id做课程表

① 三个表 student Sid（学生ID） Sname（姓名） Sage（年龄） Ssex（性别）

select student.Sid,student.Sname
from student,课程自表,成绩表
where student.Sid=成绩表.SCSid and 成绩表.Cid=课程表.CourseCid and 课程表.CourseCid="001" or 课程表.CourseCid="002"
group by student.Sid,student.Sname
having count(*)=2;

② 3张表，课程表(课程id,课程名，分类) 学生表(学生id,学生姓名) 成绩表(学生id,课程id

select a.课程名,b.学生姓名,max(c.分数) from 课程表 a ,学生表 b ,成绩表 c where a.课程id=c.课程id and b.学生id=c.学生id

③ 三张表，学生表有id.name课程表有课程id课程name选课表有学生id课程id求显示选了两门哥的学生信息

(C，10）年龄（N，2），性别（C，2） 课程表：课程编号（C，回3），答课程名称（C，10），课时（N，4），任课教师（C，10） 选课表：学号（C，6），课程编号（C，3），成绩（N，2） 是写出完成以下操作的SQL命令：1.查询所有学生的信息 2.查询所有课程的课程名称和任课教师 3.查询出姓“李”的学生的基本信息 4.查询选课表中分数介于80分至90分之间的记录 5。求学生总数 6.查询年龄比唐洁小的所有学生的基本信息 8.在学生表中插入一条记录：学号：9000101，姓名；李丽，年龄：20 9。查询出200807号学生的姓名及其所选课程的名称 10.在学生表中增加一个“电话号码”字段（文本型（8字符））

④ 如何设置外键，有三个表，学生表（ID，学号，课程号，成绩），课程表（ID，课程号，课程名）

学生表中的学号是否唯一且必须？如果是的话，建议将ID及学号合并
课程表中的课程号是否唯一且必须？如果是的话，建议将ID及课程号合并
学生表中课程号是课程表中ID的外键，成绩表中的课程号是课程表中ID的外键，成绩表中的学号是学生表中ID的外键

⑤ 我写了一个学生表（学生id，学生名字），写了一个课程表（课程id，课程名字，学生id）

外键关联的是另一张表的主键，将本表的这个字段的值约束在关联的主键范围内。

你这个需求可以写触发器实现的

⑥ 学生表、课程表,学生课程关系表中怎么修改学生id信息

问题1:原学生表中没有学号是1的??,如果没有可以改
update student set Stuid=1 where Stuid=(select stuid from card where score=100 and cid=(select cid from course where cmane='物理')) and sname='张三'

这个表改后card 表里相专应的张三的数据就与student表里不相符属了.

delete from student where Stuid in (select stuid from card where score<60 and cid=(select cid from course where cname='英语'))
同样的删除数据后,找不到对应的student表里的

这种结构的表之间应该还有外键关联

像你这么改要乱套的

⑦ 数据库查询，有三张表学生表STU，课程表Course,SC学生课程关系表（s_id,c_id）

SELECTSTU.s_nameFROMSTU,(SELECTSC.s_idFROMSCGROUPBYs_id
HAVINGCOUNT(*)=(SELECTCOUNT(*)FROMCourse)AStmpWHERESTU.s_id=tmp.s_id

⑧ 设在学生数据库中有三张表，表结构如下所示： Student(学生表): Student表的主键：sno(学号) Course(课程

(1) create table S_C
(sno char(10) not null
,cno char(8) not null
,score int null
,constraint PK_SC primary key (sno,cno)
)
(2)insert into Student (sno,sname,ssex)
values('1010','李小丽','女')
(3)create index IND_CName on Course (cname)
(4)update student set sage=23 where sno='1005'
(5)delete from course where cname='管理信息系统'
(6)select cno,cname,ctime
from course
where teacher='李元'
order by cno ASC
(7)select sno,sum(score) as score
from S_C
group by sno
(8)create view V_Student
as
select *
from student
where ssex='男' and sage>=18 and sage<=24
(9)select sno,sname
from student
where sno in (select sno from S_C where cno='001')
(10)select A.sno,A.sname
from student A
left join S_C B on A.sno=B.sno
left join Course C on B.cno=C.cno
where C.cname='关系数据库'
(11)select sno,sname from
(select A.sno,A.sname,count(1) as count_
from student A
left join S_C B on A.sno=B.sno
group by A.sno,A.sname) A
where count_>3
(12)select C.sname
from
(select * from S_C where cno='002') A
inner join
(select * from S_C where cno='004' on) B on A.sno=B.sno
left join student C on A.sno=C.sno

⑨ SQL语句的一道题 三个基本表：学生表(Student)、课程表（Course）、学生选课表（SC）

1. select * from SC
2. select Sname，Sage from Student where Sdept = '计算机'
3. select Sno,Cno,Grade from SC where Grade >= 70 and Grade <= 80
4. select Sname,Sage from Student where Sage between 18 and 20 and Ssex = '男'
5. select top 1 Grade from SC where Cno = 'C01'
6. select max(Sage),min(Sage) from Student
7. select Sdept,sum(Sno) from Student group by Sdept
8. select course.Cname,sum(sc.Sno),max(Grade) from SC
join studet on Student.Sno = SC.Sno
join Course on Course.Cno = SC.Cno
group by course.cname,max(grade)

9. select sum(Cno),avg(Grade) from SC
join Course on Course.Cno = SC.Cno
join Student on Student.Sno= SC.Sno
order by SC.Sno

10. select Stuent.Sno，Stuent.Sname，sum(Grade) A from SC
join Student on Student.Sno = SC.Sno
group by sc.Sno,student.Sname
having A > 200

11. select Student.Sname,Student.Sdept from Student
join Course on Course.Cno = SC.Cno
join SC on SC.Sno = Student.Sno
where SC.Cno = 'C02'

12. select Student.sname,course.cno,sc.grade from sc
join student on student.sno = sc.sno
join course on course.cno = sc.cno
where sc.grade >= 80
order by sc.grade desc

13. select cno,cname from
(
select course.cno,course.cname,sun(sno) from student
join course on course.cno = sc.cno
join sc on sc.sno = student.sno
group by cno,cname
having sun(sno) > 0
)

14. ① select student.sname,student.sdept from
(
select student.sname,student.sdept,course.cname from student
join sc on sc.sno = student.sno
join course on course.cno = sc.cno
where course.cname = 'C01'
)

② select student.sno,student.sname from
(
select student.sno,student.sname,student.sdept,sc.grade from sc
join student on student.sno = sc,sno
where student.sdept = '信息' and sc.grade >= 80
)

③ select top 1 student.sname from
(
select student.sname,student.sdept,sum(sc.grade) from sc
join student on student.sno = sc.sno
where student.sdept = '计算机'
group by student.sname,student.sdept
order by
)

15. delete from sc where grade < 50
16. update sc set grade += 5 from sc
join course on course.cno = sc.cn
join student on student.sno = sc.sno
where student.sno =
(
select student.sno from sc
join course on course.cno = sc.cno
where course.cname = 'c01'
)

17. update sc set grade += 10 from sc
join student on student.sno = sc.sno
where student.sno =
(
select student.sno from student
join sc on sc.sno = student.sno
join course on course.cno = sc.cno
where student.sdept = '计算机' and course.cname = '计算机文化基础'
)

18. create view [A] as
select student.sno,student.sname,student.sdept,course.cno,course.cname,sc.grade from sc
join student on student.sno = sc.sno
join course on course.cno = sc.cno

19. create view [A] as
select student.sno,avg(sc.grade) from sc
join student on student.sno = sc.sno
group by student.sno

20. create view [A] as
select student.sno,sum(sc.grade) from sc
join student on student.sno = sc.sno
group by student.sno

21. create index A on student(sname)
22. 不会

⑩ 现有2个表： 学生表：Student表（StudentId，StudentName） 课程表(课程ID，课程名称)

select UserID,student.Name UserName,课程表名.Name Cousename
from student,课程表名