From c3fe462d38a27e6207b620a64238639fc2ecd7b4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9E=97=E4=B8=96=E6=B6=9B?=
 <10033723+ClosestoolSaint@user.noreply.gitee.com>
Date: Thu, 22 Sep 2022 04:54:30 +0000
Subject: [PATCH 1/2] =?UTF-8?q?=E6=96=B0=E5=BB=BA=20=E7=AC=AC=E5=9B=9B?=
 =?UTF-8?q?=E6=AC=A1=E4=BD=9C=E4=B8=9A?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../.keep"                                                        | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 "23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/.keep"

diff --git "a/23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/.keep" "b/23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/.keep"
new file mode 100644
index 0000000..e69de29
-- 
Gitee


From 33ff64a7d731fde6e6677b4c3e35d898d10ce487 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9E=97=E4=B8=96=E6=B6=9B?=
 <10033723+ClosestoolSaint@user.noreply.gitee.com>
Date: Thu, 22 Sep 2022 04:54:50 +0000
Subject: [PATCH 2/2] =?UTF-8?q?=E6=9E=97=E4=B8=96=E6=B6=9B23?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: 林世涛 <10033723+ClosestoolSaint@user.noreply.gitee.com>
---
 .../\344\275\234\344\270\232.sql"             | 50 +++++++++++++++++++
 .../\347\254\224\350\256\260.md"              |  2 +
 2 files changed, 52 insertions(+)
 create mode 100644 "23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\344\275\234\344\270\232.sql"
 create mode 100644 "23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\347\254\224\350\256\260.md"

diff --git "a/23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\344\275\234\344\270\232.sql" "b/23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\344\275\234\344\270\232.sql"
new file mode 100644
index 0000000..9629f02
--- /dev/null
+++ "b/23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\344\275\234\344\270\232.sql"
@@ -0,0 +1,50 @@
+--13. 按平均成绩从高到低显示所有学生的所有课程的成绩以及平均成绩
+select huhu.SId,平均成绩,sc1.CId,sc1.score, sc2.CId,sc2.score, sc3.CId,sc3.score from(
+select SC.SId,AVG(SC.score)平均成绩 from SC 
+group by SC.SId 
+) huhu 
+left join SC sc1 on sc1.SId=huhu.SId and sc1.CId=1
+left join SC sc2 on sc2.SId=huhu.SId and sc2.CId=2
+left join SC sc3 on sc3.SId=huhu.SId and sc3.CId=3
+order by 平均成绩 desc
+
+
+--14. 查询各科成绩最高分、最低分和平均分：
+
+--以如下形式显示：课程 ID，课程 name，最高分，最低分，平均分，及格率，中等率，优良率，优秀率
+
+--及格为>=60，中等为：70-80，优良为：80-90，优秀为：>=90
+
+--要求输出课程号和选修人数，查询结果按人数降序排列，若人数相同，按课程号升序排列
+
+select SC.CId,Cname,MAX(score)最高分,MIN(score)最低分,AVG(score)平均成绩 from SC 
+inner join Course on Course.CId=SC.CId group by SC.CId,Cname order by COUNT(SC.CId) desc,CId
+
+--15. 按各科成绩进行排序，并显示排名， Score 重复时保留名次空缺
+select s.sid,sname,t1.语文排名,t2.数学排名,t3.英语排名 from student s
+left join
+(
+select sid,rank() over(order by score desc) 语文排名 from sc where cid = '01'
+) t1 on t1.sid = s.sid 
+left join
+(
+select sid,rank() over(order by score desc) 数学排名 from sc where cid = '02'
+) t2 on t2.sid = s.sid
+left join 
+(
+select sid,rank() over(order by score desc) 英语排名 from sc where cid = '03'
+) t3 on t3.sid = s.sid
+--15.1 按各科成绩进行排序，并显示排名， Score 重复时合并名次
+
+select * from Student s
+left join(select SId,DENSE_RANK() over(order by score desc)排名1 from SC where CId=1) sc1 on sc1.SId=s.SId
+left join (select SId,DENSE_RANK()over(order by score desc)排名2 from SC where CId=2) sc2 on sc2.SId=s.SId
+left join (select SId,DENSE_RANK()over(order by score desc)排名3 from SC where CId=3) sc3 on sc3.SId=s.SId
+
+--16. 查询学生的总成绩，并进行排名，总分重复时保留名次空缺
+
+select SId,sum(score)总分,RANK() over(order by sum(score) desc)排名  from SC group by SId
+
+--16.1 查询学生的总成绩，并进行排名，总分重复时不保留名次空缺
+
+select SId,sum(score)总分,DENSE_RANK() over(order by sum(score) desc) 排名 from SC group by SId
\ No newline at end of file
diff --git "a/23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\347\254\224\350\256\260.md" "b/23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\347\254\224\350\256\260.md"
new file mode 100644
index 0000000..895e32f
--- /dev/null
+++ "b/23\346\236\227\344\270\226\346\266\233/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\347\254\224\350\256\260.md"
@@ -0,0 +1,2 @@
+对sql的学习更深入了
+非常充实的一天
\ No newline at end of file
-- 
Gitee