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', '2n9igpvhqsofng7juhv2ea4ub2', '18.234.88.196', '1558465315', '1558465315', '/messenger_bag_tote_bag_canvas_cover/shopping_cart.php')

[XT SQL Error]