• mysql--select



    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 (1000,1,'2013-11-11 16:00:00',94),(1000,2,'2012-11-10 10:00:00',75),(1000,3,'2011-12-19 10:00:00',76),(1000,4,'2010-11-18 11:00:00',93),(1000,5,'2013-11-11 14:00:00',97),(1000,6,'2012-09-13 15:00:00',87),(1000,7,'2011-10-16 16:00:00',79),(1000,8,'2010-11-11 16:00:00',74),(1000,9,'2013-11-21 10:00:00',69),(1000,10,'2012-11-11 12:00:00',78),(1000,11,'2011-11-11 14:00:00',66),(1000,12,'2010-11-11 15:00:00',82),(1000,13,'2013-11-11 14:00:00',94),(1000,14,'2012-11-11 15:00:00',98),(1000,15,'2011-12-11 10:00:00',70),(1000,16,'2010-09-11 10:00:00',74),(1001,1,'2013-11-11 16:00:00',76),(1001,2,'2012-11-10 10:00:00',93),(1001,3,'2011-12-19 10:00:00',65),(1001,4,'2010-11-18 11:00:00',71),(1001,5,'2013-11-11 14:00:00',98),(1001,6,'2012-09-13 15:00:00',74),(1001,7,'2011-10-16 16:00:00',85),(1001,8,'2010-11-11 16:00:00',69),(1001,9,'2013-11-21 10:00:00',63),(1001,10,'2012-11-11 12:00:00',70),(1001,11,'2011-11-11 14:00:00',62),(1001,12,'2010-11-11 15:00:00',90),(1001,13,'2013-11-11 14:00:00',97),(1001,14,'2012-11-11 15:00:00',89),(1001,15,'2011-12-11 10:00:00',72),(1001,16,'2010-09-11 10:00:00',90),(1002,1,'2013-11-11 16:00:00',61),(1002,2,'2012-11-10 10:00:00',80),(1002,3,'2011-12-19 10:00:00',89),(1002,4,'2010-11-18 11:00:00',88),(1002,5,'2013-11-11 14:00:00',82),(1002,6,'2012-09-13 15:00:00',91),(1002,7,'2011-10-16 16:00:00',63),(1002,8,'2010-11-11 16:00:00',84),(1002,9,'2013-11-21 10:00:00',60),(1002,10,'2012-11-11 12:00:00',71),(1002,11,'2011-11-11 14:00:00',93),(1002,12,'2010-11-11 15:00:00',96),(1002,13,'2013-11-11 14:00:00',83),(1002,14,'2012-11-11 15:00:00',69),(1002,15,'2011-12-11 10:00:00',89),(1002,16,'2010-09-11 10:00:00',83),(1003,1,'2013-11-11 16:00:00',91),(1003,2,'2012-11-10 10:00:00',75),(1003,3,'2011-12-19 10:00:00',65),(1003,4,'2010-11-18 11:00:00',63),(1003,5,'2013-11-11 14:00:00',90),(1003,6,'2012-09-13 15:00:00',96),(1003,7,'2011-10-16 16:00:00',97),(1003,8,'2010-11-11 16:00:00',77),(1003,9,'2013-11-21 10:00:00',62),(1003,10,'2012-11-11 12:00:00',81),(1003,11,'2011-11-11 14:00:00',76),(1003,12,'2010-11-11 15:00:00',61),(1003,13,'2013-11-11 14:00:00',93),(1003,14,'2012-11-11 15:00:00',79),(1003,15,'2011-12-11 10:00:00',78),(1003,16,'2010-09-11 10:00:00',96),(1004,1,'2013-11-11 16:00:00',84),(1004,2,'2012-11-10 10:00:00',79),(1004,3,'2011-12-19 10:00:00',76),(1004,4,'2010-11-18 11:00:00',78),(1004,5,'2013-11-11 14:00:00',81),(1004,6,'2012-09-13 15:00:00',90),(1004,7,'2011-10-16 16:00:00',63),(1004,8,'2010-11-11 16:00:00',89),(1004,9,'2013-11-21 10:00:00',67),(1004,10,'2012-11-11 12:00:00',100),(1004,11,'2011-11-11 14:00:00',94),(1004,12,'2010-11-11 15:00:00',65),(1004,13,'2013-11-11 14:00:00',86),(1004,14,'2012-11-11 15:00:00',77),(1004,15,'2011-12-11 10:00:00',82),(1004,16,'2010-09-11 10:00:00',87),(1005,1,'2013-11-11 16:00:00',82),(1005,2,'2012-11-10 10:00:00',92),(1005,3,'2011-12-19 10:00:00',80),(1005,4,'2010-11-18 11:00:00',92),(1005,5,'2013-11-11 14:00:00',97),(1005,6,'2012-09-13 15:00:00',72),(1005,7,'2011-10-16 16:00:00',84),(1005,8,'2010-11-11 16:00:00',79),(1005,9,'2013-11-21 10:00:00',76),(1005,10,'2012-11-11 12:00:00',87),(1005,11,'2011-11-11 14:00:00',65),(1005,12,'2010-11-11 15:00:00',67),(1005,13,'2013-11-11 14:00:00',63),(1005,14,'2012-11-11 15:00:00',64),(1005,15,'2011-12-11 10:00:00',99),(1005,16,'2010-09-11 10:00:00',97),(1006,1,'2013-11-11 16:00:00',82),(1006,2,'2012-11-10 10:00:00',73),(1006,3,'2011-12-19 10:00:00',79),(1006,4,'2010-11-18 11:00:00',63),(1006,5,'2013-11-11 14:00:00',97),(1006,6,'2012-09-13 15:00:00',83),(1006,7,'2011-10-16 16:00:00',78),(1006,8,'2010-11-11 16:00:00',88),(1006,9,'2013-11-21 10:00:00',89),(1006,10,'2012-11-11 12:00:00',82),(1006,11,'2011-11-11 14:00:00',70),(1006,12,'2010-11-11 15:00:00',69),(1006,13,'2013-11-11 14:00:00',64),(1006,14,'2012-11-11 15:00:00',80),(1006,15,'2011-12-11 10:00:00',90),(1006,16,'2010-09-11 10:00:00',85),(1007,1,'2013-11-11 16:00:00',87),(1007,2,'2012-11-10 10:00:00',63),(1007,3,'2011-12-19 10:00:00',70),(1007,4,'2010-11-18 11:00:00',74),(1007,5,'2013-11-11 14:00:00',79),(1007,6,'2012-09-13 15:00:00',83),(1007,7,'2011-10-16 16:00:00',86),(1007,8,'2010-11-11 16:00:00',76),(1007,9,'2013-11-21 10:00:00',65),(1007,10,'2012-11-11 12:00:00',87),(1007,11,'2011-11-11 14:00:00',69),(1007,12,'2010-11-11 15:00:00',69),(1007,13,'2013-11-11 14:00:00',90),(1007,14,'2012-11-11 15:00:00',84),(1007,15,'2011-12-11 10:00:00',95),(1007,16,'2010-09-11 10:00:00',92),(1008,1,'2013-11-11 16:00:00',96),(1008,2,'2012-11-10 10:00:00',62),(1008,3,'2011-12-19 10:00:00',97),(1008,4,'2010-11-18 11:00:00',84),(1008,5,'2013-11-11 14:00:00',86),(1008,6,'2012-09-13 15:00:00',72),(1008,7,'2011-10-16 16:00:00',67),(1008,8,'2010-11-11 16:00:00',83),(1008,9,'2013-11-21 10:00:00',86),(1008,10,'2012-11-11 12:00:00',60),(1008,11,'2011-11-11 14:00:00',61),(1008,12,'2010-11-11 15:00:00',68),(1008,13,'2013-11-11 14:00:00',99),(1008,14,'2012-11-11 15:00:00',77),(1008,15,'2011-12-11 10:00:00',73),(1008,16,'2010-09-11 10:00:00',78),(1009,1,'2013-11-11 16:00:00',67),(1009,2,'2012-11-10 10:00:00',70),(1009,3,'2011-12-19 10:00:00',75),(1009,4,'2010-11-18 11:00:00',92),(1009,5,'2013-11-11 14:00:00',76),(1009,6,'2012-09-13 15:00:00',90),(1009,7,'2011-10-16 16:00:00',62),(1009,8,'2010-11-11 16:00:00',68),(1009,9,'2013-11-21 10:00:00',70),(1009,10,'2012-11-11 12:00:00',83),(1009,11,'2011-11-11 14:00:00',88),(1009,12,'2010-11-11 15:00:00',65),(1009,13,'2013-11-11 14:00:00',91),(1009,14,'2012-11-11 15:00:00',99),(1009,15,'2011-12-11 10:00:00',65),(1009,16,'2010-09-11 10:00:00',83),(1010,1,'2013-11-11 16:00:00',83),(1010,2,'2012-11-10 10:00:00',87),(1010,3,'2011-12-19 10:00:00',89),(1010,4,'2010-11-18 11:00:00',99),(1010,5,'2013-11-11 14:00:00',91),(1010,6,'2012-09-13 15:00:00',96),(1010,7,'2011-10-16 16:00:00',72),(1010,8,'2010-11-11 16:00:00',72),(1010,9,'2013-11-21 10:00:00',98),(1010,10,'2012-11-11 12:00:00',73),(1010,11,'2011-11-11 14:00:00',68),(1010,12,'2010-11-11 15:00:00',62),(1010,13,'2013-11-11 14:00:00',67),(1010,14,'2012-11-11 15:00:00',69),(1010,15,'2011-12-11 10:00:00',71),(1010,16,'2010-09-11 10:00:00',66),(1011,1,'2013-11-11 16:00:00',62),(1011,2,'2012-11-10 10:00:00',72),(1011,3,'2011-12-19 10:00:00',96),(1011,4,'2010-11-18 11:00:00',64),(1011,5,'2013-11-11 14:00:00',89),(1011,6,'2012-09-13 15:00:00',91),(1011,7,'2011-10-16 16:00:00',95),(1011,8,'2010-11-11 16:00:00',96),(1011,9,'2013-11-21 10:00:00',89),(1011,10,'2012-11-11 12:00:00',73),(1011,11,'2011-11-11 14:00:00',82),(1011,12,'2010-11-11 15:00:00',98),(1011,13,'2013-11-11 14:00:00',66),(1011,14,'2012-11-11 15:00:00',69),(1011,15,'2011-12-11 10:00:00',91),(1011,16,'2010-09-11 10:00:00',69),(1012,1,'2013-11-11 16:00:00',86),(1012,2,'2012-11-10 10:00:00',66),(1012,3,'2011-12-19 10:00:00',97),(1012,4,'2010-11-18 11:00:00',69),(1012,5,'2013-11-11 14:00:00',70),(1012,6,'2012-09-13 15:00:00',74),(1012,7,'2011-10-16 16:00:00',91),(1012,8,'2010-11-11 16:00:00',97),(1012,9,'2013-11-21 10:00:00',84),(1012,10,'2012-11-11 12:00:00',82),(1012,11,'2011-11-11 14:00:00',90),(1012,12,'2010-11-11 15:00:00',91),(1012,13,'2013-11-11 14:00:00',91),(1012,14,'2012-11-11 15:00:00',97),(1012,15,'2011-12-11 10:00:00',85),(1012,16,'2010-09-11 10:00:00',90),(1013,1,'2013-11-11 16:00:00',73),(1013,2,'2012-11-10 10:00:00',69),(1013,3,'2011-12-19 10:00:00',91),(1013,4,'2010-11-18 11:00:00',72),(1013,5,'2013-11-11 14:00:00',76),(1013,6,'2012-09-13 15:00:00',87),(1013,7,'2011-10-16 16:00:00',61),(1013,8,'2010-11-11 16:00:00',77),(1013,9,'2013-11-21 10:00:00',83),(1013,10,'2012-11-11 12:00:00',99),(1013,11,'2011-11-11 14:00:00',91),(1013,12,'2010-11-11 15:00:00',84),(1013,13,'2013-11-11 14:00:00',98),(1013,14,'2012-11-11 15:00:00',74),(1013,15,'2011-12-11 10:00:00',92),(1013,16,'2010-09-11 10:00:00',90),(1014,1,'2013-11-11 16:00:00',64),(1014,2,'2012-11-10 10:00:00',81),(1014,3,'2011-12-19 10:00:00',79),(1014,4,'2010-11-18 11:00:00',74),(1014,5,'2013-11-11 14:00:00',65),(1014,6,'2012-09-13 15:00:00',88),(1014,7,'2011-10-16 16:00:00',86),(1014,8,'2010-11-11 16:00:00',77),(1014,9,'2013-11-21 10:00:00',86),(1014,10,'2012-11-11 12:00:00',85),(1014,11,'2011-11-11 14:00:00',86),(1014,12,'2010-11-11 15:00:00',75),(1014,13,'2013-11-11 14:00:00',89),(1014,14,'2012-11-11 15:00:00',79),(1014,15,'2011-12-11 10:00:00',73),(1014,16,'2010-09-11 10:00:00',68),(1015,1,'2013-11-11 16:00:00',99),(1015,2,'2012-11-10 10:00:00',60),(1015,3,'2011-12-19 10:00:00',60),(1015,4,'2010-11-18 11:00:00',75),(1015,5,'2013-11-11 14:00:00',78),(1015,6,'2012-09-13 15:00:00',78),(1015,7,'2011-10-16 16:00:00',84),(1015,8,'2010-11-11 16:00:00',95),(1015,9,'2013-11-21 10:00:00',93),(1015,10,'2012-11-11 12:00:00',79),(1015,11,'2011-11-11 14:00:00',74),(1015,12,'2010-11-11 15:00:00',65),(1015,13,'2013-11-11 14:00:00',63),(1015,14,'2012-11-11 15:00:00',74),(1015,15,'2011-12-11 10:00:00',67),(1015,16,'2010-09-11 10:00:00',65),(1016,1,'2013-11-11 16:00:00',97),(1016,2,'2012-11-10 10:00:00',90),(1016,3,'2011-12-19 10:00:00',77),(1016,4,'2010-11-18 11:00:00',75),(1016,5,'2013-11-11 14:00:00',75),(1016,6,'2012-09-13 15:00:00',97),(1016,7,'2011-10-16 16:00:00',96),(1016,8,'2010-11-11 16:00:00',92),(1016,9,'2013-11-21 10:00:00',62),(1016,10,'2012-11-11 12:00:00',83),(1016,11,'2011-11-11 14:00:00',98),(1016,12,'2010-11-11 15:00:00',94),(1016,13,'2013-11-11 14:00:00',62),(1016,14,'2012-11-11 15:00:00',97),(1016,15,'2011-12-11 10:00:00',76),(1016,16,'2010-09-11 10:00:00',82),(1017,1,'2013-11-11 16:00:00',100),(1017,2,'2012-11-10 10:00:00',88),(1017,3,'2011-12-19 10:00:00',86),(1017,4,'2010-11-18 11:00:00',73),(1017,5,'2013-11-11 14:00:00',96),(1017,6,'2012-09-13 15:00:00',64),(1017,7,'2011-10-16 16:00:00',81),(1017,8,'2010-11-11 16:00:00',66),(1017,9,'2013-11-21 10:00:00',76),(1017,10,'2012-11-11 12:00:00',95),(1017,11,'2011-11-11 14:00:00',73),(1017,12,'2010-11-11 15:00:00',82),(1017,13,'2013-11-11 14:00:00',85),(1017,14,'2012-11-11 15:00:00',68),(1017,15,'2011-12-11 10:00:00',99),(1017,16,'2010-09-11 10:00:00',76);

     

    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','test1@bdqn.cn','450323198612111234'),(1001,'123456','李文才',1,2,'13500000002','河南洛阳','1981-12-31 00:00:00','test1@bdqn.cn','450323198112311234'),(1002,'111111','李斯文',1,1,'13500000003','天津市和平区','1986-11-30 00:00:00','test1@bdqn.cn','450323198611301234'),(1003,'123456','武松',1,3,'13500000004','上海卢湾区','1986-12-31 00:00:00','test1@bdqn.cn','450323198612314234'),(1004,'123456','张三',1,4,'13500000005','北京市通州','1989-12-31 00:00:00','test1@bdqn.cn','450323198612311244'),(1005,'123456','张秋丽',2,1,'13500000006','广西桂林市灵川','1986-12-31 00:00:00','test1@bdqn.cn','450323198612311214'),(1006,'123456','肖梅',2,4,'13500000007','地址不详','1986-12-31 00:00:00','test1@bdqn.cn','450323198612311134'),(1007,'111111','欧阳峻峰',1,1,'13500000008','北京东城区','1986-12-31 00:00:00','test1@bdqn.cn','450323198612311133'),(1008,'111111','梅超风',1,1,'13500000009','河南洛阳','1986-12-31 00:00:00','test1@bdqn.cn','450323198612311221'),(1009,'123456','刘毅',1,2,'13500000011','安徽','1986-12-31 00:00:00','test1@bdqn.cn','450323198612311231'),(1010,'111111','大凡',1,1,'13500000012','河南洛阳','1986-12-31 00:00:00','test1@bdqn.cn','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','test1@bdqn.cn','450323198412311234'),(1012,'123456','多伦',2,3,'13500000014','广西南宁中央大街','1986-12-31 00:00:00','test1@bdqn.cn','450323198612311334'),(1013,'123456','李梅',2,1,'13500000015','上海卢湾区','1986-12-31 00:00:00','test1@bdqn.cn','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','test1@bdqn.cn','450323198612311264'),(1015,'123456','李东方',1,4,'13500000017','广西桂林市灵川','1976-12-31 00:00:00','test1@bdqn.cn','450323197612311234'),(1016,'111111','刘奋斗',1,1,'13500000018','上海卢湾区','1986-12-31 00:00:00','test1@bdqn.cn','450323198612311251'),(1017,'123456','可可',2,3,'13500000019','北京长安街1号','1981-09-10 00:00:00','test1@bdqn.cn','450323198109108311'),(10066,'','Tom',1,1,'13500000000','','0000-00-00 00:00:00','email@22.com','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 *FROM `student`;
    SELECT *FROM `student` WHERE StudentNo =1006;
    #指定查询结果的数据列
    #别名的三种应用场景:表,数据列,经计算或总结的结果用另外一个新名称来表示,as可以省略不写
    SELECT s.`StudentName`,s.`Address`,s.`IdentityCard`,s.`Phone` FROM `student` AS s;
    SELECT s.`StudentName` AS '姓名',s.`Address` AS '地址',s.`IdentityCard` AS '身份证号',s.`Phone` AS '手机号'FROM `student` AS s;
    SELECT COUNT(StudentNo) AS '学生总数' FROM `student`;
    #SELECT COUNT(*) AS '学生总数' FROM `student`;
    SELECT DISTINCT r.`subjectNo` FROM `result` AS r;
    #以整行做考虑,判断是否重复, all关键字是默认的
    SELECT DISTINCT r.`subjectNo` ,r.`StudentNo` FROM `result` AS r;
    #对函数进行二次加工
    SELECT CONCAT('学生:',StudentName)'学生姓名' ,Phone '手机号' FROM `student`;
    SELECT VERSION();
    #获得当前对象的步长
    SELECT @@auto_increment_increment;
    SELECT s.`ClassHour` AS '旧课时', s.`ClassHour`+10 AS '新学时' FROM `subject` AS s;
    SELECT `StudentNo`,`SubjectNo`,`ExamDate`,`StudentResult` FROM `result` r
    #where r.`StudentResult`>=80 and r.`StudentResult`<=90;
    #where用于搜索数据中符合条件的记录,条件语句建议使用单词形式
    WHERE NOT (r.`StudentResult`)>=80;
    SELECT `a`,`b`FROM `test1` WHERE `b` IS NOT NULL;
    SELECT `StudentNo`,`SubjectNo`,`ExamDate`,`StudentResult` FROM `result` r
    WHERE r.`StudentResult` BETWEEN 80 AND 90;
    #like关键字模糊查询,%表示匹配0或任意多个字符,_表示匹配单个字符
    SELECT * FROM `student` WHERE `StudentName` LIKE '张%';
    SELECT *FROM `student` s WHERE s.`StudentName` LIKE '张%';
    SELECT * FROM `student` WHERE `StudentName` LIKE '张_';
    SELECT * FROM `student` s WHERE `StudentName` LIKE '张__';
    #含有斯的学生信息
    SELECT * FROM `student` WHERE `StudentName` LIKE '%斯%';
    #第二个字是斯的学生信息
    SELECT * FROM `student` s WHERE `StudentName` LIKE '_斯%';
    #含有特殊字符的对象,如 %:%% (:%)带转义字符的关键字,转义符':'自己定义
    SELECT * FROM `student` WHERE `StudentName` LIKE '%:%%' ESCAPE ':';
    SELECT * FROM `student` WHERE `StudentName` LIKE '%^%%' ESCAPE '^';
    # 本身为转义符
    SELECT * FROM `student` WHERE `StudentName` LIKE '%\%%' ESCAPE '\';
    SELECT * FROM `student`
    WHERE `StudentName` LIKE '%/%%' ESCAPE '/';
    这时的like相当于=
    SELECT * FROM `student` s WHERE `StudentName` LIKE '张三';
    #指定范围匹配某一个
    SELECT `StudentNo`,`SubjectNo`,`ExamDate`,`StudentResult` FROM `result` r
    WHERE r.`StudentResult` IN (80,90,100);
    SELECT `StudentNo`,`SubjectNo`,`ExamDate`,`StudentResult` FROM `result` r
    WHERE r.`StudentResult`=100;
    SELECT * FROM `student` s WHERE s.`StudentNo` IN (1004,1017);
    SELECT * FROM `student` s WHERE s.`StudentName` LIKE '李%';
    #内连接
    #查找学生的姓名,课程名称,成绩
    SELECT s.`StudentName`,st.`SubjectName`,r.`StudentResult` FROM `student` s
    INNER JOIN `result` r ON r.`StudentNo`=s.`StudentNo`
    INNER JOIN `subject` st ON st.`SubjectNo`=r.`SubjectNo`;
    #查找学生的姓名,考试日期,成绩
    SELECT s.`StudentName`, r.`ExamDate`,r.`StudentResult` FROM `student` s
    INNER JOIN `result` r ON s.`StudentNo`=r.`StudentNo`;
    SELECT DISTINCT `StudentNo` FROM `result`;
    DELETE FROM `result` WHERE `studentNo`=1017;
    #student的行在result中没有匹配,则不返回,即只找能够对应上的数据显示出来,比较懒
    SELECT DISTINCT s.`StudentNo`, s.`StudentName` FROM `student` s
    INNER JOIN `result` r ON s.`StudentNo`=r.`StudentNo`;
    #左连接,显示左表所有内容,即使右表中没有匹配的行
    SELECT s.`studentNo`,s.`StudentName`,r.`StudentResult` FROM `student` s
    LEFT JOIN `result` r ON s.`StudentNo`=r.`StudentNo` WHERE s.`StudentNo`>=1015;
    SELECT * FROM `grade`;
    #右连接,显示右表所有内容,即使左表中没有匹配的行
    SELECT s.`SubjectName`,g.`GradeName` FROM `subject` s
    RIGHT JOIN `grade` g ON s.`GradeID`=g.`GradeID`;
    #交叉连接,等效于内连接
    SELECT s.`studentNo`,s.`StudentName`,r.`StudentResult` FROM `student` s ,`result` r
    WHERE s.`StudentNo`=r.`StudentNo` AND s.`StudentNo`>1015;
    #自身连接查询
    CREATE TABLE IF NOT EXISTS category(
    categoryId INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
    pid INT(10) NOT NULL,
    categoryName VARCHAR(32) NOT NULL,
    PRIMARY KEY(categoryId)
    );
    INSERT INTO category VALUES
    (2,1,"美术设计"),
    (3,1,"软件开发"),
    (4,3,"数据库基础"),
    (5,2,"Photoshop基础"),
    (6,2,"色彩搭配学"),
    (7,3,"PHP基础"),
    (8,3,"一起学JAVA");
    #自身连接查询
    SELECT c1.categoryName AS "父栏目名称",c2.categoryName AS "子栏目名称"
    FROM category AS c1,category AS c2 WHERE c1.categoryId = c2.pid;
    #order by升序排列为ASC为默认,降序排列为DESC
    SELECT c1.categoryName AS "父栏目名称",c2.categoryName AS "子栏目名称"
    FROM category AS c1 INNER JOIN category AS c2
    ON c1.categoryId = c2.pid
    ORDER BY c1.`categoryName` ASC;


    #排序默认为ascr
    SELECT s.`SubjectName` ,r.`StudentResult` rs FROM `subject` s INNER JOIN `result` r
    ON s.`SubjectNo`=r.`SubjectNo` WHERE s.`SubjectName`='数据库结构-1'
    ORDER BY rs DESC;
    #LIMIT分页显示
    SELECT*FROM `result` ORDER BY ExamDate DESC;
    #select COUNT(*) from `result` order by ExamDate asc;
    SELECT*FROM `result` ORDER BY ExamDate DESC LIMIT 5,5;
    #练习LIMIT
    #内连接
    SELECT st.`StudentNo`,st.`StudentName`,s.`SubjectName`,r.`StudentResult` FROM `student` st
    INNER JOIN `result` r ON st.`StudentNo`=r.`StudentNo`
    INNER JOIN `subject` s ON r.`SubjectNo`=s.`SubjectNo` WHERE s.`SubjectName`='数据库结构-2'
    #ORDER BY StudentResult DESC limit 0,5 ;
    ORDER BY StudentResult DESC LIMIT 5,5 ;
    #子查询(嵌套查询)案例:课程为高等数学-2且成绩不小于80的学生的学号和名字
    SELECT student.`StudentNo`,student.`StudentName` FROM `student`
    WHERE student.`StudentNo` IN
    (SELECT result.`StudentNo` FROM `result` WHERE result.`StudentResult`>=80
    AND `result`.`SubjectNo`=(SELECT `subject`.`SubjectNo`FROM `subject`
    WHERE `subject`.`SubjectName`='高等数学-2'));
    #子查询(嵌套查询)案例:c语言-1前五名学生的成绩信息
    SELECT s.`StudentNo`,s.`StudentName`,result.`StudentResult`FROM `student` s
    INNER JOIN `result` ON result.`StudentNo`=s.`StudentNo`
    WHERE `result`.`SubjectNo`=(SELECT st.`SubjectNo` FROM `subject` st
    WHERE st.`SubjectName`='C语言-1')
    ORDER BY result.`StudentResult`DESC,s.`StudentNo` ASC LIMIT 0,5;
    #练习2LIMIT
    SELECT st.`StudentNo`,st.`StudentName`,s.`SubjectName`,r.`StudentResult` FROM `student` st
    INNER JOIN `result` r ON st.`StudentNo`=r.`StudentNo`
    INNER JOIN `subject` s ON r.`SubjectNo`=s.`SubjectNo`
    WHERE s.`SubjectName`='JAVA第一学年' AND r.`StudentResult`>80
    ORDER BY StudentResult DESC LIMIT 0,10 ;
    #count()用法
    SELECT COUNT(r.`StudentResult`) '考试人数' FROM `result` r WHERE r.`StudentResult`>=80;
    #sum()用法
    #avg()用法,#max()用法,#min()用法
    SELECT COUNT(r.`SubjectNo`) '考试人数',
    MAX(r.`StudentResult`) '最高分',
    MIN(r.`StudentResult`)'最低分',
    AVG(r.`StudentResult`)'平均分'
    #FROM `result` r WHERE r.`StudentResult`>=80
    FROM `result` r
    GROUP BY r.`SubjectNo`
    HAVING AVG(r.`StudentResult`)>=80;

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  • 原文地址:https://www.cnblogs.com/person008/p/6112408.html
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