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