MySQL 8.0

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CREATE TABLE Serians (
  id INT NOT NULL,
  region_id INT NOT NULL,
  code_id INT NOT NULL,
  created_at DATETIME NOT NULL,
  PRIMARY KEY (id)
);

INSERT INTO Serians (id, region_id, code_id, created_at) VALUES
(51015, 1510, 2, '2023-03-22 11:05:36'),
(51016, 1670, 2, '2023-03-22 11:08:52'),
(51017, 1670, 1, '2023-03-22 11:08:58'),
(51018, 1510, 2, '2023-03-22 11:32:58');

Records: 4  Duplicates: 0  Warnings: 0


SELECT sa.id, sa.region_id, sa.code_id, sa.created_at
FROM Serians AS sa
INNER JOIN (
  SELECT region_id, MAX(id) AS max_id
  FROM Serians
  WHERE region_id IN (1670,1510)
  GROUP BY region_id
) AS sb ON sa.region_id = sb.region_id AND sa.id = sb.max_id
order by sa.code_id;


id
region_id
code_id
created_at


51017
1670
1
2023-03-22 11:08:58

51018
1510
2
2023-03-22 11:32:58


SELECT id, region_id, code_id, created_at
FROM Serians
WHERE (region_id, id) IN (
  SELECT region_id, MAX(id)
  FROM Serians
  WHERE region_id IN (1670, 1510)
  GROUP BY region_id
);


id
region_id
code_id
created_at


51017
1670
1
2023-03-22 11:08:58

51018
1510
2
2023-03-22 11:32:58