SQL Triggers

这是个好东西，当某个表格某个字段更新，删除，增加时候，如果需要关联表格字段一起处理时，触发器就相当有用了。很久之前，前后端不区分的时候，当表格结构越来越复杂时候，对数据的操作，都要写不少的 .Net 代码来同步更新，后来发现了这个好动西，可以少写很多代码！

Sample:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER TRIGGER [dbo].[trigger_polist_updated]
on [dbo].[POList]
FOR INSERT, Update
AS
begin

declare @article_rows_updated int
    -- Should use @@rowcount below but there is a bug because of which sometimes in the presence of 
    -- other triggers on the table, the @@rowcount cannot be relied on.
    select @article_rows_updated = count(*) from inserted 

    if @article_rows_updated=0
        return

    UPDATE POlist SET updtime=SYSDATETIME() WHERE UID IN (SELECT DISTINCT UID FROM inserted)

end

SQL Triggers 触发器

SQL Triggers