phpmyadmin convert all empty fields to NULL

Question

is it possible to convert all empty fields in a database table to NULL.

one: without using a script to do it. meaning within myphpadmin?

if thats not possible

two: what would a script in php look like?

Thank you.

EDIT, this is after a database has already been created, with over 3000 rows.

Answer 1

UPDATE my_table
SET my_column = NULL
WHERE my_column = '';