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', 'nesnt1h3hqb9k944jf5u6lc7v5', '216.73.216.24', '1751411571', '1751411571', '/product_info.php?info=p527_800024-Einsatz-fuer-63-Liter-Futterdaempfer--vollverzinkt-.html')

[XT SQL Error]