题解 | #统计平均工资#
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 a.title, round((sum(b.salary)/count(a.title)),4) as sal_avg from titles as a inner join salaries as b on a.emp_no=b.emp_no group by a.title