1366 - Incorrect integer value: '' for column `hbl_shop`.`whos_online`.`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', 'fo0a1nvv4rk9e7ubcmgrg68vd5', '3.15.223.232', '1748720548', '1748720548', '/product_info.php?info=p17_800208-Heizspirale-fuer-26-Liter-Elektrofutterdaempfer.html')

[XT SQL Error]