1366 - Incorrect integer value: '' for column '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', '2924a05820e3d5f81107443691b52a09', '34.239.151.124', '1718725520', '1718725520', '/shop_content.php/coID/2/content/Datenschutz')

[XT SQL Error]