LeetCodeデータベース178。スコアランキング

178.スコアランキング

SELECT Score, 
    (
        SELECT COUNT(DISTINCT(b.Score))# 查看有多少个b.Score大于等于当前的a.Score
        FROM Scores AS b # 给Scores表取别名 
        WHERE b.Score>=a.Score
    ) AS Rank
FROM Scores AS a
ORDER BY Score DESC

アイデア：最初にDISTINCT、次にCOUNT