数据库 多表 查询练习题

Posted 2022-04-19 bladecheng

数据库结构代码

/*
 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', '三年二班'), ('2', '三年三班'), ('3', '一年二班'), ('4', '二年九班');
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', '生物', '1'), ('2', '物理', '2'), ('3', '体育', '3'), ('4', '美术', '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', '男', '1', '理解'), ('2', '女', '1', '钢蛋'), ('3', '男', '1', '张三'), ('4', '男', '1', '张一'), ('5', '女', '1', '张二'), ('6', '男', '1', '张四'), ('7', '女', '2', '铁锤'), ('8', '男', '2', '李三'), ('9', '男', '2', '李一'), ('10', '女', '2', '李二'), ('11', '男', '2', '李四'), ('12', '女', '3', '如花'), ('13', '男', '3', '刘三'), ('14', '男', '3', '刘一'), ('15', '女', '3', '刘二'), ('16', '男', '3', '刘四');
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', '张磊老师'), ('2', '李平老师'), ('3', '刘海燕老师'), ('4', '朱云海老师'), ('5', '李杰老师');
COMMIT;

SET FOREIGN_KEY_CHECKS = 1;

表结构如下:

题目

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 join teacher where course.teacher_id=teacher.tid;

2、查询学生表中男女生各有多少人

select gender,count(*) from student group by gender;

3、查询物理成绩等于100的学生的姓名

select student.sname from score join student where course_id=2 and num=100 and student_id=student.sid;

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 ,sum(num)/4 四门平局成绩 from score join student where score.student_id=student.sid   group by score.student_id HAVING sum(num)/4>80;

5、查询所有学生的学号，姓名，选课数，总成绩

select st.sname as 姓名 ,sc.student_id as 学号,count(sc.course_id) as 科目 ,SUM(num) as 总成绩 from student st  join score sc on st.sid = sc.student_id group by sc.student_id ;

6、 查询姓李老师的个数

select tname from teacher where tname like '李%';

7、 查询没有报李平老师课的学生姓名

select sname from student where sid not in (select student_id from score where course_id in (select cid from course where teacher_id = (select tid from teacher where tname = '李平老师')));

8、 查询物理课程比生物课程高的学生的学号

select student.sname from student where sid not in (
 select student_id from score where course_id in (
    select cid from course where cname in ("物理","体育"))
  group by student_id having count(*) = 2

9、 查询没有同时选修物理课程和体育课程的学生姓名

select caption,sname,sid from student join class 
on student.class_id = cid where sid in 
(
select student_id from score where num < 60 group by student_id having count(*) >= 2);

10、查询挂科超过两门(包括两门)的学生姓名和班级

select caption,sname,sid from student join class 
on student.class_id = cid where sid in 
(
select student_id from score where num < 60 group by student_id having count(*) >= 2);

11、查询选修了所有课程的学生姓名

select sname,sid from student where sid in (
  select student_id from score group by student_id having count(*) = (select  count(*) from course));

12、查询李平老师教的课程的所有成绩记录

select * from score where course_id in (select cid from course where teacher_id=(select tid from teacher where tname = '李平老师'));

13、查询全部学生都选修了的课程号和课程名

14、查询每门课程被选修的次数

select course.cname,count(*) from  course join score where course_id=course.cid group by 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 = (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 student.sname ,sum(num)/3 四门平局成绩 from score join student where score.student_id=student.sid   group by score.student_id order by 四门平局成绩 desc;

17、查询平均成绩大于85的学生姓名和平均成绩

select student.sname ,sum(num)/4 四门平局成绩 from score join student where score.student_id=student.sid   group by score.student_id having sum(num)/4>85;

18、查询生物成绩不及格的学生姓名和对应生物分数

select student.sname,score.num from student join score join course where score.student_id = student.sid and score.course_id=course.cid having num<60;

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

20、查询每门课程成绩最好的前两名学生姓名

21、查询不同课程但成绩相同的学号，课程号，成绩

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

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

24、任课最多的老师中学生单科成绩最高的学生姓名