MySQL: Find all non-alphanumeric rows

What?
Quick note on how to do this.

I was tasked with cleaning up an english database by replacing all special alphabets (ë to e) and non-alphanumeric symbols with URL friendly characters.

How?

-- return all records that contain non-alphanumeric characters
SELECT * FROM myTable WHERE myColumn NOT REGEXP '^[A-Za-z0-9]+$';

-- return all records that are non-alphanumeric but ignore underscores
SELECT * FROM myTable WHERE myColumn NOT REGEXP '^[A-Za-z0-9\\_]+$';