/*T-SQL: 15 個與日期時間相關的自定義函數(UDF),週日作為周的最後一天,均不受 @@DateFirst、語言版本影響都是從老文章裡收集或提煉出來的!提示:(@@Datefirst + datepart(weekday,@Date)) % 7 判斷周幾是最保險的! 與 @@DateFirst 無關,與語言版本無關@@DateFirst 可能會導致 datepart(weekday,@Date) 不一樣!無論 @@DateFirst 等於幾,無論是什麼語言版本的 SQL Server 下面永遠恆成立!(@@Datefirst + datepart(weekday,@Date)): 2、3、4、5、6、0、1 分別代表 週一 到 週日-- */
create function udf_GetAge(@StartDate datetime,@EndDate datetime)returns integer-- 返回精確年齡 select dbo.udf_GetAge('1949-10-01',getdate())beginreturn datediff(year,@StartDate,@EndDate) - case when datediff(day,dateadd(year,datediff(year,@StartDate,@EndDate),@StartDate),@EndDate) >= 0 then 0 else 1 endend
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create function udf_DaysOfYearByDate(@Date datetime)RETURNS integer-- 返回年的天數 可判斷 平(365)、潤(366) 年beginreturn datediff(day,dateadd(year,datediff(year,0,@Date),0),dateadd(year,datediff(year,0,@Date )+1,0))end
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create function udf_DaysOfYear(@Year integer)RETURNS integer-- 返回年的天數 可判斷 平(365)、潤(366) 年beginreturn datediff(day,dateadd(year,@year - year(0),0),dateadd(year,@year - year(0) + 1,0))end
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create function udf_HalfDay(@Date datetime)returns datetime-- 返回 @Date 是 上午 返回 @Date 的零點,@Date 是 下午 返回 @Date 的十二點asbeginreturn case when datepart(hour,@Date) < 12 then dateadd(day,datediff(day,0,@Date),0) --上午歸到 零點 else dateadd(hour,12,dateadd(day,datediff(day,0,@Date),0)) --下午歸到 十二點 endend
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create function udf_WeekDiff(@StartDate datetime,@EndDate datetime)returns integer-- 返回 [@StartDate , @EndDate] 之間周數 週日是當周的最後一天beginreturn datediff(week,@StartDate,@EndDate) -- + 1 + case when (@@Datefirst + datepart(weekday,@StartDate)) % 7 = 1 then 1 else 0 end - case when (@@Datefirst + datepart(weekday,@EndDate)) % 7 = 1 then 1 else 0 endend
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create function udf_WeekOfMonth(@Date datetime)-- 返回 @Date 是所在月的第幾周 週日是當周的最後一天returns integerasbeginreturn datediff(week ,case when (@@Datefirst + datepart(weekday,dateadd(month,datediff(month,0,@Date),0))) % 7 = 1 then dateadd(month,datediff(month,0,@Date),0) - 1 else dateadd(month,datediff(month,0,@Date),0) end ,case when (@@Datefirst + datepart(weekday,@Date)) % 7 = 1 then @Date-1 else @Date end ) + 1end
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create function udf_WeekOfQuarter(@Date datetime)-- 返回 @Date 是所在季度的第幾周 週日是當周的最後一天returns intasbeginreturn datediff(week ,case when (@@Datefirst + datepart(weekday,dateadd(Quarter,datediff(Quarter,0,@Date),0))) % 7 = 1 then dateadd(Quarter,datediff(Quarter,0,@Date),0) - 1 else dateadd(Quarter,datediff(Quarter,0,@Date),0) end ,case when (@@Datefirst + datepart(weekday,@Date)) % 7 = 1 then @Date - 1 else @Date end ) + 1end
go
create function udf_WeekOfYear(@Date datetime)-- 返回 @Date 是所在年的第幾周 週日是當周的最後一天returns intasbeginreturn datediff(week ,case when (@@Datefirst + datepart(weekday,dateadd(day,0,datediff(day,0,dateadd(year,datediff(year,0,@Date),0))))) % 7 = 1 then dateadd(day,-1,dateadd(day,0,datediff(day,0,dateadd(year,datediff(year,0,@Date),0)))) else dateadd(day,0,datediff(day,0,dateadd(year,datediff(year,0,@Date),0))) --date 所在年的第一天 即: 一月一號 end ,case when (@@Datefirst + datepart(weekday,@Date)) % 7 = 1 then dateadd(day,-1,@Date) else @Date end ) + 1end
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create function udf_WeekDay(@ int,@Date datetime)returns datetime-- 返回 @Date 映射到 所在周的其他天 週日是當周的最後一天begin/*--週日算作(上一)周的最後一天 當 @ <= 1 代表將 @Date 映射到 所在周的星期一 當 @ = 2 代表將 @Date 映射到 所在周的星期二 當 @ = 3 代表將 @Date 映射到 所在周的星期三 當 @ = 4 代表將 @Date 映射到 所在周的星期四 當 @ = 5 代表將 @Date 映射到 所在周的星期五 當 @ = 6 代表將 @Date 映射到 所在周的星期六 當 @ >= 7 代表將 @Date 映射到 所在周的星期日 可用於按周匯總 Group by,均支持跨年跨月數據*/return dateadd(day ,case when (@@Datefirst + datepart(weekday,@Date)) % 7 = 0 --週六 then case when @ between 1 and 6 then @ - 6 else 1 end when (@@Datefirst + datepart(weekday,@Date)) % 7 = 1 --週日(七) then case when @ between 1 and 6 then @ - 7 else 0 end when (@@Datefirst + datepart(weekday,@Date)) % 7 between 2 and 6 --週一至週五 then case when @ between 1 and 6 then @ + 1 - (@@Datefirst + datepart(weekday,@Date)) % 7 else 8 - (@@Datefirst + datepart(weekday,@Date)) % 7 end end ,@Date)end
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create function udf_WeekdayDiff(@Weekday integer,@StartDate datetime,@EndDate datetime)returns integer-- -- 返回 [@StartDate , @EndDate] 之間週一 到 週日的個數 週日是當周的最後一天begin-- @Weekday: 1: Monday , ... ,7: Sundayreturn datediff(week,@StartDate,@EndDate) + case when (@@Datefirst + datepart(weekday,@StartDate)) % 7 + case when (@@Datefirst + datepart(weekday,@StartDate)) % 7 = 0 then 7 else 0 end > @Weekday % 7 + 1 then 0 else 1 end - case when (@@Datefirst + datepart(weekday,@EndDate)) % 7 + case when (@@Datefirst + datepart(weekday,@EndDate)) % 7 = 0 then 7 else 0 end >= @Weekday % 7 + 1 then 0 else 1 end/* test:
declare @b datetimedeclare @e datetime
set @b = '2004-01-29'set @e = '2004-09-05'
select @b as BeginDate ,@e as EndDate,dbo.udf_WeekdayDiff(1,@b,@e) as CountOfMonday,dbo.udf_WeekdayDiff(2,@b,@e) as CountOfTuesday,dbo.udf_WeekdayDiff(3,@b,@e) as CountOfWednesday,dbo.udf_WeekdayDiff(4,@b,@e) as CountOfThursday,dbo.udf_WeekdayDiff(5,@b,@e) as CountOfFriday,dbo.udf_WeekdayDiff(6,@b,@e) as CountOfSaturday,dbo.udf_WeekdayDiff(7,@b,@e) as CountOfSunday*/end
go
create function udf_WeekdayID(@Date datetime)returns integer-- 返回 @Date 是 Monday 返回 1, ... ,是 Sunday 返回 1begin--1: Monday , ... ,7: Sundayreturn (@@Datefirst + datepart(weekday,@Date)) % 7 + case when (@@Datefirst + datepart(weekday,@Date)) % 7 < 2 then 6 else -1 endend
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create function udf_NextWorkDate(@Date datetime)returns datetime-- 返回 @Date 的下一個工作日begin/*declare @i intset @i = 3declare @Date datetimeset @Date = '2005-01-02'-- */return case when (@@Datefirst + datepart(weekday,@Date)) % 7 = 6 -- Friday then dateadd(day,3,@Date) when (@@Datefirst + datepart(weekday,@Date)) % 7 = 0 -- saturday then dateadd(day,2,@Date) else dateadd(day,1,@Date) endend
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create function udf_PreviousWorkDate(@Date datetime)returns datetime-- 返回 @Date 的上一個工作日begin/*declare @i intset @i = 3declare @Date datetimeset @Date = '2005-01-02'-- */return case when (@@Datefirst + datepart(weekday,@Date)) % 7 = 2 -- Monday then dateadd(day,-3,@Date) when (@@Datefirst + datepart(weekday,@Date)) % 7 = 1 -- Sunday then dateadd(day,-2,@Date) else dateadd(day,-1,@Date) endend
go
create function udf_WorkDateAdd(@i integer,@Date datetime)returns datetime-- 返回 @Date 加上一段 @i 個工作日的新值begindeclare @ intset @ = 0while @ < abs(@i)begin set @Date = case when @i >= 0 then --dbo.udf_nextworkdate(@Date) case when (@@Datefirst + datepart(weekday,@Date)) % 7 = 6 -- Friday then dateadd(day,3,@Date) when (@@Datefirst + datepart(weekday,@Date)) % 7 = 0 -- saturday then dateadd(day,2,@Date) else dateadd(day,1,@Date) end else --dbo.udf_previousworkdate(@Date) case when (@@Datefirst + datepart(weekday,@Date)) % 7 = 2 -- Monday then dateadd(day,-3,@Date) when (@@Datefirst + datepart(weekday,@Date)) % 7 = 1 -- Sunday then dateadd(day,-2,@Date) else dateadd(day,-1,@Date) end end set @ = @ + 1 endreturn @Dateend
go
create function udf_GetStar (@ datetime)RETURNS varchar(100)-- 返回日期所屬星座BEGINRETURN(--declare @ datetime--set @ = getdate()select max(star)from(select '魔羯座' as star,1 as [month],1 as [day]union all select '水瓶座',1,20union all select '雙魚座',2,19union all select '牡羊座',3,21union all select '金牛座',4,20union all select '雙子座',5,21union all select '巨蟹座',6,22union all select '獅子座',7,23union all select '處女座',8,23union all select '天秤座',9,23union all select '天蠍座',10,24union all select '射手座',11,22union all select '魔羯座',12,22) starswhere dateadd(month,[month] - 1,dateadd(year,year(@) - year(0),0)) + [day] - 1 =(select max(dateadd(month,[month] - 1,dateadd(year,year(@) - year(0),0)) + [day] - 1)from (select '魔羯座' as star,1 as [month],1 as [day]union all select '水瓶座',1,20union all select '雙魚座',2,19union all select '牡羊座',3,21union all select '金牛座',4,20union all select '雙子座',5,21union all select '巨蟹座',6,22union all select '獅子座',7,23union all select '處女座',8,23union all select '天秤座',9,23union all select '天蠍座',10,24union all select '射手座',11,22union all select '魔羯座',12,22) starswhere @ >= dateadd(month,[month] - 1,dateadd(year,year(@) - year(0),0)) + [day] - 1))end
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