SQL DateTime時間差轉換14碼

DateTime時間差轉換14碼
介紹如下：
8碼===========

set @dDate=(select CONVERT(char(8),getdate(), 112 ))

14碼==========

set @dDate=(select CONVERT(char(8),getdate(), 112 )+CONVERT(char(6),replace(CONVERT(char(8),getdate(), 114 ),':','')) )

14碼時間差=========

declare @dDate varchar(14)
set @dDate=CONVERT(char(8),dateadd(hour,-1,getdate()), 112 ) + replace(CONVERT(char(14),dateadd(hour,-1,getdate()), 114 ),':','')
select @dDate

String 轉Smalldatetime

substring(dDate,1,4)+'/'
+substring(dDate,5,2)+'/'
+substring(dDate,7,2)+' '
+substring(dDate,9,2)+':'
+substring(dDate,11,2)+':'
+substring(dDate,13,2)
where len(dDate)<>14