課程表包括哪些欄位

1. 假設當前有課程表,課程表的結構包括(課程名,學時,學分),刪除課程表中的學時欄位

在命令窗口中輸入
alter table 課程 drop column 學時
如果提示找不到表,可以先輸入set defa to 表所在路徑
如set defa to d:\練習1
或者用菜單,選擇"文件|打開",文件類型選"表",把課程表打開,然後選擇菜單"顯示|表設計器",選中"學時",然後單擊"刪除"按鈕.

2. 一張課表的資料庫，包含哪些表和哪些欄位

看你課表的設置，一般有：序號，課程名稱，課時，授課老師，時間等

3. sql 提問 查詢選課表中同一個學生選擇多門課的學生信息,選課表有學號,姓名,課目,成績等欄位.沒有主健.

你是不是要把選擇了多門課的學生以
001 語文，數學
002 語文，數學，英語
這樣的格式查詢出來，如果只選擇一門的要不要查詢出來，如果是這樣的話，你給我留言，可以寫出來的。不過要給點分哦。

4. 使用SQI語句創建三張表（學生表，課程表和成績表）欄位分別是（學號，姓名，年齡，性別，系部，課程號

1、select 姓名 from 學生表 where 系別 = '計算機系'; 2、select 學號 from 學生選課專表 where 成績 < 60 ; 3、select 學號,成績 from 學生選課表 where 課程屬號=1; 4、select 學生表.姓名,學生選課表.課程號,學生選課表.成績 from 學生表,學生選課表 where 學生表.學號 = 學生選課表.學號; 5、select 姓名,年齡,性別 from 學生表 where 年齡 > (select 年齡 from 學生表 where name = '李明');

5. 設在學生資料庫中有三張表，表結構如下所示： Student(學生表): Student表的主鍵：sno(學號) Course(課程

(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','李小麗','女')
(3)create index IND_CName on Course (cname)
(4)update student set sage=23 where sno='1005'
(5)delete from course where cname='管理信息系統'
(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='關系資料庫'
(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

6. 用查詢語句在課程表中統計所有課程的總學時 結果只包含總學時欄位 怎麼寫

select sum(學時) as 總學時 from 課程表

7. SQL命令 「學生」資料庫中有 「學生表」、「課程表」和 「成績表」。 「學生表」中包含學號、姓名

1、首先在電腦上打開資料庫軟體。然後附加有學生表和成績表的資料庫。

8. 用SQL創建一個學生表，課程表，學生成績表

第一個表是學生表Student，包含三個欄位，學生id（_id） 和 學生姓名（stu_name）和課程id（les_id）
Create Table [dbo].Student(
stu_id [uniqueidentifier] NOT NULL,
stu_name [nvarchar](425) NOT NULL,
les_id [uniqueidentifier] NOT NULL
)
第二個表課程表Lesson，兩個欄位，課程id（les_id）和課程名稱（les_name）
Create Table [dbo].Lesson(
les_id [uniqueidentifier] NOT NULL,
les_name [nvarchar](425) NOT NULL
)
第三個表學生成績表Score,三個欄位課程id（les_id），學生id（stu_id）和課程得分（les_score）
Create Table [dbo].Score(
les_id [uniqueidentifier] NOT NULL,
stu_id [uniqueidentifier] NOT NULL,
les_score [int] NOT NULL
)

9. SQL語句的一道題 三個基本表：學生表(Student)、課程表（Course）、學生選課表（SC）

1. select * from SC
2. select Sname，Sage from Student where Sdept = '計算機'
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 = '計算機'
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 = '計算機' and course.cname = '計算機文化基礎'
)

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. 不會

10. mysql 課表表的時間段可以修改，用單獨的表來維護，欄位包括id，begin_time，end

我有books 和 info 表... books表中有 ISBN Allbooks BorrowsBooks info 表有 ISBN Userno Yesorno 當我的 Yesorno 是 YES 時就從BorrowBooks中減去1； 這個觸發器我已經寫好了。可有個問題...就是當我Yesorno為Yes時.. books表中的每列Borrowbooks都減去1.。 我的觸發器代碼如下.. CREATE TRIGGER `chu` BEFORE INSERT ON `info` FOR EACH ROW BEGIN IF new.Yesorno='Yes' then UPDATE books SET Borrowbooks=Borrowbooks-1 ; else UPDATE books SET Borrowbooks=Borrowbooks+1 ; end if; END;; 就是update後面的where語句怎麼寫？？？讓他減去的是你info表中寫的ISBN號對應books表ISBN號後面的BorrowBooks數...