declare @T table
(
ID int identity,
Data varchar(10)
)
insert into @T
select 'ABCDE' union
select '12345'
;with cte as
(
select ID,
left(Data, 1) as Data,
stuff(Data, 1, 1, '') as Rest
from @T
where len(Data) > 0
union all
select ID,
left(Rest, 1) as Data,
stuff(Rest, 1, 1, '') as Rest
from cte
where len(Rest) > 0
)
select ID,
Data
from cte
order by ID