Oracle: a query, which counts occurrences of all non alphanumeric characters in a string

Question

What would be the best way to count occurrences of all non alphanumeric characters that appear in a string in an Oracle database column.

When attempting to find a solution I realised I had a query that was unrelated to the problem, but I noticed I could modify it in the hope to solve this problem. I came up with this:

SELECT  COUNT (*), SUBSTR(TITLE, REGEXP_INSTR(UPPER(TITLE), '[^A-Z,^0-9]'), 1)
FROM    TABLE_NAME
WHERE   REGEXP_LIKE(UPPER(TITLE), '[^A-Z,^0-9]')
GROUP BY    SUBSTR(TITLE, REGEXP_INSTR(UPPER(TITLE), '[^A-Z,^0-9]'), 1)
ORDER BY COUNT(*) DESC;

This works to find the FIRST non alphanumeric character, but I would like to count the occurrences throughout the entire string, not just the first occurrence. E. g. currently my query analysing "a (string)" would find one open parenthesis, but I need it to find one open parenthesis and one closed parenthesis.

Answer 1

There is an obscure Oracle TRANSLATE function that will let you do that instead of regexp:

select a.*,
       length(translate(lower(title),'.0123456789abcdefghijklmnopqrstuvwxyz','.')) 
from table_name a