Postgres 15

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CREATE TABLE products (
  id int,
  created_at date,
  sold_at date
);

CREATE TABLE product_prices (
  id int,
  product_id int,
  price numeric,
  created_at date
);

INSERT INTO products (id, created_at, sold_at) VALUES
  ( 1, '2022-01-25', '2022-02-18')
, ( 2, '2022-01-26', NULL)
, ( 3, '2022-01-28', '2022-01-30')
, ( 4, '2022-02-01', '2022-02-01')
, ( 5, '2022-02-01', '2022-02-15')
, ( 6, '2022-02-10', '2022-02-13')
, ( 7, '2022-02-14', NULL)
, ( 8, '2022-02-19', NULL)
, ( 9, '2022-02-20', '2022-02-22')
, (10, '2022-02-22', NULL)
;

INSERT INTO product_prices (id, product_id, price, created_at) VALUES
  ( 1,  1, 100.0, '2022-01-25')
, ( 2,  1,  95.0, '2022-02-02')
, ( 3,  1,  85.0, '2022-02-17')
, ( 4,  2,  89.0, '2022-01-26')
, ( 5,  2,  85.0, '2022-01-30')
, ( 6,  3,  91.0, '2022-01-28')
, ( 7,  4,  50.0, '2022-02-01')
, ( 8,  5, 100.0, '2022-02-01')
, ( 9,  5,  99.0, '2022-02-03')
, (10,  6,  79.0, '2022-02-10')
, (11,  6,  75.0, '2022-02-11')
, (12,  6,  71.0, '2022-02-12')
, (13,  7, 120.0, '2022-02-14')
, (14,  7, 110.0, '2022-02-16')
, (15,  8,  89.0, '2022-02-19')
, (16,  9,  30.0, '2022-02-20')
, (17,  9,  29.0, '2022-02-22')
, (18, 10, 100.0, '2022-02-22')
;

CREATE TABLE

CREATE TABLE

INSERT 0 10

INSERT 0 18

Date	Products for sale	Number of sold	Avg price
2022-01-23	0	0	0.00
2022-01-24	0	0	0.00
2022-01-25	1	0	100.00
2022-01-26	2	0	94.50
2022-01-27	2	0	94.50
2022-01-28	3	0	93.33
2022-01-29	3	0	93.33
2022-01-30	3	1	92.00
2022-01-31	2	0	92.50
2022-02-01	4	1	83.75
2022-02-02	3	0	93.33
2022-02-03	3	0	93.00
2022-02-04	3	0	93.00
2022-02-05	3	0	93.00
2022-02-06	3	0	93.00
2022-02-07	3	0	93.00
2022-02-08	3	0	93.00
2022-02-09	3	0	93.00
2022-02-10	4	0	89.50
2022-02-11	4	0	88.50
2022-02-12	4	0	87.50
2022-02-13	4	1	87.50
2022-02-14	4	0	99.75
2022-02-15	4	1	99.75
2022-02-16	3	0	96.67
2022-02-17	3	0	93.33
2022-02-18	3	1	93.33
2022-02-19	3	0	94.67
2022-02-20	4	0	78.50
2022-02-21	4	0	78.50
2022-02-22	5	1	82.60
2022-02-23	4	0	96.00

SELECT 32