept_no
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