use master
go
if exists(select name from sys.databases where name=N'Studentselect')
drop database Studentselect
go
create database Studentselect
on primary
(
name=Studentselect,
filename='E:\SQL Server 2005\Studentselect_data.mdf',
size=4mb,
maxsize=10MB,
filegrowth=1MB
)
log on
(
name=Studentselect_log,
filename='E:\SQL Server 2005\Studentselect_log.ldf',
size=1MB,
maxsize=6MB,
filegrowth=1%
)
go
create table student
(
sno char(8) primary key,
sname char(8) not null,
age int,
sex char(2),
dept varchar(50)
)
create table course
(
cno char(4) primary key,
cname char(20) not null,
credit float,
pcno varchar(20),
describe varchar(100)
)
create table SC
(
sno char(8),
cno char(4),
grade float,
primary key(sno,cno),
foreign key (sno) references student(sno),
foreign key (cno) references course(cno)
)
create table SCC
(
sno char(8),
cno char(4),
grade float,
unique(sno,cno),
foreign key (sno) references student(sno),
foreign key (cno) references course(cno)
)
create table SCCCCCC
(
sno char(8),
cno char(4),
grade float,
foreign key (sno) references student(sno),
foreign key (cno) references course(cno)
)
insert into student(sno,sname,age,sex,dept)
values('09001101','张林',18,'男','计算机系')
insert into student(sno,sname,age,sex,dept)
values('09001102','程明',18,'男','计算机系')
insert into student(sno,sname,age,sex,dept)
values('09001103','王艳',19,'女','计算机系')
insert into student(sno,sname,age,sex,dept)
values('09001104','严平平',20,'女','计算机系')
insert into student(sno,sname,age,sex,dept)
values('09001105','王洪敏',19,'女','信息管理系')
insert into student(sno,sname,age,sex,dept)
values('09001106','孙祥新',18,'男','信息管理系')
insert into student(sno,sname,age,sex,dept)
values('09001107','吕占英',19,'女','信息管理系')
insert into student(sno,sname,age,sex,dept)
values('09001108','李义',19,'男','机械工程系')
insert into student(sno,sname,age,sex,dept)
values('09001109','牟万里',18,'男','机械工程系')
insert into student(sno,sname,age,sex,dept)
values('09001110','刘丽霞',20,'女','机械工程系')
insert into course(cno,cname,credit,pcno,describe )
values ('0101','计算机基础',5,0101,'可自学')
insert into course(cno,cname,credit,pcno,describe )
values ('0102','C++程序设计',4,null,'可自学')
insert into course(cno,cname,credit,pcno,describe )
values ('0206','离散数学',4,0102,'可自学')
insert into course(cno,cname,credit,pcno,describe )
values ('0208','数据结构',4,0101,'可自学')
insert into course(cno,cname,credit,pcno,describe )
values ('0209','操作系统',4,0101,'可自学')
insert into course(cno,cname,credit,pcno,describe )
values ('0210','微机原理',5,0101,'可自学')
insert into course(cno,cname,credit,pcno,describe )
values ('0211','图形学',3,0102,'可自学')
insert into course(cno,cname,credit,pcno,describe )
values ('0212','数据库原理',4,0102,'可自学')
insert into course(cno,cname,credit,pcno,describe )
values ('0301','计算机网络',3,0102,'可自学')
insert into course(cno,cname,credit,pcno,describe )
values ('0302','软件工程',2,0102,'可自学')
insert into SC(sno,cno,grade)
values ('09001101','0101',68)
insert into SC(sno,cno,grade)
values ('09001101','0206',76)
insert into SC(sno,cno,grade)
values ('09001103','0101',62)
insert into SC(sno,cno,grade)
values ('09001106','0209',75)
insert into SC(sno,cno,grade)
values ('09001106','0210',77)
insert into SC(sno,cno,grade)
values ('09001106','0212',75)
insert into SC(sno,cno,grade)
values ('09001106','0301',87)
insert into SC(sno,cno,grade)
values ('09001108','0101',68)
insert into SC(sno,cno,grade)
values ('09001109','0212',88)
insert into SC(sno,cno,grade)
values ('09001109','0302',76)
insert into SC(sno,cno,grade)
values ('09001110','0101',66)
insert into SC(sno,cno,grade)
values('09001109','0101',88)
alter table SCCCCCC
ADD constraint sxx
unique(sno,cno)
alter table SCCCCCC
add constraint unique_cno
unique nonclustered(sno,cno)
alter table SC
add constraint sccc foreign
key (sno) references student(sno)
on delete cascade
alter table student
add constraint
age check(age>10)
alter table course
add constraint credit check(credit<8)
alter table student
add constraint sx check(sex
in('男','女'))
create default department_default as 'student'
sp_bindefault department_default, 'student.dept'
sp_unbindefault 'student.dept'
drop default department_default
alter table student
add class varchar(50)
alter table student
alter column class varchar(20)
alter table student
drop column class
alter table student
drop column sno
select cno from course where cname='离散数学'
select sno from SC where cno='0206'
select sno,sname from student where sno='09001101'
select student.sno,student.sname from student
join
SC
on SC.sno=student.sno
join
course
on course.cno=SC.cno
where course.cname='离散数学'
select student.sno,student.sname from student
join
SC
on SC.sno=student.sno and SC.cno='0101'
where
SC.grade>(select grade from SC join student on SC.sno=student.sno and SC.cno='0101'
where student.sname='张林')
select student.sno,student.sname,student.age,student.dept from student
where student.age<(select min(student.age) from student where dept='计算机系')
and
student.dept not like
'计算机系'
select student.sno,student.sname from student
join
SC
on SC.sno=student.sno
join
course
on course.cno=SC.cno and course.cname='数据库原理'
where SC.grade=(select SC.grade from SC join student on student.sno=SC.sno and student.sname='王洪敏' join course on course.cno=SC.cno and course.cname='数据库原理')
select student.sno,student.sname from student
join
SC
on SC.sno=student.sno and
SC.cno not like '0206'
select student.sno,student.sname from student
join
SC
on SC.sno=student.sno and SC.cno in(select cno from course)
select student.sno,student.sname from student where student.sno in(
)
select SC.cno from SC
group by cno
select SC.sno from SC
group by sno
select sno,count(cno) as cout from SC group by sno
select count(cno) from course
/*
select student.sno,student.sname from student
join
(select sno,count(cno) as cout from SC group by sno)
on sc.sno=student.sno
join
(select count(cno) as cout from course)
on cs.cout=sc.cout
*/
--这个例子应该说明，你从一个表中查询或者其他操作，得到一个表后，这个表就是另外一个表 用as重新命名这个表名
select student.sno,student.sname from student
join
(select sno,count(cno) as cout from SC group by sno) as sc
on sc.sno=student.sno
join
(select count(cno) as cout from course) as cs
on cs.cout=sc.cout
select student.sno,student.sname,SC.grade from student,SC
where student.sno=SC.sno and SC.cno=(select cno from course where cname='计算机基础') and SC.grade>(select avg(grade) from SC where SC.cno=(select cno from course where cname='计算机基础'))
-- 如何优化这个查询呢，让其简洁
select student.sno,student.sname,SC.grade from student
join
(select sno,cno,grade from SC where cno=(select cno from course where cname='计算机基础')) as sc
on sc.sno=student.sno and sc.grade>(select avg(sc.grade) from sc)
select SC.sno,SC.cno,SC.grade from SC where SC.cno=(select cno from course where cname='计算机基础')
select dept,count(sno) as cout from student
group by dept
order by cout desc
create view vstu_grade
as
select student.sno,student.sname,course.cname,SC.grade
from student,course,SC
where student.sno=SC.sno and SC.cno=course.cno
--过程'vstu_grade' 的请求失败，因为 'vstu_grade' 是 视图 对象。
--exec vstu_grade
create index X_dept on student(dept)
exec sp_helpindex student
drop index X_dept on student--猜的，书上P32有问题？
alter table student --不能这样写
drop index X_dept
alter table student
drop index PK_primary key_1(PK_student_7C8480AE)--删除主键有问题
--游标的作用
declare cs_cursor scroll cursor
for
select sno,sname,age,sex,dept from student order by sno
for read only
open cs_cursor
fetch from cs_cursor--会一条一条进行下去
fetch last from cs_cursor--表中最后一条记录
fetch first from cs_cursor--第一条记录
fetch prior from cs_cursor--当前行前面一行
fetch absolute 2 from cs_cursor--第二行
fetch relative 2 from cs_cursor--当前行的第二行，是一个动态的往下读取的游标
close cs_cursor
deallocate cs_cursor
select * from SC
exec proCharg '09001101'
sp_addlogin 'abc' '123'
backup database Studentselect
to disk='d:\1002\studentselect.bak'
with format
restore database Studentselect
from disk='d:\1002\studentselect.bak'
select student.sno,student.sname from student
join SC
ON SC.sno=student.sno and student.sname not like '王洪敏'
join course
on course.cno=SC.cno
where course.cname='数据库原理' and SC.grade=(select grade from SC where course.cno=SC.cno and SC.sno=(select sno from student where sname='王洪敏'))
来源：https://www.cnblogs.com/woshare/archive/2012/11/19/2776887.html