USE [learn2]GO/****** Object:  Trigger [dbo].[trigger_AdClass]    Script Date: 09/30/2014 09:01:03 ******/SET ANSI_NULLS ONGOSET QUOTED_IDENTIFIER ONGO-- =============================================-- Author:        <Author,,sushine>-- Create date: <Create Date,,2014-9-29>-- Description:    <Description,,保证子父级 webpageId 关联一致；或者子级单独是可以的>-- =============================================create TRIGGER [dbo].[trigger_AdClass] on [dbo].[AdClass]   AFTER insert,updateAS BEGIN try    declare @err nvarchar(256),@classId int,@parentId int;    if(exists(select 1 from inserted))--当增加一条数据的时候和当修改parentId的时候    begin        select @classId=classId from inserted;        select @parentId=parentId from inserted;        if(@parentId is not null)        begin            update AdClass set WebPageId=(select WebPageId from AdClass where ClassId=@parentId) where AdClass.ClassId=@classId;        end    end    if(update(webpageId))--当修改webpageId的时候    begin        select @classId=classId from inserted;        update AdClass set WebPageId=i.WebPageId from inserted i where adclass.ClassId in(select ClassId from dbo.AdClassTree(@classId,null) where Depth>1);    end    --else if(update(parentId))    --begin    --    select @parentId= parentId from inserted;    --    select @classId=classId from inserted;    --    update AdClass set WebPageId=(select WebPageId from AdClass where ClassId=@parentId) where adclass.ClassId=@classId;    --endend try    begin catch    rollback;    set @err=ERROR_MESSAGE();    Raiserror(@err,16,0);end catch