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SQL练习
drop table if exists `books`;
create table `books` (
`id` int(11) not null auto_increment,
`name` varchar(50) default null,
`author` varchar(20) default null,
`price` decimal(11,0) default null,
`quantity` int(11) default '0',
primary key (`id`)
) engine=innodb default charset=utf8;
-- ----------------------------
-- Records of books
-- ----------------------------
insert into `books` values ('1', '水浒', '施耐庵', '188', '3');
insert into `books` values ('2', '计算机网络', '谢希仁', '49', '3');
insert into `books` values ('3', '计算方法', '严蔚敏', '58', '3');
insert into `books` values ('4', '计算方法习题集', '殷人昆', '188', '3');
insert into `books` values ('5', '数据库技术及应用', '王珊', '38', '3');
insert into `books` values ('6', '组合数学', '周伟', '28', '3');
insert into `books` values ('7', 'Redis初探', '周旭龙', '25', '3');
-- ----------------------------
-- Table structure for borrow
-- ----------------------------
drop table if exists `borrow`;
create table `borrow` (
`pk` int(11) not null auto_increment,
`cardId` int(11) default null,
`bookId` int(11) default null,
`returnDate` timestamp null default current_timestamp,
primary key (`pk`),
unique key `pk` (`pk`)
) engine=innodb default charset=utf8;
-- ----------------------------
-- Records of borrow
-- ----------------------------
insert into `borrow` values ('4', '1', '1', '2017-02-16 00:00:00');
insert into `borrow` values ('5', '2', '1', '2017-02-16 00:00:00');
insert into `borrow` values ('6', '3', '1', '2016-12-14 11:00:44');
insert into `borrow` values ('7', '4', '3', '2016-12-14 11:00:48');
insert into `borrow` values ('8', '4', '6', '2016-12-14 11:00:53');
insert into `borrow` values ('9', '5', '6', '2016-12-14 11:00:57');
insert into `borrow` values ('10', '7', '7', '2016-12-14 11:01:01');
-- ----------------------------
-- Table structure for cards
-- ----------------------------
drop table if exists `cards`;
create table `cards` (
`id` int(11) not null auto_increment,
`name` varchar(20) default null,
`class` varchar(20) default null,
primary key (`id`)
) engine=innodb default charset=utf8;
-- ----------------------------
-- Records of cards
-- ----------------------------
insert into `cards` values ('1', '张三', '计科一班');
insert into `cards` values ('2', '李四', '计科一班');
insert into `cards` values ('3', '王五', '计科二班');
insert into `cards` values ('4', '六四', '计科二班');
insert into `cards` values ('5', '七七', '软工一班');
insert into `cards` values ('6', '粑粑', '软工二班');
-- ----------------------------
-- Table structure for course
-- ----------------------------
drop table if exists `course`;
create table `course` (
`courseNo` int(11) default null,
`name` varchar(20) default null,
`teacherNo` int(11) default null
) engine=innodb default charset=utf8;
-- ----------------------------
-- Records of course
-- ----------------------------
insert into `course` values ('1', '语文', '1');
insert into `course` values ('2', '数学', '2');
insert into `course` values ('3', '英语', '3');
insert into `course` values ('4', '物理', '4');
-- ----------------------------
-- Table structure for fruits
-- ----------------------------
drop table if exists `fruits`;
create table `fruits` (
`type` varchar(20) default null,
`variety` varchar(20) default null,
`price` double(15,3) default null
) engine=innodb default charset=utf8;
-- ----------------------------
-- Records of fruits
-- ----------------------------
insert into `fruits` values ('apple', 'gala', '2.790');
insert into `fruits` values ('apple', 'fuji', '0.240');
insert into `fruits` values ('apple', 'limbertwig', '2.870');
insert into `fruits` values ('orange', 'valencia', '3.590');
insert into `fruits` values ('orange', 'navel', '9.360');
insert into `fruits` values ('pear', 'bradford', '6.050');
insert into `fruits` values ('pear', 'bartlett', '2.140');
insert into `fruits` values ('cherry', 'bing', '2.550');
insert into `fruits` values ('cherry', 'chelan', '6.330');
-- ----------------------------
-- Table structure for score
-- ----------------------------
drop table if exists `score`;
create table `score` (
`StudentNo` int(11) default null,
`CourseNo` int(11) default null,
`score` int(11) default null
) engine=innodb default charset=utf8;
-- ----------------------------
-- Records of score
-- ----------------------------
insert into `score` values ('1', '2', '78');
insert into `score` values ('1', '3', '67');
insert into `score` values ('1', '4', '67');
insert into `score` values ('2', '1', '52');
insert into `score` values ('2', '2', '81');
insert into `score` values ('2', '3', '92');
insert into `score` values ('2', '4', '67');
insert into `score` values ('3', '1', '52');
insert into `score` values ('3', '2', '47');
insert into `score` values ('3', '3', '88');
insert into `score` values ('3', '4', '67');
insert into `score` values ('4', '2', '88');
insert into `score` values ('4', '3', '90');
insert into `score` values ('4', '4', '67');
insert into `score` values ('5', '1', '52');
insert into `score` values ('5', '3', '78');
insert into `score` values ('5', '4', '67');
insert into `score` values ('6', '1', '52');
insert into `score` values ('6', '2', '68');
insert into `score` values ('6', '4', '67');
insert into `score` values ('1', '1', '52');
insert into `score` values ('5', '2', '72');
insert into `score` values ('7', '2', '72');
-- ----------------------------
-- Table structure for student
-- ----------------------------
drop table if exists `student`;
create table `student` (
`name` varchar(32) default null,
`age` int(11) default null,
`sex` varchar(8) default null,
`studentNo` int(11) default null
) engine=innodb default charset=utf8;
-- ----------------------------
-- Records of student
-- ----------------------------
insert into `student` values ('钱二', '19', '女', '2');
insert into `student` values ('刘一', '18', '男', '1');
insert into `student` values ('张三', '17', '男', '3');
insert into `student` values ('李四', '18', '女', '4');
insert into `student` values ('王五', '17', '男', '5');
insert into `student` values ('赵6', '19', '女', '6');
insert into `student` values ('钱二', '25', '男', '7');
-- ----------------------------
-- Table structure for teacher
-- ----------------------------
drop table if exists `teacher`;
create table `teacher` (
`teacherNo` int(11) default null,
`name` varchar(20) default null
) engine=innodb default charset=utf8;
-- ----------------------------
-- Records of teacher
-- ----------------------------
insert into `teacher` values ('1', '叶平');
insert into `teacher` values ('2', '贺高');
insert into `teacher` values ('3', '杨艳');
insert into `teacher` values ('4', '叶平');
（1）查询“001”课程比“002”课程成绩低的所有学生的学号、001学科成绩、002学科成绩
#成绩表
#即选择了1号课程又选择了2号课程的学生
select s1.StudentNo,s1.score,s2.score from
(select * from score where courseNo = 1) s1
join
(select * from score where courseNo = 2) s2
on s1.studentNo = s2.studentNo
where s1.score < s2.score
（2）查询平均成绩大于60分的同学的学号和平均成绩
#成绩表
select StudentNo, avg(score)
from score
group by StudentNo
lihaving avg(score) > 60
（3）查询所有同学的学号、姓名、选课数、总成绩
#学生表 成绩表
select sc.StudentNo, st.name, count(*), sum(score)
from score sc join student st
on sc.StudentNo = st.StudentNo
group by sc.StudentNo
（4）查询姓“李”的老师的个数
#教师表
select count(*) from teacher where name like '李%'
（5）查询没学过“叶平”老师课的同学的学号、姓名
#教师表 学生表 课程表 成绩表
select studentNo,name from student where StudentNo not in(
#选择了叶平老师课程的学生编号
select StudentNo from score where courseNo in (
#查询叶平老师教了哪些课
select courseNo from course where teacherNo in (
select teacherNo from teacher where name = '叶平')
)
)
（6）查询学过“001”并且也学过编号“002”课程的同学的学号、姓名
select s1.StudentNo, s.name from
(select * from score where courseNo = 1) s1
join
(select * from score where courseNo = 2) s2
on s1.studentNo = s2.studentNo
join
student s
on s1.studentNo = s.studentNo
（7）查询学过“叶平”老师所教的所有课的同学的学号、姓名(*****)
#教师表 学生表 课程表 成绩表
#查询学生选修过的叶平老师的课程数量
#如果一个学生选修叶平老师课程的数量 = 叶平老师所教的课程数量
select s.StudentNo, s.name
from score sc
join Student s on sc.StudentNo = s.StudentNo where CourseNo in(
#查询叶平老师教了哪些课
select courseNo from course where teacherNo in(
select teacherNo from teacher where name = '叶平'))
group by sc.StudentNo having count(*) = (
#查询叶平老师教了几门课
select count(*) from course where teacherNo in(
select teacherNo from teacher where name = '叶平')
)
（8）查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名
（9）查询有课程成绩小于60分的同学的学号、姓名
#成绩表 学生表
select studentNo,name from student where studentNo in (
select distinct studentNo from score where score < 60
)
查询所有课程成绩小于60分的同学的学号、姓名
select studentNo,name from student where studentNo in (
select studentNo from score group by studentNo having max(score) < 60
)
（10）查询没有学全所有课的同学的学号、姓名
（11）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
#学生表 成绩表
select studentNo,name from student where studentNo in(
select distinct StudentNo from score where CourseNo in(
select CourseNo from score where StudentNo = 1
) and StudentNo <> 1
)
（12）查询至少学过学号为“001”同学所有门课的其他同学学号和姓名
1 - 1,2,3,4
2 - 1,2,4,5
#计算其他学生和1号学生所选相同课程的数量 = 1号学生总课程数量
#学生表 #成绩表
select * from student where studentNo in(
select s1.StudentNo from score s1 join score s2
on s1.courseNo = s2.courseNo
where s1.studentNo <> s2.studentNo and s2.studentNo = 1
group by s1.StudentNo having count(*) =
(
select count(*) from score where studentNo = 1
)
)
（13）把“score”表中“叶平”老师教的课的成绩都更改为此课程的平均成绩
update score sc set sc.score = (
select avg(s.score)
from (select * from score) s group by
s.courseNo having s.courseNo = sc.courseNo
) where sc.courseNo in (
select courseNo from course where teacherNo in(
select teacherNo from teacher where name = '叶平')
)
select avg(score) from score where courseNo = 1 #38
select avg(score) from score where courseNo = 4 #51
（14）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
#所有学生和2号学生的课程做一个连接
#每个学生和2号学生选择相同课程的数量
#2号学生选择的课程数量
#每个学生选择的课程数量
（15）删除学习“叶平”老师课的SC表记录
start transaction;
delete from score where courseNo in(
select courseNo from course where teacherNo in(
select teacherNo from teacher where name = '叶平')
)
rollback;
（16）向SC表中插入一些记录，这些记录要求符合以下条件：
1、没有上过编号“002”课程的同学学号；
2、插入“002”号课程的平均成绩
insert into score(studentNo, score)
select * from
(select studentNo from student where studentNo not in(
select studentNo from score where courseNo = 2
)) t1
join
(select avg(score) from score group by courseNo having courseNo = 2) t2
insert into 表名(xxxx) select xxxxx
create table stu2 select * from student where 1 <> 1
（17）按学号由低到高显示所有学生的“语文”、“数学”、“英语”三门的课程成绩，按如下形式显示： 学生ID,语文,数学,英语,有效课程数,有效平均分
#课程表 成绩表
select sc.StudentNo,
(select s.score from score s
join course c
on s.courseNo = c.courseNo
where c.name = '语文' and s.studentNo = sc.studentNo) as '语文',
(select s.score from score s
join course c
on s.courseNo = c.courseNo
where c.name = '数学' and s.studentNo = sc.studentNo) as '数学',
(select s.score from score s
join course c
on s.courseNo = c.courseNo
where c.name = '英语' and s.studentNo = sc.studentNo) as '英语'
from score sc group by sc.studentNo order by sc.studentNo
（18）查询各科成绩最高和最低的分：以如下形式显示：课程ID，最高分，最低分；
（19）按各科平均成绩从低到高和及格率的百分数从高到低顺序；
select sc.courseNo as '课程编号',avg(sc.score) as '平均成绩',
((select count(*) from score where score >= 60 and courseNo = sc.courseNo)/(select count(*) from score where courseNo = sc.courseNo)) as '及格率'
from score sc
group by sc.courseNo
order by
avg(sc.score) asc,
((select count(*) from score where score >= 60 and courseNo = sc.courseNo)/(select count(*) from score where courseNo = sc.courseNo)) desc
（20）查询不同老师所教不同课程平均分从高到低显示
select courseNo, avg(score) from score group by courseNo order by avg(score) desc
（21）统计列印各科成绩，各分数段人数：课程ID，课程名称，(100-85)，(85-70，(70-60)，( 低于60)
课程ID，课程名称，(100-85)，(85-70，(70-60)，( 低于60)
select sc.courseNo as '课程ID',
c.name as '课程名称',
(select count(*) from score s where s.courseNo = sc.courseNo and s.score > 85 and s.score <= 100) as '(100~85)',
(select count(*) from score s where s.courseNo = sc.courseNo and s.score > 70 and s.score <= 85) as '(85~70)',
(select count(*) from score s where s.courseNo = sc.courseNo and s.score > 60 and s.score <= 70) as '(70~60)',
(select count(*) from score s where s.courseNo = sc.courseNo and s.score <= 60) as '(<=60)'
from score sc
join course c on sc.courseNo = c.courseNo group by sc.courseNo
（22）查询各科成绩前三名的记录（不考虑成绩并列情况）
#成绩降序 limit 3
（23）查询每门课程被选修的学生数
（24）查询出只选修了一门课程的全部学生的学号和姓名
（25）查询男生、女生的人数
（26）查询同名同姓学生名单，并统计同名人数
（27）查询1991年出生的学生名单
（28）查询每门课程的平均成绩，结果按平均成绩升序排列
（29）查询平均成绩大于85的所有学生的学号、姓名和平均成绩
（30）查询课程名称为“数学”，且分数低于60的学生姓名和分数
（31）查询所有学生的选课情况
（32）查询任何一门课程成绩在70分以上的姓名、课程名称和分数
（33）查询不及格的课程，并按课程号从大到小排列
create table student (
id int primary key,
course varchar(2),
name varchar(10),
score double
);
insert into student values(1, '语文', '小明', 80);
insert into student values(2, '数学', '小明', 10);
insert into student values(3, '英语', '小明', 91);
insert into student values(4, '语文', '小红', 70);
insert into student values(5, '数学', '小红', 90);
insert into student values(6, '英语', '小红', 81);
请编写一条sql语句，查询出如下格式的数据（行转列）：
姓名 语文 数学 英语
小明 80 10 91
小红 70 90 81
select s.name as '姓名',
(select score from student where course = '语文' and name = s.name) as '语文',
(select score from student where course = '数学' and name = s.name) as '数学',
(select score from student where course = '英语' and name = s.name) as '英语'
from student s group by name
题目：
create table student (
id int primary key,
name varchar(2),
yuwen int,
shuxue int,
yingyu int
)
insert into student values(1, '小明', 10, 20, 30);
insert into student values(2, '小红', 50, 60, 70);
请编写一条sql语句，查询出如下格式的数据（列转行）：
姓名 学科 分数
小明 语文 10
小明 数学 20
小明 英语 30
小红 语文 50
小红 数学 60
小红 英语 70
select s.name as '姓名', '语文' as '学科',
(select yuwen from student where name = s.name) as '分数' from student s
union
select s.name as '姓名', '数学' as '学科',
(select shuxue from student where name = s.name) as '分数' from student s
union
select s.name as '姓名', '英语' as '学科',
(select yingyu from student where name = s.name) as '分数' from student s