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', 'rluecd3pd06635nid1bcp630n5', '18.234.88.196', '1558465333', '1558465333', '/lkw_plane_tasche_lkw_plane/product_info.php/info/p111_Tasche-30-25-10-grau-mit-gebogenem-Gecko-in-orange.html')

[XT SQL Error]