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', '22a2onqn0ncooatnt3krbtodf0', '216.73.216.165', '1752389690', '1752389690', '/shop_content.php?coID=3&XTCsid=38f09672db884903e3803adf9d076819')

[XT SQL Error]