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', 'svjjo6c5331b42rgojrpkpcq75', '216.73.216.197', '1751520753', '1751520753', '/product_info.php?info=p10_3-packs-Blow-outs.html&XTCsid=bf13b0b0f6f4b4114715539f49cc1fe6')

[XT SQL Error]