SQL 创建随机时间的函数

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go

ALTER function [dbo].[fn_Randtime]   
(  
 @begin_date datetime,  --開始時間
 @end_date datetime     --結束時間
)  
returns Datetime  
as  
begin  
  
declare @second varchar(50)  
declare @Holiday int
declare @Holiday2 int
if @begin_date is null  
 SET @begin_date=DateAdd(month,-1,cast((convert(varchar(7),getdate(),121)+'-01 08:01:01') as datetime));  
if @end_date is null  
 SET @end_date=DateAdd(month,-1,cast((convert(varchar(7),getdate(),121)+'-28 17:30:00') as datetime));  
SET @second = DATEDIFF ( second , @begin_date,@end_date)  
  
declare @d1 datetime  
declare @rand float 
declare @SunHoliDay int
declare @Extended datetime 
declare @MaxHoliDay datetime
 
select @rand=re from v_RAND 
set @d1 =dateadd(second,@rand*@second,@begin_date)
Select @HoliDay=Count(Holiday) From Topmixdata.dbo.HolidayCalendar Where Holiday=convert(varchar(10),@d1,120) And Status=0 

--除去假日順延時間
Select @SunHoliDay=Count(Holiday) From Topmixdata.dbo.HolidayCalendar where Convert(varchar(7),Holiday,120)=Convert(varchar(7),@begin_date,120) And datepart(weekday,Holiday)=1
if @SunHoliDay>0
begin
SELECT @MaxHoliDay=dateadd(DAY,1,Max(Holiday)) FROM Topmixdata.dbo.HolidayCalendar where Convert(varchar(7),Holiday,120)=Convert(varchar(7),@begin_date,120)
Set @Extended=@MaxHoliDay
end

--除去假日時間
while @HoliDay>0 OR datepart(weekday,@d1)=1 OR datepart(weekday,@d1)=7 OR (Convert(varchar(10),@d1,120)=Convert(varchar(10),@Extended,120))
begin
    select @rand=re from v_RAND 
    set @d1 =dateadd(second,@rand*@second,@begin_date)
    Select @HoliDay2=Count(Holiday) From Topmixdata.dbo.HolidayCalendar Where Holiday=convert(varchar(10),@d1,120) And Status=0 
    set @HoliDay=@HoliDay2
end

--if datepart(weekday,@d1)=1
--begin
--  set @d1=dateadd(dd,2,@d1)
--end
--if datepart(weekday,@d1)=7
--begin
--    if datepart(dd,@d1)=1
--    set @d1=dateadd(dd,2,@d1)
--    else
--    set @d1=dateadd(dd,-1,@d1)
--end

if datepart(hour,@d1) >17
begin  
  set @d1=dateadd(hour,-8,@d1)
end  
if datepart(hour,@d1) <8  
begin  
  set @d1=dateadd(hour,8,@d1)     
end  
if datepart(hour,@d1)>11 and datepart(hour,@d1)<14
begin
  set @d1=dateadd(hour,-2,@d1)
end
if datepart(hour,@d1)=17 and datepart(mi,@d1)>30
begin
  set @d1=dateadd(mi,-30,@d1)
end

return @d1  
end