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 query should return 200 as the second highest salary. If there is no second highest salary, then the query should return null.
+---------------------+
| SecondHighestSalary |
+---------------------+
| 200 |
+---------------------+解答：
这个相比于“第 n 高的薪水”的就简单多啦~
# Write your MySQL query statement below
select MAX(Salary) as SecondHighestSalary from Employee
where Salary < (
select MAX(Salary) from Employee);