题解 | #平均工资#
平均工资
http://www.nowcoder.com/practice/95078e5e1fba4438b85d9f11240bc591
select avg(salary) from salaries a where to_date='9999-01-01' and salary!= (select min(salary) from salaries where to_date='9999-01-01') and salary<>(select max(salary) from salaries where to_date='9999-01-01')