Mysql学习---SQL测试题之表结构
创建表结果和数据准备[直接执行即可]
1 /*
2 Navicat MySQL Data Transfer
3
4 Source Server : ftl1012
5 Source Server Version : 50617
6 Source Host : localhost:3306
7 Source Database : test_python
8
9 Target Server Type : MYSQL
10 Target Server Version : 50617
11 File Encoding : 65001
12
13 Date: 2017-12-30 13:12:57
14 */
15
16 SET FOREIGN_KEY_CHECKS=0;
17
18 -- ----------------------------
19 -- Table structure for class
20 -- ----------------------------
21 DROP TABLE IF EXISTS `class`;
22 CREATE TABLE `class` (
23 `cid` int(11) NOT NULL AUTO_INCREMENT,
24 `caption` varchar(32) NOT NULL,
25 PRIMARY KEY (`cid`)
26 ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;
27
28 -- ----------------------------
29 -- Records of class
30 -- ----------------------------
31 INSERT INTO `class` VALUES ('1', '三年二班');
32 INSERT INTO `class` VALUES ('2', '三年三班');
33 INSERT INTO `class` VALUES ('3', '一年二班');
34 INSERT INTO `class` VALUES ('4', '二年九班');
35
36 -- ----------------------------
37 -- Table structure for course
38 -- ----------------------------
39 DROP TABLE IF EXISTS `course`;
40 CREATE TABLE `course` (
41 `cid` int(11) NOT NULL AUTO_INCREMENT,
42 `cname` varchar(32) NOT NULL,
43 `teacher_id` int(11) NOT NULL,
44 PRIMARY KEY (`cid`),
45 KEY `fk_course_teacher` (`teacher_id`),
46 CONSTRAINT `fk_course_teacher` FOREIGN KEY (`teacher_id`) REFERENCES `teacher` (`tid`)
47 ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;
48
49 -- ----------------------------
50 -- Records of course
51 -- ----------------------------
52 INSERT INTO `course` VALUES ('1', '生物', '1');
53 INSERT INTO `course` VALUES ('2', '物理', '2');
54 INSERT INTO `course` VALUES ('3', '体育', '3');
55 INSERT INTO `course` VALUES ('4', '美术', '2');
56
57 -- ----------------------------
58 -- Table structure for score
59 -- ----------------------------
60 DROP TABLE IF EXISTS `score`;
61 CREATE TABLE `score` (
62 `sid` int(11) NOT NULL AUTO_INCREMENT,
63 `student_id` int(11) NOT NULL,
64 `course_id` int(11) NOT NULL,
65 `num` int(11) NOT NULL,
66 PRIMARY KEY (`sid`),
67 KEY `fk_score_student` (`student_id`),
68 KEY `fk_score_course` (`course_id`),
69 CONSTRAINT `fk_score_course` FOREIGN KEY (`course_id`) REFERENCES `course` (`cid`),
70 CONSTRAINT `fk_score_student` FOREIGN KEY (`student_id`) REFERENCES `student` (`sid`)
71 ) ENGINE=InnoDB AUTO_INCREMENT=53 DEFAULT CHARSET=utf8;
72
73 -- ----------------------------
74 -- Records of score
75 -- ----------------------------
76 INSERT INTO `score` VALUES ('1', '1', '1', '10');
77 INSERT INTO `score` VALUES ('2', '1', '2', '9');
78 INSERT INTO `score` VALUES ('5', '1', '4', '66');
79 INSERT INTO `score` VALUES ('6', '2', '1', '8');
80 INSERT INTO `score` VALUES ('8', '2', '3', '68');
81 INSERT INTO `score` VALUES ('9', '2', '4', '99');
82 INSERT INTO `score` VALUES ('10', '3', '1', '77');
83 INSERT INTO `score` VALUES ('11', '3', '2', '66');
84 INSERT INTO `score` VALUES ('12', '3', '3', '87');
85 INSERT INTO `score` VALUES ('13', '3', '4', '99');
86 INSERT INTO `score` VALUES ('14', '4', '1', '79');
87 INSERT INTO `score` VALUES ('15', '4', '2', '11');
88 INSERT INTO `score` VALUES ('16', '4', '3', '67');
89 INSERT INTO `score` VALUES ('17', '4', '4', '100');
90 INSERT INTO `score` VALUES ('18', '5', '1', '79');
91 INSERT INTO `score` VALUES ('19', '5', '2', '11');
92 INSERT INTO `score` VALUES ('20', '5', '3', '67');
93 INSERT INTO `score` VALUES ('21', '5', '4', '100');
94 INSERT INTO `score` VALUES ('22', '6', '1', '9');
95 INSERT INTO `score` VALUES ('23', '6', '2', '100');
96 INSERT INTO `score` VALUES ('24', '6', '3', '67');
97 INSERT INTO `score` VALUES ('25', '6', '4', '100');
98 INSERT INTO `score` VALUES ('26', '7', '1', '9');
99 INSERT INTO `score` VALUES ('27', '7', '2', '100');
100 INSERT INTO `score` VALUES ('28', '7', '3', '67');
101 INSERT INTO `score` VALUES ('29', '7', '4', '88');
102 INSERT INTO `score` VALUES ('30', '8', '1', '9');
103 INSERT INTO `score` VALUES ('31', '8', '2', '100');
104 INSERT INTO `score` VALUES ('32', '8', '3', '67');
105 INSERT INTO `score` VALUES ('33', '8', '4', '88');
106 INSERT INTO `score` VALUES ('34', '9', '1', '91');
107 INSERT INTO `score` VALUES ('35', '9', '2', '88');
108 INSERT INTO `score` VALUES ('36', '9', '3', '67');
109 INSERT INTO `score` VALUES ('37', '9', '4', '22');
110 INSERT INTO `score` VALUES ('38', '10', '1', '90');
111 INSERT INTO `score` VALUES ('39', '10', '2', '77');
112 INSERT INTO `score` VALUES ('40', '10', '3', '43');
113 INSERT INTO `score` VALUES ('41', '10', '4', '87');
114 INSERT INTO `score` VALUES ('42', '11', '1', '90');
115 INSERT INTO `score` VALUES ('43', '11', '2', '77');
116 INSERT INTO `score` VALUES ('44', '11', '3', '43');
117 INSERT INTO `score` VALUES ('45', '11', '4', '87');
118 INSERT INTO `score` VALUES ('46', '12', '1', '90');
119 INSERT INTO `score` VALUES ('47', '12', '2', '77');
120 INSERT INTO `score` VALUES ('48', '12', '3', '43');
121 INSERT INTO `score` VALUES ('49', '12', '4', '87');
122 INSERT INTO `score` VALUES ('52', '13', '3', '87');
123
124 -- ----------------------------
125 -- Table structure for student
126 -- ----------------------------
127 DROP TABLE IF EXISTS `student`;
128 CREATE TABLE `student` (
129 `sid` int(11) NOT NULL AUTO_INCREMENT,
130 `gender` char(1) NOT NULL,
131 `class_id` int(11) NOT NULL,
132 `sname` varchar(32) NOT NULL,
133 PRIMARY KEY (`sid`),
134 KEY `fk_class` (`class_id`),
135 CONSTRAINT `fk_class` FOREIGN KEY (`class_id`) REFERENCES `class` (`cid`)
136 ) ENGINE=InnoDB AUTO_INCREMENT=17 DEFAULT CHARSET=utf8;
137
138 -- ----------------------------
139 -- Records of student
140 -- ----------------------------
141 INSERT INTO `student` VALUES ('1', '男', '1', '理解');
142 INSERT INTO `student` VALUES ('2', '女', '1', '钢蛋');
143 INSERT INTO `student` VALUES ('3', '男', '1', '张三');
144 INSERT INTO `student` VALUES ('4', '男', '1', '张一');
145 INSERT INTO `student` VALUES ('5', '女', '1', '张二');
146 INSERT INTO `student` VALUES ('6', '男', '1', '张四');
147 INSERT INTO `student` VALUES ('7', '女', '2', '铁锤');
148 INSERT INTO `student` VALUES ('8', '男', '2', '李三');
149 INSERT INTO `student` VALUES ('9', '男', '2', '李一');
150 INSERT INTO `student` VALUES ('10', '女', '2', '李二');
151 INSERT INTO `student` VALUES ('11', '男', '2', '李四');
152 INSERT INTO `student` VALUES ('12', '女', '3', '如花');
153 INSERT INTO `student` VALUES ('13', '男', '3', '刘三');
154 INSERT INTO `student` VALUES ('14', '男', '3', '刘一');
155 INSERT INTO `student` VALUES ('15', '女', '3', '刘二');
156 INSERT INTO `student` VALUES ('16', '男', '3', '刘四');
157
158 -- ----------------------------
159 -- Table structure for teacher
160 -- ----------------------------
161 DROP TABLE IF EXISTS `teacher`;
162 CREATE TABLE `teacher` (
163 `tid` int(11) NOT NULL AUTO_INCREMENT,
164 `tname` varchar(32) NOT NULL,
165 PRIMARY KEY (`tid`)
166 ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
167
168 -- ----------------------------
169 -- Records of teacher
170 -- ----------------------------
171 INSERT INTO `teacher` VALUES ('1', '张磊老师');
172 INSERT INTO `teacher` VALUES ('2', '李平老师');
173 INSERT INTO `teacher` VALUES ('3', '刘海燕老师');
174 INSERT INTO `teacher` VALUES ('4', '朱云海老师');
175 INSERT INTO `teacher` VALUES ('5', '李杰老师');View Code
经验： join, 临时表的学习[in 的使用，右边只能输出一个]
-- 查询平均成绩大于60分的同学的学号和平均成绩,按照平均成绩降序排序 操作score张表关联student查姓名
方案一[FTL]：
select * from (select student_id, avg(num) from score group by student_id having avg(num) > 60) as T left join student on student.sid = T.student_id;
方案二：
select score.student_id, student.sname, avg(num),max(num),min(num) from score LEFT JOIN student on student.sid = score.student_id
GROUP BY score.student_id having avg(num) > 60 order by avg(num) desc;
-- 查询所有同学的学号、姓名、选课数、总成绩；
SELECT a.sid, a.sname,
SUM(s.num) as zongchengji, count(s.course_id) as xuankeshu from score s
LEFT JOIN student a on a.sid = s.student_id GROUP BY s.student_id
-- 查询姓“李”的老师的个数；
方案一[FTL]：select count(tname) from teacher where tname like '李%';
方案二：select count(1) from teacher where tname like '李%';
-- 查询没学过“李平”老师课的同学的学号、姓名；
方案一[FTL]：局限性：不能查其他表中的内容
-- 没学过 ==> not int ==> sid not in 成绩表
-- 利用成绩表查找课程信息 ==>关联老师的信息
-- 李平老师 ==> where tname like '李平'
select student.sid, student.sname from student where sid not in
(
select student_id from score LEFT JOIN
course on score.course_id = course.cid
LEFT JOIN teacher on teacher.tid = course.teacher_id
where tname like '李平%'
);
方案二：
思路：
先查到“李平老师”老师教的所有课ID
获取选过课的所有学生ID
学生表中筛选
select * from student where sid not in (
select DISTINCT student_id from score where score.course_id in (
select cid from course left join teacher on course.teacher_id = teacher.tid where tname = '李平老师'
)
)
-- 查询学过“001”并且也学过编号“002”课程的同学的学号、姓名；
方案一[FTL]：
-- 选出课程为1或者2的课 ==> 关联student表查询
SELECT sid,sname from student where sid in
(select DISTINCT student_id from score where score.course_id in
(select cid from course where cid in (1,2)))
方案二：
SELECT sid, sname from
(SELECT student_id, count(student_id) FROM
(SELECT student_id, course_id FROM score WHERE course_id = 1 OR course_id = 2) AS B
GROUP BY student_id HAVING count(student_id) > 1
) as C LEFT JOIN student on student.sid = C.student_id;
方案三：
select student_id,sname from
(select student_id,course_id from score where course_id = 1 or course_id = 2) as B left join student on B.student_id = student.sid group by student_id HAVING count(student_id) > 1;
-- 查询没有学全所有课的同学的学号、姓名；
-- 查询没有学全所有课的同学的学号、姓名；
-- 所有课 ==> count(1) from course
-- 同学的学号、姓名 ==> sid, sname from student
-- 没有学全所有课 ==> count(course_id)
方案二:
SELECT student.sid, sname from student LEFT JOIN score on score.student_id = student.sid
group by student_id HAVING count(course_id) = (select count(1) from course)
-- 查询学过“李平老师“所教的所有课的同学的学号、姓名；
-- 查询学过“李平老师“所教的所有课的同学的学号、姓名；
-- 找到李平老师教过的课程ID
方案一[FTL]:
SELECT sid, sname FROM student where sid in (SELECT student_id FROM score WHERE course_id IN (SELECT cid FROM course LEFT JOIN teacher ON teacher_id = tid WHERE teacher.tname LIKE '%李平%' ))
方案二:
select sid, sname from (select student_id from score where course_id in (select cid from course left join teacher on course.teacher_id = teacher.tid where teacher.tname='李平老师') group by student_id)
as B left JOIN student on student.sid = B.student_id
-- 查询所有课程成绩小于60分的同学的学号、姓名；
-- 查询所有课程成绩小于60分的同学的学号、姓名；
方案一[FTL]:
select * from (
select student_id, num from score LEFT JOIN student on student.sid = score.student_id where num < 60 ORDER BY num asc ) as B LEFT JOIN student on B.student_id = student.sid
-- 查询至少有一门课与学号为“001”的同学所学相同的同学的学号和姓名
-- 查询至少有一门课与学号为“001”的同学所学相同的同学的学号和姓名
方案一[FTL_有错误，未解决]
select student.sid, sname from
(SELECT * from score where course_id in (
select course_id from score where student_id = 1
)) as B LEFT JOIN student on B.sid = student.sid
方案二：
思路：
获取 001 同学选择的所有课程
获取课程在其中的所有人以及所有课程
根据学生筛选，获取所有学生信息
再与学生表连接，获取姓名
select student_id, sname, count(course_id) from score
LEFT JOIN student on student.sid = score.student_id where student_id != 1 and course_id in (
select course_id from score where course_id = 1) GROUP BY student_id
-- 查询至少学过学号为“001”同学所有课数目相同的其他同学学号和姓名
-- 查询至少学过学号为“001”同学所有课数目相同的其他同学学号和姓名
-- 001 所学习的课程
-- 其他人的课 >= 001里面的课
方案一[FTL]：
select sid, sname from
(select student_id, course_id from score where course_id in
(select course_id from score where student_id = 1) group by student_id
HAVING count(1) = (select count(1) from score WHERE student_id = 1) ) as B
LEFT JOIN student on student.sid = B.student_id GROUP BY student_id
-- 查询和“002”号的同学学习的课程完全相同的其他同学学号和姓名；【高难度】
-- 查询和“002”号的同学学习的课程完全相同的其他同学学号和姓名；【高难度】
-- 002号学习的课程
-- count(1) == 002的课程count(1)
-- left JOIN student 拼接姓名和学号
-- 数量相同学生ID
select student_id, course_id, count(1) from score GROUP BY student_id having count(1) =
(select count(1) from score where student_id = 2 )
-- 课程相同
select student_id, course_id from score where course_id in
(select DISTINCT course_id from score where student_id = 2) GROUP BY student_id
-- 综合完成
select student_id,sname from score left join student on score.student_id = student.sid where student_id in (select student_id from score where student_id != 1 group by student_id HAVING count(course_id) = (select count(1) from score where student_id = 1)) and course_id in (select course_id from score where student_id = 1) group by student_id HAVING count(course_id) = (select count(1) from score where student_id = 1)
-- 删除学习“叶平”老师课的score表记录；
作者：小a玖拾柒
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个性签名: 所有的事情到最後都是好的，如果不好，那說明事情還沒有到最後～
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