sql_01-07

with tbl as (
    select distinct date_trunc('month', event_time)::date as month
        , count(event_id) over(partition by date_trunc('month', event_time)) as events
    from tools_shop.events e
    right join tools_shop.orders o on o.user_id=e.user_id
    where event_name='view_item'
)
select month , events::numeric, sum(events) over(order by month)
from tbl