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', '78a904f0f7f4e1607e307fbde1aaca33', '44.192.94.86', '1656318996', '1656318996', '/shop/index.php')

[XT SQL Error]