編寫一個 SQL 查詢,獲取 Employee
表中第二高的薪水(Salary) 。
+----+--------+ | Id | Salary | +----+--------+ | 1 | 100 | | 2 | 200 | | 3 | 300 | +----+--------+
例如上述 Employee
表,SQL查詢應該返回 200
作爲第二高的薪水。如果不存在第二高的薪水,那麼查詢應返回 null
。
+---------------------+ | SecondHighestSalary | +---------------------+ | 200 | +---------------------+
MySQL:
select max(salary) as SecondHighestSalary from Employee
where salary<(select max(salary) from Employee)