发布时间 : 星期日 文章《数据库技术及应用》课程大作业-2014.更新完毕开始阅读2f37944ffd4ffe4733687e21af45b307e871f9fd
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