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', '820e37f339f2a1f0bc3b05b3a5c13f4b', '18.117.196.217', '1714128257', '1714128257', '/shop_content.php/coID/1/content/Liefer--und-Versandkosten')

[XT SQL Error]