-- 다음함수를 이용하세요.

CREATE function FN_DEC2HEX(@intVal bigint,@byte tinyint)
returns varchar(100)
begin
   declare @rHex varchar(100)
   declare @t table(id int identity(1,1) primary key, val int)

  if @intVal < 0
  set @intVal = POWER(2.000,32) + @intVal

   while(@intVal >= 16)
   begin
      insert into @t values (@intVal % 16)
      set @intVal = @intVal / 16
   end
   insert into @t values (@intVal)

 set @rHex = ''
   select @rHex = @rHex + case when val >= 10 then char(val+55) else convert(varchar(1),val) end
   from @t order by id desc
 set @rHex = '0x' +  RIGHT(REPLICATE('0',@byte * 2) + @rHex,@byte * 2)
   return (@rHex)
end

-- 테스트

select dbo.FN_DEC2HEX(1,4)