Delete inactive Drupal users – sql query

Delete users who have no role assigned, created no content and who have not logged in in a few years:

DELETE u.* FROM users u LEFT JOIN users_roles r on u.uid = r.uid LEFT JOIN node n ON u.uid = n.uid WHERE r.rid IS NULL AND n.nid IS NULL AND u.login < 1400000000 AND u.uid > 1;
DELETE a.* FROM authmap a LEFT JOIN users u ON a.uid = u.uid WHERE u.uid IS NULL;