select * from (select to_char(days, 'DD.MM.YY') as day
FROM generate_series(
    (now() - '30 days'::interval) :: DATE,
    now() :: DATE ,
    '1 day'
) AS days) as pickups
left join
select * from (select to_char(orders.orderdate, 'DD.MM.YY') as day,
sum(orders.total) as revenue,
TO_CHAR(days, 'YYYY-MM-DD') AS tage
FROM generate_series(
    (now() - '30 days'::interval) :: DATE,
    now() :: DATE ,
    '1 day'
) AS days, orders
where to_char(orders.orderdate, 'YYYY-MM-DD') = TO_CHAR(days, 'YYYY-MM-DD')
group by orders.orderdate, days
order by tage desc) as allorders
on pickups.day = allorders.day