From 5bc06e86e6613f68e2d673aefdea69af7e02ab23 Mon Sep 17 00:00:00 2001
From: zeek <984294471@qq.com>
Date: Tue, 7 Apr 2020 21:37:35 +0800
Subject: [PATCH] =?UTF-8?q?=E7=AC=ACn=E9=AB=98=E7=9A=84=E8=96=AA=E6=B0=B4?=
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---
 sql/getNthHighestSalary.sql | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 sql/getNthHighestSalary.sql

diff --git a/sql/getNthHighestSalary.sql b/sql/getNthHighestSalary.sql
new file mode 100644
index 0000000..8185708
--- /dev/null
+++ b/sql/getNthHighestSalary.sql
@@ -0,0 +1,29 @@
+
+/**
+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
+  RETURN (
+      # Write your MySQL query statement below.
+      SELECT DISTINCT e.salary
+      FROM employee e
+      WHERE (SELECT count(DISTINCT salary) FROM employee WHERE salary>e.salary) = N-1
+  );
+END