DROP TABLE IF EXISTS `grade`;
CREATE TABLE `grade` (
`GradeID` INT(11) NOT NULL AUTO_INCREMENT COMMENT '年级编号',
`GradeName` VARCHAR(50) NOT NULL COMMENT '年级名称',
PRIMARY KEY (`GradeID`)
) ENGINE=INNODB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
INSERT INTO `grade`(`GradeID`,`GradeName`) VALUES (1,'大一'),(2,'大二'),(3,'大三'),(4,'大四'),(5,'预科班');
DROP TABLE IF EXISTS `result`;
CREATE TABLE `result` (
`StudentNo` INT(4) NOT NULL COMMENT '学号',
`SubjectNo` INT(4) NOT NULL COMMENT '课程编号',
`ExamDate` DATETIME NOT NULL COMMENT '考试日期',
`StudentResult` INT(4) NOT NULL COMMENT '考试成绩',
KEY `SubjectNo` (`SubjectNo`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
INSERT INTO `result`(`StudentNo`,`SubjectNo`,`ExamDate`,`StudentResult`) VALUES (1000,'111111','郭靖',1,1,'13500000001','北京海淀区中关村大街1号','1986-12-11 00:00:00','[email protected]','450323198612111234'),(1001,'123456','李文才',1,2,'13500000002','河南洛阳','1981-12-31 00:00:00','[email protected]','450323198112311234'),(1002,'111111','李斯文',1,1,'13500000003','天津市和平区','1986-11-30 00:00:00','[email protected]','450323198611301234'),(1003,'123456','武松',1,3,'13500000004','上海卢湾区','1986-12-31 00:00:00','[email protected]','450323198612314234'),(1004,'123456','张三',1,4,'13500000005','北京市通州','1989-12-31 00:00:00','[email protected]','450323198612311244'),(1005,'123456','张秋丽 ',2,1,'13500000006','广西桂林市灵川','1986-12-31 00:00:00','[email protected]','450323198612311214'),(1006,'123456','肖梅',2,4,'13500000007','地址不详','1986-12-31 00:00:00','[email protected]','450323198612311134'),(1007,'111111','欧阳峻峰',1,1,'13500000008','北京东城区','1986-12-31 00:00:00','[email protected]','450323198612311133'),(1008,'111111','梅超风',1,1,'13500000009','河南洛阳','1986-12-31 00:00:00','[email protected]','450323198612311221'),(1009,'123456','刘毅',1,2,'13500000011','安徽','1986-12-31 00:00:00','[email protected]','450323198612311231'),(1010,'111111','大凡',1,1,'13500000012','河南洛阳','1986-12-31 00:00:00','[email protected]','450323198612311044'),(1011,'111111','奥丹斯',1,1,'13500000013','北京海淀区中关村大街*号','1984-12-31 00:00:00','[email protected]','450323198412311234'),(1012,'123456','多伦',2,3,'13500000014','广西南宁中央大街','1986-12-31 00:00:00','[email protected]','450323198612311334'),(1013,'123456','李梅',2,1,'13500000015','上海卢湾区','1986-12-31 00:00:00','[email protected]','450323198612311534'),(1014,'123456','张得',2,4,'13500000016','北京海淀区中关村大街*号','1986-12-31 00:00:00','[email protected]','450323198612311264'),(1015,'123456','李东方',1,4,'13500000017','广西桂林市灵川','1976-12-31 00:00:00','[email protected]','450323197612311234'),(1016,'111111','刘奋斗',1,1,'13500000018','上海卢湾区','1986-12-31 00:00:00','[email protected]','450323198612311251'),(1017,'123456','可可',2,3,'13500000019','北京长安街1号','1981-09-10 00:00:00','[email protected]','450323198109108311'),(10066,'','Tom',1,1,'13500000000','','0000-00-00 00:00:00','[email protected]','33123123123123123');
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
`StudentNo` INT(4) NOT NULL COMMENT '学号',
`LoginPwd` VARCHAR(20) DEFAULT NULL,
`StudentName` VARCHAR(20) DEFAULT NULL COMMENT '学生姓名',
`Sex` TINYINT(1) DEFAULT NULL COMMENT '性别，取值0或1',
`GradeId` INT(11) DEFAULT NULL COMMENT '年级编号',
`Phone` VARCHAR(50) NOT NULL COMMENT '联系电话，允许为空，即可选输入',
`Address` VARCHAR(255) NOT NULL COMMENT '地址，允许为空，即可选输入',
`BornDate` DATETIME DEFAULT NULL COMMENT '出生时间',
`Email` VARCHAR(50) NOT NULL COMMENT '邮箱账号，允许为空，即可选输入',
`IdentityCard` VARCHAR(18) DEFAULT NULL COMMENT '身份证号',
PRIMARY KEY (`StudentNo`),
UNIQUE KEY `IdentityCard` (`IdentityCard`),
KEY `Email` (`Email`)
) ENGINE=MYISAM DEFAULT CHARSET=utf8;
INSERT INTO `student`(`StudentNo`,`LoginPwd`,`StudentName`,`Sex`,`GradeId`,`Phone`,`Address`,`BornDate`,`Email`,`IdentityCard`) VALUES (1000,'111111','郭靖',1,1,'13500000001','北京海淀区中关村大街1号','1986-12-11 00:00:00','[email protected]','450323198612111234'),(1001,'123456','李文才',1,2,'13500000002','河南洛阳','1981-12-31 00:00:00','[email protected]','450323198112311234'),(1002,'111111','李斯文',1,1,'13500000003','天津市和平区','1986-11-30 00:00:00','[email protected]','450323198611301234'),(1003,'123456','武松',1,3,'13500000004','上海卢湾区','1986-12-31 00:00:00','[email protected]','450323198612314234'),(1004,'123456','张三',1,4,'13500000005','北京市通州','1989-12-31 00:00:00','[email protected]','450323198612311244'),(1005,'123456','张秋丽 ',2,1,'13500000006','广西桂林市灵川','1986-12-31 00:00:00','[email protected]','450323198612311214'),(1006,'123456','肖梅',2,4,'13500000007','地址不详','1986-12-31 00:00:00','[email protected]','450323198612311134'),(1007,'111111','欧阳峻峰',1,1,'13500000008','北京东城区','1986-12-31 00:00:00','[email protected]','450323198612311133'),(1008,'111111','梅超风',1,1,'13500000009','河南洛阳','1986-12-31 00:00:00','[email protected]','450323198612311221'),(1009,'123456','刘毅',1,2,'13500000011','安徽','1986-12-31 00:00:00','[email protected]','450323198612311231'),(1010,'111111','大凡',1,1,'13500000012','河南洛阳','1986-12-31 00:00:00','[email protected]','450323198612311044'),(1011,'111111','奥丹斯',1,1,'13500000013','北京海淀区中关村大街*号','1984-12-31 00:00:00','[email protected]','450323198412311234'),(1012,'123456','多伦',2,3,'13500000014','广西南宁中央大街','1986-12-31 00:00:00','[email protected]','450323198612311334'),(1013,'123456','李梅',2,1,'13500000015','上海卢湾区','1986-12-31 00:00:00','[email protected]','450323198612311534'),(1014,'123456','张得',2,4,'13500000016','北京海淀区中关村大街*号','1986-12-31 00:00:00','[email protected]','450323198612311264'),(1015,'123456','李东方',1,4,'13500000017','广西桂林市灵川','1976-12-31 00:00:00','[email protected]','450323197612311234'),(1016,'111111','刘奋斗',1,1,'13500000018','上海卢湾区','1986-12-31 00:00:00','[email protected]','450323198612311251'),(1017,'123456','可可',2,3,'13500000019','北京长安街1号','1981-09-10 00:00:00','[email protected]','450323198109108311'),(10066,'','Tom',1,1,'13500000000','','0000-00-00 00:00:00','[email protected]','33123123123123123');
DROP TABLE IF EXISTS `subject`;
CREATE TABLE `subject` (
`SubjectNo` INT(11) NOT NULL AUTO_INCREMENT COMMENT '课程编号',
`SubjectName` VARCHAR(50) DEFAULT NULL COMMENT '课程名称',
`ClassHour` INT(4) DEFAULT NULL COMMENT '学时',
`GradeID` INT(4) DEFAULT NULL COMMENT '年级编号',
PRIMARY KEY (`SubjectNo`)
) ENGINE=INNODB AUTO_INCREMENT=18 DEFAULT CHARSET=utf8;
INSERT INTO `subject`(`SubjectNo`,`SubjectName`,`ClassHour`,`GradeID`) VALUES (1,'高等数学-1',110,1),(2,'高等数学-2',110,2),(3,'高等数学-3',100,3),(4,'高等数学-4',130,4),(5,'C语言-1',110,1),(6,'C语言-2',110,2),(7,'C语言-3',100,3),(8,'C语言-4',130,4),(9,'JAVA第一学年',110,1),(10,'JAVA第二学年',110,2),(11,'JAVA第三学年',100,3),(12,'JAVA第四学年',130,4),(13,'数据库结构-1',110,1),(14,'数据库结构-2',110,2),(15,'数据库结构-3',100,3),(16,'数据库结构-4',130,4),(17,'C#基础',130,1);
#select concat('学生:',studentname) 学生姓名 ,concat('+86',phone) 电话 from student;
# select count(studnetno) 学生总数 from student;
#DISTINCT关键字作用：去掉SELECT查询返回的记录结果中重复的记录（所有返回列 的值都相同），只返回一条 语法： SELECT DISTINCT 字段名1,字段名2... FROM 表名
#注意：ALL 关键字是默认的，返回所有的记录，与之相反
#DISTINCT关键字的使用
#查询成绩表中的所包含的课程ID
SELECT DISTINCT SubjectNo FROM result;
#BETWEEN AND查询
SELECT * FROM SUBJECT WHERE ClassHour BETWEEN 110 AND 120;
#等同于:
SELECT * FROM SUBJECT WHERE ClassHour >= 110 AND ClassHour <=120;
#查询课程名称、总课时及每天10课时计算的天数
SELECT
SubjectName AS "课程名称",
ClassHour AS "总课时",
(ClassHour/10) AS "均课时/天"
FROM SUBJECT;
#查询包含“数学”的所有课程
SELECT * FROM SUBJECT WHERE SubjectName LIKE "%数学%";
#查询所有姓名为“李**”三个字的学生信息
SELECT StudentNo,StudentName FROM student WHERE StudentName
LIKE "李__";
#案例 查找地址不为空的学生信息
SELECT *
FROM student
WHERE Address IS NOT NUL
#内连接 左连接 右链接
SELECT s.studentno,s.studentname,g.Gradename FROM
student s INNER JOIN `grade` g ON g.gradeid=s.GradeID;
SELECT s.studentno,s.studentname,g.Gradename FROM
student s LEFT JOIN `grade` g ON g.gradeid=s.GradeID;
SELECT s.studentno,s.studentname,g.Gradename FROM
student s RIGHT JOIN `grade` g ON g.gradeid=s.GradeID;
#使用IN进行范围查询
SELECT * FROM SUBJECT WHERE ClassHour = 100 OR ClassHour =110 OR ClassHour = 120; #普通组处理方式
SELECT * FROM SUBJECT WHERE ClassHour IN ( 100, 110,120 );#使用IN进行查询方式，更为简洁，效率更高
#子查询 in
SELECT studentno,studentname
FROM student
WHERE StudentNo IN
(SELECT studentno FROM result WHERE
subjectno=(SELECT subjectno FROM `subject` WHERE subjectname='高等数学-2' )
AND StudentResult>=80
) ;
#常用统计函数
#COUNT(),MAX(),MIN(),AVG(),SUM
SELECT COUNT(StudentResult) AS "成绩总个数", MAX(StudentResult) AS "最高分" , MIN(StudentResult) AS "最低分" , AVG(StudentResult) AS "平均分"
FROM result;
#按照不同的课程，分别算出其平均分、最高分和最低分，对于低于60分平均分的不予显示
SELECT
s.SubjectName AS "课程名",MAX(StudentResult) AS "最高分" , MIN(StudentResult) AS "最低分" , AVG(StudentResult) AS "平均分"
FROM
result AS r
LEFT JOIN
`subject` AS s ON s.SubjectNo = r.SubjectNo
GROUP BY r.SubjectNo HAVING AVG(StudentResult) >= 60 ;
# ORDER BY 排序
SELECT studentresult
FROM result r WHERE
r.subjectno IN(SELECT subjectno FROM `subject` WHERE subjectname="数据库结构-1" )
ORDER BY studentresult DESC ; #默认ASC
#查询所有课程《数据库结构-2》的考试成绩，并按照由高到低的显示，同时把该成绩对应的学生的学号、姓名打印出来
#要求：
#第一次查询前10条记录
#第二次查询11-20条记录
SELECT s.studentno,s.studentname,c.subjectname,r.studentresult
FROM student s JOIN result r
ON s.StudentNo=r.StudentNo
JOIN SUBJECT c
ON r.SubjectNo=c.SubjectNo
WHERE c.subjectname="数据库结构-2"
ORDER BY r.StudentResult DESC LIMIT 0,5; #limit 5,5
#要求：从subject和grade数据表查询课程名称和所属年级 名称
#非等值连接查询
SELECT SubjectName,GradeName FROM SUBJECT,grade;
#等值查询
SELECT SubjectName,GradeName FROM SUBJECT,grade WHERE subject.GradeID= grade.GradeID; .GradeID;
DROP TABLE IF EXISTS `grade`;
CREATE TABLE `grade`
