From 46adbcbfa82f51d25f690c7d0965fc892f83c881 Mon Sep 17 00:00:00 2001
From: Mars Liu <mars.liu@outlook.com>
Date: Thu, 2 Dec 2021 15:19:01 +0800
Subject: [PATCH] add window function

---
 .pre-commit-config.yaml                       |  2 +-
 .../2.Window Function/salary.md"              | 67 +++++++++++++++++++
 2 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 "data/3.PostgreSQL\351\253\230\351\230\266/3.SQL\351\253\230\347\272\247\346\212\200\345\267\247/2.Window Function/salary.md"

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index bb1c157..427f3af 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
   - repo: git@codechina.csdn.net:csdn/skill_tree_hook.git
-    rev: 15a330214a4d7c2e0c0e42b5dfc3121a56f4dc23
+    rev: 9430721405a57a809c0d93170fe307a89d979a4b
     hooks:
       - id: pre-commit
         verbose: true
\ No newline at end of file
diff --git "a/data/3.PostgreSQL\351\253\230\351\230\266/3.SQL\351\253\230\347\272\247\346\212\200\345\267\247/2.Window Function/salary.md" "b/data/3.PostgreSQL\351\253\230\351\230\266/3.SQL\351\253\230\347\272\247\346\212\200\345\267\247/2.Window Function/salary.md"
new file mode 100644
index 0000000..8b5f5da
--- /dev/null
+++ "b/data/3.PostgreSQL\351\253\230\351\230\266/3.SQL\351\253\230\347\272\247\346\212\200\345\267\247/2.Window Function/salary.md"	
@@ -0,0 +1,67 @@
+# 工资最高的人
+
+现有员工信息表如下：
+
+```postgresql
+create table employee
+(
+    id     serial primary key,
+    name   text,
+    dept   text,
+    salary money
+);
+```
+
+下面哪条查询，可以给出每个部门工资最高的前五个员工的 id, name, dept, salary 四项信息？
+
+## 答案
+
+```postgresql
+select id, name, dept, salary
+from (select id, name, dept, salary, rank() over (partition by dept order by salary desc) as r
+      from employee) as t
+where r <= 5;
+```
+
+## 选项
+
+### 结构错误
+
+```postgresql
+select id, name, dept, max(salary) as salary
+from employee
+group by dept
+having id < 6;
+```
+
+### 结构错误
+
+```postgresql
+select l.id, l.name, l.dept, l.salary
+from employee as l
+         join (select max(salary) as salary, dept
+               from employee
+               group by dept) as r
+              on l.dept = r.dept and l.salary = r.salary
+where count(r.id) <= 5;
+```
+
+### 结构错误
+
+```postgresql
+select l.id, l.name, l.dept, l.salary
+from employee as l
+         join (select max(salary, 5) as salary, dept
+               from employee
+               group by dept) as r
+              on l.dept = r.dept and l.salary = r.salary
+```
+
+### 结构错误
+
+```postgresql
+select id, name, dept, salary, rank() over (partition by dept order by salary desc) as r
+from employee
+where r <= 5;
+```
+
-- 
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