favorite.sql

完成一个网上书店系统

USE [BookShop]
GO
/****** 对象:  Trigger [dbo].[favorite]    脚本日期: 12/14/2008 11:11:14 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
alter trigger [dbo].[favorite]
on [dbo].[OrderContent]
for insert
as
begin
--注：如果favorite没有BookID，就插不进去
if exists
	(
		select count(*) from Inserted,FavoriteBook
		where Inserted.BookID=FavoriteBook.BookID
	)
begin 
	update FavoriteBook 
	set BookCount=FavoriteBook.BookCount+Inserted.BookCount
	from FavoriteBook,Inserted
	where Inserted.BookID=FavoriteBook.BookID
end
if not exists
	(
		select count(*) from Inserted,FavoriteBook
		where Inserted.BookID=FavoriteBook.BookID
	)
begin
	insert into FavoriteBook(BookID,BookCount)
	select BookID,BookCount
	from Inserted
end
end


select * from FavoriteBook
select * from OrderContent

delete from FavoriteBook
delete from OrderContent