Description：
Write a SQL query to get the second highest salary from the Employee table.
+----+--------+ | Id | Salary | +----+--------+ | 1 | 100 | | 2 | 200 | | 3 | 300 | +----+--------+
For example, given the above Employee table, the second highest salary is 200. If there is no second highest salary, then the query should return null.
大意是选出第二高的Salary。
# Write your MySQL query statement below select max(Salary) from Employee where Salary < (select max(Salary) from Employee );