init.sql文件
/*
数据导入：
Navicat Premium Data Transfer
Source Server : localhost
Source Server Type : MySQL
Source Server Version : 50624
Source Host : localhost
Source Database : sqlexam
Target Server Type : MySQL
Target Server Version : 50624
File Encoding : utf-8
Date: 10/21/2016 06:46:46 AM
*/
SET NAMES utf8;
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`
-- ----------------------------
BEGIN;
INSERT INTO `class` VALUES (‘1‘, ‘class 2 grade 3‘), (‘2‘, ‘class 3 grade 3‘), (‘3‘, ‘class 2 grade 1‘), (‘4‘, ‘class 9 grade 2‘);
COMMIT;
-- ----------------------------
-- 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`
-- ----------------------------
BEGIN;
INSERT INTO `course` VALUES (‘1‘, ‘biology‘, ‘1‘), (‘2‘, ‘physics‘, ‘2‘), (‘3‘, ‘physical‘, ‘3‘), (‘4‘, ‘art‘, ‘2‘);
COMMIT;
-- ----------------------------
-- 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`
-- ----------------------------
BEGIN;
INSERT INTO `score` VALUES (‘1‘, ‘1‘, ‘1‘, ‘10‘), (‘2‘, ‘1‘, ‘2‘, ‘9‘), (‘5‘, ‘1‘, ‘4‘, ‘66‘), (‘6‘, ‘2‘, ‘1‘, ‘8‘), (‘8‘, ‘2‘, ‘3‘, ‘68‘), (‘9‘, ‘2‘, ‘4‘, ‘99‘), (‘10‘, ‘3‘, ‘1‘, ‘77‘), (‘11‘, ‘3‘, ‘2‘, ‘66‘), (‘12‘, ‘3‘, ‘3‘, ‘87‘), (‘13‘, ‘3‘, ‘4‘, ‘99‘), (‘14‘, ‘4‘, ‘1‘, ‘79‘), (‘15‘, ‘4‘, ‘2‘, ‘11‘), (‘16‘, ‘4‘, ‘3‘, ‘67‘), (‘17‘, ‘4‘, ‘4‘, ‘100‘), (‘18‘, ‘5‘, ‘1‘, ‘79‘), (‘19‘, ‘5‘, ‘2‘, ‘11‘), (‘20‘, ‘5‘, ‘3‘, ‘67‘), (‘21‘, ‘5‘, ‘4‘, ‘100‘), (‘22‘, ‘6‘, ‘1‘, ‘9‘), (‘23‘, ‘6‘, ‘2‘, ‘100‘), (‘24‘, ‘6‘, ‘3‘, ‘67‘), (‘25‘, ‘6‘, ‘4‘, ‘100‘), (‘26‘, ‘7‘, ‘1‘, ‘9‘), (‘27‘, ‘7‘, ‘2‘, ‘100‘), (‘28‘, ‘7‘, ‘3‘, ‘67‘), (‘29‘, ‘7‘, ‘4‘, ‘88‘), (‘30‘, ‘8‘, ‘1‘, ‘9‘), (‘31‘, ‘8‘, ‘2‘, ‘100‘), (‘32‘, ‘8‘, ‘3‘, ‘67‘), (‘33‘, ‘8‘, ‘4‘, ‘88‘), (‘34‘, ‘9‘, ‘1‘, ‘91‘), (‘35‘, ‘9‘, ‘2‘, ‘88‘), (‘36‘, ‘9‘, ‘3‘, ‘67‘), (‘37‘, ‘9‘, ‘4‘, ‘22‘), (‘38‘, ‘10‘, ‘1‘, ‘90‘), (‘39‘, ‘10‘, ‘2‘, ‘77‘), (‘40‘, ‘10‘, ‘3‘, ‘43‘), (‘41‘, ‘10‘, ‘4‘, ‘87‘), (‘42‘, ‘11‘, ‘1‘, ‘90‘), (‘43‘, ‘11‘, ‘2‘, ‘77‘), (‘44‘, ‘11‘, ‘3‘, ‘43‘), (‘45‘, ‘11‘, ‘4‘, ‘87‘), (‘46‘, ‘12‘, ‘1‘, ‘90‘), (‘47‘, ‘12‘, ‘2‘, ‘77‘), (‘48‘, ‘12‘, ‘3‘, ‘43‘), (‘49‘, ‘12‘, ‘4‘, ‘87‘), (‘52‘, ‘13‘, ‘3‘, ‘87‘);
COMMIT;
-- ----------------------------
-- 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`
-- ----------------------------
BEGIN;
INSERT INTO `student` VALUES (‘1‘, ‘male‘, ‘1‘, ‘lijie‘), (‘2‘, ‘female‘, ‘1‘, ‘gangdan‘), (‘3‘, ‘male‘, ‘1‘, ‘zhangsan‘), (‘4‘, ‘male‘, ‘1‘, ‘zhangyi‘), (‘5‘, ‘female‘, ‘1‘, ‘zhanger‘), (‘6‘, ‘male‘, ‘1‘, ‘zhangsi‘), (‘7‘, ‘female‘, ‘2‘, ‘tiechui‘), (‘8‘, ‘male‘, ‘2‘, ‘lisan‘), (‘9‘, ‘male‘, ‘2‘, ‘liyi‘), (‘10‘, ‘female‘, ‘2‘, ‘lier‘), (‘11‘, ‘male‘, ‘2‘, ‘lisi‘), (‘12‘, ‘female‘, ‘3‘, ‘ruhua‘), (‘13‘, ‘male‘, ‘3‘, ‘liusan‘), (‘14‘, ‘male‘, ‘3‘, ‘liuyi‘), (‘15‘, ‘female‘, ‘3‘, ‘liuer‘), (‘16‘, ‘male‘, ‘3‘, ‘liusi‘);
COMMIT;
-- ----------------------------
-- 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`
-- ----------------------------
BEGIN;
INSERT INTO `teacher` VALUES (‘1‘, ‘zhanglei‘), (‘2‘, ‘liping‘), (‘3‘, ‘liuhaiyan‘), (‘4‘, ‘zhuyunhai‘), (‘5‘, ‘lijie‘);
COMMIT;
SET FOREIGN_KEY_CHECKS = 1;
答案
1、查询所有的课程的名称以及对应的任课老师姓名
SELECT course.cname, teacher.tname FROM course
INNER JOIN
teacher on course.teacher_id = teacher.tid;
2、查询学生表中男女生各有多少人
SELECT gender as ‘sex‘,count(sid) as ‘count:‘ FROM student group by gender;
3、查询物理成绩等于100的学生的姓名
# 1
SELECT
sname
FROM
student
WHERE sid IN
(SELECT student_id FROM score
WHERE
course_id=(SELECT cid FROM course WHERE cname=‘physics‘)
AND
num=100);
# 2
SELECT
sname
FROM
student
WHERE sid IN
(SELECT student_id FROM course
INNER JOIN
score
ON
course.cid = score.course_id
WHERE
course.cname=‘physics‘
AND
score.num=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
student.sname, t.avg_num
FROM
student
INNER JOIN
(SELECT student_id,avg(num) avg_num FROM score group by student_id having avg(num)>80)
AS t
ON student.sid=t.student_id
;
5、查询所有学生的学号，姓名，选课数，总成绩
SELECT
student.sid,student.sname,t.course_sum,sum_num
FROM
student LEFT JOIN(
SELECT
student_id,count(course_id) course_sum, sum(num) sum_num
FROM
score
GROUP BY
student_id)
AS t ON student.sid=t.student_id
;
6、 查询姓李老师的个数
SELECT count(tid) FROM teacher where tname LIKE ‘li%‘;
7、 查询没有报李平老师课的学生姓名
# 查询报了李平老师的课的学生，取反
SELECT
sname
FROM
student
WHERE sid not in(
SELECT
DISTINCT score.student_id
FROM
score
LEFT JOIN course
ON score.course_id=course.cid
WHERE
course.teacher_id in (SELECT tid from teacher WHERE tname=‘liping‘)
);
8、查询物理课程比生物课程高的学生的学号
SELECT
a.student_id
FROM (
SELECT student_id,num FROM score WHERE course_id in(
SELECT cid FROM course WHERE cname=‘physics‘)
)AS a
INNER JOIN(
SELECT student_id,num FROM score WHERE course_id in (
SELECT cid FROM course WHERE cname=‘biology‘)
)
AS b ON a.student_id=b.student_id WHERE a.num>b.num;
SELECT sname FROM student WHERE sid NOT IN (
SELECT
a.student_id
FROM (
SELECT student_id,num FROM score WHERE course_id in(
SELECT cid FROM course WHERE cname=‘physics‘)
)AS a
INNER JOIN(
SELECT student_id,num FROM score WHERE course_id in (
SELECT cid FROM course WHERE cname=‘biology‘)
)
AS b ON a.student_id=b.student_id);
9、查询没有同时选修物理课程和体育课程的学生姓名
#1
SELECT sname FROM student WHERE sid NOT IN (
SELECT
a.student_id
FROM (
SELECT student_id,num FROM score WHERE course_id IN(
SELECT cid FROM course WHERE cname=‘physics‘)
)AS a
INNER JOIN(
SELECT student_id,num FROM score WHERE course_id IN(
SELECT cid FROM course WHERE cname=‘physical‘)
)
AS b ON a.student_id=b.student_id);
#2
SELECT sname FROM student WHERE sid NOT IN (
SELECT
student_id
FROM
score
WHERE
course_id IN (
SELECT
cid
FROM
course WHERE cname =‘physics‘ OR cname=‘physical‘)
GROUP BY
student_id having count(course_id) =2
)
;
10、查询挂科超过两门(包括两门)的学生姓名和班级
SELECT
student.sname,class.caption
FROM
student
INNER JOIN
class
ON student.class_id=class.cid
INNER JOIN
(
SELECT student_id FROM score where num<60 GROUP BY student_id HAVING COUNT(course_id) >=2
) AS t1 ON t1.student_id= student.sid ;
11、查询选修了所有课程的学生姓名
SELECT
sname
FROM
student
INNER JOIN
(SELECT
student_id
FROM
score
GROUP BY
student_id
HAVING
count(course_id)=(SELECT count(cid) FROM course))
AS t ON t.student_id = student.sid;
12、查询李平老师教的课程的所有成绩记录
SELECT * FROM score WHERE score.course_id IN
(
SELECT course.cid
FROM
teacher
INNER JOIN
course
ON course.teacher_id=teacher.tid WHERE teacher.tname=‘liping‘
);
13、查询全部学生都选修了的课程号和课程名
SELECT cid, course.cname FROM course
WHERE cid IN (
SELECT course_id FROM score GROUP BY course_id
HAVING
count(student_id)=(SELECT count(sid) FROM student)
);
14、查询每门课程被选修的次数
SELECT cname, t.t_count FROM course INNER JOIN(
SELECT course_id, count(course_id) AS t_count FROM score GROUP BY course_id) t
ON course.cid = t.course_id
;
15、查询之选修了一门课程的学生姓名和学号
SELECT sid,sname FROM student WHERE sid IN
(
SELECT student_id FROM score GROUP BY student_id HAVING count(course_id)=1
);
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 FROM score ORDER BY num DESC;
17、查询平均成绩大于85的学生姓名和平均成绩
SELECT sname,t.avg_num FROM student INNER JOIN
(SELECT student_id,avg(num) avg_num FROM score GROUP BY student_id HAVING avg(num)>85)
AS t ON student.sid=t.student_id
18、查询生物成绩不及格的学生姓名和对应生物分数
SELECT sname,t.num FROM student INNER JOIN
(SELECT student_id, num FROM score WHERE course_id IN (SELECT cid FROM course WHERE cname=‘biology‘) AND num<60)
AS t ON t.student_id=student.sid;
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 sname FROM student WHERE sid=
(
SELECT student_id FROM score WHERE course_id IN
(
SELECT cid FROM course
INNER JOIN
teacher ON teacher.tid = course.teacher_id
)
ORDER BY num DESC LIMIT 1
);
20、查询每门课程成绩最好的前两名学生姓名
#取最高分:
SELECT course_id, max(num) AS first_num FROM score GROUP BY course_id
#取第二高分
SELECT score.course_id, max(num) AS second_num FROM score
INNER JOIN
(SELECT course_id, max(num) AS first_num FROM score GROUP BY course_id ) as t
ON
score.course_id=t.course_id
WHERE
score.num < t.first_num
GROUP BY
score.course_id
# 合并（考虑并列）
SELECT t1.course_id,t1.first_num,t2.second_num
FROM
(SELECT course_id, max(num) AS first_num FROM score GROUP BY course_id) AS t1
INNER JOIN
(
SELECT
score.course_id, max(num) AS second_num
FROM
score
INNER JOIN
(SELECT course_id, max(num) AS first_num FROM score GROUP BY course_id ) as t
ON
score.course_id=t.course_id
WHERE
score.num < t.first_num
GROUP BY
course_id
) AS t2 ON t1.course_id = t2.course_id
# 查询
SELECT score.student_id,t3.course_id,t3.first_num,t3.second_num FROM score
INNER JOIN
(
SELECT t1.course_id,t1.first_num,t2.second_num
FROM
(SELECT course_id, max(num) AS first_num FROM score GROUP BY course_id) AS t1
INNER JOIN
(
SELECT
score.course_id, max(num) AS second_num
FROM
score
INNER JOIN
(SELECT course_id, max(num) AS first_num FROM score GROUP BY course_id ) as t
ON
score.course_id=t.course_id
WHERE
score.num < t.first_num
GROUP BY
course_id
) AS t2 ON t1.course_id = t2.course_id
) AS t3 ON t3.course_id=score.course_id
WHERE
score.num >= t3.second_num
AND
score.num <= t3.first_num
# 最后
SELECT sname FROM student WHERE sid IN (
SELECT score.student_id FROM score
INNER JOIN
(
SELECT t1.course_id,t1.first_num,t2.second_num
FROM
(SELECT course_id, max(num) AS first_num FROM score GROUP BY course_id) AS t1
INNER JOIN
(
SELECT
score.course_id, max(num) AS second_num
FROM
score
INNER JOIN
(SELECT course_id, max(num) AS first_num FROM score GROUP BY course_id ) as t
ON
score.course_id=t.course_id
WHERE
score.num < t.first_num
GROUP BY
course_id
) AS t2 ON t1.course_id = t2.course_id
) AS t3 ON t3.course_id=score.course_id
WHERE
score.num >= t3.second_num
AND
score.num <= t3.first_num
);
21、查询不同课程但成绩相同的学号，课程号，成绩
SELECT
s1.student_id,s1.course_id,s2.course_id,num
FROM
score as s1,score as s2
WHERE
s1.num=s2.num AND s1.course_id != s2.course_id;
22、查询没学过“叶平”老师课程的学生姓名以及选修的课程名称；
SELECT student.sname,t1.cname FROM student INNER JOIN
(
SELECT score.student_id,t.cname FROM score INNER JOIN
(
SELECT cid,cname FROM course WHERE teacher_id
NOT IN
(SELECT tid FROM teacher WHERE tname=‘liping‘)
) AS t ON t.cid=score.course_id
)AS t1 ON t1.student_id = student.sid
23、查询所有选修了学号为1的同学选修过的一门或者多门课程的同学学号和姓名；
SELECT sname FROM student
WHERE
sid
IN
(
SELECT DISTINCT student_id FROM score WHERE course_id
IN (SELECT course_id FROM score WHERE student_id=1)
) AS t ON t.student_id = student;
24、任课最多的老师中学生单科成绩最高的学生姓名
SELECT sname FROM student
WHERE
sid=(
SELECT student_id FROM score WHERE course_id
IN (
SELECT cid FROM course
WHERE
teacher_id=(SELECT teacher_id FROM course GROUP BY teacher_id ORDER BY count(cid) DESC LIMIT 1)
) ORDER BY num LIMIT 1
);
