diff --git "a/40 \351\237\251\351\234\207\346\264\213/20230311 \346\237\245\350\257\242\344\275\234\344\270\232.md" "b/40 \351\237\251\351\234\207\346\264\213/20230311 \346\237\245\350\257\242\344\275\234\344\270\232.md"
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@@ -0,0 +1,83 @@
+```mysql
+
+CREATE DATABASE class10 charset utf8;
+use class10;
+CREATE TABLE stuinfo (
+ stuNO VARCHAR(20) PRIMARY KEY,
+ stuName VARCHAR(20),
+ stuAge INT,
+ stuAddress VARCHAR(20),
+ stuSeat INT,
+ stuSex int
+);
+DESC stuinfo;
+INSERT INTO stuinfo VALUES('s2501','张秋利',20,'美国硅谷',1,1),('s2502','李斯文',18,'湖北武汉',2,0),('s2503','马文才',22,'湖南长沙',3,1),('s2504','欧阳俊熊',21,'湖北武汉',4,0),('s2505','梅超风',20,'湖北武汉',5,1),('s2506','陈旋风',19,'美国硅谷',6,1),
+('s2507','陈风',20,'美国硅谷',7,0);
+
+
+CREATE TABLE stuExam(
+	examNo INT,
+	stuNo VARCHAR(20) PRIMARY KEY,
+	writtenExam INT,
+	labExam INT,
+	FOREIGN KEY (stuNo) REFERENCES stuinfo(stuNo)
+);
+INSERT INTO stuexam VALUES(1,'s2501',50,70),(2,'s2502',60,65),(3,'s2503',86,85),(4,'s2504',40,80),(5,'s2505',70,90),(6,'s2506',85,90);
+
+
+-- 按图片所给的数据进行数据表的建立和数据插入，然后进行以下查询操作
+ 
+-- 1.查询学生信息表（stuinfo）中所有列信息，给每列取上中文名称
+
+ select stuNO 学号, stuName 姓名, stuAge 年龄, stuAddress 住址, stuSeat 座位号, stuSex 性别 from stuinfo;
+-- 2.查询学生信息表（stuinfo）中的姓名，年龄和地址三列的信息
+select stuName,stuAge,stuAddress from stuinfo;
+-- 3.查询学生分数表（stuexam）中的学号，笔试和机试三列的信息，并为这三列取中文名字
+select stuinfo.stuNO 学号,writtenExam 笔试,labExam 机试 from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo;
+-- 5.查询学生分数表（stuexam）中的学生的学号，笔试，机试以及总分这四列的信息
+ select stuinfo.stuNO,writtenExam,labExam,(writtenExam+labExam) from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo;
+-- 6.查询学生信息表（stuInfo）中学生来自哪几个地方 
+ select stuAddress from stuinfo group by stuAddress;
+-- 7.查询学生信息表（stuInfo）中学生有哪几种年龄，并为该列取对应的中文列名
+ select stuAge 学生年龄分类 from stuinfo group by stuAge;
+-- 8.查询学生信息表（stuInfo）中前3行记录 
+select * from stuinfo order by stuNO limit 3;
+-- 9.查询学生信息表（stuInfo）中前4个学生的姓名和座位号
+ select stuName,stuSeat from stuinfo order by stuNO limit 4;
+-- 11.将地址是湖北武汉，年龄是20的学生的所有信息查询出来
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where stuAddress = '湖北武汉' and stuAge = '20';
+-- 12.将机试成绩在60-80之间的信息查询出来，并按照机试成绩降序排列
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where labExam between 60 and 80 order by labExam desc;
+-- 13.查询来自湖北武汉或者湖南长沙的学生的所有信息
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where stuAddress = '湖北武汉' or stuAddress = '湖南长沙';
+-- 14.查询出笔试成绩不在70-90之间的信息,并按照笔试成绩升序排列
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where labExam not between 70 and 90 order by labExam ;
+-- 15.查询年龄没有写的学生所有信息
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where stuAge is null;
+-- 16.查询年龄写了的学生所有信息
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where stuAge is not null;
+-- 17.查询姓张的学生信息
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where stuName like '张%';
+-- 18.查询学生地址中有‘湖’字的信息
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where stuAddress like '%湖%';
+-- 19.查询姓张但名为一个字的学生信息
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where stuName = '张_';
+-- 20.查询姓名中第三个字为‘俊’的学生的信息，‘俊’后面有多少个字不限制
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo where stuName like '__俊%';
+-- 21.按学生的年龄降序显示所有学生信息
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo order by stuAge desc;
+-- 22.按学生的年龄降序和座位号升序来显示所有学生的信息
+select * from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo order by stuAge desc, stuSeat;
+-- 23显示笔试第一名的学生的考试号，学号，笔试成绩和机试成绩
+
+select examNo,stuNo,writtenExam,labExam,writtenExam from stuexam where writtenExam = (select max(writtenExam) from stuexam);
+-- 24.显示机试倒数第一名的学生的考试号，学号，笔试成绩和机试成绩
+select examNo,stuNo,writtenExam,labExam,writtenExam from stuexam where labExam = (select min(labExam) from stuexam);
+-- 25.查询每个地方的学生的平均年龄
+select stuAddress,avg(stuAge) from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo group by stuAddress;
+-- 26.查询男女生的分别的年龄总和
+select sum(stuAge),stuSex from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo group by stuSex;
+-- 27.查询每个地方的男女生的平均年龄和年龄的总和
+select stuAddress,sum(stuAge),avg(stuAge) from stuinfo left join stuexam on stuinfo.stuNO = stuexam.stuNo group by stuAddress;
+```
+