U132

--U132
CREATE TABLE products
AS SELECT id FROM generate_series(1, 5) AS seq(id);

CREATE TABLE sellers
(email varchar);

INSERT INTO sellers
VALUES ('predajca@gmail.com'),
       ('obchodnik@gmail.com'),
       ('diler@gmail.com');

CREATE TABLE sales
(id serial, kedy timestamp, price numeric, product_id integer, seller_id varchar);

INSERT INTO sales (kedy, price, product_id, seller_id)
SELECT
TIMESTAMP '2011-11-11' + floor((random() * 60)) * INTERVAL '1 day',
floor(random() * 50 + 5)::numeric AS price,
products.id AS product_id,
sellers.email AS seller_id
FROM products, sellers
WHERE random() > 0.1;

CREATE VIEW monthly_sales AS
  SELECT date_part('year', s.kedy) AS rok,
         date_part('month', s.kedy) AS mesiac,
         s.seller_id,
         sum(s.price) AS total_price
  FROM sales s
  GROUP BY rok, mesiac, s.seller_id;

SELECT * FROM monthly_sales ORDER BY seller_id;

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