SQL Server：每月的第一个工作日

Question

如何将假日表合并到下面的SQL中？结果返回第一个工作日，但自从1/1/18是星期一假期，我需要工作日2。

DECLARE @DATE DATETIME;
SET @DATE = '1/1/2018';

SELECT 
    CASE
       WHEN DATENAME(WEEKDAY, DATEADD(mm, DATEDIFF(MM, 0, @DATE), 0)) = 'Saturday'
          THEN DATEADD(mm, DATEDIFF(MM, 0, @DATE), 0) + 2
       WHEN DATENAME(WEEKDAY, DATEADD(mm, DATEDIFF(MM, 0, @DATE), 0)) = 'Sunday'
          THEN DATEADD(mm, DATEDIFF(MM, 0, @DATE), 0) + 2
       WHEN DATENAME(WEEKDAY, DATEADD(mm, DATEDIFF(MM, 0, @DATE), 0)) = 'Monday'
          THEN DATEADD(mm, DATEDIFF(MM, 0, @DATE), 0) + 1
       ELSE DATEADD(mm, DATEDIFF(MM, 0, @DATE), 0)
   END;

Answer 1

我想这会对你有所帮助，你可以检查这个sqlscript，我给你3个不同的日期来检查正确的答案：

Declare @date date = '01/01/2018' --getdate()

SELECT CASE 
        WHEN DATENAME(WEEKDAY, dateadd(mm, DATEDIFF(MM, 0, @date), 0)) = 'Saturday'
            THEN dateadd(mm, DATEDIFF(MM, 0, getdate()), 0) + 2
        WHEN DATENAME(WEEKDAY, dateadd(mm, DATEDIFF(MM, 0, @date), 0)) = 'Sunday'
            THEN dateadd(mm, DATEDIFF(MM, 0, @date), 0) + 1
        ELSE dateadd(mm, DATEDIFF(MM, 0, @date), 0)
        END

set @date = '04/01/2018' --getdate()

SELECT CASE 
        WHEN DATENAME(WEEKDAY, dateadd(mm, DATEDIFF(MM, 0, @date), 0)) = 'Saturday'
            THEN dateadd(mm, DATEDIFF(MM, 0, getdate()), 0) + 2
        WHEN DATENAME(WEEKDAY, dateadd(mm, DATEDIFF(MM, 0, @date), 0)) = 'Sunday'
            THEN dateadd(mm, DATEDIFF(MM, 0, @date), 0) + 1
        ELSE dateadd(mm, DATEDIFF(MM, 0, @date), 0)
        END

set @date = '09/01/2018' --getdate()

SELECT CASE 
        WHEN DATENAME(WEEKDAY, dateadd(mm, DATEDIFF(MM, 0, @date), 0)) = 'Saturday'
            THEN dateadd(mm, DATEDIFF(MM, 0, getdate()), 0) + 2
        WHEN DATENAME(WEEKDAY, dateadd(mm, DATEDIFF(MM, 0, @date), 0)) = 'Sunday'
            THEN dateadd(mm, DATEDIFF(MM, 0, @date), 0) + 1
        ELSE dateadd(mm, DATEDIFF(MM, 0, @date), 0)
        END

请参考： - First business day of the current month - SQL Server