具有灵活选项的SQL Server函数中日期之间的工作日
灵活且可重复使用的SQL Server函数，它将计算两个日期之间的天数，并可以选择排除假日或周末
如果您已签出其他文章，则可能已经有了该表，如果没有，请使用下面的代码来创建它。这些基于英格兰和威尔士的标准假期。主页上提供其他国家的功能。
CREATE TABLE Dates.Calendar(CalendarDate DATETIME2 NOT NULL CONSTRAINT PK_CalendarDate PRIMARY KEY,CalendarCA AS (DATEDIFF(DAY,DATEADD(DAY,1-DATEPART(DAY,CalendarDate),CalendarDate),CalendarDate)/7)+1 PERSISTED,CalendarCD AS (DATEDIFF(DAY,CalendarDate,DATEADD(DAY,-1,DATEADD(MONTH,1,DATEADD(DAY,1-DATEPART(DAY,CalendarDate),CalendarDate))))/7)+1 PERSISTED,WeekDayID AS (DATEPART(weekday,[CalendarDate])),WeekDayName AS (case DATEPART(weekday,[CalendarDate]) when (1) then 'Sunday' when (2) then 'Monday' when (3) then 'Tuesday' when (4) then 'Wednesday' when (5) then 'Thursday' when (6) then 'Friday' when (7) then 'Saturday' end))GODECLARE @D DATETIME2='1850-01-01'WHILE @D<='2099-12-31' BEGININSERT INTO Dates.Calendar(CalendarDate) SELECT @DSET @D=DATEADD(DAY,1,@D)ENDGOCREATE TABLE Dates.CalendarHolidays(CalendarDate DATETIME2 NOT NULL,CalendarFunction INT NOT NULL,HolidayType VARCHAR(100) NULL,CONSTRAINT PK_Holidays_Id PRIMARY KEY(CalendarDate,CalendarFunction))GO/*English & Welsh Holidays*/INSERT INTO Dates.CalendarHolidaysSELECT CalendarDate,0,'New Years Day' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=1 AND DATEPART(DAY,CalendarDate)=1 UNION --New Years DaySELECT CalendarDate,0,'Good Friday' FROM Dates.Calendar WHERE CalendarDate=DATEADD(DAY,-2,Dates.GetEasterDate(DATEPART(YEAR,CalendarDate))) UNION --Good FridaySELECT CalendarDate,0,'Easter Monday' FROM Dates.Calendar WHERE CalendarDate=DATEADD(DAY,1,Dates.GetEasterDate(DATEPART(YEAR,CalendarDate))) UNION --Easter MondaySELECT CalendarDate,0,'May Holidays' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=5 AND WeekDayID=2 AND (CalendarCA=1 OR CalendarCD=1)UNION --May HolidaysSELECT CalendarDate,0,'August Holidays' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=8 AND WeekDayID=2 AND (CalendarCD=1) UNION --August HolidaysSELECT CalendarDate,0,'Christmas Day' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=12 AND DATEPART(DAY,CalendarDate)=25 UNION --Christmas DaySELECT CalendarDate,0,'Boxing Day' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=12 AND DATEPART(DAY,CalendarDate)=26 --Boxing DayGO 现在我们有了数据，我们可以创建一个从开始日期到结束日期的每天循环的函数，并根据插入的变量加1，如下所示：
- @DateFrom-计算的开始日期
- @CalendarFunction-您要使用的假期类型函数
- @DateTo-您要使用的日期范围的结束
- @AdjustMode-计算日期之间的天数，第一天为0排除或1包括。
- @AdjustWeekend-从计算中排除周末
- @AdjustHolidays-如果假期功能匹配，则排除假期
CREATE FUNCTION Dates.GetDaysAdjusted(@DateFrom DATETIME2,@CalendarFunction INT,@DateTo AS DATETIME2,@AdjustMode BIT,@AdjustWeekEnds BIT,@AdjustHolidays BIT) RETURNS INT AS BEGIN/*@AdjustMode 0=Count whole days only,1=Any day counts as 1*/IF @DateFrom>@DateTo BEGINDECLARE @T DATETIME2=@DateTo,@F DATETIME2=@DateFromSELECT @DateFrom=@T,@DateTo=@FENDDECLARE @Count AS INT=0,@DateAs DATETIME2=@DateFromWHILE @Date < @DateTo BEGINIF ((DATEPART(WEEKDAY,@Date)IN (1,7)AND @AdjustWeekEnds=1)OREXISTS (SELECT * FROM Dates.CalendarHolidays WHERE CalendarDate=@Date AND CalendarFunction=@CalendarFunctionAND @AdjustHolidays=1))BEGINSELECT @Count = @Count + 1ENDSELECT @Date=DATEADD(DAY,1,@Date)ENDRETURN (DATEDIFF(DAY,@DateFrom,@DateTo)-(@Count))+@AdjustModeENDGOSELECT Dates.GetDaysAdjusted('2014-01-01',0,'2014-01-31',1,1,1)--22SELECT Dates.GetDaysAdjusted('2014-02-01',0,'2014-02-28',1,1,1)--20SELECT Dates.GetDaysAdjusted('2014-05-01',0,'2014-05-02',1,1,1)--2SELECT Dates.GetDaysAdjusted('2014-05-01',0,'2014-05-05',1,1,1)--2SELECT Dates.GetDaysAdjusted('2014-05-01',0,'2014-05-06',1,1,1)--3