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', 'd1364f7fc59de95c0295ca034f9a4af6', '44.200.40.97', '1711635157', '1711635157', '/product_info.php/info/p25_Sanddorn-im-Honig.html')

[XT SQL Error]