diff --git "a/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/.keep" "b/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/.keep"
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git "a/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\344\275\234\344\270\232/.keep" "b/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\344\275\234\344\270\232/.keep"
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git "a/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\344\275\234\344\270\232/test.sql" "b/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\344\275\234\344\270\232/test.sql"
new file mode 100644
index 0000000000000000000000000000000000000000..eed3433d9a1160b71a9e0d7a5629ada9761e0770
--- /dev/null
+++ "b/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\344\275\234\344\270\232/test.sql"	
@@ -0,0 +1,71 @@
+--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 sc.SId,c.Cname,score,t.平均分 from sc
+inner join Course c on c.cid = sc.CId
+inner join
+(
+select sid,avg(score)平均分 from sc
+group by sid 
+) t
+on t.SId = sc.sid 
+
+order by t.平均分 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,c.Cname,
+(select max(score) from sc sc1 where sc.CId = sc1.CId)最高分,
+(select min(score) from sc sc1 where sc.CId = sc1.CId)最低分,
+convert(decimal(5,2),(select avg(score) from sc sc1 where sc.cid = sc1.cid))平均分,
+concat(convert(decimal(5,2),(select (count(*)*100)/1.0/(select count(*) from sc sc3 where sc3.cid = sc.cid ) from sc sc2 where sc.cid = sc2.cid and sc2.score >= 60)),'%') 及格率,
+concat(convert(decimal(5,2),(select (count(*)*100)/1.0/(select count(*) from sc sc3 where sc3.cid = sc.cid ) from sc sc2 where sc.cid = sc2.cid and sc2.score  between 70 and 80)),'%') 中等率,
+concat(convert(decimal(5,2),(select (count(*)*100)/1.0/(select count(*) from sc sc3 where sc3.cid = sc.cid ) from sc sc2 where sc.cid = sc2.cid and sc2.score between 80 and 90)),'%') 优良率,
+concat(convert(decimal(5,2),(select (count(*)*100)/1.0/(select count(*) from sc sc3 where sc3.cid = sc.cid ) from sc sc2 where sc.cid = sc2.cid and sc2.score >= 90)),'%') 优秀率
+from sc
+inner join Course c 
+on c.CId = sc.CId
+group by sc.CId,c.Cname
+
+
+--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 
+inner 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 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,dense_rank() over(order by score desc) 语文排名 from sc where cid = '01'
+) t1 on t1.sid = s.sid 
+inner join
+(
+select sid,dense_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,dense_rank() over(order by score desc) 英语排名 from sc where cid = '03'
+) t3 on t3.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 t.SId,t.总分,dense_rank() over (order by 总分 desc) 排名
+from
+(
+select sid,sum(score) 总分 from sc
+group by sid 
+) t
+--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 t.SId,t.总分,rank() over (order by 总分 desc) 排名
+from
+(
+select sid,sum(score) 总分 from sc
+group by sid 
+) t
\ No newline at end of file
diff --git "a/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\347\254\224\350\256\260/.keep" "b/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\347\254\224\350\256\260/.keep"
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git "a/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\347\254\224\350\256\260/2022-9-21-\347\252\227\345\217\243\346\216\222\345\210\227\345\207\275\346\225\260.md" "b/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\347\254\224\350\256\260/2022-9-21-\347\252\227\345\217\243\346\216\222\345\210\227\345\207\275\346\225\260.md"
new file mode 100644
index 0000000000000000000000000000000000000000..07ce4e4f9398b056c5c4c95ee8f7790663c304af
--- /dev/null
+++ "b/22 \346\235\250\345\207\214\347\277\224/\347\254\254\345\233\233\346\254\241\344\275\234\344\270\232/\347\254\224\350\256\260/2022-9-21-\347\252\227\345\217\243\346\216\222\345\210\227\345\207\275\346\225\260.md"	
@@ -0,0 +1,3 @@
+--Rank	             ����, ռλ��
+--DENSE_RANK      ����, ��ռλ��
+--ROW_NUMBER   ������, ռλ��
\ No newline at end of file