Question

Answer 1

我意识到这是一个非常古老的线索，但是＆＃34;在一周内获得第一个约会，给出周数＃34;正是我想做的事情，我没有实际的约会对象，所以接受的答案对我不起作用。我以为我会为后代发布我的解决方案。请注意，我怀疑不同的文化设置可能会破坏这一点，所以在使用前进行测试。

我的答案是从this开始构建的。

让我们假设您知道一周和一年，并且您希望获得该年该周的开始和结束日期。这就是我所拥有的：

--These 2 "declared" variables would be passed in somehow
declare @WeekNumber int = DATEPART(wk, GETDATE())
declare @ForYear int = YEAR(GETDATE())-1

--Since we don't have a raw date to work with, I figured I could just start with 
--Jan 1 of that year.  I'll store that date in a cte here, but if you are doing this
--in a stored proc or function, it would make much more sense to use another @variable
;with x as
(
    --this method works in SQL 2008:
    SELECT CONVERT(DateTime, ('1/1/' + CONVERT(varchar, @ForYear))) as Jan1ForSelectedYear
    --If you are using 2014 or higher, you can use this instead:
    --DATETIME2FROMPARTS(@ForYear, 1, 1, 0,0,0,0,0)
)
--Now that we have a date to work with, we'll just add the number of weeks to that date
--That will bring us to the right week number of the given year.
--Once we have THAT date, we can get the beginning and ending of that week
--Sorry to make you scroll, but I think this is easier to see what is going on this way
SELECT  CONVERT(varchar(50), DateAdd(wk, (@WeekNumber - 1), (DATEADD(dd, @@DATEFIRST - DATEPART(dw, x.Jan1ForSelectedYear) - 6, x.Jan1ForSelectedYear))), 101) as FirstDayOfWeekXForSelectedYear,
        CONVERT(varchar(50), DateAdd(wk, (@WeekNumber - 1), (DATEADD(dd, @@DATEFIRST - DATEPART(dw, x.Jan1ForSelectedYear)    , x.Jan1ForSelectedYear))), 101) as LastDayOfWeekXForSelectedYear
FROM x

2 个答案: