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', '25p48d8r7r5pipgs2b446gdei1', '216.73.216.217', '1751521762', '1751521762', '/product_info.php?info=p14_800147-Ofenrohrset---fuer-alle-Daempfergroe-en-feueraluminiert.html')

[XT SQL Error]