是否有可能设置一周的开始了T-SQL DATEDIFF功能？

Question

我使用 DATEDIFF 功能来筛选记录仅上星期增加：

DATEDIFF(week, DateCreated, GETDATE()) = 0

和我注意到什么它假设上周日开始一周什么。但在我的情况下，我宁愿设置每周星期一开始。是否有可能以某种方式在T-SQL？

谢谢！

---

<强>更新

下面是表示什么DATEDIFF不检查 @@ DATEFIRST 变量，所以我需要另一解决方案。

SET DATEFIRST 1;

SELECT 
    DateCreated, 
    DATEDIFF(week, DateCreated, CAST('20090725' AS DATETIME)) AS D25, 
    DATEDIFF(week, DateCreated, CAST('20090726' AS DATETIME)) AS D26
FROM
(
    SELECT CAST('20090724' AS DATETIME) AS DateCreated
    UNION 
    SELECT CAST('20090725' AS DATETIME) AS DateCreated
) AS T

输出：

DateCreated             D25         D26
----------------------- ----------- -----------
2009-07-24 00:00:00.000 0           1
2009-07-25 00:00:00.000 0           1

(2 row(s) affected)

2009年7月26日是星期天，我想在DATEDIFF第三列返回0太。

Answer 1

是能够

SET DATEFIRST 1; -- Monday

这 http://msdn.microsoft.com/en-us/library /ms181598.aspx

似乎DATEDIFF不尊重DATEFIRST，所以使它做这样的运行它

create table #testDates (id int identity(1,1), dateAdded datetime)
insert into #testDates values ('2009-07-09 15:41:39.510') -- thu
insert into #testDates values ('2009-07-06 15:41:39.510') -- mon
insert into #testDates values ('2009-07-05 15:41:39.510') -- sun
insert into #testDates values ('2009-07-04 15:41:39.510') -- sat

SET DATEFIRST 7 -- Sunday (Default
select * from #testdates where datediff(ww, DATEADD(dd,-@@datefirst,dateadded), DATEADD(dd,-@@datefirst,getdate())) = 0
SET DATEFIRST 1 -- Monday
select * from #testdates where datediff(ww, DATEADD(dd,-@@datefirst,dateadded), DATEADD(dd,-@@datefirst,getdate())) = 0

这

被盗

HTTP：// social.msdn.microsoft.com/Forums/en-US/transactsql/thread/8cc3493a-7ae5-4759-ab2a-e7683165320b

Answer 2

我有另一种解决方案。 这应该是比较容易理解，纠正我，如果我错了

SET DATEFIRST 1
select DATEDIFF(week, 0, DATEADD(day, -@@DATEFIRST, '2018-04-15 00:00:00.000'))

我们从日期减去“-1”和周日将成为周六（这是一周的7nth日） 和Mondфy（2）将一周的第一天