如何选择列值最高的行，如果重复则返回最上面的行？

Question

I have a table called player_ratings which contains two columns: player_id and rating . For example:

 |  player_id     |       rating       | 
 |     1          |        950         |
 |     1          |        945         |
 |     2          |        850         |
 |     2          |        850         |

I want to return a list of players with the highest player_rating.

If there are duplicate rows in the table, return the topmost row. For example, player_id 2 has two rows with the same rating so return row 3 in the table.

the list shouldn't contain any duplicate players. (see the expected output)

I tried the following query but it doesn't remove duplicates rows:

SELECT * 
FROM player_ratings 
INNER JOIN ( SELECT player_id, MAX(rating) as max_rating FROM player_ratings GROUP BY player_id) topratings 
 ON player_ratings.player_id = topratings.player_id
 AND player_ratings.rating = topratings.max_rating 
ORDER BY player_ratings.rating DESC ;

ACTUAL OUTPUT

 |  player_id     |       ranking       | 
 |     1          |         950         |
 |     2          |         850         |
 |     2          |         850         |

EXPECTED OUTPUT

 |  player_id     |       ranking       | 
 |     1          |         950         |
 |     2          |         850         |

Answer 1

You can try below -

   SELECT player_id, MAX(rating) as max_rating FROM player_ratings 
   GROUP BY player_id
   order by max_rating desc

Answer 2

As it's just about two columns, the player ID and the ranking, you can simply aggregate:

select player_id, max(rating)
from player_ratings
group by player_id
order by max(rating) desc;

Answer 3

Assuming you have a unique id in player_ratings , then you can do:

select pr.*
from player_ratings pr
where pr.player_ratings_id in (select pr2.player_ratings_id
                               from player_ratings pr2
                               where pr2.player_id = pr.player_id
                               order by pr2.max_rating desc, 
                                        pr2.player_ratings_id asc
                              );

Answer 4

Use GROUP BY and MAX()

SELECT player_id, MAX(rating) as Rating
FROM player_ratings GROUP BY player_id
ORDER BY 2 DESC