下面的代码返回什么？mssql服务器2012

我在钻研Somebody代码，但我不是sql方面的专家。谁能告诉我，下面的回报是什么

select DATEADD(day, DATEPART(weekday, GETDATE()) * - 1, GETDATE())

一周中的哪一天还给你

• 星期日=1
• 星期一=2

• 等等

然后：

select DATEADD(day, DATEPART(weekday, GETDATE()) * - 1, GETDATE())

星期三的例子=4

---

加上（4天*-1）到今天=今天-4天用外行的话说，这返回“上周六”。如果“今天”是星期六，它仍然返回上一个星期六之前的星期六

-- This will make it very apparent
-- Please note that the DatePart() function is language/settings dependant. So while on one server set up it may return "last Saturday", on others it may return "last Sunday"
select DATEADD(day, DATEPART(weekday, '11/01/2013') * -1, '11/01/2013')
select DATEADD(day, DATEPART(weekday, '11/02/2013') * -1, '11/02/2013')
select DATEADD(day, DATEPART(weekday, '11/03/2013') * -1, '11/03/2013')
select DATEADD(day, DATEPART(weekday, '11/04/2013') * -1, '11/04/2013')
select DATEADD(day, DATEPART(weekday, '11/05/2013') * -1, '11/05/2013')
select DATEADD(day, DATEPART(weekday, '11/06/2013') * -1, '11/06/2013')
select DATEADD(day, DATEPART(weekday, '11/07/2013') * -1, '11/07/2013')

---

答案取决于日期；）@gvee，它只是给了某人每天发布正确答案的机会！；）离题旗被误用了，太误用了，谢谢。如果你不介意的话，还有一个问题。星星做什么？（*）这是乘法。它将一个数字乘以负一，得出该数字的倒数。倒数是用来“倒数”到最后一个星期六。谢谢！这帮了大忙！请注意，该功能取决于语言/设置。因此，在一台服务器上设置时，它可能返回“上周六”，而在其他服务器上，它可能返回“上周日”。gvee，我在答案中添加了这个非常重要的注释。

-- This will make it very apparent
-- Please note that the DatePart() function is language/settings dependant. So while on one server set up it may return "last Saturday", on others it may return "last Sunday"
select DATEADD(day, DATEPART(weekday, '11/01/2013') * -1, '11/01/2013')
select DATEADD(day, DATEPART(weekday, '11/02/2013') * -1, '11/02/2013')
select DATEADD(day, DATEPART(weekday, '11/03/2013') * -1, '11/03/2013')
select DATEADD(day, DATEPART(weekday, '11/04/2013') * -1, '11/04/2013')
select DATEADD(day, DATEPART(weekday, '11/05/2013') * -1, '11/05/2013')
select DATEADD(day, DATEPART(weekday, '11/06/2013') * -1, '11/06/2013')
select DATEADD(day, DATEPART(weekday, '11/07/2013') * -1, '11/07/2013')