使用灵活的选项在SQL Server函数中添加最新的工作日
灵活且可重复使用的SQL Server函数，它将为日期增加若干天，并可以选择排除假日或周末
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))
GO
DECLARE @D DATETIME2='1850-01-01'
WHILE @D<='2099-12-31' BEGIN
INSERT INTO Dates.Calendar(CalendarDate) SELECT @D
SET @D=DATEADD(DAY,1,@D)
END
GO
CREATE 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.CalendarHolidays
SELECT CalendarDate,0,'New Years Day' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=1 AND DATEPART(DAY,CalendarDate)=1 UNION --New Years Day
SELECT CalendarDate,0,'Good Friday' FROM Dates.Calendar WHERE CalendarDate=DATEADD(DAY,-2,Dates.GetEasterDate(DATEPART(YEAR,CalendarDate))) UNION--Good Friday
SELECT CalendarDate,0,'Easter Monday' FROM Dates.Calendar WHERE CalendarDate=DATEADD(DAY,1,Dates.GetEasterDate(DATEPART(YEAR,CalendarDate))) UNION--Easter Monday
SELECT CalendarDate,0,'May Holidays' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=5 AND WeekDayID=2 AND (CalendarCA=1 OR CalendarCD=1)UNION--May Holidays
SELECT CalendarDate,0,'August Holidays' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=8 AND WeekDayID=2 AND (CalendarCD=1) UNION--August Holidays
SELECT CalendarDate,0,'Christmas Day' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=12 AND DATEPART(DAY,CalendarDate)=25 UNION --Christmas Day
SELECT CalendarDate,0,'Boxing Day' FROM Dates.Calendar WHERE DATEPART(MONTH,CalendarDate)=12 AND DATEPART(DAY,CalendarDate)=26 --Boxing Day
GO现在我们有了数据，我们可以创建一个从头到尾循环遍历每一天的函数，并将它添加到@Count中，而不是星期六，星期日或假期数据库中。
我们收到了一些反馈意见，认为可以使以前的功能变得灵活，并重新访问一些其他客户需求，我们对此进行了更新，增加了更多选项：
- @AdjustDate-您要更改的日期
- @CalenderFunction-您要使用的假期功能（英国的某些国家/地区具有不同的日期，因此我们可以将它们存储在不同的功能中）
- @AdjustDats-从基准日期添加或删除的天数
- @AdjustMode-0表示添加天数，1表示减去天数
- @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.GetDateAdjusted(@AdjustDate AS DATETIME2,@CalendarFunction INT,@AdjustDays AS INT,@AdjustMode BIT,@AdjustWeekEnds BIT,@AdjustHolidays BIT) RETURNS DATETIME2 AS BEGIN
SELECT @AdjustDate=DATEADD(DAY,(CASE @AdjustMode WHEN 0 THEN -1 ELSE 1 END),@AdjustDate),
@AdjustDays=(CASE @AdjustMode WHEN 0 THEN @AdjustDays+1 ELSE (0-@AdjustDays)-1 END)
DECLARE @AdjustCount INT=0,@AdjustWorkDays INT=0,@Date DATETIME2=@AdjustDate
/*Add Days*/
WHILE @AdjustMode=0 AND @AdjustWorkDays < @AdjustDays
BEGIN
SET @AdjustCount=@AdjustCount+1
SET @Date=DATEADD(DAY,@AdjustCount,@AdjustDate)
IF NOT ((DATEPART(WEEKDAY,@Date) IN (1,7) AND @AdjustWeekEnds=1)
OR
EXISTS (SELECT * FROM Dates.CalendarHolidays WHERE CalendarDate=@Date AND CalendarFunction=@CalendarFunction AND @AdjustHolidays=1))
BEGIN
SET @AdjustWorkDays = @AdjustWorkDays + 1
END
END
/*Subtract Days*/
WHILE @AdjustMode=1 AND @AdjustWorkDays > @AdjustDays
BEGIN
SET @AdjustCount=@AdjustCount-1
SET @Date=DATEADD(DAY,@AdjustCount,@AdjustDate)
IF NOT ((DATEPART(WEEKDAY,@Date) IN (1,7)AND @AdjustWeekEnds=1)
OR
EXISTS (SELECT * FROM Dates.CalendarHolidays WHERE CalendarDate=@Date AND CalendarFunction=@CalendarFunction AND @AdjustHolidays=1))
BEGIN
SET @AdjustWorkDays = @AdjustWorkDays - 1
END
END
RETURN @Date
END
GO
SELECT Dates.GetDateAdjusted('2014-05-01',0,1,0,1,1)--'2014-05-02'
SELECT Dates.GetDateAdjusted('2014-05-01',0,2,0,0,0)--'2014-05-03'
SELECT Dates.GetDateAdjusted('2014-05-01',0,2,0,1,1)--'2014-05-06'
SELECT Dates.GetDateAdjusted('2014-05-01',0,3,0,1,1)--'2014-05-07'
SELECT Dates.GetDateAdjusted('2014-05-01',0,4,0,1,1)--'2014-05-08'
SELECT Dates.GetDateAdjusted('2014-05-01',0,5,0,1,1)--'2014-05-09'
SELECT Dates.GetDateAdjusted('2014-05-01',0,6,0,1,1)--'2014-05-12'