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', 'd75c02e5661dca57b4d0458ad4af65fb', '3.15.211.19', '1722064311', '1722064311', '/shop_content.php/coID/1/content/Liefer--und-Versandkosten')

[XT SQL Error]