sql語句練習
阿新 • • 發佈:2017-09-14
sql語句 練習
表結構圖如下:
創建表和插入數據:
SET FOREIGN_KEY_CHECKS=0; -- ---------------------------- -- Table structure for class -- ---------------------------- DROP TABLE IF EXISTS `class`; CREATE TABLE `class` ( `cid` int(11) NOT NULL AUTO_INCREMENT, `caption` varchar(32) NOT NULL, PRIMARY KEY (`cid`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8; -- ---------------------------- -- Records of class -- ---------------------------- INSERT INTO `class` VALUES (‘1‘, ‘三年二班‘); INSERT INTO `class` VALUES (‘2‘, ‘三年三班‘); INSERT INTO `class` VALUES (‘3‘, ‘一年二班‘); INSERT INTO `class` VALUES (‘4‘, ‘二年九班‘); -- ---------------------------- -- Table structure for course -- ---------------------------- DROP TABLE IF EXISTS `course`; CREATE TABLE `course` ( `cid` int(11) NOT NULL AUTO_INCREMENT, `cname` varchar(32) NOT NULL, `teacher_id` int(11) NOT NULL, PRIMARY KEY (`cid`), KEY `fk_course_teacher` (`teacher_id`), CONSTRAINT `fk_course_teacher` FOREIGN KEY (`teacher_id`) REFERENCES `teacher` (`tid`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8; -- ---------------------------- -- Records of course -- ---------------------------- INSERT INTO `course` VALUES (‘1‘, ‘生物‘, ‘1‘); INSERT INTO `course` VALUES (‘2‘, ‘物理‘, ‘2‘); INSERT INTO `course` VALUES (‘3‘, ‘體育‘, ‘3‘); INSERT INTO `course` VALUES (‘4‘, ‘美術‘, ‘2‘); -- ---------------------------- -- Table structure for score -- ---------------------------- DROP TABLE IF EXISTS `score`; CREATE TABLE `score` ( `sid` int(11) NOT NULL AUTO_INCREMENT, `student_id` int(11) NOT NULL, `course_id` int(11) NOT NULL, `num` int(11) NOT NULL, PRIMARY KEY (`sid`), KEY `fk_score_student` (`student_id`), KEY `fk_score_course` (`course_id`), CONSTRAINT `fk_score_course` FOREIGN KEY (`course_id`) REFERENCES `course` (`cid`), CONSTRAINT `fk_score_student` FOREIGN KEY (`student_id`) REFERENCES `student` (`sid`) ) ENGINE=InnoDB AUTO_INCREMENT=53 DEFAULT CHARSET=utf8; -- ---------------------------- -- Records of score -- ---------------------------- INSERT INTO `score` VALUES (‘1‘, ‘1‘, ‘1‘, ‘10‘); INSERT INTO `score` VALUES (‘2‘, ‘1‘, ‘2‘, ‘9‘); INSERT INTO `score` VALUES (‘5‘, ‘1‘, ‘4‘, ‘66‘); INSERT INTO `score` VALUES (‘6‘, ‘2‘, ‘1‘, ‘8‘); INSERT INTO `score` VALUES (‘8‘, ‘2‘, ‘3‘, ‘68‘); INSERT INTO `score` VALUES (‘9‘, ‘2‘, ‘4‘, ‘99‘); INSERT INTO `score` VALUES (‘10‘, ‘3‘, ‘1‘, ‘77‘); INSERT INTO `score` VALUES (‘11‘, ‘3‘, ‘2‘, ‘66‘); INSERT INTO `score` VALUES (‘12‘, ‘3‘, ‘3‘, ‘87‘); INSERT INTO `score` VALUES (‘13‘, ‘3‘, ‘4‘, ‘99‘); INSERT INTO `score` VALUES (‘14‘, ‘4‘, ‘1‘, ‘79‘); INSERT INTO `score` VALUES (‘15‘, ‘4‘, ‘2‘, ‘11‘); INSERT INTO `score` VALUES (‘16‘, ‘4‘, ‘3‘, ‘67‘); INSERT INTO `score` VALUES (‘17‘, ‘4‘, ‘4‘, ‘100‘); INSERT INTO `score` VALUES (‘18‘, ‘5‘, ‘1‘, ‘79‘); INSERT INTO `score` VALUES (‘19‘, ‘5‘, ‘2‘, ‘11‘); INSERT INTO `score` VALUES (‘20‘, ‘5‘, ‘3‘, ‘67‘); INSERT INTO `score` VALUES (‘21‘, ‘5‘, ‘4‘, ‘100‘); INSERT INTO `score` VALUES (‘22‘, ‘6‘, ‘1‘, ‘9‘); INSERT INTO `score` VALUES (‘23‘, ‘6‘, ‘2‘, ‘100‘); INSERT INTO `score` VALUES (‘24‘, ‘6‘, ‘3‘, ‘67‘); INSERT INTO `score` VALUES (‘25‘, ‘6‘, ‘4‘, ‘100‘); INSERT INTO `score` VALUES (‘26‘, ‘7‘, ‘1‘, ‘9‘); INSERT INTO `score` VALUES (‘27‘, ‘7‘, ‘2‘, ‘100‘); INSERT INTO `score` VALUES (‘28‘, ‘7‘, ‘3‘, ‘67‘); INSERT INTO `score` VALUES (‘29‘, ‘7‘, ‘4‘, ‘88‘); INSERT INTO `score` VALUES (‘30‘, ‘8‘, ‘1‘, ‘9‘); INSERT INTO `score` VALUES (‘31‘, ‘8‘, ‘2‘, ‘100‘); INSERT INTO `score` VALUES (‘32‘, ‘8‘, ‘3‘, ‘67‘); INSERT INTO `score` VALUES (‘33‘, ‘8‘, ‘4‘, ‘88‘); INSERT INTO `score` VALUES (‘34‘, ‘9‘, ‘1‘, ‘91‘); INSERT INTO `score` VALUES (‘35‘, ‘9‘, ‘2‘, ‘88‘); INSERT INTO `score` VALUES (‘36‘, ‘9‘, ‘3‘, ‘67‘); INSERT INTO `score` VALUES (‘37‘, ‘9‘, ‘4‘, ‘22‘); INSERT INTO `score` VALUES (‘38‘, ‘10‘, ‘1‘, ‘90‘); INSERT INTO `score` VALUES (‘39‘, ‘10‘, ‘2‘, ‘77‘); INSERT INTO `score` VALUES (‘40‘, ‘10‘, ‘3‘, ‘43‘); INSERT INTO `score` VALUES (‘41‘, ‘10‘, ‘4‘, ‘87‘); INSERT INTO `score` VALUES (‘42‘, ‘11‘, ‘1‘, ‘90‘); INSERT INTO `score` VALUES (‘43‘, ‘11‘, ‘2‘, ‘77‘); INSERT INTO `score` VALUES (‘44‘, ‘11‘, ‘3‘, ‘43‘); INSERT INTO `score` VALUES (‘45‘, ‘11‘, ‘4‘, ‘87‘); INSERT INTO `score` VALUES (‘46‘, ‘12‘, ‘1‘, ‘90‘); INSERT INTO `score` VALUES (‘47‘, ‘12‘, ‘2‘, ‘77‘); INSERT INTO `score` VALUES (‘48‘, ‘12‘, ‘3‘, ‘43‘); INSERT INTO `score` VALUES (‘49‘, ‘12‘, ‘4‘, ‘87‘); INSERT INTO `score` VALUES (‘52‘, ‘13‘, ‘3‘, ‘87‘); -- ---------------------------- -- Table structure for student -- ---------------------------- DROP TABLE IF EXISTS `student`; CREATE TABLE `student` ( `sid` int(11) NOT NULL AUTO_INCREMENT, `gender` char(1) NOT NULL, `class_id` int(11) NOT NULL, `sname` varchar(32) NOT NULL, PRIMARY KEY (`sid`), KEY `fk_class` (`class_id`), CONSTRAINT `fk_class` FOREIGN KEY (`class_id`) REFERENCES `class` (`cid`) ) ENGINE=InnoDB AUTO_INCREMENT=17 DEFAULT CHARSET=utf8; -- ---------------------------- -- Records of student -- ---------------------------- INSERT INTO `student` VALUES (‘1‘, ‘男‘, ‘1‘, ‘理解‘); INSERT INTO `student` VALUES (‘2‘, ‘女‘, ‘1‘, ‘鋼蛋‘); INSERT INTO `student` VALUES (‘3‘, ‘男‘, ‘1‘, ‘張三‘); INSERT INTO `student` VALUES (‘4‘, ‘男‘, ‘1‘, ‘張一‘); INSERT INTO `student` VALUES (‘5‘, ‘女‘, ‘1‘, ‘張二‘); INSERT INTO `student` VALUES (‘6‘, ‘男‘, ‘1‘, ‘張四‘); INSERT INTO `student` VALUES (‘7‘, ‘女‘, ‘2‘, ‘鐵錘‘); INSERT INTO `student` VALUES (‘8‘, ‘男‘, ‘2‘, ‘李三‘); INSERT INTO `student` VALUES (‘9‘, ‘男‘, ‘2‘, ‘李一‘); INSERT INTO `student` VALUES (‘10‘, ‘女‘, ‘2‘, ‘李二‘); INSERT INTO `student` VALUES (‘11‘, ‘男‘, ‘2‘, ‘李四‘); INSERT INTO `student` VALUES (‘12‘, ‘女‘, ‘3‘, ‘如花‘); INSERT INTO `student` VALUES (‘13‘, ‘男‘, ‘3‘, ‘劉三‘); INSERT INTO `student` VALUES (‘14‘, ‘男‘, ‘3‘, ‘劉一‘); INSERT INTO `student` VALUES (‘15‘, ‘女‘, ‘3‘, ‘劉二‘); INSERT INTO `student` VALUES (‘16‘, ‘男‘, ‘3‘, ‘劉四‘); -- ---------------------------- -- Table structure for teacher -- ---------------------------- DROP TABLE IF EXISTS `teacher`; CREATE TABLE `teacher` ( `tid` int(11) NOT NULL AUTO_INCREMENT, `tname` varchar(32) NOT NULL, PRIMARY KEY (`tid`) ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8; -- ---------------------------- -- Records of teacher -- ---------------------------- INSERT INTO `teacher` VALUES (‘1‘, ‘張磊老師‘); INSERT INTO `teacher` VALUES (‘2‘, ‘李平老師‘); INSERT INTO `teacher` VALUES (‘3‘, ‘劉海燕老師‘); INSERT INTO `teacher` VALUES (‘4‘, ‘朱雲海老師‘); INSERT INTO `teacher` VALUES (‘5‘, ‘李傑老師‘); SET FOREIGN_KEY_CHECKS=1;
sql練習:
1、查詢所有的課程的名稱以及對應的任課老師姓名
select course.cname 課程,teacher.tname 講師 from course inner join teacher on course.teacher_id=teacher.tid;
2、查詢學生表中男女生各有多少人
select gender 性別,count(*) 人數 from student group by gender;
3、查詢物理成績等於100的學生的姓名
select sname 姓名 from student where sid in(select student_id from score inner join course on score.course_id=course.cid where course.cname=‘物理‘ and score.num=100);
4、查詢平均成績大於八十分的同學的姓名和平均成績
select student.sname 姓名,avg(score.num) 平均分 from score left join student on score.student_id=student.sid group by student_id;
5、查詢所有學生的學號,姓名,選課數,總成績
select student.sid 學號,student.sname 姓名,count(score.course_id) 課程數,sum(score.num) 總成績 from student left join score on student.sid=score.student_id group by student.sid;
6、 查詢姓李老師的個數
select tname 姓李的老師 from teacher where tname like "李%";
7、 查詢沒有報李平老師課的學生姓名
select sid 學號,sname 姓名 from student where sid not in (select student_id from score where course_id in(select course.cid from teacher left join course on teacher.tid=course.teacher_id where teacher.tname="李平老師"));
8、 查詢物理課程比生物課程高的學生的學號
select phy.student_id 學號 from (select score.student_id,score.num from score left join course on score.course_id=course.cid where cname="物理") as phy inner join (select score.student_id,score.num from score left join course on score.course_id=course.cid where cname="生物") as bio on phy.student_id=bio.student_id where phy.num>bio.num
9、 查詢沒有同時選修物理課程和體育課程的學生姓名
select sname 姓名 from student where sid not in (select student_id from score left join course on score.course_id=course.cid where cname="體育" or cname="物理" group by student_id having count(course_id)>1) );
10、查詢掛科超過兩門(包括兩門)的學生姓名和班級
select sname,caption from student inner join class on student.class_id=class.cid where student.sid in (select student_id from score where score.num<60 group by student_id having count(student_id)>=2);
11 、查詢選修了所有課程的學生姓名
select sname 姓名 from student where sid in (select student_id from score group by student_id having count(student_id) = (select count(cid) from course));
12、查詢李平老師教的課程的所有成績記錄
select course.cname 課程,score.num 成績 from score inner join course on course_id=cid where course_id in (select cid from course left join teacher on teacher_id=tid where tname like"李平%");
13、查詢全部學生都選修了的課程號和課程名
select cid,cname from course where cid in (select course_id from score group by course_id having count(course_id) = (select count(sid) from student));
14、查詢每門課程被選修的次數
select course.cname 課程,count(course_id) 選修次數 from score inner join course on score.course_id=course.cid group by course_id;
15、查詢只選修了一門課程的學生姓名和學號
select sid 學號,sname 姓名 from student where sid in (select student_id from score group by student_id having count(student_id)=1);
16、查詢所有學生考出的成績並按從高到低排序(成績去重)
select sname 姓名,sum(num) 總分 from score inner join student on score.student_id=student.sid group by student_id order by sum(num) desc;
17、查詢平均成績大於85的學生姓名和平均成績
select student.sname 姓名,avg(num) 平均成績 from student inner join score on student.sid=student_id group by student_id having avg(num)>85;
18、查詢生物成績不及格的學生姓名和對應生物分數
select sname 姓名,num 分數 from score inner join student on student_id=student.sid where course_id in (select cid from course where cname="生物") having num <60;
19、查詢在所有選修了李平老師課程的學生中,這些課程(李平老師的課程,不是所有課程)平均成績最高的學生姓名
select student.sname 姓名,avg(num) 平均成績 from score inner join student on score.student_id=student.sid where course_id in (select cid from course inner join teacher on teacher_id=tid where teacher.tname like "李平%" ) group by student_id order by avg(num) desc limit 1
本文出自 “lyndon” 博客,請務必保留此出處http://lyndon.blog.51cto.com/11474010/1965155
sql語句練習