Этап: Аналитические запросы

sql/anomalies.sql

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+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
+),
+categories AS (
+    SELECT DISTINCT category FROM daily_category_revenue
+),
+daily AS (
+    SELECT day, c.category, COALESCE(r.revenue_kopecks, 0) AS revenue_kopecks
+    FROM calendar CROSS JOIN categories AS c
+    LEFT JOIN daily_category_revenue AS r ON r.order_date = day AND r.category = c.category
+),
+-- Вычитаем общий для категории минимум в целых копейках до перехода AVG к REAL.
+-- Такой сдвиг сохраняет отклонения и различия в копейку при большом базовом уровне.
+shifted AS (
+    SELECT *, revenue_kopecks - MIN(revenue_kopecks) OVER (PARTITION BY category) AS amount
+    FROM daily
+),
+deviations AS (
+    SELECT *, amount - AVG(amount) OVER (PARTITION BY category) AS deviation
+    FROM shifted
+),
+stats AS (
+    SELECT *, COUNT(*) OVER (PARTITION BY category) AS days,
+           AVG(deviation * deviation) OVER (PARTITION BY category) AS variance
+    FROM deviations
+)
+SELECT day AS order_date, category, revenue_kopecks
+FROM stats
+WHERE days >= 7 AND variance > 0 AND deviation * deviation > 4 * variance
+ORDER BY day, category;

sql/daily_revenue.sql

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+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;

sql/top_categories.sql

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+SELECT category,
+       SUM(order_count) AS order_count,
+       SUM(revenue_kopecks) AS revenue_kopecks
+FROM daily_category_revenue
+GROUP BY category
+ORDER BY revenue_kopecks DESC, category
+LIMIT 5;