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', 'kb8n1eadv7pt70jbd9rk2ptr60', '3.148.168.26', '1746788646', '1746788646', '/shop_content.php/coID/52/product/Warum-Rauchmelder-')

[XT SQL Error]