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', 'bkku3igq09jg5svr1ptjku5k25', '216.73.216.80', '1751321088', '1751321088', '/product_info.php?info=p19_10-Paper-Plates.html&XTCsid=0308d34f52db367f9a7068f51bec2a23')

[XT SQL Error]