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 | +---------------------+
Solution:
select if(count(*) != 0,max(salary),null) from Employee where salary != (select max(salary) from Employee)
176. Second Highest Salary(Easy)
原文：http://www.cnblogs.com/sixu/p/6884718.html