sql string split for defined number of char - sql

Question

i've a string like 'aabbcczx' and i need to split that string by 2 char.
The result expected is something like:
aabbcczx aa
aabbcczx bb
aabbcczx cc
aabbcczx zx
How can I do this?
consider also that the length of the string change row by row.
Thanks

Answer 1

If it's always 2 chars:
SELECT A.Val,
CA1.N,
SUBSTRING(A.Val,n,2)
FROM (
VALUES ('aabbcczx')
) AS A(Val)
CROSS
APPLY dbo.GetNums(1,LEN(A.Val)) AS CA1
WHERE CA1.n % 2 = 1;
GetNums is a number table/tally table generator you can find some several sources online.
It will provide the position of each character and we can use that in the substring start position. The where clause uses MOD to so we only show every other starting position

Answer 2

You can use a recursive query:
with cte as (
select convert(varchar(max), left(str, 2)) as val2, convert(varchar(max), stuff(str, 1, 2, '')) as rest, str
from (values ( 'aabbcczx' )) v(str)
union all
select left(rest, 2) as val2, stuff(rest, 1, 2, '') as rest, str
from cte
where rest <> ''
)
select str, val2
from cte;

Answer 3

You can use a recursive query to extract pairs of characters:
with instring as
( select 'aabbcczx' as s )
, splitter as
(
select s, substring(s, 1, 2) as rslt, 3 as next -- first two chars
from instring
union all
select s, substring(s, next, 2), next + 2 -- next two chars
from splitter
where len(s) >= next
)
select *
from splitter
See dbfiddle