【牛客SQL】SQL16 统计出当前各个title类型对应的员工当前薪水对应的平均工资

题目描述

描述 有一个员工职称表titles简况如下:

有一个薪水表salaries简况如下:

请你统计出各个title类型对应的员工薪水对应的平均工资avg。结果给出title以及平均工资avg，并且以avg升序排序，以上例子输出如下:

示例1
输入：
drop table if exists  `salaries` ; 
drop table if exists  titles;
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`));
CREATE TABLE titles (
`emp_no` int(11) NOT NULL,
`title` varchar(50) NOT NULL,
`from_date` date NOT NULL,
`to_date` date DEFAULT NULL);
INSERT INTO salaries VALUES(10001,88958,'1986-06-26','9999-01-01');
INSERT INTO salaries VALUES(10003,43311,'2001-12-01','9999-01-01');
INSERT INTO salaries VALUES(10004,74057,'1995-12-01','9999-01-01');
INSERT INTO salaries VALUES(10006,43311,'2001-08-02','9999-01-01');
INSERT INTO salaries VALUES(10007,88070,'2002-02-07','9999-01-01');

INSERT INTO titles VALUES(10001,'Senior Engineer','1986-06-26','9999-01-01');
INSERT INTO titles VALUES(10003,'Senior Engineer','2001-12-01','9999-01-01');
INSERT INTO titles VALUES(10004,'Senior Engineer','1995-12-01','9999-01-01');
INSERT INTO titles VALUES(10006,'Senior Engineer','2001-08-02','9999-01-01');
INSERT INTO titles VALUES(10007,'Senior Staff','1996-02-11','9999-01-01');
复制
输出：
Senior Engineer|62409.2500
Senior Staff|88070.0000

题解

考察JOIN连表查询，考察GROUP BY 分组统计：

运行时间：22ms 超过20.38% 用Sqlite提交的代码 占用内存：3424KB 超过29.01%用Sqlite提交的代码

SELECT t.title, AVG(s.salary) FROM titles t JOIN salaries s
ON t.emp_no == s.emp_no
WHERE t.to_date == '9999-01-01' AND s.to_date == '9999-01-01'
GROUP BY t.title
ORDER BY AVG(s.salary) ASC;