Я не понимаю, почему я получаю эту ошибку. Похоже на простой запрос.
select *,age(last_order,first_order_date) from
(
select organization,first_order_date::date, max(delivery_date::date) as last_order
from [orderdetailreport]
group by organization,first_order_date::date
)a