1. 插入数据前判断数据是否存在

SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
-- ============================================= 
-- Author: <Author,,Name> 
-- Create date: <Create Date,,> 
-- Description: <Description,,> 
-- ============================================= 
alter TRIGGER CategoryExistTrigger 
ON ProductCategory 
instead of insert 
AS 

declare @categoryName varchar(50); 
BEGIN 
-- SET NOCOUNT ON added to prevent extra result sets from 
-- interfering with SELECT statements. 
SET NOCOUNT ON; 

-- Insert statements for trigger here 
select @categoryName = CategoryName from inserted; 
if exists(select * from ProductCategory where CategoryName =@categoryName) 
begin 
print 'Category exists..' 
end; 
else 
begin 
insert into ProductCategory select * from inserted; 
end; 

END

2. 删除表中数据时需要先删除外键表的数据

SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
-- ============================================= 
-- Author: <Author,,Name> 
-- Create date: <Create Date,,> 
-- Description: <Description,,> 
-- ============================================= 
alter TRIGGER DeleteOrderTrigger 
ON OrderHeader 
instead of delete 
AS 
declare @OrderId varchar(50); 
BEGIN 

SET NOCOUNT ON; 
select @OrderId = OrderId from deleted; 
delete from OrderLine where OrderId = @OrderId; 

END 
GO
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!