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', '3a7271400148f1a87430f68c3403ce7a', '3.15.235.196', '1713615235', '1713615235', '/index.php')

[XT SQL Error]