Split and Concat String on SQL and SSIS - sql

Question

I am trying to split and concat a string.
Example: Data value1: "12abc,34efg,56hij"
Data value2: "12abc"
Expected result:
Numbers Column 1: "12,34,56"
Numbers Column 2: "12"
Alphabets Column 1: "abc,efg,hij"
Alphabets Column 2 "abc"
Several attempts made:
1.
SELECT [String], value, CONCAT(SUBSTRING(value,1,2), ',') AS Numbers, CONCAT(SUBSTRING(value,3,3), ',') AS Alphabets, LEFT(String,LEN(String)-CHARINDEX(',',String))
FROM [Test].[dbo].[TEST]
CROSS APPLY string_split([String],',') value
WHERE String = String
2.
SELECT [String], LEFT(String,LEN(String)-CHARINDEX(',',String)), LEFT(String,2) AS Numbers, RIGHT(STRING,3) AS Alphabets
FROM [Test].[dbo].[TEST]
WHERE String = String
I have followed [How to split a string after specific character in SQL Server and update this value to specific column] because I thought it was pretty similar but I did not receive the results I want so I do not know how to proceed or what I went wrong.
I am unsure of how to concatenate different columns into 1 column.
Additional info:
I am currently using SQL Server Management Studio v18.9.2.
*Apologies if my explanation is horrible.

Answer 1

Firstly, let's get to the point; your design is flawed. Never store delimited data in your database, it breaks the fundamental rules of normalisation. I strongly suggest that what you actually do here is fix your design and normalise your data.
Next, the assumptions:
You are using SQL Server 2017+
The column string can only contain alphanumerical characters (A-z, 0-9)
You are using a case insensitive collation or all characters are lowercase
If this is the case, then you can just use TRANSLATE and REPLACE to remove the characters. You'll need to create some variables (or use the tally inline) to create the replacement strings first.
So, firstly, we get the 2 variables we need, which is one containing the letters a-z, and the other with the numbers 0-9. I use a tally to achieve this:
DECLARE #Alphas varchar(26),
#Numerics varchar(10);
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL))N(N)),
Tally AS(
SELECT TOP (26)
ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS I
FROM N N1, N N2, N N3)
SELECT #Alphas = STRING_AGG(CHAR(96 + T.I),''),
#Numerics = STRING_AGG(CASE WHEN T.I <= 10 THEN CHAR(47+T.I) END,'')
FROM Tally T;
Now we can use those values to TRANSLATE all those characters to a different character (I'm going to use a pipe (|)) and the REPLACE those pipe characters with nothing:
SELECT YT.String,
REPLACE(TRANSLATE(YT.String, #Alphas,REPLICATE('|',LEN(#Alphas))),'|','') AS Numerics,
REPLACE(TRANSLATE(YT.String, #Numerics,REPLICATE('|',LEN(#Numerics))),'|','') AS Alphas
FROM dbo.YourTable YT;
Or, of course, you could just type it out. ;)
SELECT YT.String,
REPLACE(TRANSLATE(YT.String, 'abcdefghijklmnopqrstuvwxyz',REPLICATE('|',LEN('abcdefghijklmnopqrstuvwxyz'))),'|','') AS Numerics,
REPLACE(TRANSLATE(YT.String, '0123456789',REPLICATE('|',LEN('0123456789'))),'|','') AS Numerics
FROM dbo.YourTable YT;

Answer 2

You can CROSS APPLY to a STRING_SPLIT that uses STRING_AGG (since Sql Server 2017) to stick the numbers and alphabets back together.
select Numbers, Alphabets
from TEST
cross apply (
select
string_agg(left(value, patindex('%[0-9][^0-9]%', value)), ',') as Numbers
, string_agg(right(value, len(value)-patindex('%[0-9][^0-9]%', value)), ',') as Alphabets
from string_split(String, ',') s
) ca;
GO
Numbers | Alphabets
:------- | :----------
12,34,56 | abc,efg,hij
12 | abc
db<>fiddle here