select
res_partner."ref",
date(res_partner.create_date),
res_partner.installment_sum,
res_partner.overdue_installment_sum,
res_partner.write_uid,
(select res_partner."name" as username from res_partner where id = (select res_users.partner_id from res_users where res_users.id = res_partner.write_uid)),
name as customer_name
from res_partner where res_partner."ref" = 'L503039';