WooCommerce - delete users with customer role and no orders (likely spam accounts)

delete_bad_usermeta.sql

/* Delete usermeta that nas no related user in users */
DELETE FROM wp_usermeta WHERE wp_usermeta.user_id NOT IN (SELECT ID FROM wp_users);

delete_customers.sql

/**
 * 1. MAKE A BACKUP FIRST!!!!
 * 2. DO A PREFLIGHT - USE SELECT * (not DELETE wp_users.*)
 */
DELETE wp_users.* FROM wp_users
INNER JOIN wp_usermeta
ON wp_users.ID = wp_usermeta.user_id
WHERE wp_usermeta.meta_key = 'wp_capabilities'
AND wp_usermeta.meta_value = 'a:1:{s:8:"customer";b:1;}'
AND wp_users.ID not in (
	SELECT meta_value FROM wp_postmeta WHERE meta_key = '_customer_user'
) AND wp_users.ID not in (
	select distinct(post_author) from wp_posts
);