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', 'ebdc9031fb7c77a268d150d2ee6ee7c1', '3.17.162.140', '1714089941', '1714089941', '/redirect.php?action=product&id=11')

[XT SQL Error]