Чистовик статьи + материалы
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-- ===============================================
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-- 1. Создание схем
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-- ===============================================
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DROP SCHEMA IF EXISTS stg CASCADE;
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DROP SCHEMA IF EXISTS ods CASCADE;
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DROP SCHEMA IF EXISTS dds CASCADE;
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CREATE SCHEMA stg;
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CREATE SCHEMA ods;
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CREATE SCHEMA dds;
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-- ===============================================
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-- 2. STG: таблицы «как пришло»
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-- ===============================================
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-- Сырые данные: строки, как из CSV/API
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CREATE TABLE stg.customers_raw (
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customer_id TEXT, -- может быть '101' или 'CUST-101'
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email TEXT,
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phone TEXT,
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city TEXT,
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_load_ts TIMESTAMP DEFAULT NOW()
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);
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CREATE TABLE stg.orders_raw (
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order_id TEXT,
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order_date TEXT, -- формат: '2024-01-10'
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customer_id TEXT
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);
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CREATE TABLE stg.order_items_raw (
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order_item_id TEXT,
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order_id TEXT,
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product_id TEXT,
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qty TEXT, -- может быть '2', 'NULL'
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price_at_sale TEXT -- может быть '100.00'
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);
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CREATE TABLE stg.products_raw (
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product_id TEXT,
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name TEXT
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);
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-- Загрузка тестовых данных (вместо COPY FROM CSV)
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INSERT INTO stg.customers_raw (customer_id, email, phone, city) VALUES
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('101', 'a@ex.com', '700', 'Москва'),
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('101', 'b@ex.com', '700', 'Москва'), -- изменение email
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('102', 'c@ex.com', '701', 'СПб');
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INSERT INTO stg.orders_raw (order_id, order_date, customer_id) VALUES
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('5001', '2024-01-10', '101'),
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('5002', '2024-02-05', '102');
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INSERT INTO stg.order_items_raw (order_item_id, order_id, product_id, qty, price_at_sale) VALUES
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('1', '5001', '9001', '2', '100.00'),
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('2', '5001', '9002', '1', '50.00'),
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('3', '5002', '9001', '1', '100.00');
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INSERT INTO stg.products_raw (product_id, name) VALUES
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('9001', 'Phone'),
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('9002', 'Case');
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-- ===============================================
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-- 3. ODS: очистка и типизация
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-- ===============================================
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-- Очищенные клиенты
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CREATE TABLE ods.customers AS
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SELECT
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customer_id::INT AS customer_id, -- приведение к INT
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NULLIF(TRIM(email), '') AS email, -- пустые → NULL
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NULLIF(TRIM(phone), '') AS phone,
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NULLIF(TRIM(city), '') AS city
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FROM stg.customers_raw
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WHERE customer_id ~ '^\d+$'; -- валидация: только цифры
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-- Очищенные заказы
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CREATE TABLE ods.orders AS
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SELECT
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order_id::INT,
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TO_DATE(order_date, 'YYYY-MM-DD') AS order_date,
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customer_id::INT
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FROM stg.orders_raw
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WHERE order_date IS NOT NULL AND customer_id ~ '^\d+$';
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-- Очищенные позиции заказа
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CREATE TABLE ods.order_items AS
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SELECT
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order_item_id::INT,
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order_id::INT,
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product_id::INT,
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NULLIF(qty, '')::INT AS qty,
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NULLIF(price_at_sale, '')::NUMERIC(10,2) AS price_at_sale
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FROM stg.order_items_raw
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WHERE qty ~ '^\d+$' AND price_at_sale ~ '^\d+(\.\d+)?$';
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-- Очищенные товары
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CREATE TABLE ods.products AS
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SELECT
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product_id::INT,
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TRIM(name) AS name
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FROM stg.products_raw
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WHERE product_id ~ '^\d+$';
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-- Добавим первичные ключи (для ускорения JOIN и проверки)
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ALTER TABLE ods.customers ADD PRIMARY KEY (customer_id);
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ALTER TABLE ods.orders ADD PRIMARY KEY (order_id);
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ALTER TABLE ods.order_items ADD PRIMARY KEY (order_item_id);
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ALTER TABLE ods.products ADD PRIMARY KEY (product_id);
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-- ===============================================
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-- 4. DDS: интеграция + SCD Type 2
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-- ===============================================
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-- 4.1 dim_date — справочник дат (на 5 лет: 2023–2027)
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CREATE TABLE dds.dim_date AS
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WITH RECURSIVE dates AS (
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SELECT DATE '2023-01-01' AS d
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UNION ALL
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SELECT d + INTERVAL '1 day'
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FROM dates
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WHERE d + INTERVAL '1 day' <= DATE '2027-12-31'
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)
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SELECT
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CAST(TO_CHAR(d, 'YYYYMMDD') AS INT) AS date_key,
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d AS date_actual,
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EXTRACT(YEAR FROM d) AS year,
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EXTRACT(QUARTER FROM d) AS quarter,
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EXTRACT(MONTH FROM d) AS month,
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EXTRACT(DAY FROM d) AS day,
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TO_CHAR(d, 'Day') AS weekday_name,
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EXTRACT(DOW FROM d) AS weekday_num, -- 0 = воскресенье
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d BETWEEN
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DATE_TRUNC('month', d)
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AND DATE_TRUNC('month', d) + INTERVAL '1 month' - INTERVAL '1 day'
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AND EXTRACT(DAY FROM d) <= 7
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AS is_first_week
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FROM dates;
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ALTER TABLE dds.dim_date ADD PRIMARY KEY (date_key);
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-- 4.2 dim_product — измерение «Товар» (без истории — атрибуты стабильны)
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CREATE TABLE dds.dim_product (
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product_sk BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
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product_bk INT NOT NULL,
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product_name VARCHAR(100) NOT NULL
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);
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INSERT INTO dds.dim_product (product_bk, product_name)
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SELECT product_id, name
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FROM ods.products;
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-- 4.3 dim_customer — SCD Type 2 (с историей)
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CREATE TABLE dds.dim_customer (
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customer_sk BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
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customer_bk INT NOT NULL,
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email VARCHAR(100),
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phone VARCHAR(20),
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city VARCHAR(50),
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valid_from DATE NOT NULL,
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valid_to DATE NOT NULL DEFAULT '9999-12-31',
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is_current BOOLEAN NOT NULL DEFAULT TRUE
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);
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-- Загрузка первой версии (SCD Type 2 — простой алгоритм)
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-- Группируем по customer_bk и сортируем по времени (по _load_ts из STG)
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-- Для учебного примера имитируем хронологию через порядок строк
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WITH ranked AS (
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SELECT
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customer_id AS customer_bk,
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email,
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phone,
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city,
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ROW_NUMBER() OVER (
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PARTITION BY customer_id
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ORDER BY _load_ts, email -- хронология изменений
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) AS rn
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FROM stg.customers_raw
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WHERE customer_id ~ '^\d+$'
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),
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changes AS (
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SELECT
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customer_bk,
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email,
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phone,
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city,
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-- начальная дата — день первого появления в источнике
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'2023-01-01'::DATE + (rn - 1) * INTERVAL '1 day' AS eff_from
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FROM ranked
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),
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final AS (
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SELECT
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customer_bk,
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email,
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phone,
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city,
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eff_from::DATE AS valid_from,
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COALESCE(
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LEAD(eff_from) OVER (PARTITION BY customer_bk ORDER BY eff_from) - INTERVAL '1 day',
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'9999-12-31'::DATE
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) AS valid_to,
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CASE WHEN
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LEAD(eff_from) OVER (PARTITION BY customer_bk ORDER BY eff_from) IS NULL
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THEN TRUE ELSE FALSE END AS is_current
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FROM changes
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)
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INSERT INTO dds.dim_customer (customer_bk, email, phone, city, valid_from, valid_to, is_current)
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SELECT customer_bk, email, phone, city, valid_from, valid_to, is_current
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FROM final;
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-- 4.4 fact_sales — факт продаж
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CREATE TABLE dds.fact_sales (
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sale_id BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
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customer_sk BIGINT NOT NULL, -- ссылка на DDS-измерение
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product_sk BIGINT NOT NULL,
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date_key INT NOT NULL, -- YYYYMMDD
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quantity INT NOT NULL CHECK (quantity > 0),
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amount NUMERIC(18,2) NOT NULL CHECK (amount >= 0)
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);
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-- Заполнение fact_sales с учётом истории клиента (SCD!)
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INSERT INTO dds.fact_sales (customer_sk, product_sk, date_key, quantity, amount)
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SELECT
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dc.customer_sk,
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dp.product_sk,
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CAST(TO_CHAR(o.order_date, 'YYYYMMDD') AS INT) AS date_key,
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oi.qty,
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oi.price_at_sale * oi.qty AS amount
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FROM ods.orders o
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JOIN ods.order_items oi ON o.order_id = oi.order_id
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JOIN ods.products p ON oi.product_id = p.product_id
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JOIN dds.dim_product dp ON p.product_id = dp.product_bk
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JOIN dds.dim_customer dc
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ON o.customer_id = dc.customer_bk
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AND o.order_date BETWEEN dc.valid_from AND dc.valid_to; -- ← ключевая строка SCD!
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-- Добавим внешние ключи (опционально, для целостности)
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ALTER TABLE dds.fact_sales
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ADD FOREIGN KEY (customer_sk) REFERENCES dds.dim_customer(customer_sk),
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ADD FOREIGN KEY (product_sk) REFERENCES dds.dim_product(product_sk),
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ADD FOREIGN KEY (date_key) REFERENCES dds.dim_date(date_key);
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-- ===============================================
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-- 5. Проверка: посчитаем выручку по клиентам
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-- ===============================================
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SELECT
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dc.customer_bk,
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dc.email,
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dc.city,
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SUM(f.amount) AS total_revenue
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FROM dds.fact_sales f
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JOIN dds.dim_customer dc
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ON f.customer_sk = dc.customer_sk
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AND dc.is_current -- только актуальная версия
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GROUP BY dc.customer_bk, dc.email, dc.city
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ORDER BY total_revenue DESC;
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