1、查询Student表中的所有记录的Sname、Ssex和Class列。
select sname,ssex,class from student;
2、查询教师所有的单位即不重复的Depart列。
select distinct depart from teacher;
3、查询Student表的所有记录。
select * from student;
4、查询Score表中成绩在60到80之间的所有记录。
select * from score where degree between 60 and 80;
5、查询Score表中成绩为85，86或88的记录。
select * from score where degree in (85,86,88);
6、查询Student表中“95031”班或性别为“女”的同学记录。
select * from student where class = 95031 or ssex = "女";
7、以Class降序查询Student表的所有记录。
select * from student order by class desc;
8、以Cno升序、Degree降序查询Score表的所有记录。
select * from score order by cno asc,degree desc;
9、查询“95031”班的学生人数。
select count(*) from student where class = 95031;
10、查询Score表中的最高分的学生学号和课程号。（子查询或者排序）
select sno,cno from score order by degree desc limit 1;
select sno,cno from score where degree = (select max(degree) from score);
11、查询每门课的平均成绩。
select cno,avg(degree) from score group by cno ;
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 cno,avg(degree) from score group by cno having cno like "3%" and count(*) >5 ;
13、查询分数大于70，小于90的Sno列。
select sno,degree from score where degree between 70 and 90;
14、查询所有学生的Sname、Cno和Degree列。
select Sname,Cno,Degree from student join score on student.sno = score.sno
15、查询所有学生的Sno、Cname和Degree列。
select Sno,Cname,Degree from score a join course b on a.cno = b.cno;
16、查询所有学生的Sname、Cname和Degree列。
select Sname,Cname,Degree from student as stu
join score as sc
join course as c on c.cno = sc.cno and stu.sno = sc.sno;
select student.sname, course.cname, score.degree from student,course,score
where course.cno=score.cno and student.sno=score.sno;
17、查询“95033”班学生的平均分。
select avg(degree) from score where sno in(
select sno from student where class = 95033
)
18、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 * from score where cno = "3-105" and
degree > (select degree from score where cno = "3-105" and sno = "109");
19、查询score中选学多门课程的同学中分数为非最高分成绩的记录。
理解1
select * from Score a where Sno in (select Sno from Score group by Sno having count(*)>1 ) and Degree not in (select max(Degree) from Score b where b.Cno = a.Cno)
理解2
select * from Score a
where Sno in (select Sno from Score group by Sno having count(*)>1 )
and Degree not in
(select max(Degree) from Score a
where Sno in (select Sno from Score group by Sno having count(*)>1 ))
20、查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。
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。
21、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 Sno,Sname,Sbirthday from student where year(Sbirthday) =
(select year(Sbirthday) from student where sno = 108) and sno != 108;
22、查询“张旭“教师任课的学生成绩（姓名）。
select tno from teacher where tname in ("张旭"); -- 825 12138
select cno from course where tno in 825; 6-166
select sno from score where cno in 6-166
23、查询考计算机导论的学生成绩
select degree from score where cno in (select cno from course where cname = "计算机导论")
26、查询李诚老师教的课程名称
select cname from course where tno = (select tno from teacher where tname="李诚")
27、教高等数学的老师是哪个系的
select depart from teacher where tno = (select tno from course where cname = "高等数学")
28、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 where tno =
(select tno from course where cno =
(select cno from score gruop by cno having count(*) > 5) )
29、查询95033班和95031班全体学生的记录。
select * from student where class in ("95031","95033");
30、查询成绩表中存在有85分以上成绩的课程Cno.
select distinct Cno from score where degree > 85
select Cno from score where degree > 85 group by cno
31、查询出“计算机系“教师所教课程的成绩表。
select * from score where cno in
(select cno from course where tno in
(select tno from teacher where depart = "计算机系"));
32、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.
条件 3-105 成绩 大于 max(3-245的成绩)
select cno,sno,degree from score where cno = "3-105" and degree >
(select max(degree) from score where cno = "3-245");
33、查询所有教师和同学的name、sex和birthday.
select sname,ssex,sbirthday from student
union
select tname,tsex,tbirthday from teacher;
34、查询所有“女”教师和“女”同学的name、sex和birthday.
select sname,ssex,sbirthday from student where ssex = "女"
union
select tname,tsex,tbirthday from teacher where tsex = "女";
35、查询所有成绩比3-105课程平均成绩低的同学的成绩表。
select * from score where degree <
(select avg(degree) from score where cno = "3-105");
36、查询所有任课教师的Tname和Depart.
select tname,depart from teacher;
37、查询所有未讲课的教师的Tname和Depart.
select distinct cno from score;
select * from course where cno not in (select distinct cno from score);831
select * from teacher where tno = 831
38、查询至少有2名男生的班号。
select ssex,count(*),group_concat(class)
from student
group by ssex,class
having ssex="男" and count(*) >1;
39、查询Student表中不姓“王”的同学记录。
select * from student where sname not like "王%";
40、查询Student表中每个学生的姓名和年龄。
select sname,year(now())-year(sbirthday) as age from student;
41、查询Student表中最大和最小的Sbirthday日期值。
select max(sbirthday),min(sbirthday) from student;
42、以班号和年龄从大到小的顺序查询Student表中的全部记录。
select *,year(now())-year(sbirthday) as age from student order by class desc,age desc
43、查询“男”教师及其所上的课程。
select * from course where tno in
(select tno from teacher where tsex = "男");
44、查询最高分同学的Sno、Cno和Degree列。
select sno,cno from score order by degree desc limit 1;
select sno,cno from score where degree = (select max(degree) from score);
45、查询和“李军”同性别的所有同学的Sname.
select * from student where ssex = ();
46、查询和“李军”同性别并同班的同学Sname.
select * from student where ssex = () and class =();
查询所有选修“计算机导论”课程的“男”同学的成绩表。
select * from score where sno in (从学生表中查男同学) and cno = (计算机导论的课程号)
select * from score where sno in (select sno from student where ssex = "男")
and cno = (select cno from course where cname= "计算机导论");