sql 学习笔记 2

--------------第6章-------------------
--上机实验题---1---Use stsc
Go 
Create View st_co_sr
As
Select Student.stno,stname,stsex,Score.cno,cname,grade from Student,Score,Course
Where Student.stno=Score.stno and Score.cno=Course.cno;
Go
Select * From st_co_sr;
--上机实验题---2---
Use stsc
Go
Create View st_computer
As 
Select stname,cname,grade from Student,Course,Score 
Where Student.stno=Score.stno and Score.cno=Course.cno and specialist=‘计算机‘;
Go
Select * from st_computer;
--上机实验题---3---
Go
Create View st_av
As
Select stname,AVG(grade) 平均分 from Student,Score
Where Student.stno=Score.stno
Group by stname;
Go
Select * from st_av;
--------------第7章-------------------
--上机实验题---1---
Use stsc
Go
--如果存在索引先删除它(没成功)
--If Exists(select object_name(object_id) tableName,name,type_desc from sys.indexes where name=‘tno‘)
--Drop Index Teacher.tno
--Else
Create Unique Clustered Index itno On Teacher(tno);--唯一聚集索引
--上机实验题---2---
Go 
Create NonClustered Index icredit On Teacher(credit);--非聚集索引
Go
Alter Index icredit
On Teacher
Rebuild
With(Pad_Index=On,FillFactor=90)
Go
--------------第8章-------------------
--上机实验题---1---
Use stsc
--Alter table Score drop constraint CK_grade
Alter Table Score
Add Constraint CK_grade check(grade between 0 and 100);
--上机实验题---2---
Use stsc
Alter Table Student
Add Constraint DF_stsex Default(‘男‘) for stsex;
--上机实验题---3---
--删除
Alter table Student 
drop constraint PK_stno;
--添加
Alter table Student 
add constraint PK_stno Primary Key(stno);
--上机实验题---4---
Alter table Score
add constraint FK_stno foreign key(stno) references Student(stno);
--上机实验题---5---(没做出来)
--Declare @credit;
--Create Rule credit_rule
--As
--@credit between 1 and 4;
--上机实验题---6---
Alter Table Teacher
add constraint school_dft Default(‘通信学院‘) for school;
--------------第9章-------------------
--上机实验题---1---
If Exists(select * from sysobjects where name=‘Score‘ and type=‘Table‘)
Drop Table Score;
--上机实验题---2---使用游标解决
Use stsc
Declare @stn char(8),@gr int,@cn char(16)
Declare CR_Rank Cursor
For (select stname,grade,cname From Student,Score,Course 
Where Student.stno=Score.stno and Score.cno=Course.cno 
group by stname,grade,cname)
Open CR_Rank
Fetch Next From CR_Rank Into @stn,@gr,@cn
print ‘姓名    分数 课程名‘
print ‘----------------------------------------------‘
While @@FETCH_STATUS=0--代表执行成功
Begin
if(@gr<60) print @stn+cast(@gr as char(8))+@cn+‘不及格‘
else if(@gr<70) print @stn+cast(@gr as char(8))+@cn+‘D‘
else if(@gr<80) print @stn+cast(@gr as char(8))+@cn+‘C‘
else if(@gr<90) print @stn+cast(@gr as char(8))+@cn+‘B‘
else print @stn+cast(@gr as char(8))+@cn+‘A‘--非字符型要转换成字符型
Fetch Next From CR_Rank Into @stn,@gr,@cn
End
Close CR_RAnk
Deallocate CR_Rank;
--上机实验题---3---
Use stsc
GO
Create Function allcourse_Avg(@_tname char(8))
Returns @tn Table
(
_tname char(8),
_cname char(16),
average float
)
As
Begin
Insert @tn
Select tname,cname,AVG(grade) From Teacher,Course,Score
Where Teacher.tno=Course.tno and Course.cno=Score.cno and tname=@_tname
Group By tname,cname,grade
Return
End
GO
Select * From allcourse_Avg(‘刘林卓‘);