From fd6fa877952cc9f38818e22325956f1106b7b96b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E9=99=88=E7=81=B5=E9=92=B0111?= <11785101+chen-lingyu-111@user.noreply.gitee.com> Date: Wed, 6 Sep 2023 17:16:17 +0000 Subject: [PATCH 1/6] =?UTF-8?q?=E9=99=88=E7=81=B5=E9=92=B0?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: 陈灵钰111 <11785101+chen-lingyu-111@user.noreply.gitee.com> --- 20230904.md | 15 +++++ 20230905.md | 163 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 178 insertions(+) create mode 100644 20230904.md create mode 100644 20230905.md diff --git a/20230904.md b/20230904.md new file mode 100644 index 0000000..1097697 --- /dev/null +++ b/20230904.md @@ -0,0 +1,15 @@ +九月四日 + +开学第一课，没有正式上课，好困 + +邱邱老师讲了以下几点 + +。。。新学期学习规划 + +。。。课余时间主动学习 + +。。。VIP视频：VIP解析 + +。。。百度网盘资源：盘搜搜 + +晚上没课，去city walk，因为走不动，变成city drive，最后到达了中山街，可能这就是缘分，吃到了好吃的炸鸡柳、年糕、薯条、肉夹馍..... \ No newline at end of file diff --git a/20230905.md b/20230905.md new file mode 100644 index 0000000..3fa83df --- /dev/null +++ b/20230905.md @@ -0,0 +1,163 @@ +```mysql +九月五日 +今天上课不困，下课不知道要吃什么，走了一大圈最后决定去吃冒菜，好辣，雨好大 +-- 笔记 +表之间的关系 + 1.一对一：将其中一表主键做另一表的外键 + 2.一对多：将一所在表的主键做多的外键 + 3.多对多：建第三张表，将两个表的主键作为第三表的外键 +E-R图 +概念：实体关系图，以三基本要素组成 +三基本要素：实体，属性，关系 + +CREATE DATABASE MXDX CHARSET utf8; +use MXDX; +-- 1院系表-- +CREATE TABLE Yuanxi ( +Yname varchar(10),-- 院系名称 +Ynumber int PRIMARY key-- 院系编号 +); +-- 插入数据 +INSERT into Yuanxi VALUES +('软件工程学院',1), +('智能制造学院',2), +('城乡建筑学院',3), +('信息工程学院',4), +('教育与艺术学院',5), +('医学护理学院',6), +('财经商贸学院',7), +('文化与旅游学院',8); + +-- 2专业表-- +CREATE TABLE Zhuanye( +Zname varchar(10),-- 专业名称 +Znumber int PRIMARY key,-- 专业编号 +Ynumber int,-- 院系编号 +FOREIGN key (Ynumber) REFERENCES Yuanxi(Ynumber) +); +-- 插入数据 +INSERT into Zhuanye VALUES +('软件技术后端',1,1), +('软件技术前端',2,1), +('软件技术新媒体',3,1); + +-- 3教室表-- +CREATE TABLE classroom( +Cname VARCHAR(10),-- 教室名称 +Cnumber int PRIMARY key-- 教室编号 +); +-- 插入数据 +INSERT into classroom VALUES +('实训一',1), +('实训二',2), +('实训三',3), +('实训四',4), +('实训五',5), +('实训六',6), +('实训七',7), +('实训八',8); +-- 4班级表-- +CREATE TABLE Aclass( +Aname VARCHAR(15),-- 班级名称 +Anumber int PRIMARY key,-- 班级编号 +Znumber int ,-- 专业编号 +FOREIGN key (Znumber) REFERENCES Zhuanye(Znumber), +Cnumber int,-- 教室编号 +FOREIGN key (Cnumber) REFERENCES Classroom(Cnumber) +); +-- 插入数据 +INSERT into Aclass VALUES +('22级1班',1,1,8), +('22级2班',2,1,7), +('22级3班',3,1,6), +('22级4班',4,1,6), +('22级5班',5,1,3), +('22级6班',6,1,2), +('22级7班',7,1,1), +('22级8班',8,1,4), +('22级9班',9,1,5), +('22级10班',10,1,1); +-- 5学生表-- +CREATE TABLE student( +Snumber int PRIMARY key,-- 学生编号 +Sname VARCHAR(10),-- 学生名称 +sex VARCHAR(10),-- 学生性别 +Cnumber int,-- 教室编号 +FOREIGN key (Cnumber) REFERENCES Classroom(Cnumber), +Anumber int,-- 班级编号 +FOREIGN key (Anumber) REFERENCES Aclass(Anumber) +); +-- 插入数据 +INSERT into student VALUES +(1,'张三','男',1,7), +(2,'李四','女',6,3), +(3,'王五','男',8,1); +-- 6教师表-- +CREATE TABLE teacher( +tnumber int PRIMARY key,-- 教师编号 +tname VARCHAR(10),-- 教师名称 +Znumber int,-- 专业编号 +FOREIGN key (Znumber) REFERENCES Zhuanye(Znumber) +); +-- 插入数据 +INSERT into teacher VALUES +(1,'邱邱',1), +(2,'张三',2), +(3,'李四',3); + +-- 7课程-- +CREATE table Kecheng( +Knumber int PRIMARY key,-- 课程编号 +Kname VARCHAR(10),-- 课程名称 +Tnumber int,-- 教师编号 +FOREIGN key (Tnumber) REFERENCES teacher(Tnumber) +); +-- 插入数据 +INSERT into Kecheng VALUES +(1,'mysql',1), +(2,'java',2), +(3,'ps',3); +-- 8选修-- +CREATE table Xuanxiu( +Xnumber int,-- 选修编号 +Knumber int,-- 课程编号 +FOREIGN key (Knumber) REFERENCES Kecheng(Knumber), +Snumber int,-- 学生编号 +FOREIGN key (Snumber) REFERENCES student(Snumber) +); +-- 插入数据 +INSERT into Xuanxiu VALUES +(1,1,3), +(2,3,2), +(3,2,1); +-- 9课程表-- +CREATE table Bkecheng( +time VARCHAR(10),-- 时间 +Knumber int,-- 课程编号 +FOREIGN key (Knumber) REFERENCES Kecheng(Knumber), +Anumber int ,-- 班级编号 +FOREIGN key (Anumber) REFERENCES Aclass(Anumber) +); +-- 插入数据 +INSERT into Bkecheng VALUES +('周一上午',1,1), +('周二下午',2,1), +('周四下午',1,1), +('周五上午',1,1), +('周六上午',2,1); + + +-- 查询 +SELECT * from Yuanxi; +SELECT * from Zhuanye; +SELECT * from classroom; +SELECT * from Aclass; +SELECT * from student; +SELECT * from teacher; +SELECT * from Kecheng; +SELECT * from Xuanxiu; +SELECT * from Bkecheng; + +SELECT DISTINCT S.Snumber 学生编号,S.sname 姓名, A.Anumber 班级编号 from Aclass A INNER JOIN Student S on A.Cnumber=S.Cnumber ,Student inner JOIN Classroom C on Student.Cnumber=C.Cnumber where S.Snumber =(SELECT Snumber from Student WHERE Sname='王五'); +``` + -- Gitee From e98c356fc08d4c80e943eead25fc6b135c98d9f0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E9=99=88=E7=81=B5=E9=92=B0111?= <11785101+chen-lingyu-111@user.noreply.gitee.com> Date: Wed, 6 Sep 2023 23:54:49 +0000 Subject: [PATCH 2/6] =?UTF-8?q?=E6=96=B0=E5=BB=BA=2031=20=E9=99=88?= =?UTF-8?q?=E7=81=B5=E9=92=B0?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- "31 \351\231\210\347\201\265\351\222\260/.keep" | 0 1 file changed, 0 insertions(+), 0 deletions(-) create mode 100644 "31 \351\231\210\347\201\265\351\222\260/.keep" diff --git "a/31 \351\231\210\347\201\265\351\222\260/.keep" "b/31 \351\231\210\347\201\265\351\222\260/.keep" new file mode 100644 index 0000000..e69de29 -- Gitee From da3a063613459501a7b8d42b1ad44cef260f98b3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E9=99=88=E7=81=B5=E9=92=B0111?= <11785101+chen-lingyu-111@user.noreply.gitee.com> Date: Fri, 8 Sep 2023 04:34:18 +0000 Subject: [PATCH 3/6] =?UTF-8?q?=E5=88=A0=E9=99=A4=E6=96=87=E4=BB=B6=2031?= =?UTF-8?q?=20=E9=99=88=E7=81=B5=E9=92=B0?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- "31 \351\231\210\347\201\265\351\222\260/.keep" | 0 1 file changed, 0 insertions(+), 0 deletions(-) delete mode 100644 "31 \351\231\210\347\201\265\351\222\260/.keep" diff --git "a/31 \351\231\210\347\201\265\351\222\260/.keep" "b/31 \351\231\210\347\201\265\351\222\260/.keep" deleted file mode 100644 index e69de29..0000000 -- Gitee From 7b14c40c771fbf526fbbadf587965ac500b34163 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E9=99=88=E7=81=B5=E9=92=B0111?= <11785101+chen-lingyu-111@user.noreply.gitee.com> Date: Fri, 8 Sep 2023 04:35:01 +0000 Subject: [PATCH 4/6] =?UTF-8?q?=E5=88=A0=E9=99=A4=E6=96=87=E4=BB=B6=202023?= =?UTF-8?q?0904.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- 20230904.md | 15 --------------- 1 file changed, 15 deletions(-) delete mode 100644 20230904.md diff --git a/20230904.md b/20230904.md deleted file mode 100644 index 1097697..0000000 --- a/20230904.md +++ /dev/null @@ -1,15 +0,0 @@ -九月四日 - -开学第一课，没有正式上课，好困 - -邱邱老师讲了以下几点 - -。。。新学期学习规划 - -。。。课余时间主动学习 - -。。。VIP视频：VIP解析 - -。。。百度网盘资源：盘搜搜 - -晚上没课，去city walk，因为走不动，变成city drive，最后到达了中山街，可能这就是缘分，吃到了好吃的炸鸡柳、年糕、薯条、肉夹馍..... \ No newline at end of file -- Gitee From 427323f185b465977bd9eab5478c25834ba62887 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E9=99=88=E7=81=B5=E9=92=B0111?= <11785101+chen-lingyu-111@user.noreply.gitee.com> Date: Fri, 8 Sep 2023 04:35:17 +0000 Subject: [PATCH 5/6] =?UTF-8?q?=E5=88=A0=E9=99=A4=E6=96=87=E4=BB=B6=202023?= =?UTF-8?q?0905.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- 20230905.md | 163 ---------------------------------------------------- 1 file changed, 163 deletions(-) delete mode 100644 20230905.md diff --git a/20230905.md b/20230905.md deleted file mode 100644 index 3fa83df..0000000 --- a/20230905.md +++ /dev/null @@ -1,163 +0,0 @@ -```mysql -九月五日 -今天上课不困，下课不知道要吃什么，走了一大圈最后决定去吃冒菜，好辣，雨好大 --- 笔记 -表之间的关系 - 1.一对一：将其中一表主键做另一表的外键 - 2.一对多：将一所在表的主键做多的外键 - 3.多对多：建第三张表，将两个表的主键作为第三表的外键 -E-R图 -概念：实体关系图，以三基本要素组成 -三基本要素：实体，属性，关系 - -CREATE DATABASE MXDX CHARSET utf8; -use MXDX; --- 1院系表-- -CREATE TABLE Yuanxi ( -Yname varchar(10),-- 院系名称 -Ynumber int PRIMARY key-- 院系编号 -); --- 插入数据 -INSERT into Yuanxi VALUES -('软件工程学院',1), -('智能制造学院',2), -('城乡建筑学院',3), -('信息工程学院',4), -('教育与艺术学院',5), -('医学护理学院',6), -('财经商贸学院',7), -('文化与旅游学院',8); - --- 2专业表-- -CREATE TABLE Zhuanye( -Zname varchar(10),-- 专业名称 -Znumber int PRIMARY key,-- 专业编号 -Ynumber int,-- 院系编号 -FOREIGN key (Ynumber) REFERENCES Yuanxi(Ynumber) -); --- 插入数据 -INSERT into Zhuanye VALUES -('软件技术后端',1,1), -('软件技术前端',2,1), -('软件技术新媒体',3,1); - --- 3教室表-- -CREATE TABLE classroom( -Cname VARCHAR(10),-- 教室名称 -Cnumber int PRIMARY key-- 教室编号 -); --- 插入数据 -INSERT into classroom VALUES -('实训一',1), -('实训二',2), -('实训三',3), -('实训四',4), -('实训五',5), -('实训六',6), -('实训七',7), -('实训八',8); --- 4班级表-- -CREATE TABLE Aclass( -Aname VARCHAR(15),-- 班级名称 -Anumber int PRIMARY key,-- 班级编号 -Znumber int ,-- 专业编号 -FOREIGN key (Znumber) REFERENCES Zhuanye(Znumber), -Cnumber int,-- 教室编号 -FOREIGN key (Cnumber) REFERENCES Classroom(Cnumber) -); --- 插入数据 -INSERT into Aclass VALUES -('22级1班',1,1,8), -('22级2班',2,1,7), -('22级3班',3,1,6), -('22级4班',4,1,6), -('22级5班',5,1,3), -('22级6班',6,1,2), -('22级7班',7,1,1), -('22级8班',8,1,4), -('22级9班',9,1,5), -('22级10班',10,1,1); --- 5学生表-- -CREATE TABLE student( -Snumber int PRIMARY key,-- 学生编号 -Sname VARCHAR(10),-- 学生名称 -sex VARCHAR(10),-- 学生性别 -Cnumber int,-- 教室编号 -FOREIGN key (Cnumber) REFERENCES Classroom(Cnumber), -Anumber int,-- 班级编号 -FOREIGN key (Anumber) REFERENCES Aclass(Anumber) -); --- 插入数据 -INSERT into student VALUES -(1,'张三','男',1,7), -(2,'李四','女',6,3), -(3,'王五','男',8,1); --- 6教师表-- -CREATE TABLE teacher( -tnumber int PRIMARY key,-- 教师编号 -tname VARCHAR(10),-- 教师名称 -Znumber int,-- 专业编号 -FOREIGN key (Znumber) REFERENCES Zhuanye(Znumber) -); --- 插入数据 -INSERT into teacher VALUES -(1,'邱邱',1), -(2,'张三',2), -(3,'李四',3); - --- 7课程-- -CREATE table Kecheng( -Knumber int PRIMARY key,-- 课程编号 -Kname VARCHAR(10),-- 课程名称 -Tnumber int,-- 教师编号 -FOREIGN key (Tnumber) REFERENCES teacher(Tnumber) -); --- 插入数据 -INSERT into Kecheng VALUES -(1,'mysql',1), -(2,'java',2), -(3,'ps',3); --- 8选修-- -CREATE table Xuanxiu( -Xnumber int,-- 选修编号 -Knumber int,-- 课程编号 -FOREIGN key (Knumber) REFERENCES Kecheng(Knumber), -Snumber int,-- 学生编号 -FOREIGN key (Snumber) REFERENCES student(Snumber) -); --- 插入数据 -INSERT into Xuanxiu VALUES -(1,1,3), -(2,3,2), -(3,2,1); --- 9课程表-- -CREATE table Bkecheng( -time VARCHAR(10),-- 时间 -Knumber int,-- 课程编号 -FOREIGN key (Knumber) REFERENCES Kecheng(Knumber), -Anumber int ,-- 班级编号 -FOREIGN key (Anumber) REFERENCES Aclass(Anumber) -); --- 插入数据 -INSERT into Bkecheng VALUES -('周一上午',1,1), -('周二下午',2,1), -('周四下午',1,1), -('周五上午',1,1), -('周六上午',2,1); - - --- 查询 -SELECT * from Yuanxi; -SELECT * from Zhuanye; -SELECT * from classroom; -SELECT * from Aclass; -SELECT * from student; -SELECT * from teacher; -SELECT * from Kecheng; -SELECT * from Xuanxiu; -SELECT * from Bkecheng; - -SELECT DISTINCT S.Snumber 学生编号,S.sname 姓名, A.Anumber 班级编号 from Aclass A INNER JOIN Student S on A.Cnumber=S.Cnumber ,Student inner JOIN Classroom C on Student.Cnumber=C.Cnumber where S.Snumber =(SELECT Snumber from Student WHERE Sname='王五'); -``` - -- Gitee From 440e0a3f70cdb8b8da77478908dd67ac26e1797f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E9=99=88=E7=81=B5=E9=92=B0?= <3279815787@qq.com> Date: Fri, 8 Sep 2023 12:53:05 +0800 Subject: [PATCH 6/6] =?UTF-8?q?=E9=99=88=E7=81=B5=E9=92=B0?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../20230904.md" | 15 ++ .../20230905.md" | 163 ++++++++++++++++++ .../20230907.md" | 0 3 files changed, 178 insertions(+) create mode 100644 "31 \351\231\210\347\201\265\351\222\260/20230904.md" create mode 100644 "31 \351\231\210\347\201\265\351\222\260/20230905.md" create mode 100644 "31 \351\231\210\347\201\265\351\222\260/20230907.md" diff --git "a/31 \351\231\210\347\201\265\351\222\260/20230904.md" "b/31 \351\231\210\347\201\265\351\222\260/20230904.md" new file mode 100644 index 0000000..aabcbdf --- /dev/null +++ "b/31 \351\231\210\347\201\265\351\222\260/20230904.md" @@ -0,0 +1,15 @@ +九月四日 + +开学第一课，没有正式上课，好困 + +邱邱老师讲了以下几点 + +。。。新学期学习规划 + +。。。课余时间主动学习 + +。。。VIP视频：VIP解析 + +。。。百度网盘资源：盘搜搜 + +晚上没课，去city walk，因为走不动，变成city drive，最后到达了中山街，可能这就是缘分，吃到了好吃的炸鸡柳、年糕、薯条、肉夹馍..... \ No newline at end of file diff --git "a/31 \351\231\210\347\201\265\351\222\260/20230905.md" "b/31 \351\231\210\347\201\265\351\222\260/20230905.md" new file mode 100644 index 0000000..99985bf --- /dev/null +++ "b/31 \351\231\210\347\201\265\351\222\260/20230905.md" @@ -0,0 +1,163 @@ +```mysql +九月五日 +今天上课不困，下课不知道要吃什么，走了一大圈最后决定去吃冒菜，好辣，雨好大 +-- 笔记 +表之间的关系 + 1.一对一：将其中一表主键做另一表的外键 + 2.一对多：将一所在表的主键做多的外键 + 3.多对多：建第三张表，将两个表的主键作为第三表的外键 +E-R图 +概念：实体关系图，以三基本要素组成 +三基本要素：实体，属性，关系 + +CREATE DATABASE MXDX CHARSET utf8; +use MXDX; +-- 1院系表-- +CREATE TABLE Yuanxi ( +Yname varchar(10),-- 院系名称 +Ynumber int PRIMARY key-- 院系编号 +); +-- 插入数据 +INSERT into Yuanxi VALUES +('软件工程学院',1), +('智能制造学院',2), +('城乡建筑学院',3), +('信息工程学院',4), +('教育与艺术学院',5), +('医学护理学院',6), +('财经商贸学院',7), +('文化与旅游学院',8); + +-- 2专业表-- +CREATE TABLE Zhuanye( +Zname varchar(10),-- 专业名称 +Znumber int PRIMARY key,-- 专业编号 +Ynumber int,-- 院系编号 +FOREIGN key (Ynumber) REFERENCES Yuanxi(Ynumber) +); +-- 插入数据 +INSERT into Zhuanye VALUES +('软件技术后端',1,1), +('软件技术前端',2,1), +('软件技术新媒体',3,1); + +-- 3教室表-- +CREATE TABLE classroom( +Cname VARCHAR(10),-- 教室名称 +Cnumber int PRIMARY key-- 教室编号 +); +-- 插入数据 +INSERT into classroom VALUES +('实训一',1), +('实训二',2), +('实训三',3), +('实训四',4), +('实训五',5), +('实训六',6), +('实训七',7), +('实训八',8); +-- 4班级表-- +CREATE TABLE Aclass( +Aname VARCHAR(15),-- 班级名称 +Anumber int PRIMARY key,-- 班级编号 +Znumber int ,-- 专业编号 +FOREIGN key (Znumber) REFERENCES Zhuanye(Znumber), +Cnumber int,-- 教室编号 +FOREIGN key (Cnumber) REFERENCES Classroom(Cnumber) +); +-- 插入数据 +INSERT into Aclass VALUES +('22级1班',1,1,8), +('22级2班',2,1,7), +('22级3班',3,1,6), +('22级4班',4,1,6), +('22级5班',5,1,3), +('22级6班',6,1,2), +('22级7班',7,1,1), +('22级8班',8,1,4), +('22级9班',9,1,5), +('22级10班',10,1,1); +-- 5学生表-- +CREATE TABLE student( +Snumber int PRIMARY key,-- 学生编号 +Sname VARCHAR(10),-- 学生名称 +sex VARCHAR(10),-- 学生性别 +Cnumber int,-- 教室编号 +FOREIGN key (Cnumber) REFERENCES Classroom(Cnumber), +Anumber int,-- 班级编号 +FOREIGN key (Anumber) REFERENCES Aclass(Anumber) +); +-- 插入数据 +INSERT into student VALUES +(1,'张三','男',1,7), +(2,'李四','女',6,3), +(3,'王五','男',8,1); +-- 6教师表-- +CREATE TABLE teacher( +tnumber int PRIMARY key,-- 教师编号 +tname VARCHAR(10),-- 教师名称 +Znumber int,-- 专业编号 +FOREIGN key (Znumber) REFERENCES Zhuanye(Znumber) +); +-- 插入数据 +INSERT into teacher VALUES +(1,'邱邱',1), +(2,'张三',2), +(3,'李四',3); + +-- 7课程-- +CREATE table Kecheng( +Knumber int PRIMARY key,-- 课程编号 +Kname VARCHAR(10),-- 课程名称 +Tnumber int,-- 教师编号 +FOREIGN key (Tnumber) REFERENCES teacher(Tnumber) +); +-- 插入数据 +INSERT into Kecheng VALUES +(1,'mysql',1), +(2,'java',2), +(3,'ps',3); +-- 8选修-- +CREATE table Xuanxiu( +Xnumber int,-- 选修编号 +Knumber int,-- 课程编号 +FOREIGN key (Knumber) REFERENCES Kecheng(Knumber), +Snumber int,-- 学生编号 +FOREIGN key (Snumber) REFERENCES student(Snumber) +); +-- 插入数据 +INSERT into Xuanxiu VALUES +(1,1,3), +(2,3,2), +(3,2,1); +-- 9课程表-- +CREATE table Bkecheng( +time VARCHAR(10),-- 时间 +Knumber int,-- 课程编号 +FOREIGN key (Knumber) REFERENCES Kecheng(Knumber), +Anumber int ,-- 班级编号 +FOREIGN key (Anumber) REFERENCES Aclass(Anumber) +); +-- 插入数据 +INSERT into Bkecheng VALUES +('周一上午',1,1), +('周二下午',2,1), +('周四下午',1,1), +('周五上午',1,1), +('周六上午',2,1); + + +-- 查询 +SELECT * from Yuanxi; +SELECT * from Zhuanye; +SELECT * from classroom; +SELECT * from Aclass; +SELECT * from student; +SELECT * from teacher; +SELECT * from Kecheng; +SELECT * from Xuanxiu; +SELECT * from Bkecheng; + +SELECT DISTINCT S.Snumber 学生编号,S.sname 姓名, A.Anumber 班级编号 from Aclass A INNER JOIN Student S on A.Cnumber=S.Cnumber ,Student inner JOIN Classroom C on Student.Cnumber=C.Cnumber where S.Snumber =(SELECT Snumber from Student WHERE Sname='王五'); +``` + diff --git "a/31 \351\231\210\347\201\265\351\222\260/20230907.md" "b/31 \351\231\210\347\201\265\351\222\260/20230907.md" new file mode 100644 index 0000000..e69de29 -- Gitee