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', 'ohcallcqcefdblj2rpfieno423', '216.73.216.45', '1758048541', '1758048541', '/shop_content.php/coID/7/content/Kontakt')

[XT SQL Error]