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', 'ojdvaqrag8v0q9i5pn6sihl0f1', '216.73.216.15', '1790793414', '1790793414', '/product_info.php?XTCsid=38f09672db884903e3803adf9d076819&info=p17_20-Tissue-Napkins.html')

[XT SQL Error]