1366 - Incorrect integer value: '' for column 'customer_id' at row 1

insert into whos_online (customer_id, full_name, session_id, ip_address, time_entry, time_last_click, last_page_url) values ('', 'Guest', 'c51fda6db242e738da6ad8ce567de88e', '54.160.133.33', '1711633374', '1711633374', '/redirect.php?action=product&id=1')

[XT SQL Error]