创建表
1、创建学生表，分数表和课程表
create table student(
sid int(11) primary key not null,
sname char(25) not null,
age int(11) not null,
sex char(2) not null,
department char(40) ,
address char(200) ,
birthplace varchar(256)
);
create table sc(
sid int(11) not null,
cid int(11) not null,
grade int(11)
);
create table course(
cid int(11) not null primary key default 4,
cname char(40),
teacher char(40)
);
#以下是插入课程表的数据
delete from course ;
insert into course values(\'8108001\',\'math\',\'sandy\');
insert into course values(\'8108002\',\'english\',\'sherry\');
insert into course values(\'8108003\',\'computer\',\'sandy\');
insert into course values(\'8108004\',\'web\',\'sandy\');
insert into course values(\'8108005\',\'java\',\'sandy\');
insert into course values(\'8108006\',\'C languge\',\'sherry\');
insert into course values(\'8108007\',\'python\',\'xiaozhu\');
insert into course values(\'8108008\',\'testing\',\'xiaozhu\');
insert into course values(\'8108009\',\'linux\',\'sherry\');
insert into course values(\'8108010\',\'shell\',\'sherry\');
#以下是插入成绩级表的数据
delete from sc;
insert into sc values(\'3108001\',\'8108010\',\'90\');
insert into sc values(\'3108001\',\'8108003\',\'67\');
insert into sc values(\'3108002\',\'8108003\',\'54\');
insert into sc values(\'3108002\',\'8108010\',\'84\');
insert into sc values(\'3108003\',\'8108003\',\'78\');
insert into sc values(\'3108004\',\'8108004\',\'89\');
insert into sc values(\'3108005\',\'8108006\',\'56\');
insert into sc values(\'3108006\',\'8108005\',\'60\');
insert into sc values(\'3108007\',\'8108004\',\'79\');
insert into sc values(\'3108008\',\'8108008\',\'89\');
insert into sc values(\'3108009\',\'8108002\',\'46\');
insert into sc values(\'3108010\',\'8108003\',\'87\');
insert into sc values(\'3108011\',\'8108001\',\'85\');
insert into sc values(\'3108011\',\'8108002\',\'81\');
insert into sc values(\'3108012\',\'8108001\',\'97\');
insert into sc values(\'3108012\',\'8108002\',\'55\');
insert into sc values(\'3108013\',\'8108002\',\'86\');
insert into sc values(\'3108013\',\'8108001\',\'71\');
insert into sc values(\'3108014\',\'8108002\',\'69\');
insert into sc values(\'3108014\',\'8108001\',\'78\');
insert into sc values(\'3108015\',\'8108002\',\'67\');
insert into sc values(\'3108016\',\'8108001\',\'85\');
insert into sc values(\'3108016\',\'8108003\',\'85\');
insert into sc values(\'3108016\',\'8108002\',\'85\');
insert into sc values(\'3108016\',\'8108004\',\'85\');
insert into sc values(\'3108016\',\'8108005\',\'85\');
insert into sc values(\'3108016\',\'8108006\',\'80\');
insert into sc values(\'3108016\',\'8108007\',\'79\');
insert into sc values(\'3108016\',\'8108009\',\'36\');
insert into sc values(\'3108016\',\'8108010\',\'78\');
insert into sc values(\'3108016\',\'8108008\',\'88\');
insert into sc values(\'3108016\',\'8108021\',\'83\');
insert into sc values(\'3108015\',\'8108001\',\'85\');
insert into sc values(\'3108015\',\'8108003\',\'85\');
insert into sc values(\'3108015\',\'8108004\',\'85\');
insert into sc values(\'3108015\',\'8108005\',\'85\');
insert into sc values(\'3108015\',\'8108006\',\'80\');
insert into sc values(\'3108015\',\'8108007\',\'79\');
insert into sc values(\'3108015\',\'8108009\',\'36\');
insert into sc values(\'3108015\',\'8108010\',\'78\');
insert into sc values(\'3108015\',\'8108008\',\'88\');
insert into sc values(\'3108015\',\'8108021\',\'83\');
#以下是插入学生信息数据
delete from student;
insert into student values(\'3108001\',\'wang min\',21,\'f\',\'computer-tec\',\'zhongshan
road\',\'jiangsu\');
insert into student values(\'3108002\',\'jidu\',20,\'m\',\'english\',\'zhongshan road\',\'fujian\');
insert into student values(\'3108003\',\'wangqing\',19,\'f\',\'computer-tec\',\'zhongshan
road\',\'jiangsu\');
insert into student values(\'3108004\',\'liuxin\',23,\'f\',\'chinese\',\'zhongshan road\',\'shanghai\');
insert into student values(\'3108005\',\'ligu\',22,\'f\',\'computer-tec\',\'zhongshan road\',\'jiangsu\');
insert into student values(\'3108006\',\'songjia\',19,\'m\',\'english\',\'zhongshan road\',\'jiangsu\');
insert into student values(\'3108007\',\'huamao\',20,\'f\',\'chinese\',\'zhongshan road\',\'shanghai\');
insert into student values(\'3108008\',\'zhujiao\',21,\'f\',\'english\',\'zhongshan road\',\'jiangsu\');
insert into student values(\'3108009\',\'wuyi\',23,\'m\',\'computer-tec\',\'zhongshan road\',\'jiangsu\');
insert into student values(\'3108010\',\'jilian\',18,\'f\',\'chinese\',\'zhongshan road\',\'hunan\');
insert into student values(\'3108011\',\'linbiao\',22,\'m\',\'computer-tec\',\'zhongshan
road\',\'jiangsu\');
insert into student values(\'3108012\',\'maoguai\',21,\'m\',\'english\',\'zhongshan road\',\'fujian\');
insert into student values(\'3108013\',\'rongqi\',23,\'m\',\'computer-tec\',\'zhongshan
road\',\'jiangsu\');
insert into student values(\'3108014\',\'sangzi\',20,\'f\',\'chinese\',\'zhongshan road\',\'hunan\');
insert into student values(\'3108015\',\'surui\',16,\'f\',\'computer-tec\',\'zhongshan road\',\'fujian\');
insert into student values(\'3108016\',\'liushaoqi\',24,\'m\',\'english\',\'zhongshan road\',\'hunan\');
commit;
问题列表
1.sandy老师所教的课程号、课程名称；
select c.cid,cname from student s,sc,course c where s.sid=sc.sid and sc.cid=c.cid and teacher=\'sandy\';
2.年龄大于20岁的女学生的学号和姓名；
select s.sid,sname from student s where age>20 and sex=f;
3.在学生表中按性别排序，且男在前女在后显示记录。
select * from student order by sex desc;
4.“wuyi”所选修的全部课程名称；
select cname from student s,sc t,course c where s.sid=t.sid and t.cid=c.cid and sname=\'wuyi\';
5.所有成绩都在80分以上的学生姓名及所在系；
select DISTINCT sname,department from student s,sc t,course c where s.sid=t.sid and t.cid=c.cid and t.sid not in (select sid from sc where grade<80 )；
6.没有选修“english”课的学生的姓名；
select sname from student where not sid in(SELECT sid from sc where cid in(SELECT cid from
course where cname = \'english\' ))
7.与“jilian”同乡的男生姓名及所在系；
select sname,department from student where sex=\'m\' and birthplace = (select birthplace from student where sname=\'jilian\');
8.英语成绩比数学成绩好的学生;
select * from student s,(select t.sid,grade from sc t,course c,student s where c.cid=t.cid and s.sid=t.sid and cname = \'english\') a,(select t1.sid,grade from sc t1,course c1,student s1 where c1.cid=t1.cid and s1.sid=t1.sid and cname = \'math\') b where s.sid=a.sid and a.sid=b.sid and a.grade>b.grade;
9.选修同一门课程时，女生比所有男生成绩都好的学生名单；
select * from student s,sc t,student s1,sc t1 where s.sid=t.sid and s1.sid=t1.sid and s.sid=s1.sid and s.sex=\'f\'and s1.sex=\'m\' and
t.cid=t1.cid and t.grade>t1.grade;
10.至少选修两门及以上课程的学生姓名、性别；
select sname,sex from student s,sc t where s.sid=t.sid having count(t.cid)>=2
11.选修了sandy老师所讲课程的学生人数；
select count(sid) from student s where sid in (select distinct sid from sc where cid in (select cid from course where
teacher=\'sandy\'));
12.本校学生中有学生姓名/性别重复的同学，请编写脚本查出本校所有学生的信息，显示学号，姓名，性别，总成绩，对于姓名/性别重复的学生信息只取总成绩最高的那一条记录。
select s.sid,sname,sex,sum(grade) from student s,sc t where s.sid=t.sid
group by s.sid,sname;
13.“english”课程得最高分的学生姓名、性别、所在系；
select sname,sex,department from student where sid = (select sid from sc where grade =(select max(grade) from sc where cid= (select cid
from course where cname=\'english\')));