编写一个 SQL 查询,获取 Employee
表中第 n 高的薪水(Salary)。
+----+--------+ | Id | Salary | +----+--------+ | 1 | 100 | | 2 | 200 | | 3 | 300 | +----+--------+
例如上述 Employee
表,n = 2 时,应返回第二高的薪水 200
。如果不存在第 n 高的薪水,那么查询应返回 null
。
+------------------------+ | getNthHighestSalary(2) | +------------------------+ | 200 | +------------------------+
CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
BEGIN
SET N = N - 1;
RETURN (
# Write your MySQL query statement below.
SELECT (
SELECT DISTINCT Salary
FROM Employee
ORDER BY Salary DESC
LIMIT 1 OFFSET N
)
);
END