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', 'ha4ieo7dm6kqa7m1skjjjhoka7', '54.162.109.90', '1495804267', '1495804267', '/shop_content.php?coID=9&watch=1076')

[XT SQL Error]