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', '0kb5pj8o6j4cvb6cisna8pftm4', '18.188.13.212', '1746980670', '1746980670', '/xtshop/product_info.php?info=p995_.html')

[XT SQL Error]