问题遇到的现象和发生背景
问题相关代码,请勿粘贴截图
CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
BEGIN
RETURN (
# Write your MySQL query statement below.
select distinct e1.Salary
from Employee e1 left join Employee e2 on e1.Salary<e2.Salary
group by e1.Salary
having count(distinct e2.Salary)=N-1
);
END
运行结果及报错内容
我的解答思路和尝试过的方法
以为是count会算null值,但是count会忽略空值