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', '6a2c4353f128fa8f4ed3397cb65af0e9', '18.221.15.15', '1714100026', '1714100026', '/index.php')

[XT SQL Error]