Create function F_Num(@Num numeric(18,4))
returns varchar(20)
as
begin
declare @Str varchar(20)
set @Str=RTRIM(@Num)

set @Str=left(@Str,len(@Str)-PATINDEX('%[^0]%',REVERSE(@Str))+1)
return(case when right(@Str,1)='.' then left(@Str,len(@Str)-1) else @Str end)
end

go
declare @T table (ID numeric(18,4))
insert @T select 100
insert @T select 100.12
select dbo.F_Num(ID),ID from @T