SQL以百分比获取类似的“匹配”结果

Question

该表存储用户匹配之间的用户投票。总是有一个赢家，一个失败者和选民。

CREATE TABLE `user_versus` (
  `id_user_versus` int(11) NOT NULL AUTO_INCREMENT,
  `id_user_winner` int(10) unsigned NOT NULL,
  `id_user_loser` int(10) unsigned NOT NULL,
  `id_user` int(10) unsigned NOT NULL,
  `date_versus` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id_user_versus`),
  KEY `id_user_winner` (`id_user_winner`,`id_user_loser`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=17 ;

INSERT INTO `user_versus` (`id_user_versus`, `id_user_winner`, `id_user_loser`, `id_user`, `date_versus`) VALUES
(1, 6, 7, 1, '2013-10-25 23:02:57'),
(2, 6, 8, 1, '2013-10-25 23:02:57'),
(3, 6, 9, 1, '2013-10-25 23:03:04'),
(4, 6, 10, 1, '2013-10-25 23:03:04'),
(5, 6, 11, 1, '2013-10-25 23:03:10'),
(6, 6, 12, 1, '2013-10-25 23:03:10'),
(7, 6, 13, 1, '2013-10-25 23:03:18'),
(8, 6, 14, 1, '2013-10-25 23:03:18'),
(9, 7, 6, 2, '2013-10-26 04:02:57'),
(10, 8, 6, 2, '2013-10-26 04:02:57'),
(11, 9, 8, 2, '2013-10-26 04:03:04'),
(12, 9, 10, 2, '2013-10-26 04:03:04'),
(13, 9, 11, 2, '2013-10-26 04:03:10'),
(14, 9, 12, 2, '2013-10-26 04:03:10'),
(15, 9, 13, 2, '2013-10-26 04:03:18'),
(16, 9, 14, 2, '2013-10-26 04:03:18');

我正在研究一个获取相似配置文件的查询。当投票百分比（Wins vs Loss）为指定配置文件的10％时，配置文件是相似的。

SELECT id_user_winner AS id_user,
    IFNULL(wins, 0) AS wins,
    IFNULL(loses, 0) AS loses,
    IFNULL(wins, 0) + IFNULL(loses, 0) AS total,
    IFNULL(wins, 0) / (IFNULL(wins, 0) + IFNULL(loses, 0)) AS percent
FROM
(
    SELECT id_user_winner AS id_user FROM user_versus 
    UNION
    SELECT id_user_loser FROM user_versus 
) AS u
LEFT JOIN
(
    SELECT id_user_winner, COUNT(*) AS wins
    FROM user_versus
    GROUP BY id_user_winner
) AS w
ON u.id_user = id_user_winner
LEFT JOIN
(
    SELECT id_user_loser, COUNT(*) AS loses
    FROM user_versus
    GROUP BY id_user_loser
) AS l
ON u.id_user = l.id_user_loser

这是当前的结果：

它目前正在返回空行，他们不应该在那里。仍然需要进行优化（并且不能完全伸出手指）是：

1. 将用户仅带来类似于用户ABC的用户
2. 指定定义谁与用户ID = 6相似的用户的条件

任何帮助将不胜感激。谢谢！

Answer 1

要计算每个用户的获胜和损失而无需加入表格并使用外部连接，可以单独选择获胜和损失，并在他们之间进行联合，但是如果给出的行代表胜利，则有其他信息用户或损失。

然后，很容易计算每个用户的所有胜利和损失。棘手的部分是将选项合并用于指定您要比较哪个用户的配置文件的选项。我以一个变量设置为 percentage 给定的用户 user_id, ，您可以从常数更改为变量。

这是我的建议（与ID = 6的用户进行比较）：

SELECT
    player_id AS id_user,
    wins,
    losses,
    wins + losses AS total,
    wins / (wins + losses) AS percent
  FROM (
    SELECT
        player_id,
        SUM(is_a_win) wins,
        SUM(is_a_loss) losses,
        CASE
          WHEN player_id = 6
            THEN @the_user_score := SUM(is_a_win) / (SUM(is_a_win) + SUM(is_a_loss))
          ELSE NULL
         END
      FROM (
        SELECT id_user_winner AS player_id, 1 AS is_a_win, 0 AS is_a_loss FROM user_versus
        UNION ALL SELECT id_user_loser, 0, 1 FROM user_versus
      ) games
    GROUP BY player_id
  ) data
WHERE
  ABS(wins / (wins + losses) - @the_user_score) <= 0.1
;

输出：

ID_USER WINS   LOSSES  TOTAL   PERCENT
6       8       2       10      0.8
9       6       1       7       0.8571

当然，您可以删除通过添加的用户的个人资料是进行比较的基础 player_id != 6 （或者，在最终解决方案中，一些可变名称）条件到最外面 WHERE 条款。

sqlfiddle的示例： 匹配配置文件 - 示例

如果您要寻找的是，您能提供一些反馈，如果没有，您会期望什么？