Средняя цена за единицу по каналам за последний квартал
SQL, по которому посчитано
WITH p AS (
SELECT date_trunc('quarter', max(date)) AS start_date
FROM sales
)
SELECT s.channel,
round(SUM(s.revenue), 0) AS revenue,
SUM(s.units) AS units,
round(SUM(s.revenue) / NULLIF(SUM(s.units), 0), 0) AS avg_price
FROM sales s
JOIN p ON s.date >= p.start_date
GROUP BY s.channel
ORDER BY avg_price DESC