如何在視圖中使datepart（）函數接受星期一作為一周的第一天

Question

對於一個Web應用程序，我創建了以下視圖：

alter view [dbo].[vwBookingData] 
as
    select concat(rtrim(ltrim(str(datepart(year, bookingdata.booking_datetime)))), '-', rtrim(ltrim(str(datepart(week, bookingdata.booking_datetime))))) as  WeekNumber, 
           bookingdata.booking_customerCode as ClientCode, customer.Name as ClientName, concat(bookingdata.booking_provider, concat('-', bookingdata.booking_system)) as ProviderCombo,
           bookingdata.segments_carrierCode as CarrierCode, bookingdata.booking_datetime as BookingDate, bookingdata.booking_bookingId, flgConfirmed, flgFailed
    from dbo.flights_bookingdata bookingdata
         inner join dbo.Customer on Customer.Number = bookingdata.booking_customerCode

我的問題是所用查詢的1個特定部分：

datepart(week, bookingdata.booking_datetime)

我已經注意到datepart（）似乎需要在周日開始而不是在星期一開始，這打破了視圖應該生成的概述。

有沒有辦法可以在查詢本身中解決此問題？

Answer 1

也許您可以嘗試（我首先是1而不是2）

SET DATEFIRST 1;

在查詢的頂部

SET DATEFIRST 7;  -- The Default
Select *
      ,WeedDay=DateName(DW,RetVal)
      ,WeekNo=DatePart(WK,RetVal) 
 From [dbo].[udf-Range-Date]('2016-10-01','2016-10-14','DD',1)

而

SET DATEFIRST 1;
Select *
      ,WeedDay=DateName(DW,RetVal)
      ,WeekNo=DatePart(WK,RetVal) 
 From [dbo].[udf-Range-Date]('2016-10-01','2016-10-14','DD',1)

Answer 2

看到您無法使用SET DATEFIRST選項，我將在調用DATEPART函數時從日期時間中減去一天，如下所示：

DATEPART(WEEK, DATEADD(DAY, -1, bookingdata.booking_datetime))

Answer 3

使用此功能，您可以從星期一開始以任何服務器語言或DATEFIRST設置返回星期幾：

-- =============================================
-- Author:      Javier Cañon
-- Create date: 2019-04-23
-- Description: Return day of week without know of server SET DATEFIRST setting
-- =============================================
CREATE FUNCTION [dbo].[fnGetWeekDayFromMonday]
(
    -- Add the parameters for the function here
    @SomeDate DATE
)
RETURNS int
AS
BEGIN

DECLARE @SqlWeekDay INT, @ResultVar int;

    SET  @SqlWeekDay= DATEPART(dw, @SomeDate);
    SET @ResultVar = ((@SqlWeekDay + @@DATEFIRST - 1 - 1) % 7) + 1;

    -- Return the result of the function
    RETURN @ResultVar;

END
GO