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', 'bse7s9ti290goma3acabpce540', '216.73.216.70', '1752611169', '1752611169', '/product_info.php?info=p7_Garland-13-feet.html&XTCsid=c5b0faa060c5a2a58a484a921d860fc7')

[XT SQL Error]