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', '1iv4qi6odph8u89527replkno3', '18.219.43.26', '1746981735', '1746981735', '/xtshop/product_info.php?info=p918_.html')

[XT SQL Error]