1366 - Incorrect integer value: '' for column `abtecsho_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', '4q9nu0lq2ntlnlomd21p2nl1h0', '216.73.216.116', '1762008316', '1762008316', '/shop_content.php/coID/9/content/Zahlung')

[XT SQL Error]