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', '7rag3ko2h37p32hcue9i2eab33', '216.73.216.147', '1751838054', '1751838054', '/shop_content.php?coID=8&XTCsid=2f0d32e80e0e3a7e9efdd2dc2a571c8d')

[XT SQL Error]