Question

需要列出名人堂的最佳球员，数据库包含不同游戏中的每个单一游戏玩家。

级别具有优先级，如果级别相同，请检查最高分。

我有一个包含user_id，级别，分数，游戏和数据的数据库。架构在这里：

CREATE TABLE IF NOT EXISTS `docs` (`user_id` int(6) unsigned NOT NULL,
`level` int(3) unsigned NOT NULL,`game` varchar(30) NOT NULL,
`score` int(5) unsigned NOT NULL,
`data` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
INSERT INTO `docs` (`user_id`, `level`, `game`, `score`,`data`) VALUES
  ('1', '7', 'pacman', '8452','2018-02-14 15:00:00'),
  ('1', '9', 'pacman', '9999','2018-02-10 16:30:00'),
  ('2', '8', 'pacman', '8500','2018-02-24 17:30:00'),
  ('1', '10', 'pacman', '9100','2018-02-15 18:30:00'),
  ('1', '10', 'pacman', '8800','2018-02-15 18:11:00'),
  ('1', '11', 'snake', '9600','2018-02-14 15:00:00'),
  ('1', '6', 'snake', '7020','2018-02-11 11:30:00'),
  ('2', '8', 'snake', '8500','2018-02-24 14:00:00'),
  ('2', '12', 'snake', '9200','2018-02-25 19:00:00'),
  ('2', '12', 'snake', '9800','2018-02-25 19:20:00'),
  ('1', '4', 'pacman', '2452','2018-03-11 15:00:00'),
  ('1', '6', 'pacman', '4999','2018-03-07 16:30:00'),
  ('2', '7', 'pacman', '5500','2018-03-02 17:30:00'),
  ('1', '7', 'pacman', '5100','2018-03-01 18:30:00'),
  ('1', '3', 'snake', '3600','2018-03-03 15:00:00'),
  ('1', '5', 'snake', '4220','2018-03-01 11:30:00'),
  ('2', '5', 'snake', '3900','2018-03-04 14:00:00'),
  ('2', '5', 'snake', '5200','2018-03-05 19:00:00');

我希望在选定的月份和游戏中找回名人堂，例如，如果我在行军上选择 pacman ，结果应为：

user level score
2     7    5500
1     7    5100

我试过这个如何在其他类似话题中提出建议

select d1.*
from docs d1 
left outer join docs d2
on (d1.user_id = d2.user_id and d1.level < d2.level)
where d2.user_id is null
order by level desc;

但是我为同一个用户重复了级别，然后我就无法选择游戏或月份了。

这里有SQL Fiddle

Answer 1

SELECT x.* FROM docs x
JOIN 
(select user_id
      , game
      , MONTH(data) month
      , MAX(score) score
   from docs 
  where game = 'pacman' 
    and MONTH(data) = 3 
  group 
     by user_id
      , game
      , MONTH(data)
 ) y
 ON y.user_id = x.user_id
 AND y.game = x.game
 AND y.month = MONTH(x.data)
 AND y.score = x.score;

或类似的东西

Answer 2

经过长时间的工作，研究和研究，这对我来说是最好的解决方案：

SELECT user_id, level, score, game
  FROM (
            SELECT *, 
                   @rn := IF(user_id = @g, @rn + 1, 1) rn, 
                   @g := user_id
              FROM (select @g := null, @rn := 0) x, 
                   docs where game='pacman'
          ORDER BY user_id, level desc, score desc, game
       ) X
 WHERE rn = 1 order by level desc, score desc;

解释在本主题Select one value from a group based on order from other columns

中

名人堂关系（团体球员，最高等级，然后当月份时每场比赛的最高分数......）

2 个答案: