《数据库技术及应用》课程大作业-2014.

on[dbo].[borrow] for insert as

declare@BookID char(9 select@BookID=book_id from inserted update book

set book.stock=book.stock-1 where book_id=@BookID; INSERT

INTO borrow(stu_id,book_id,borrow_date,return_date VALUES('21411062','0002','2015-01-10','2015-03-10';

插入之前:

插入之后:

2、当在借书记录表中删除一条借书记录时,使图书表中相应的图书的库存量增

加1。CREATE TRIGGER borrow_delete

ON borrow FOR DELETE AS

DECLARE@BookID CHAR(10 SELECT@BookID=book_id FROM DELETED UPDATE book

SET book.stock=book.stock+1

WHERE book_id=@BookID; DELETE FROM borrow

WHERE book_id='0008';

删除前