题解 | #title类型对应的员工当前薪水对应的平均工资#
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
https://www.nowcoder.com/practice/c8652e9e5a354b879e2a244200f1eaae
select title,AVG(salary) from ( select t.emp_no,t.title,s.salary from titles as t left join salaries as s on t.emp_no = s.emp_no )a group by title