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', 'rhco2f0e12hdi2c53k6akhtnc6', '3.84.182.112', '1555938994', '1555938994', '/lkw_plane_tasche_lkw_plane/product_info.php/info/p149_Tasche-30-38-10-schwarz-orange-mit-Katze-mit-Katzenbuckel-in-sch.html')

[XT SQL Error]