By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
CREATE TABLE tablename (
`id` INTEGER,
`country` VARCHAR(8),
`col1` INTEGER,
`col2` INTEGER,
`col3` INTEGER
);
INSERT INTO tablename
(`id`, `country`, `col1`, `col2`, `col3`)
VALUES
('1', 'country1', '1', '2', '3'),
('2', 'country1', '2', '2', '1'),
('3', 'country1', '1', '3', '2'),
('4', 'country2', '3', '2', '2'),
('5', 'country2', '3', '3', '3'),
('6', 'country3', '3', '2', '2'),
('7', 'country3', '3', '1', '1');
select * from tablename
where id in (select max(id) from tablename group by country)
| id | country | col1 | col2 | col3 |
|---|---|---|---|---|
| 3 | country1 | 1 | 3 | 2 |
| 5 | country2 | 3 | 3 | 3 |
| 7 | country3 | 3 | 1 | 1 |
select t.* from tablename t
where not exists (
select 1 from tablename
where country = t.country and id > t.id
);
| id | country | col1 | col2 | col3 |
|---|---|---|---|---|
| 3 | country1 | 1 | 3 | 2 |
| 5 | country2 | 3 | 3 | 3 |
| 7 | country3 | 3 | 1 | 1 |