题解 | #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#

1、查询title，avg，avg = AVG(s.salary)：SELECT title, AVG(s.salary) AS avg
2、在titles和salaries内连接的表中查询：FROM titles JOIN salaries AS s ON titles.emp_no = s.emp_no
3、查询不同title的人群的平均工资：GROUP BY title
4、按照avg排序：ORDER BY avg
5、串联：
SELECT title, AVG(s.salary) AS avg
FROM titles JOIN salaries AS s ON titles.emp_no = s.emp_no
GROUP BY title
ORDER BY avg