CREATE TABLE student
(sno VARCHAR(3) NOT NULL,
 sname VARCHAR(4) NOT NULL,
 ssex VARCHAR(2) NOT NULL,
 sbirthday DATETIME,
 class VARCHAR(5));

CREATE TABLE course
(cno VARCHAR(5) NOT NULL,
 cname VARCHAR(10) NOT NULL,
 tno VARCHAR(10) NOT NULL);

CREATE TABLE score
(sno VARCHAR(3) NOT NULL,
 cno VARCHAR(5) NOT NULL,
 degree NUMERIC(10, 1) NOT NULL);

CREATE TABLE teacher
(tno VARCHAR(3) NOT NULL,
 tname VARCHAR(4) NOT NULL, tsex VARCHAR(2) NOT NULL,
 tbirthday DATETIME NOT NULL, prof VARCHAR(6),
 depart VARCHAR(10) NOT NULL);

INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (108 ,'曾华' ,'男' ,'1977-09-01',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (105 ,'匡明' ,'男' ,'1975-10-02',95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (107 ,'王丽' ,'女' ,'1976-01-23',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (101 ,'李军' ,'男' ,'1976-02-20',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (109 ,'王芳' ,'女' ,'1975-02-10',95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (103 ,'陆君' ,'男' ,'1974-06-03',95031);

INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-105' ,'计算机导论',825);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-245' ,'操作系统' ,804);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('6-166' ,'数据电路' ,856);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('9-888' ,'高等数学' ,100);

INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-245',86);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-245',75);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-245',68);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-105',92);INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-105',88);INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-105',76);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'3-105',64);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'3-105',91);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'3-105',78);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'6-166',85);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'6-106',79);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'6-166',81);

INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (804,'李诚','男','1958-12-02','副教授','计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (856,'张旭','男','1969-03-12','讲师','电子工程系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (825,'王萍','女','1972-05-05','助教','计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (831,'刘冰','女','1977-08-14','助教','电子工程系');

# 11、查询‘3-105’号课程的平均分。
  select AVG(score.degree),course.cno
from course join score
on score.cno = course.cno and course.cno='3-105';
# 12、查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。
select course.cname,AVG(score.degree)
from student join score
on student.sno = score.sno
join course on score.cno=course.cno
and course.cno like '3%'
group by course.cname
having count(score.cno)>= 5;
# 13、查询最低分大于70，最高分小于90的Sno列。
  select score.sno from score
group by score.sno
having MIN(score.degree) >70 and MAX(score.degree)<90;

# 14、查询所有学生的Sname、Cno和Degree列。
select student.sname,score.cno,score.degree
from student join score
on student.sno = score.sno;

# 15、查询所有学生的Sno、Cname和Degree列。
select score.sno,course.cname,score.degree
from score join course
on score.cno = course.cno;
# 16、查询所有学生的Sname、Cname和Degree列。
select student.sname,course.cname,score.degree
from student join score
on student.sno = score.sno
join course
on course.cno=score.cno;
# 17、查询“95033”班所选课程的平均分。
 select AVG(score.degree)
from score join  student
on score.sno=student.sno
and student.class = '95033';
# 18、假设使用如下命令建立了一个grade表：
create table grade(low INTEGER,upp INTEGER,rank VARCHAR(1));
insert into grade values(90,100,'A');
insert into grade values(80,89,'B');
insert into grade values(70,79,'C');
insert into grade values(60,69,'D');
insert into grade values(0,59,'E');
# commit;
# 现查询所有同学的Sno、Cno和rank列。
select score.sno,score.cno,grade.rank
from grade join score
on score.degree>grade.low and score.degree<grade.upp;
# 19、查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。
select student.* from student join score
on student.sno = score.sno
and score.cno ='3-105'and score.degree >
                          (select score.degree from score
                           where score.sno='109'and score.cno='3-105');

# 20、查询score中选学一门以上课程的同学中分数为非最高分成绩的记录。
select score.sno,score.cno,score.degree,cmax
from score inner join(
  select cno,max(degree) as cmax
  from score group by cno
 ) as mc
on score.degree < cmax and score.cno = mc.cno
where sno in(
  select sno from score
  group by sno
  having count(*) > 1
 );

# 21、查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。
select score.* from student join score
on student.sno =score.sno and
score.cno='3-105'and score.degree>
 (select score.degree from score
  where score.sno = '109'and score.cno = '3-105');
# 22、查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列。
select student.sno,sname,sbirthday from student join(
  select year(sbirthday),sno from student
  where sno ='108'
 ) as sb
on student.sno = sb.sno and student.sno !='108';
# 23、查询“张旭“教师任课的学生成绩。
select score.degree
from score join course join teacher
on score.cno=course.cno and course.tno = teacher.tno
where teacher.tname ='张旭';
# 24、查询选修某课程的同学人数多于5人的教师姓名。
select tname from teacher join course
on teacher.tno = course.tno join score
on score.cno = course.cno
group by tname
having count(score.sno)>5;

# 25、查询95033班和95031班全体学生的记录。
select * from student
where class = '95033'or '95031';
# 26、查询存在有85分以上成绩的课程Cno.
select course.cno from course join score
on course.cno = score.cno
and score.degree>85;
# 27、查询出“计算机系“教师所教课程的成绩表。
select score.* from score join course
on score.cno = course.cno join teacher
on teacher.tno = course.tno and
 teacher.depart='计算机系';
# 28、查询在“计算机系”中, 与“电子工程系“不同职称的教师的Tname和Prof。
select tname,prof from teacher
where depart ='计算机系' and prof not in (
 select teacher.prof
 from teacher
 where depart = '电子工程系');
# 29、查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。
select score.cno,sno,degree from score join course
on course.cno=score.cno
where score.cno='3-105' and degree >=
                           any  ( select score.degree
                               from score
                               where score.cno = '3-245'
                             )
order by degree desc;
# 30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree.
select score.cno,sno,degree from score join course
on score.cno=course.cno
where score.cno='3-105'and degree>= any (select score.degree from score
  where score.cno='3-245');
# 31、查询所有教师和同学的name、sex和birthday.
select student.sname,student.ssex,student.sbirthday
from student union
select teacher.tname,teacher.tsex,teacher.tbirthday
from teacher;
# 32、查询所有“女”教师和“女”同学的name、sex和birthday.
select student.sname,student.ssex,student.sbirthday from studentwhere ssex='女' unionselect teacher.tname,teacher.tsex,teacher.tbirthday from teacherwhere tsex='女';

# 33、查询成绩比该课程平均成绩低的同学的成绩表。
 select * from score as a
where a.degree <
      (select AVG(score.degree) from score
        where score.cno=a.cno );
# 34、查询所有任课教师的Tname和Depart.
 select teacher.tname,depart from teacher join course
on teacher.tno= course.tno;

# 35  查询所有未讲课的教师的Tname和Depart.
select teacher.tname,depart from teacher
where tno not in (select course.tno from course
  where course.tno=teacher.tno);
# 36、查询至少有2名男生的班号。
select student.class from student
where ssex='男'
group by class
having count(*)>=2;
# 37、查询Student表中不姓“王”的同学记录。
 select student.* from student
where sname not like '王%';
# 38、查询Student表中每个学生的姓名和年龄。
select student.sname,year(now())-year(sbirthday)
from student;
# 39、查询Student表中最大和最小的Sbirthday日期值。
select MAX(sbirthday),MIN(sbirthday) from student;

# 40、以班号和年龄从大到小的顺序查询Student表中的全部记录。
select student.* from student
order by class desc,sbirthday ;

# 41、查询“男”教师及其所上的课程。
  select teacher.*,course.cname from teacher join course
on course.tno=teacher.tno
and teacher.tsex='男';

# 42、查询最高分同学的Sno、Cno和Degree列。
 select score.sno,cno,degree from score
where degree=(select MAX(degree) from score);

# 43、查询和“李军”同性别的所有同学的Sname.
select student.sname from student
where ssex = (select ssex from student
 where sname='李军') and sname!='李军';

# 44、查询和“李军”同性别并同班的同学Sname.
select student.sname from student
where ssex=(select ssex from student
  where sname='李军') and class=(select class from student
    where sname='李军')and sname!='李军';

# 45、查询所有选修“计算机导论”课程的“男”同学的成绩表
select score.* from score join course
on score.cno = course.cno and course.cname='计算机导论'
join student
on score.sno = student.sno and student.ssex='男';