创建表和插入数据
1 DROP TABLE IF EXISTS `class`;
2 CREATE TABLE `class` (
3 `cid` int(11) NOT NULL AUTO_INCREMENT,
4 `caption` varchar(32) NOT NULL,
5 PRIMARY KEY (`cid`)
6 ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;
7
8 -- ----------------------------
9 -- Records of class
10 -- ----------------------------
11 INSERT INTO `class` VALUES ('1', '三年二班');
12 INSERT INTO `class` VALUES ('2', '三年三班');
13 INSERT INTO `class` VALUES ('3', '一年二班');
14 INSERT INTO `class` VALUES ('4', '二年九班');
15
16 -- ----------------------------
17 -- Table structure for course
18 -- ----------------------------
19 DROP TABLE IF EXISTS `course`;
20 CREATE TABLE `course` (
21 `cid` int(11) NOT NULL AUTO_INCREMENT,
22 `cname` varchar(32) NOT NULL,
23 `teacher_id` int(11) NOT NULL,
24 PRIMARY KEY (`cid`),
25 KEY `fk_course_teacher` (`teacher_id`),
26 CONSTRAINT `fk_course_teacher` FOREIGN KEY (`teacher_id`) REFERENCES `teacher` (`tid`)
27 ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;
28
29 -- ----------------------------
30 -- Records of course
31 -- ----------------------------
32 INSERT INTO `course` VALUES ('1', '生物', '1');
33 INSERT INTO `course` VALUES ('2', '物理', '2');
34 INSERT INTO `course` VALUES ('3', '体育', '3');
35 INSERT INTO `course` VALUES ('4', '美术', '2');
36
37 -- ----------------------------
38 -- Table structure for score
39 -- ----------------------------
40 DROP TABLE IF EXISTS `score`;
41 CREATE TABLE `score` (
42 `sid` int(11) NOT NULL AUTO_INCREMENT,
43 `student_id` int(11) NOT NULL,
44 `course_id` int(11) NOT NULL,
45 `num` int(11) NOT NULL,
46 PRIMARY KEY (`sid`),
47 KEY `fk_score_student` (`student_id`),
48 KEY `fk_score_course` (`course_id`),
49 CONSTRAINT `fk_score_course` FOREIGN KEY (`course_id`) REFERENCES `course` (`cid`),
50 CONSTRAINT `fk_score_student` FOREIGN KEY (`student_id`) REFERENCES `student` (`sid`)
51 ) ENGINE=InnoDB AUTO_INCREMENT=53 DEFAULT CHARSET=utf8;
52
53 -- ----------------------------
54 -- Records of score
55 -- ----------------------------
56 INSERT INTO `score` VALUES ('1', '1', '1', '10');
57 INSERT INTO `score` VALUES ('2', '1', '2', '9');
58 INSERT INTO `score` VALUES ('5', '1', '4', '66');
59 INSERT INTO `score` VALUES ('6', '2', '1', '8');
60 INSERT INTO `score` VALUES ('8', '2', '3', '68');
61 INSERT INTO `score` VALUES ('9', '2', '4', '99');
62 INSERT INTO `score` VALUES ('10', '3', '1', '77');
63 INSERT INTO `score` VALUES ('11', '3', '2', '66');
64 INSERT INTO `score` VALUES ('12', '3', '3', '87');
65 INSERT INTO `score` VALUES ('13', '3', '4', '99');
66 INSERT INTO `score` VALUES ('14', '4', '1', '79');
67 INSERT INTO `score` VALUES ('15', '4', '2', '11');
68 INSERT INTO `score` VALUES ('16', '4', '3', '67');
69 INSERT INTO `score` VALUES ('17', '4', '4', '100');
70 INSERT INTO `score` VALUES ('18', '5', '1', '79');
71 INSERT INTO `score` VALUES ('19', '5', '2', '11');
72 INSERT INTO `score` VALUES ('20', '5', '3', '67');
73 INSERT INTO `score` VALUES ('21', '5', '4', '100');
74 INSERT INTO `score` VALUES ('22', '6', '1', '9');
75 INSERT INTO `score` VALUES ('23', '6', '2', '100');
76 INSERT INTO `score` VALUES ('24', '6', '3', '67');
77 INSERT INTO `score` VALUES ('25', '6', '4', '100');
78 INSERT INTO `score` VALUES ('26', '7', '1', '9');
79 INSERT INTO `score` VALUES ('27', '7', '2', '100');
80 INSERT INTO `score` VALUES ('28', '7', '3', '67');
81 INSERT INTO `score` VALUES ('29', '7', '4', '88');
82 INSERT INTO `score` VALUES ('30', '8', '1', '9');
83 INSERT INTO `score` VALUES ('31', '8', '2', '100');
84 INSERT INTO `score` VALUES ('32', '8', '3', '67');
85 INSERT INTO `score` VALUES ('33', '8', '4', '88');
86 INSERT INTO `score` VALUES ('34', '9', '1', '91');
87 INSERT INTO `score` VALUES ('35', '9', '2', '88');
88 INSERT INTO `score` VALUES ('36', '9', '3', '67');
89 INSERT INTO `score` VALUES ('37', '9', '4', '22');
90 INSERT INTO `score` VALUES ('38', '10', '1', '90');
91 INSERT INTO `score` VALUES ('39', '10', '2', '77');
92 INSERT INTO `score` VALUES ('40', '10', '3', '43');
93 INSERT INTO `score` VALUES ('41', '10', '4', '87');
94 INSERT INTO `score` VALUES ('42', '11', '1', '90');
95 INSERT INTO `score` VALUES ('43', '11', '2', '77');
96 INSERT INTO `score` VALUES ('44', '11', '3', '43');
97 INSERT INTO `score` VALUES ('45', '11', '4', '87');
98 INSERT INTO `score` VALUES ('46', '12', '1', '90');
99 INSERT INTO `score` VALUES ('47', '12', '2', '77');
100 INSERT INTO `score` VALUES ('48', '12', '3', '43');
101 INSERT INTO `score` VALUES ('49', '12', '4', '87');
102 INSERT INTO `score` VALUES ('52', '13', '3', '87');
103
104 -- ----------------------------
105 -- Table structure for student
106 -- ----------------------------
107 DROP TABLE IF EXISTS `student`;
108 CREATE TABLE `student` (
109 `sid` int(11) NOT NULL AUTO_INCREMENT,
110 `gender` char(1) NOT NULL,
111 `class_id` int(11) NOT NULL,
112 `sname` varchar(32) NOT NULL,
113 PRIMARY KEY (`sid`),
114 KEY `fk_class` (`class_id`),
115 CONSTRAINT `fk_class` FOREIGN KEY (`class_id`) REFERENCES `class` (`cid`)
116 ) ENGINE=InnoDB AUTO_INCREMENT=17 DEFAULT CHARSET=utf8;
117
118 -- ----------------------------
119 -- Records of student
120 -- ----------------------------
121 INSERT INTO `student` VALUES ('1', '男', '1', '理解');
122 INSERT INTO `student` VALUES ('2', '女', '1', '钢蛋');
123 INSERT INTO `student` VALUES ('3', '男', '1', '张三');
124 INSERT INTO `student` VALUES ('4', '男', '1', '张一');
125 INSERT INTO `student` VALUES ('5', '女', '1', '张二');
126 INSERT INTO `student` VALUES ('6', '男', '1', '张四');
127 INSERT INTO `student` VALUES ('7', '女', '2', '铁锤');
128 INSERT INTO `student` VALUES ('8', '男', '2', '李三');
129 INSERT INTO `student` VALUES ('9', '男', '2', '李一');
130 INSERT INTO `student` VALUES ('10', '女', '2', '李二');
131 INSERT INTO `student` VALUES ('11', '男', '2', '李四');
132 INSERT INTO `student` VALUES ('12', '女', '3', '如花');
133 INSERT INTO `student` VALUES ('13', '男', '3', '刘三');
134 INSERT INTO `student` VALUES ('14', '男', '3', '刘一');
135 INSERT INTO `student` VALUES ('15', '女', '3', '刘二');
136 INSERT INTO `student` VALUES ('16', '男', '3', '刘四');
137
138 -- ----------------------------
139 -- Table structure for teacher
140 -- ----------------------------
141 DROP TABLE IF EXISTS `teacher`;
142 CREATE TABLE `teacher` (
143 `tid` int(11) NOT NULL AUTO_INCREMENT,
144 `tname` varchar(32) NOT NULL,
145 PRIMARY KEY (`tid`)
146 ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
147
148 -- ----------------------------
149 -- Records of teacher
150 -- ----------------------------
151 INSERT INTO `teacher` VALUES ('1', '张磊老师');
152 INSERT INTO `teacher` VALUES ('2', '李平老师');
153 INSERT INTO `teacher` VALUES ('3', '刘海燕老师');
154 INSERT INTO `teacher` VALUES ('4', '朱云海老师');
155 INSERT INTO `teacher` VALUES ('5', '李杰老师');
156 SET FOREIGN_KEY_CHECKS=1;
1、查询所有的课程的名称以及对应的任课老师姓名
SELECT cname 课程,tname 老师 from teacher,course WHERE teacher.tid=course.teacher_id;
+--------+-----------------+
| 课程 | 老师 |
+--------+-----------------+
| 生物 | 张磊老师 |
| 物理 | 李平老师 |
| 体育 | 刘海燕老师 |
| 美术 | 李平老师 |
+--------+-----------------+
2、查询学生表中男女生各有多少人
SELECT gender 性别 ,COUNT(gender) 人数 from student GROUP BY gender;
+--------+--------+
| 性别 | 人数 |
+--------+--------+
| 女 | 6 |
| 男 | 10 |
+--------+--------+
3、查询物理成绩等于100的学生的姓名
SELECT student.sname ,course.cname,score.num FROM score,student,course
WHERE num=100 and course_id=2 AND score.student_id=student.sid AND course.cid=score.course_id;
+--------+--------+-----+
| sname | cname | num |
+--------+--------+-----+
| 张四 | 物理 | 100 |
| 铁锤 | 物理 | 100 |
| 李三 | 物理 | 100 |
+--------+--------+-----+
4、查询平均成绩大于八十分的同学的姓名和平均成绩
SELECT AVG(num),student.sname FROM score,student
WHERE score.student_id=student.sid GROUP BY student_id HAVING AVG(num) > 80;
+----------+--------+
| AVG(num) | sname |
+----------+--------+
| 82.2500 | 张三 |
| 87.0000 | 刘三 |
+----------+--------+
5、查询所有学生的学号，姓名，选课数，总成绩
SELECT student.sid 学号,COUNT(*) 课程数,student.sname 姓名,SUM(score.num) 总成绩 FROM score,student
WHERE student.sid=score.student_id GROUP BY student_id ORDER BY 学号;
+--------+-----------+--------+-----------+
| 学号 | 课程数 | 姓名 | 总成绩 |
+--------+-----------+--------+-----------+
| 1 | 3 | 理解 | 85 |
| 2 | 3 | 钢蛋 | 175 |
| 3 | 4 | 张三 | 329 |
| 4 | 4 | 张一 | 257 |
| 5 | 4 | 张二 | 257 |
| 6 | 4 | 张四 | 276 |
| 7 | 4 | 铁锤 | 264 |
| 8 | 4 | 李三 | 264 |
| 9 | 4 | 李一 | 268 |
| 10 | 4 | 李二 | 297 |
| 11 | 4 | 李四 | 297 |
| 12 | 4 | 如花 | 297 |
| 13 | 1 | 刘三 | 87 |
+--------+-----------+--------+-----------+
6、查询姓李老师的个数
SELECT count(*) FROM teacher WHERE tname LIKE '李%';
+----------+
| count(*) |
+----------+
| 2 |
+----------+
7、查询没有报李平老师课的学生姓名
SELECT sid 学号,sname 姓名 from student WHERE sid NOT IN
(SELECT student_id FROM score RIGHT JOIN
(SELECT cid FROM course LEFT JOIN teacher ON teacher.tid=course.teacher_id WHERE tname LIKE "李平%") AS A
ON score.course_id=A.cid GROUP BY student_id);
+--------+--------+
| 学号 | 姓名 |
+--------+--------+
| 13 | 刘三 |
| 14 | 刘一 |
| 15 | 刘二 |
| 16 | 刘四 |
+--------+--------+
8、 查询物理课程比生物课程高的学生的学号
SELECT * from (SELECT student_id ,cname,num FROM score LEFT JOIN course ON score.course_id=course.cid WHERE cname="物理") AS A
INNER JOIN (SELECT student_id,cname,num FROM score LEFT JOIN course ON score.course_id=course.cid WHERE cname="生物")AS B
ON A.student_id=B.student_id WHERE A.num > B.num;
+------------+--------+-----+------------+--------+-----+
| student_id | cname | num | student_id | cname | num |
+------------+--------+-----+------------+--------+-----+
| 6 | 物理 | 100 | 6 | 生物 | 9 |
| 7 | 物理 | 100 | 7 | 生物 | 9 |
| 8 | 物理 | 100 | 8 | 生物 | 9 |
+------------+--------+-----+------------+--------+-----+
9、 查询没有同时选修物理课程和体育课程的学生姓名
SELECT sid 学号,sname 学员 FROM student WHERE sid not in (SELECT student_id FROM score
LEFT JOIN course on course.cid=score.course_id
WHERE cname="物理" OR cname="体育" GROUP BY student_id HAVING count(cname) >1);
+--------+--------+
| 学号 | 学员 |
+--------+--------+
| 1 | 理解 |
| 2 | 钢蛋 |
| 13 | 刘三 |
| 14 | 刘一 |
| 15 | 刘二 |
| 16 | 刘四 |
+--------+--------+
10、查询挂科超过两门(包括两门)的学生姓名和班级
SELECT sname,caption FROM (SELECT student_id,class_id,sname FROM score LEFT JOIN student ON student.sid=score.student_id
WHERE num < 60 GROUP BY score.student_id HAVING COUNT(*) > 1) AS A LEFT JOIN class ON class.cid=A.class_id;
+--------+--------------+
| sname | caption |
+--------+--------------+
| 理解 | 三年二班 |
+--------+--------------+
11、查询选修了所有课程的学生姓名
SELECT student_id 学号,sname 姓名 FROM (SELECT * FROM score GROUP BY student_id HAVING COUNT(*) >= (SELECT COUNT(cname) FROM course )) AS A LEFT JOIN student
ON A.student_id=student.sid;
+--------+--------+
| 学号 | 姓名 |
+--------+--------+
| 3 | 张三 |
| 4 | 张一 |
| 5 | 张二 |
| 6 | 张四 |
| 7 | 铁锤 |
| 8 | 李三 |
| 9 | 李一 |
| 10 | 李二 |
| 11 | 李四 |
| 12 | 如花 |
+--------+--------+
12、查询李平老师教的课程的所有成绩记录
SELECT tname 老师, cname 课程,num 分数 FROM (SELECT cid,tname,cname FROM teacher LEFT JOIN course ON teacher.tid=course.teacher_id WHERE tname LIKE "李平%") AS A
LEFT JOIN score ON score.course_id=A.cid;
+--------------+--------+--------+
| 老师 | 课程 | 分数 |
+--------------+--------+--------+
| 李平老师 | 物理 | 9 |
| 李平老师 | 物理 | 66 |
| 李平老师 | 物理 | 11 |
| 李平老师 | 物理 | 11 |
| 李平老师 | 物理 | 100 |
| 李平老师 | 物理 | 100 |
| 李平老师 | 物理 | 100 |
| 李平老师 | 物理 | 88 |
| 李平老师 | 物理 | 77 |
| 李平老师 | 物理 | 77 |
| 李平老师 | 物理 | 77 |
| 李平老师 | 美术 | 66 |
| 李平老师 | 美术 | 99 |
| 李平老师 | 美术 | 99 |
| 李平老师 | 美术 | 100 |
| 李平老师 | 美术 | 100 |
| 李平老师 | 美术 | 100 |
| 李平老师 | 美术 | 88 |
| 李平老师 | 美术 | 88 |
| 李平老师 | 美术 | 22 |
| 李平老师 | 美术 | 87 |
| 李平老师 | 美术 | 87 |
| 李平老师 | 美术 | 87 |
+--------------+--------+--------+
13、查询全部学生都选修了的课程号和课程名
SELECT course_id FROM score
GROUP BY course_id
HAVING COUNT(course_id)=(SELECT COUNT(sid) FROM student);
Empty set (0.00 sec)
14、查询每门课程被选修的次数
SELECT cname 课程名称,COUNT(course_id)次数 FROM score LEFT JOIN course on course.cid=score.course_id GROUP BY course_id;
+--------------+--------+
| 课程名称 | 次数 |
+--------------+--------+
| 生物 | 12 |
| 物理 | 11 |
| 体育 | 12 |
| 美术 | 12 |
+--------------+--------+
15、查询只选修了一门课程的学生姓名和学号
SELECT student.sid 学号 ,sname 姓名 FROM score LEFT JOIN student ON student.sid=score.student_id
GROUP BY student_id HAVING COUNT(course_id)=1;
+--------+--------+
| 学号 | 姓名 |
+--------+--------+
| 13 | 刘三 |
+--------+--------+
16、查询所有学生考出的成绩并按从高到低排序（成绩去重）
SELECT DISTINCT num 成绩 from score ORDER BY num DESC;
+--------+
| 成绩 |
+--------+
| 100 |
| 99 |
| 91 |
| 90 |
| 88 |
| 87 |
| 79 |
| 77 |
| 68 |
| 67 |
| 66 |
| 43 |
| 22 |
| 11 |
| 10 |
| 9 |
| 8 |
+--------+
17、查询平均成绩大于85的学生姓名和平均成绩
SELECT student.sname 姓名,avg(num) 平均成绩 FROM score LEFT JOIN student ON student.sid=score.student_id
GROUP BY student_id HAVING avg(num) > 85;
+--------+--------------+
| 姓名 | 平均成绩 |
+--------+--------------+
| 刘三 | 87.0000 |
+--------+--------------+
18、查询生物成绩不及格的学生姓名和对应生物分数
SELECT sname 姓名,cname 课程,num 分数 FROM (SELECT student_id,cname,num FROM score LEFT JOIN course on course.cid=score.course_id
WHERE cname="生物" and num<60) AS A
LEFT JOIN
student ON A.student_id=student.sid;
+--------+--------+--------+
| 姓名 | 课程 | 分数 |
+--------+--------+--------+
| 理解 | 生物 | 10 |
| 钢蛋 | 生物 | 8 |
| 张四 | 生物 | 9 |
| 铁锤 | 生物 | 9 |
| 李三 | 生物 | 9 |
+--------+--------+--------+
19、查询在所有选修了李平老师课程的学生中，这些课程(李平老师的课程，不是所有课程)平均成绩最高的学生姓名
SELECT sid 学号,sname 学生, tname 老师,平均成绩 from (SELECT student_id,tname,AVG(num) 平均成绩 FROM
(SELECT cid,tid,tname FROM course RIGHT JOIN teacher ON teacher.tid=course.teacher_id WHERE tname LIKE "李平%") AS A
LEFT JOIN score ON A.cid=score.course_id GROUP BY student_id ORDER BY AVG(num) DESC LIMIT 1) AS B
LEFT JOIN student ON student.sid=B.student_id;
+--------+--------+--------------+--------------+
| 学号 | 学生 | 老师 | 平均成绩 |
+--------+--------+--------------+--------------+
| 6 | 张四 | 李平老师 | 100.0000 |
+--------+--------+--------------+--------------+