触发器-----------数据库（SQL）

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create trigger tri_name
on table_name
[for （insert/update/delete）]
/[instead of （insert/update/delete）]
as
statement


create trigger 名称
on 表名for (insert update delete 其中之一)
as
语句

一

alter trigger tri_insert
on course for insert
as
declare @name nchar(5)
select @name=coursename from inserted
print '名称'+@name+'已被加入表！'

insert course
values ('007','计算机英语','004')

二

create trigger tri_delname
on course for delete
as
declare @name nchar(10)
select @name=coursename from deleted
print '名称'+@name+'已被删除出表！'

delete from course
where course_id='006'

三

create trigger tri_upname
on course for update
as
declare @oldname nchar(10)
declare @newname nchar(10)
select @oldname=coursename from deleted
select @newname=coursename from inserted
print '名称'+@oldname+'已被更新为'+@newname

update course
set coursename='计算机管理'
where course_id='007'

四

alter trigger tri_inname
on course instead of insert
as
print '名称'+@name+'未被加入表！'

insert into course
values('006','信息管理','002')

五

create trigger tri_upsc
on sc for update
 as
   declare @sid nchar(10)
   declare @cid nchar(10)
   declare @oldscore int
   declare @newscore int
   select @sid=student_id,@cid=course_id,@oldscore=score
   from deleted
   select @newscore=score from inserted
print '在'+convert(nvarchar(30),getdate())+
      @sid+'的'+@cid+'课程成绩由'+
       convert(nvarchar(3),@oldscore)+
      '改变为'+ convert(nvarchar(3),@newscore)

update sc
set score=60
where student_id='002' and course_id='003'

六

create trigger tri_insname
on teacher for insert
as
 declare @name nchar(10)
 select @name=tname from inserted
 print '教师'+@name+'插入到教师表中！'

七

create trigger tri_delname
on teacher for delete
as
   declare @name nchar(10)
 select @name=tname from deleted
 print '教师'+@name+'从教师表中删除了！'

八

create trigger tri_upname
on teacher for update
as
   declare @oldname nchar(10),@newname nchar(10)
 select @oldname=tname from deleted
 select @newname=tname from inserted
 print '教师'+@oldname+'改名为'+@newname

九

create trigger tri_upsc
on sc for update
 as
   declare @sid nchar(10)
   declare @cid nchar(10)
   declare @oldscore int
   declare @newscore int
   select @sid=sid,@cid=cid,@oldscore=score
   from deleted
   select @newscore=score from inserted
print '在'+convert(nvarchar(30),getdate())+
      @sid+'的'+@cid+'课程成绩由'+
       convert(nvarchar(3),@oldscore)+
      '改变为'+ convert(nvarchar(3),@newscore)

十

create trigger tri_inssc
on sc for insert
as
   declare @sid nchar(10)
   declare @cid nchar(10)
   declare @s int
   select @sid=sid,@cid=cid,@s=score
   from inserted
   print @sid+'的'+@cid+'课程成绩'+convert(nvarchar(3),@s)
          +'插入到成绩表中'

insert into sc
values ('004','004',100)
update sc
set score=60
where sid='002' and cid='003'

update teacher
set tname='叶问'
where tid='004'

insert into teacher
values ('005','李云松')

十一

create trigger tri_inscourse
on course for insert
as
 declare @name nchar(10)
 select @name=cname from inserted
 print '名称为：'+@name+'的课程插入到课程表中！'

insert into course
 values('006','数据库程序设计','001')

十二

create trigger tri_upcname
on course for update
as
   declare @oldname nchar(10)
   declare @newname nchar(10)
   select @oldname=cname from deleted
   select @newname=cname from inserted
   print '课程名：'+@oldname+'改名为'+@newname

update course
set cname='数据库管理'
where cid='006'

十三

create trigger tri_delname1
on course for delete
as
 declare @name nchar(10)
 select @name=cname from deleted
 print '课程'+@name+'删除了！'

delete from course
where cid='006'

十四

create trigger tri_insofname
on course instead of insert
 as
   print '当前用户无权插入数据！'

insert into course
values('006','数据库管理','001')

十五

create trigger tri_insofname1
on course instead of update
 as
   print '当前用户无权更新数据！'

update course
set cname='专业英语'
where cid='005'

create trigger tri_insertname
 on student for insert
 as
    declare @name nchar(10)
    select @name=sname from inserted
    print '学生:'+@name+'插入到学生表中！'

--执行
 insert into .....


create trigger tri_deletename
 on student for delete
 as
     declare @name nchar(10)
    select @name=sname from deleted
    print '学生:'+@name+'从学生表中删除了！'

--执行
    delete from student
    where ....

create trigger tri_updatename
on student for update
as
    declare @oldname nchar(10)
    declare @newname nchar(10)
    select @oldname=sname from deleted
    select @newname=sname from inserted
    print '学生：'+@oldname+ '更改为'+@newname

--执行
 update student
 set sname='' --新名
 where sname='' --旧名

create trigger insof_update
on student instead of update
as
   declare @sex nchar(10),@sid nchar(10)
   select @sex=ssex from inserted
   select @sid=sid from inserted
   if @sex not in ('男','女')
        print '插入值错误，请重做！'
      else
         update student
         set ssex='男'
         where sid=@sid


--执行
   update student
   set ssex='va'
   where sid=''

   update student
   set ssex='男'
   where sid=''