Средний чек с рекламы по категориям, вымышленный мебельный магазин, последний месяц
SQL, по которому посчитано
WITH last_month AS (
SELECT date_trunc('month', max(date)) AS month_start
FROM ads
)
SELECT
category,
round(sum(revenue) / nullif(sum(orders), 0), 2) AS avg_check
FROM ads
WHERE date >= (SELECT month_start FROM last_month)
AND category <> 'Все'
AND category IS NOT NULL
GROUP BY category
HAVING sum(orders) > 0
ORDER BY avg_check DESC
LIMIT 30