【牛腩新闻】——触发器

创建触发器 

-- =============================================
-- Author:		张文慧
-- Create date: 2019-1-1
-- Description:	删除类别触发器
-- =============================================
ALTER TRIGGER [dbo].[trigCategoryDelete]
   ON [dbo].[category]
   AFTER DELETE
AS 
BEGIN
	select * from deleted 
END

---

 

---

执行两个表相关联的删除 

按理说，应该是

但是，此时，不能删除，因为，触发器用的是after，是在删除category后再删除news,明显是不行的，所以，用代替

-- =============================================
-- Author:		张文慧
-- Create date: 2019-1-1
-- Description:	删除类别触发器
-- =============================================
ALTER TRIGGER [dbo].[trigCategoryDelete]
   ON [dbo].[category]
   instead of DELETE
AS 
BEGIN
	declare @id int 
	select @id=id from deleted
	delete news where caId=@id
	delete category where id=@id
END

如此，就成功了

温馨提示：写完代码后，不要忘记选择，执行哦！