[SQL]LeetCode177. 第N高的薪水 | Nth Highest Salary

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Write a SQL query to get the nth highest salary from the Employee table.

+----+--------+
| Id | Salary |
+----+--------+
| 1  | 100    |
| 2  | 200    |
| 3  | 300    |
+----+--------+

For example, given the above Employee table, the nth highest salary where n = 2 is 200. If there is no nth highest salary, then the query should return null.

+------------------------+
| getNthHighestSalary(2) |
+------------------------+
| 200                    |
+------------------------+

---

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                    |
+------------------------+

---

140ms

CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
BEGIN
    set N = N-1;
  RETURN (
      # Write your MySQL query statement below.
      select distinct Salary from Employee order by Salary desc limit N,1
  );
END

---

149ms

CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
BEGIN
  set N = N-1;
  RETURN (      
      select distinct Salary as 'getNthHighestSalary(2)'
      from Employee
      order by Salary desc
      limit N, 1
  );
END