I'm using this SQL below to manually assign guest orders to registered users.
UPDATE sales_order SET customer_id = {YOUR CUSTOMER ID}, customer_is_guest = 0 where entity_id = {YOUR ORDER ID};
UPDATE sales_order_grid SET customer_id = {YOUR CUSTOMER ID} where entity_id = {YOUR ORDER ID};
UPDATE downloadable_link_purchased SET customer_id = {YOUR CUSTOMER ID} WHERE order_id = {YOUR ORDER ID};
How could I automatically assign every order made by guest users assigned to registered clients by email?