From b6ad03fede98e0c18b1c8a01a13bcce01b51ef06 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=BB=84=E8=AF=97=E9=BE=99?= <2483323272@qq.com>
Date: Wed, 8 Mar 2023 06:54:43 +0000
Subject: [PATCH] =?UTF-8?q?=E9=BB=84=E8=AF=97=E9=BE=99=E4=BD=9C=E4=B8=9A?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: 黄诗龙 <2483323272@qq.com>
---
 ...06\345\255\220\346\237\245\350\257\242.md" | 91 +++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 "18 \351\273\204\350\257\227\351\276\231/20230306\345\255\220\346\237\245\350\257\242.md"

diff --git "a/18 \351\273\204\350\257\227\351\276\231/20230306\345\255\220\346\237\245\350\257\242.md" "b/18 \351\273\204\350\257\227\351\276\231/20230306\345\255\220\346\237\245\350\257\242.md"
new file mode 100644
index 0000000..a399d3d
--- /dev/null
+++ "b/18 \351\273\204\350\257\227\351\276\231/20230306\345\255\220\346\237\245\350\257\242.md"	
@@ -0,0 +1,91 @@
+```sql
+create database class9 charset utf8;
+use class9;
+
+create table stuinfo(
+	stuNO varchar(10) primary key,
+	stuName varchar(20),
+	stuSex varchar(10),
+	stuAge varchar(20),
+	stuAddress varchar(20),
+	stuSeat char
+);
+
+create table stuExam(
+	ExamNo char primary key,
+	stuNo varchar(20),
+	writtenExam varchar(20),
+	labExam char(11),
+	foreign key(stuNo) references stuinfo(stuNo)
+);
+
+create table stuMarks(
+	examNo varchar(10),
+	stuID varchar(10),
+	score varchar(10),
+	foreign key(examNo) references stuExam(examNo)
+);
+
+insert into stuinfo values ('s2501','张秋利','男',20,'美国硅谷',1),('s2502','李斯文','女',18,'湖北武汉',2),('s2503','马文才','男',22,'湖南长沙',3),('s2504','欧阳俊雅','女',21,'湖北武汉',4),('s2505','梅超风','男',20,'湖北武汉',5),('s2506','陈旋风','男',19,'美国硅谷',6);
+
+desc stuexam;
+
+insert into stuExam values (1,'s2501',50,70),(2,'s2502',60,65),(3,'s2503',86,70),(4,'s2504',40,80),(5,'s2505',70,85),(6,'s2506',85,90);
+
+insert into stuMarks values (1,'s2501',88),(2,'s2501',92),(3,'s2501',53),(4,'s2502',60),(5,'s2502',99),(6,'s2503',82);
+
+
+
+
+-- 在如图的数据表上完成以下题目
+
+-- 1.查询出年龄比班上平均年龄大的学生的信息
+select * from stuinfo where stuAge>(select avg(stuAge) from stuinfo);
+-- 2.查询出每个学生的学号，姓名，性别和选修课程的最高分（stuMarks）
+select stuNo,stuName,stuSex,max(score) from stuinfo a inner join stuMarks b on a.stuNO=b.stuID group by stuNo; 
+-- 3.查询出每个学生的学号，姓名，性别和考试平均分（stuExam）
+select stuinfo.stuNO,stuName,stuSex,aug from stuinfo left join (select stuNo,(writtenExam+labExam)/2 aug from stuexam) li on stuinfo.stuNO=li.stuNO;
+
+-- 4.查询性别是男并且年龄大于等于20的学生的信息(用两种方法实现：普通查询和子查询)
+select * from stuinfo where stuAge>=20 and stuSex='男';
+
+select * from stuinfo left join (select * from stuinfo where stuage>=20) aug on aug.stuNO=stuinfo.stuNO where aug.stuSex='男'
+
+-- 5.查询出年龄比所有男生年龄都大的女生的信息
+select * from stuinfo where stuAge>any(select stuAge from stuinfo where stuSex='男') and stuSex='女';
+-- 6.查询出所有选修课程都及格的学生的信息   （stuMarks）
+select * from stuinfo a left join stumarks b on a.stuNo=b.stuID where score>=60;
+-- 7.查询出参加考试的学生的信息（用表连接，in二种方法做）（stuMarks）
+select distinct a.* from stuinfo a inner join stumarks b on a.stuNo=b.stuID
+-- 8.查询出没有参加考试的学生的信息（用表连接，in二种方法做）（stuMarks）
+SELECT* FROM stuinfo a LEFT JOIN ( SELECT DISTINCT stuid FROM stuMarks ) b ON a.stuNO = b.stuid WHERE stuid IS NULL;
+
+select * from stuinfo where stuNO not in(select distinct stuID from stumarks);
+
+-- 9.将有一门成绩成绩大于90分的学生的基本信息查询出来（stuMarks）
+select * from stuinfo where stuNO in(select stuID from stuMarks where score>90);
+-- 10.查询出平均成绩在80分以上的学生的基本信息（stuMarks）
+select * from stuinfo where stuNO =(select stuNO from stuexam where (writtenexam + labexam)/2>80);
+
+
+--                                                                  11.查询出某同学所有考试成绩比“张秋利”同学所有分数都高的学生基本信息（stuMarks）
+select * from stuinfo where stuNO=any(select stuNO from stuexam where writtenExam > (SELECT writtenExam FROM stuexam AS a
+INNER JOIN (SELECT stuNO FROM stuinfo WHERE stuName = '张秋利' ) AS b ON a.stuNO = b.stuNO) 
+AND labExam > (
+SELECT labExam FROM stuexam AS a INNER JOIN ( SELECT stuNO FROM stuinfo WHERE stuName = '张秋利' ) AS b ON a.stuNO = b.stuNO) ); 
+		
+
+
+-- 12.查询出某同学所有考试成绩只需要比“张秋利”同学某个分数高的学生基本信息（stuMarks）
+select * from stuinfo where stuNO=any(select stuNO from stuexam where writtenExam > (SELECT writtenExam FROM stuexam AS a
+INNER JOIN (SELECT stuNO FROM stuinfo WHERE stuName = '张秋利' ) AS b ON a.stuNO = b.stuNO) 
+xor labExam > (
+SELECT labExam FROM stuexam AS a INNER JOIN ( SELECT stuNO FROM stuinfo WHERE stuName = '张秋利' ) AS b ON a.stuNO = b.stuNO) ); 
+
+
+-- 13.查询班上比所有男生年龄都要大的女生的信息
+select * from stuinfo where stuAge>all(select stuAge from stuinfo where stuSex='男') and stuSex='女';
+-- 14.查询出只是比某个男生年龄大的女生的信息
+select * from stuinfo where stuAge>any(select stuAge from stuinfo where stuSex='男') and stuSex='女';
+```
+
-- 
Gitee