关于触发器

alter trigger [TriggerName] on [table]

for(after) insert(update delete)

as

sql语句

例：

create

alter trigger Borrow_Insert on Borrow

for insert

as

  declare @count int 

select @count=BookCount from Book

where BookId=(select BookId from inserted)

if(@count>0)

update Book Set BookCount=BookCount-1

where BookId=(select BookId from inserted)

else

rollback tran