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', '8cdhcn6p62c2oirdtcm3tqbd56', '18.234.88.196', '1558465227', '1558465227', '/lkw_plane_tasche_lkw_plane/index.php/cat/c12_gutscheine_taschen_aus_lkw_plane_portemonnaie_brieftasche_geldboerse_schluesselanhaenger.html')

[XT SQL Error]