7.sql

with dates as (
select
    dt
from 
    unnest(generate_date_array(date_sub(current_date(), interval 90 day), current_date(), interval 1 day)) as dt
)

, data as (
    select dt
        , CEIL(RAND()*1000) as revenue -- just some random data.
    from
        dates
)
select
  dt
, revenue
, AVG(revenue) OVER(ORDER BY unix_date(dt) RANGE BETWEEN 6 PRECEDING AND CURRENT ROW) as seven_day_moving_average
from data
;