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', 'eja7u14m6q3uc9debf1mqp9da1', '54.162.109.90', '1495804392', '1495804392', '/shop_content.php?coID=9&watch=1069')

[XT SQL Error]