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', 'mpha8p50l71cavfep04vaf5tp1', '216.73.216.113', '1775399633', '1775399633', '/product_info.php?XTCsid=3dfedf8e10ab51b65faa7b7d7332d93a&info=p14_65-drinking-cups-1-2-Liter.html')

[XT SQL Error]