-- 班级表
mysql> create table class(
-> cid int auto_increment primary key,
-> caption int not null
-> )charset utf8;
Query OK, 0 rows affected (0.41 sec)
-- 学生表
mysql> create table student(
-> sid int not null primary key,
-> sname varchar(255) not null default 1,
-> gender enum('male', 'female'),
-> class_id int not null,
-> CONSTRAINT fk_id FOREIGN KEY (class_id) REFERENCES class(cid)
-> )charset utf8;
Query OK, 0 rows affected (0.41 sec)
-- 教师表
mysql> create table teacher(
-> tid int not null primary key,
-> tname varchar(255) not null
-> )charset utf8;
Query OK, 0 rows affected (0.34 sec)-- 课程表
mysql> create table course(
-> cid int not null primary key,
-> cname varchar(255) not null,
-> teacher_id int not null,
-> constraint fk_tch_id foreign key (teacher_id) references teacher(tid)
-> )charset utf8;
Query OK, 0 rows affected (0.37 sec)-- 成绩表
mysql> create table score(
-> sid int not null primary key,
-> student_id int not null,
-> course_id int not null,
-> number tinyint not null,
-> constraint fk_stu_id foreign key (student_id) references student(sid),
-> constraint fk_crs_id foreign key (course_id) references course(cid)
-> )charset utf8;
Query OK, 0 rows affected (0.53 sec)
mysql> alter table score add unique key(student_id,course_id);
Query OK, 0 rows affected (0.58 sec)-- 插入班级
mysql> insert into class values
-> (1, '三年二班'),
-> (2, '三年三班'),
-> (3, '一年二班'),
-> (4, '三年七班');
Query OK, 4 rows affected (0.07 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> select * from class;
+-----+----------+
| cid | capiton |
+-----+----------+
| 1 | 三年二班 |
| 2 | 三年三班 |
| 3 | 一年二班 |
| 4 | 三年七班 |
+-----+----------+
4 rows in set (0.00 sec)-- 插入学生
mysql> insert into student values
-> (1, '张三', 'male', 1),
-> (2, '李四', 'male', 2),
-> (3, '王五', 'male', 3),
-> (4, '赵六', 'male', 4),
-> (5, '钢蛋', 'female', 4);
mysql> insert into student values
-> (6, '铁锤', 'female', 1),
-> (7, '如花', 'male', 2),
-> (8, '锅炉', 'female', 3),
->
-> (9, '小乔', 'female', 4),
-> (10, '公孙离 ', 'female',1);
Query OK, 5 rows affected (0.05 sec)
mysql> insert into student values
-> (11, '沈雷锴', 'male', 1);
Query OK, 1 row affected (0.06 sec)
mysql> insert into student values
-> (12, 'xzn', 'male', 2),
-> (13, 'cjl', 'male', 3),
-> (14, 'xwj', 'male', 4),
-> (15, 'egon', 'male', 2);
Query OK, 4 rows affected (0.04 sec)-- 插入老师
mysql> insert into teacher values
-> (1, '张磊'),
-> (2, '李平'),
-> (3, '刘海燕'),
-> (4, '朱云海'),
-> (5, '李杰');
Query OK, 5 rows affected (0.05 sec)
Records: 5 Duplicates: 0 Warnings: 0-- 插入课程
mysql> insert into course values
-> (1, '生物', 1),
-> (2, '物理', 2),
-> (3, '体育', 3),
-> (4, '美术', 2);
Query OK, 4 rows affected (0.13 sec)-- 插入成绩
mysql> insert into score values
-> (1, 1, 1, 10),
-> (2, 1, 2, 9),
-> (3, 1, 4, 66),
-> (4, 2, 1, 8),
-> (5, 2, 3, 68),
-> (6, 2, 4, 88),
-> (7, 3, 2, 8),
-> (8, 3, 3, 55),
-> (9, 3, 4, 66),
-> (10, 4, 1, 6),
-> (11, 4, 3, 89),
-> (12, 4, 4, 96),
-> (13, 5, 1, 33),
-> (14, 5, 2, 34),
-> (15, 5, 4, 34);
Query OK, 15 rows affected (0.11 sec)
Records: 15 Duplicates: 0 Warnings: 0
mysql> insert into score values
-> (16,6,1,44),
-> (17,6,2,33),
-> (18,7,3,66),
-> (19,7,4,88),
-> (20,8,1,78),
-> (21,8,2,42),
-> (22,9,3,99),
-> (23,9,4,100),
-> (24,10,1,12),
-> (25,10,4,66),
-> (26,11,1,56),
-> (27,12,1,68),
-> (28,12,2,33);
Query OK, 13 rows affected (0.19 sec)
Records: 13 Duplicates: 0 Warnings: 0
mysql> insert into score values
-> (29,13,1,33),
-> (30,14,1,58),
-> (31,15,1,100);
Query OK, 3 rows affected (0.12 sec)
Records: 3 Duplicates: 0 Warnings: 0mysql> select * from class;
+-----+----------+
| cid | capiton |
+-----+----------+
| 1 | 三年二班 |
| 2 | 三年三班 |
| 3 | 一年二班 |
| 4 | 三年七班 |
+-----+----------+
mysql> select * from student;
+-----+---------+--------+----------+
| sid | sname | gender | class_id |
+-----+---------+--------+----------+
| 1 | 张三 | male | 1 |
| 2 | 李四 | male | 2 |
| 3 | 王五 | male | 3 |
| 4 | 赵六 | male | 4 |
| 5 | 钢蛋 | female | 4 |
| 6 | 铁锤 | female | 1 |
| 7 | 如花 | male | 2 |
| 8 | 锅炉 | female | 3 |
| 9 | 小乔 | female | 4 |
| 10 | 公孙离 | female | 1 |
| 11 | 沈雷锴 | male | 1 |
| 12 | xzn | male | 2 |
| 13 | cjl | male | 3 |
| 14 | xwj | male | 4 |
| 15 | egon | male | 2 |
+-----+---------+--------+----------+
mysql> select * from teacher;
+-----+--------+
| tid | tname |
+-----+--------+
| 1 | 张磊 |
| 2 | 李平 |
| 3 | 刘海燕 |
| 4 | 朱云海 |
| 5 | 李杰 |
+-----+--------+
5 rows in set (0.00 sec)
mysql> select * from course;
+-----+-------+------------+
| cid | cname | teacher_id |
+-----+-------+------------+
| 1 | 生物 | 1 |
| 2 | 物理 | 2 |
| 3 | 体育 | 3 |
| 4 | 美术 | 2 |
+-----+-------+------------+
4 rows in set (0.00 sec)
mysql> select * from score;
+-----+------------+-----------+--------+
| sid | student_id | course_id | number |
+-----+------------+-----------+--------+
| 1 | 1 | 1 | 10 |
| 2 | 1 | 2 | 9 |
| 3 | 1 | 4 | 66 |
| 4 | 2 | 1 | 8 |
| 5 | 2 | 3 | 68 |
| 6 | 2 | 4 | 88 |
| 7 | 3 | 2 | 8 |
| 8 | 3 | 3 | 55 |
| 9 | 3 | 4 | 66 |
| 10 | 4 | 1 | 6 |
| 11 | 4 | 3 | 89 |
| 12 | 4 | 4 | 96 |
| 13 | 5 | 1 | 33 |
| 14 | 5 | 2 | 34 |
| 15 | 5 | 4 | 34 |
| 16 | 6 | 1 | 44 |
| 17 | 6 | 2 | 33 |
| 18 | 7 | 3 | 66 |
| 19 | 7 | 4 | 88 |
| 20 | 8 | 1 | 78 |
| 21 | 8 | 2 | 42 |
| 22 | 9 | 3 | 99 |
| 23 | 9 | 4 | 100 |
| 24 | 10 | 1 | 12 |
| 25 | 10 | 4 | 66 |
| 26 | 11 | 1 | 56 |
| 27 | 12 | 1 | 68 |
| 28 | 12 | 2 | 33 |
| 29 | 13 | 1 | 33 |
| 30 | 14 | 1 | 58 |
| 31 | 15 | 1 | 100 |
+-----+------------+-----------+--------+
31 rows in set (0.00 sec)- 1. Query greater than 60 points all students name and student number (DISTINCT: de-emphasis)
mysql> select distinct student.sid, sname
-> from student left join score on
-> student.sid = score.student_id where
-> number > 60;
+-----+---------+
| sid | sname |
+-----+---------+
| 1 | 张三 |
| 2 | 李四 |
| 3 | 王五 |
| 4 | 赵六 |
| 7 | 如花 |
| 8 | 锅炉 |
| 9 | 小乔 |
| 10 | 公孙离 |
| 12 | xzn |
| 15 | egon |
+-----+---------+
10 rows in set (0.00 sec)- 2. Query the number of courses taught per teacher and teacher information
mysql> select tid, tname, count(tid)
-> from teacher left join course on
-> tid = teacher_id
-> group by tid;
+-----+--------+------------+
| tid | tname | count(tid) |
+-----+--------+------------+
| 1 | 张磊 | 1 |
| 2 | 李平 | 2 |
| 3 | 刘海燕 | 1 |
| 4 | 朱云海 | 1 |
| 5 | 李杰 | 1 |
+-----+--------+------------+
5 rows in set (0.13 sec)- 3. Query class student information and student information is located
mysql> select *
-> from student left join class on
-> class_id = cid;
+-----+---------+--------+----------+------+----------+
| sid | sname | gender | class_id | cid | capiton |
+-----+---------+--------+----------+------+----------+
| 1 | 张三 | male | 1 | 1 | 三年二班 |
| 6 | 铁锤 | female | 1 | 1 | 三年二班 |
| 10 | 公孙离 | female | 1 | 1 | 三年二班 |
| 11 | 沈雷锴 | male | 1 | 1 | 三年二班 |
| 2 | 李四 | male | 2 | 2 | 三年三班 |
| 7 | 如花 | male | 2 | 2 | 三年三班 |
| 12 | xzn | male | 2 | 2 | 三年三班 |
| 15 | egon | male | 2 | 2 | 三年三班 |
| 3 | 王五 | male | 3 | 3 | 一年二班 |
| 8 | 锅炉 | female | 3 | 3 | 一年二班 |
| 13 | cjl | male | 3 | 3 | 一年二班 |
| 4 | 赵六 | male | 4 | 4 | 三年七班 |
| 5 | 钢蛋 | female | 4 | 4 | 三年七班 |
| 9 | 小乔 | female | 4 | 4 | 三年七班 |
| 14 | xwj | male | 4 | 4 | 三年七班 |
+-----+---------+--------+----------+------+----------+
15 rows in set (0.12 sec)- the number of students in the number of boys and girls 4
mysql> select gender, count(gender)
-> from student
-> group by gender
-> ;
+--------+---------------+
| gender | count(gender) |
+--------+---------------+
| male | 10 |
| female | 5 |
+--------+---------------+
2 rows in set (0.00 sec)--5, get all the learning 'biological' number of students learning and achievement; Name
mysql> select student.sid, sname, number
-> from score
-> left join student on
-> score.student_id = student.sid
-> left join course on
-> score.course_id = course.cid where
-> course.cname = '生物';
+------+---------+--------+
| sid | sname | number |
+------+---------+--------+
| 1 | 张三 | 10 |
| 2 | 李四 | 8 |
| 4 | 赵六 | 6 |
| 5 | 钢蛋 | 33 |
| 6 | 铁锤 | 44 |
| 8 | 锅炉 | 78 |
| 10 | 公孙离 | 12 |
| 11 | 沈雷锴 | 56 |
| 12 | xzn | 68 |
| 13 | cjl | 33 |
| 14 | xwj | 58 |
| 15 | egon | 100 |
+------+---------+--------+
12 rows in set (0.11 sec)- 6, the query is greater than the average score of 60 points and the number of students in school grade point average;
mysql> select student.sid, avg(number)
-> from student
-> left join score on
-> student.sid = score.student_id
-> group by student.sid;
+-----+-------------+
| sid | avg(number) |
+-----+-------------+
| 1 | 28.3333 |
| 2 | 54.6667 |
| 3 | 43.0000 |
| 4 | 63.6667 |
| 5 | 33.6667 |
| 6 | 38.5000 |
| 7 | 77.0000 |
| 8 | 60.0000 |
| 9 | 99.5000 |
| 10 | 39.0000 |
| 11 | 56.0000 |
| 12 | 50.5000 |
| 13 | 33.0000 |
| 14 | 58.0000 |
| 15 | 100.0000 |
+-----+-------------+
15 rows in set (0.02 sec)--7 query teacher surnamed "Li" of the number;
mysql> select count(tname) '姓李的老师的个数'
-> from teacher
-> where tname like '李%';
+------------------+
| 姓李的老师的个数 |
+------------------+
| 2 |
+------------------+
1 row in set (0.00 sec)- 8, 60 points less than the query course grade students of school, name;
mysql> select distinct student.sid, sname
-> from student left join score on
-> student.sid = score.student_id where
-> number < 60;
+-----+---------+
| sid | sname |
+-----+---------+
| 1 | 张三 |
| 2 | 李四 |
| 3 | 王五 |
| 4 | 赵六 |
| 5 | 钢蛋 |
| 6 | 铁锤 |
| 8 | 锅炉 |
| 10 | 公孙离 |
| 11 | 沈雷锴 |
| 12 | xzn |
| 13 | cjl |
| 14 | xwj |
+-----+---------+
12 rows in set (0.00 sec)- 9. Delete learning "flat leaf" class teacher SC table records
mysql> delete from score
-> where course_id =(
-> select cid
-> from teacher
-> left join course on
-> teacher.tid = course.teacher_id
-> where tname = '叶平');
Query OK, 0 rows affected (0.00 sec)- 10. Query subjects the highest score and lowest points: Displayed in the following form: Course ID, highest score, lowest score;
mysql> select course_id '课程ID', max(number) '最高分' , min(number) '最低分'
-> from score
-> group by course_id;
+--------+--------+--------+
| 课程ID | 最高分 | 最低分 |
+--------+--------+--------+
| 1 | 100 | 6 |
| 2 | 42 | 8 |
| 3 | 99 | 55 |
| 4 | 100 | 34 |
+--------+--------+--------+
4 rows in set (0.00 sec)- 11 queries per course is elective students
mysql> select cname, count(cname)
-> from score left join course on
-> course.cid = score.course_id
-> group by cname;
+-------+--------------+
| cname | count(cname) |
+-------+--------------+
| 体育 | 5 |
| 物理 | 6 |
| 生物 | 12 |
| 美术 | 8 |
+-------+--------------+
4 rows in set (0.00 sec)- 12. Query surname "Chang" in the list of students;
mysql> select *
-> from student where
-> sname like '张%';
+-----+-------+--------+----------+
| sid | sname | gender | class_id |
+-----+-------+--------+----------+
| 1 | 张三 | male | 1 |
+-----+-------+--------+----------+
1 row in set (0.00 sec)- 13. The average scores for each query of course, results in ascending order according to the average score, average score of the same, according to the course number in descending order
mysql> select course_id, avg(number)
-> from score
-> group by course_id
-> order by avg(number),course_id desc;
+-----------+-------------+
| course_id | avg(number) |
+-----------+-------------+
| 2 | 26.5000 |
| 1 | 42.1667 |
| 3 | 75.4000 |
| 4 | 75.5000 |
+-----------+-------------+
4 rows in set (0.00 sec)- 14. Query all students grade point average of more than 85 school number, name and grade point average
mysql> select student.sid, student.sname, avg(number)
-> from student
-> left join score on
-> student.sid = score.student_id
-> group by student.sid
-> having avg(number) > 85;
+-----+-------+-------------+
| sid | sname | avg(number) |
+-----+-------+-------------+
| 9 | 小乔 | 99.5000 |
| 15 | egon | 100.0000 |
+-----+-------+-------------+
2 rows in set (0.00 sec)- No. 15. The details of the curriculum and course grade 3 students learn numbers and names of 80 points or more;
mysql> select student.sid, student.sname
-> from student
-> left join score on
-> student.sid = score.student_id
-> where
-> course_id = 3 and
-> number > 80;
+-----+-------+
| sid | sname |
+-----+-------+
| 4 | 赵六 |
| 9 | 小乔 |
+-----+-------+
2 rows in set (0.12 sec)- 16. For inquiries each elective courses and the corresponding number of
mysql> select cname, count(cname)
-> from score left join course on
-> course.cid = score.course_id
-> group by cname;
+-------+--------------+
| cname | count(cname) |
+-------+--------------+
| 体育 | 5 |
| 物理 | 6 |
| 生物 | 12 |
| 美术 | 8 |
+-------+--------------+
4 rows in set (0.00 sec)- 17. Query "4" course score less than 60, students learn numbers in descending order by score
mysql> select student.sid from
-> student left join score on
-> student.sid = score.student_id
->
-> where course_id = 4 and
-> number < 60
-> order by number desc;
+-----+
| sid |
+-----+
| 5 |
+-----+
1 row in set (0.01 sec)- 18. delete student number to score a "1" course students of "2"
mysql> delete from score
-> where course_id = 1
-> and student_id = 2;
Query OK, 1 row affected (0.04 sec)