MySQL 8.0

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CREATE TABLE MovieRating (
  `movie_id` INTEGER,
  `user_id` INTEGER,
  `rating` INTEGER,
  `created_at` DATETIME
);

INSERT INTO MovieRating
  (`movie_id`, `user_id`, `rating`, `created_at`)
VALUES
  ('1', '1', '3', '2020-01-12'),
  ('1', '2', '4', '2020-02-11'),
  ('1', '3', '2', '2020-02-12'),
  ('1', '4', '1', '2020-01-01'),
  ('2', '1', '5', '2020-02-17'),
  ('2', '2', '2', '2020-02-01'),
  ('2', '3', '2', '2020-03-01'),
  ('3', '1', '3', '2020-02-22'),
  ('3', '2', '4', '2020-02-25');

Records: 9  Duplicates: 0  Warnings: 0


SELECT movie_id,
       AVG(rating) AS average_rating,
       RANK() OVER (ORDER BY AVG(rating) DESC) AS rank_rate
FROM MovieRating
GROUP BY movie_id
ORDER BY rank_rate;


movie_id
average_rating
rank_rate


3
3.5000
1

2
3.0000
2

1
2.5000
3


SELECT movie_id,
       RANK() OVER (ORDER BY AVG(rating) DESC) AS rank_rate
FROM MovieRating
GROUP BY movie_id
ORDER BY rank_rate;


movie_id
rank_rate


3
1

2
2

1
3