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', '2sq8158a5h31l5qa95cj09s9o6', '3.84.182.112', '1555937767', '1555937767', '/lkw_plane_tasche_lkw_plane/newsletter.php')

[XT SQL Error]