应该用 SQLite 完成

像这样;

是的，我知道，这是很容易的任务，如果我使用UDF（用户定义函数）。

但是，我对此有很大的困难。

所以，寻找另一种方式（no UDF方式）来实现我的目标。

Thanks

供你参考，

我留下了一个我未能制作UDF的链接（使用AutoHotkey）

SQLite/AutoHotkey，我对 sqlite3_result_text 返回函数的编码有问题 https://stackoverflow.com/questions/59422168/sqlite-autohotkey-i-have-problem-with-encoding-of-sqlite3-result-text-return-fu

我相信您的决议可以基于：-

WITH RECURSIVE eachchar(counter,rowid,c,rest) AS (
        SELECT 1,rowid,'',mycolumn AS rest FROM mytable
        UNION ALL 
            SELECT counter+1,rowid,substr(rest,1,1),substr(rest,2) FROM eachchar WHERE length(rest) > 0 LIMIT 100
    )
SELECT group_concat(c,'') AS mycolumn, myothercolumn, mycolumn AS original
FROM eachchar JOIN mytable ON eachchar.rowid = mytable.rowid 
WHERE length(c) > 0 
    AND (
        unicode(c) BETWEEN unicode('a') AND unicode('z') 
        OR unicode(c) BETWEEN unicode('A') AND unicode('Z')
    )
GROUP BY rowid;

Demo :-

也许考虑以下几点：-

/* Create the Test Environment */
DROP TABLE IF EXISTS mytable;
CREATE TABLE IF NOT EXISTS mytable (mycolumn TEXT, myothercolumn);
/* Add the Testing data */
INSERT INTO mytable VALUES
    ('123-abc_"D E F()[]{}~`!@#$%^&*-+=|\?><<:;''','A')
    ,('123-xyz_"X Y Z()[]{}~`!@#$%^&*-+=|\?><<:;''','B')
    ,('123-abc_"A B C()[]{}~`!@#$%^&*-+=|\?><<:;''','C')
;

/* split each character thenconcatenat only the required characters*/
WITH RECURSIVE eachchar(counter,rowid,c,rest) AS (
        SELECT 1,rowid,'',mycolumn AS rest FROM mytable
        UNION ALL 
            SELECT counter+1,rowid,substr(rest,1,1),substr(rest,2) FROM eachchar WHERE length(rest) > 0 LIMIT 100
    )
SELECT group_concat(c,'') AS mycolumn, myothercolumn, mycolumn AS original
FROM eachchar JOIN mytable ON eachchar.rowid = mytable.rowid 
WHERE length(c) > 0 
    AND (
        unicode(c) BETWEEN unicode('a') AND unicode('z') 
        OR unicode(c) BETWEEN unicode('A') AND unicode('Z')
    )
GROUP BY rowid;
/* Cleanup Test Environment */
DROP TABLE IF EXISTS mytable;

这导致：-