第六章：事务，视图和索引

最新推荐文章于 2024-07-26 20:20:10 发布

Star_Gemini

最新推荐文章于 2024-07-26 20:20:10 发布

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本文链接：https://blog.youkuaiyun.com/qq_36074093/article/details/57387498

--上机1
use MySchool
go
begin transaction
declare @errornum int
set @errornum=0
insert into Result values('23219',1,90,'2013-09-12')
set @errornum+=@@ERROR
insert into Result values('23219',1,90,'2013-09-13')
set @errornum+=@@ERROR
insert into Result values('23219',1,90,'2014-09-12')
set @errornum+=@@ERROR
insert into Result values('23219',1,90,'2013-09-11')
set @errornum+=@@ERROR
insert into Result values('23219',1,90,'2003-09-12')
set @errornum+=@@ERROR
if @errornum<>0
begin
print '操作失败,回滚事务'
rollback transaction
end
else
begin
print '操作成功,保存事务'
commit transaction
end
--上机2
go
begin transaction
declare @errornum int
set @errornum=0
select * into historyresult from Result
where StudentNo in(select StudentNo from Student
where GradeId=(select GradeId from Grade where GradeName='Y2'))
set @errornum+=@@ERROR
delete from Result
where StudentNo in(select StudentNo from Student
where GradeId=(select GradeId from Grade where GradeName='Y2'))
set @errornum+=@@ERROR
select * into historystudent from Student
where GradeId=(select GradeId from Grade where GradeName='Y2')
set @errornum+=@@ERROR
delete from Student
where GradeId=(select GradeId from Grade where GradeName='Y2')
set @errornum+=@@ERROR
if @errornum<>0
begin
print '操作失败,回滚事务'
rollback transaction
end
else
begin
print '操作成功,保存事务'
commit transaction
end
--上机3
go
CREATE VIEW vw_student_result_info
AS
SELECT 姓名=StudentName,学号=Student.StudentNo,
联系电话=Phone,学期=GradeName,成绩=Total
FROM Student
LEFT OUTER JOIN (
SELECT r.StudentNo,GradeName,SUM(StudentResult) Total
FROM Result r
INNER JOIN (
SELECT StudentNo,SubjectId,MAX(ExamDate) ExamDate
FROM Result
GROUP BY StudentNo,Subjectid) tmp
ON r.ExamDate=tmp.ExamDate
AND r.Subjectid = tmp.Subjectid AND r.StudentNo = tmp.StudentNo
INNER JOIN Subject sub ON sub.Subjectid = r.Subjectid
INNER JOIN Grade g ON g.GradeId = sub.GradeId
GROUP By r.StudentNo,GradeName ) TmpResult2
ON Student.StudentNo = TmpResult2.StudentNo
GROUP BY StudentName,Student.StudentNo,Phone,GradeName,Total
GO
SELECT * FROM vw_student_result_info
--上机4
go
create nonclustered index index_result
on result(studentresult)
select studentname,Subjectname,ExamDate,StudentResult from Result
with(index=index_result)
inner join Student on Student.StudentNo=Result.StudentNo
inner join Subject on Subject.SubjectId=Result.SubjectId
where StudentResult between 80 and 90