WITH RECURSIVE calendar(day, last_day) AS (
    SELECT MIN(order_date), MAX(order_date) FROM daily_category_revenue
    HAVING COUNT(*) > 0
    UNION ALL
    SELECT date(day, '+1 day'), last_day FROM calendar WHERE day < last_day
),
daily AS (
    SELECT day AS order_date, COALESCE(SUM(r.revenue_kopecks), 0) AS revenue_kopecks
    FROM calendar
    LEFT JOIN daily_category_revenue AS r ON r.order_date = day
    GROUP BY day
)
SELECT order_date, revenue_kopecks,
       revenue_kopecks - LAG(revenue_kopecks) OVER (ORDER BY order_date) AS change_kopecks
FROM daily
ORDER BY order_date;