如何引用外表值约束

来源:百度知道 编辑:UC知道 时间:2024/09/24 22:49:57
分别有两张表book1(书编号、书名、作者、出版社、入库时间、是否借出)和book2(书名、某书总数、某书借出总数)如何使用SQL语句实现book2中某书总数会等于book1中相同书名的数目。请高手指教!!!!!!!!11

book1中添加两个触发器:insert触发器和delete触发器
下面是insert触发器,仅作参考,希望对你有所帮助!
CREATE TRIGGER book1_insert ON dbo.book1
FOR INSERT
AS
begin
declare @li_count integer,ls_book varchar(50)
select @ls_book= book1.书名 from inserted
select @li_count = book2.某书总数 from book2
where book2.书名=@ls_book
if (@li_count >0)
update book2 set book2.某书总数 =book2.某书总数 + 1
where book2.书名=@ls_book
if (@li_count <1)
insert into book2 values(@ls_book,@li_count,0)
end