숫자 앞자리를 0으로 채우기

create function get_static_str(@num int, @size int)
returns varchar(250)
begin
 declare @i int
 declare @newNum varchar(250)
 declare @oldNum varchar(250)
 set @i = 0
 set @oldNum = cast(@num as varchar(250))
 set @newNum = ''
 
 while(@i < @size - len(@oldNum))
 begin
  set @newNum = @newNum + '0'
  set @i = @i + 1
 end

 set @newNum = @newNum + @oldNum
 return @newNum
end

--실행방법
select BoardSample.dbo.get_static_str(1234,7)