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 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
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 0000000000000000000000000000000000000000..9629f025379d2a2a2332f3610ecf6847e3f313d7
--- /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 0000000000000000000000000000000000000000..895e32f2a423617c4b5bc4d12b758172ae60d038
--- /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