DataBase -- Second Highest Salary

Question:

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.

Analysis:

写一个SQL语句找出Employee表中第二高的年薪，如果没有，则返回null。

我们可以先取出最大的Salary，然后再取出比最大的Salary小的最大Salary。

Answer：

select max(Salary) from Employee
where Salary < (select max(Salary) from Employee);