How to iterate over a string in one line in SQL - sql

Question

I am writing a query that roughly has this structure:
SELECT Name, <calculated-valued> as Version FROM <tables>
This calculated value needs to work like so: I have a varchar column 'Name' that could contain something like 'ABC' and I want to convert each letter into ASCII, and append them back together to form '65.66.67' in this example. (An empty string should return '0') Is there any way to do this?
My approach wasn't very good, but up to 5 characters I could do the following:
SELECT
CASE WHEN LEN(Name) = 0 THEN '0'
ELSE CAST(ASCII(SUBSTRING(Name, 1, 1)) as varchar(max)) +
CASE WHEN LEN(Name) = 1 THEN ''
ELSE '.' + CAST(ASCII(SUBSTRING(Name, 2, 1)) as varchar(max)) +
CASE WHEN LEN(Name) = 2 THEN ''
ELSE '.' + CAST(ASCII(SUBSTRING(Name, 3, 1)) as varchar(max)) +
CASE WHEN LEN(Name) = 3 THEN ''
ELSE '.' + CAST(ASCII(SUBSTRING(Name, 4, 1)) as varchar(max)) +
CASE WHEN LEN(Name) = 4 THEN ''
ELSE '.' + CAST(ASCII(SUBSTRING(Name, 5, 1)) as varchar(max))
END
END
END
END
END AS MyColumn
FROM <tables>
Is there a better way to do this? Ideally a method that can take any length of string?
Either that or can I cast letters into a hierarchyid datatype? I need to create things like 1/2/a/bc/4// or whatever, but hierarchyid doesn't support that. So instead I'm trying to convert it to 1/2/97/98.99/4/0 so I can convert and maintain the correct order. This column is only used for sorting.
Thanks for any help!

Answer 1

One method is a recursive CTE:
with cte as (
select Name, 1 as lev
cast(ascii(substring(name, 1, 1)) as varchar(max)) as ascii_name
from t
union all
select Name, lev + 1,
ascii_name + '.' + cast(ascii(substring(name, lev + 1, 1)) as varchar(max))
from cte
where len(Name) > lev
)
select Name, ascii_name
from cte;

Answer 2

Another option is with an ad-hoc tally table and a CROSS APPLY
Declare #YourTable table (Name varchar(25))
Insert Into #YourTable values
('ABC'),
('Jack'),
('Jill'),
('')
Select A.Name
,Version = isnull(B.String,'0')
From #YourTable A
Cross Apply (
Select String=Stuff((Select '.' +cast(S as varchar(5))
From (Select Top (len(A.Name))
S=ASCII(substring(A.Name,Row_Number() Over (Order By (Select NULL)),1))
From master..spt_values ) S
For XML Path ('')),1,1,'')
) B
Returns
Name String
ABC 65.66.67
Jack 74.97.99.107
Jill 74.105.108.108
0