Function to get a Sub String after a selected character in place selectively and dynamically - sql

Question

In one of the database tables, I have a nvarchar type field that contains a series of special strings combined with some special characters. For example:
'HGHGSD_JHJSD_HGSDHGJD_GFSDGFSHDGF_GFSD'
or
'SJDGh-SUDYSUI-jhsdhsj-YTsagh-ytetyyuwte-sagd'
or
'hwerweyri~sdjhfkjhsdkjfhds~jsdfhjsdhf~mdnfsd,mfn'
Based on a formula, a sub string is always returned after the special character. But this string may be after the first, second or third place of the special character - or _ or ~. I used Charindex and Substring function in SQL server. But always only the first part of the character string after the selected character is returned. for example:
select SUBSTRING ('hwerweyri~sdjhfkjhsdkjfhds~jsdfhjsdhf~mdnfsd,mfn', 0, CHARINDEX('~', 'hwerweyri~sdjhfkjhsdkjfhds~jsdfhjsdhf~mdnfsd,mfn', 0))
returned value: hwerweyri
If there is a solution for this purpose or you have a piece of code that can work in solving this problem, please advise.
It is important to mention that the location of the special character must be entered by ourselves in the function, for example, after the third repetition or the second repetition or the tenth repetition. The method or code should be such that the location can be entered dynamically and the function does not need to be defined statically.
For Example:
'HGHGSD_JHJSD_HGSDHGJD_GFSDGFSHDGF_GFSD' ==> 3rd substring ==> 'GFSDGFSHDGF'
'HGHGSD_JHJSD_HGSDHGJD_GFSDGFSHDGF_GFSD' ==> second substring ==> 'HGSDHGJD'
'HGHGSD_JHJSD_HGSDHGJD_GFSDGFSHDGF_GFSD' ==> 1st substring ==> 'JHJSD'
And The formula will be sent to the function through a programmed form and the generated numbers will be numbers between 1 and 15. These numbers are actually the production efficiency of a product whose form is designed in C# programming language. These numbers sent to the function are variable and each time these numbers may be sent to the function and applied to the desired character string. The output should look something like the one above. I don't know if I managed to get my point across or if I managed to make my request correctly or not.

Answer 1

Try the following function:
CREATE FUNCTION [dbo].[SplitWithCte]
(
#String NVARCHAR(4000),
#Delimiter NCHAR(1),
#PlaceOfDelimiter int
)
RETURNS Table
AS
RETURN
(
WITH SplitedStrings(Ends,Endsp)
AS (
SELECT 0 AS Ends, CHARINDEX(#Delimiter,#String) AS Endsp
UNION ALL
SELECT Endsp+1, CHARINDEX(#Delimiter,#String,Endsp+1)
FROM SplitedStrings
WHERE Endsp > 0
)
SELECT f.DataStr
FROM (
SELECT 'RowId' = ROW_NUMBER() OVER (ORDER BY (SELECT 1)),
'DataStr' = SUBSTRING(#String,Ends,COALESCE(NULLIF(Endsp,0),LEN(#String)+1)-Ends)
FROM SplitedStrings
) f WHERE f.RowId = #PlaceOfDelimiter + 1
)
How to use:
select * from [dbo].[SplitWithCte](N'HGHGSD_JHJSD_HGSDHGJD_GFSDGFSHDGF_GFSD', N'_', 3)
or
select DataStr from [dbo].[SplitWithCte](N'HGHGSD_JHJSD_HGSDHGJD_GFSDGFSHDGF_GFSD', N'_', 3)
Result: GFSDGFSHDGF