Seven-Day Revenue Signal :Calculate a Seven-Day Moving Average of Daily Revenue Intermediate

          with daily_revenue as
  (select orderdate::date as order_day,
          sum(totalamount) as daily_total
   from orders
   group by orderdate::date)
select order_day,
       daily_total,
       avg(daily_total) over (
                              order by order_day rows between 6 preceding and current row) as moving_avg_7_day
from daily_revenue
order by order_day;