從日期範圍獲取星期SQL Server

Question

你好可以有人告訴我如何根據給定的日期範圍（不是按年份或月份的星期數）而是日期範圍來獲取星期否。

Eg : From Date : '6/26/2017' and To Date: '7/23/2017' 

結果

Week 1 - (6/26/2017 - 7/2/2017) 
Week 2 - (7/3/2017 - 7/10/2017) 
Week 3 - (7/11/2017 - 7/18/2017) 
Week 4 - (7/19/2017 - 7/23/2017) 

Answer 1

如果你是開放的TVF（表值函數）

我會經常使用UDF來創建動態的日期/時間範圍。它比遞歸CTE更快並且是參數驅動的。您提供日期/時間範圍，日期部分和增量。

例

Select WeekNbr = 'Week '+cast(RetSeq as varchar(10)) 
     ,WeekBeg = cast(RetVal as date) 
     ,WeekEnd = cast(RetVal+6 as date) 
From [dbo].[udf-Range-Date]('2017-06-26','2017-07-23','WK',1) 

返回

WeekNbr WeekBeg  WeekEnd 
Week 1 2017-06-26 2017-07-02 
Week 2 2017-07-03 2017-07-09 
Week 3 2017-07-10 2017-07-16 
Week 4 2017-07-17 2017-07-23 

如果有興趣

CREATE FUNCTION [dbo].[udf-Range-Date] (@R1 datetime,@R2 datetime,@Part varchar(10),@Incr int) 
Returns Table 
Return (
    with cte0(M) As (Select 1+Case @Part When 'YY' then DateDiff(YY,@R1,@R2)/@Incr When 'QQ' then DateDiff(QQ,@R1,@R2)/@Incr When 'MM' then DateDiff(MM,@R1,@R2)/@Incr When 'WK' then DateDiff(WK,@R1,@R2)/@Incr When 'DD' then DateDiff(DD,@R1,@R2)/@Incr When 'HH' then DateDiff(HH,@R1,@R2)/@Incr When 'MI' then DateDiff(MI,@R1,@R2)/@Incr When 'SS' then DateDiff(SS,@R1,@R2)/@Incr End), 
     cte1(N) As (Select 1 From (Values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N(N)), 
     cte2(N) As (Select Top (Select M from cte0) Row_Number() over (Order By (Select NULL)) From cte1 a, cte1 b, cte1 c, cte1 d, cte1 e, cte1 f, cte1 g, cte1 h), 
     cte3(N,D) As (Select 0,@R1 Union All Select N,Case @Part When 'YY' then DateAdd(YY, N*@Incr, @R1) When 'QQ' then DateAdd(QQ, N*@Incr, @R1) When 'MM' then DateAdd(MM, N*@Incr, @R1) When 'WK' then DateAdd(WK, N*@Incr, @R1) When 'DD' then DateAdd(DD, N*@Incr, @R1) When 'HH' then DateAdd(HH, N*@Incr, @R1) When 'MI' then DateAdd(MI, N*@Incr, @R1) When 'SS' then DateAdd(SS, N*@Incr, @R1) End From cte2) 

    Select RetSeq = N+1 
      ,RetVal = D 
    From cte3,cte0 
    Where D<=@R2 
) 
/* 
Max 100 million observations -- Date Parts YY QQ MM WK DD HH MI SS 
Syntax: 
Select * from [dbo].[udf-Range-Date]('2016-10-01','2020-10-01','YY',1) 
Select * from [dbo].[udf-Range-Date]('2016-01-01','2017-01-01','MM',1) 
*/