SQL如何通過當前日期獲取上周一日期【轉】

--當前時間 
select getdate()
--當前時間周的起始日期（以周一為例）
select DATEADD(week,DATEDIFF(week,0,getdate()),0)
--上周起始：
select dateadd(week,-1,DATEADD(week,DATEDIFF(week,0,getdate()),0))
--上上周起始：
select dateadd(week,-2,DATEADD(week,DATEDIFF(week,0,getdate()),0))
--上上上周起始：s
elect dateadd(week,-3,DATEADD(week,DATEDIFF(week,0,getdate()),0))