MySQL选择内连接和联合答案

【问题标题】：MySQL select inner join and unionMySQL选择内连接和联合
【发布时间】：2013-01-20 12:45:54
【问题描述】：

我有这两张桌子。我有当前玩家 id_player，我想从该玩家 (id_player) 和他的对手信息中选择所有游戏。当前玩家和对手玩家连接到相同的 id_game。或

table game:`id_game` (...)
table game_player:`id_game_player, id_player, id_game`(...)

“给我所有与当前玩家和他的对手不同的游戏信息并加入他们游戏的信息（按游戏分组）”

结果为：

      +---player game info
game1 |
      +---opponent game info

      +---player game info
game2 |
      +---opponent1 game info

      +---player game info
game2 |
      +---opponent2 game info

谁能提供我的 MySQL 解决方案？

谢谢

编辑：我尝试使用这段代码，但我不确定这是最快的方式（在哪里），有没有办法像上面那样对结果进行分组？

SELECT * FROM game_player
    JOIN `game` ON game.id_game = game_player.id_game
    WHERE game_player.id_game
    IN (
    SELECT game_player.id_game
    FROM `game_player`
    WHERE game_player.id_player =2)

【问题讨论】：

游戏信息在哪里？
“游戏信息”表示表中的所有其他字段 *
问题措辞“给我所有单独的游戏信息...” 使这听起来很像作业问题。你能发布你到目前为止的努力吗？
我只看到一个player_id 每场比赛的另一个对手 player_id 在哪里？
对手player_id是其他同id_game的玩家

标签： mysql sql union inner-join

【解决方案1】：

试试看

SET @player_ID = 0;                  -- <<== the playerID
SELECT  a.*, b.*, 'player' Status         -- this is the first part of the union
FROM    game a                            -- which gets all the game of
        INNER JOIN game_player b          -- the selected player and its info
            ON a.id_game = b.id_game
WHERE   id_player = @player_ID 
UNION ALL
SELECT  d.*, c.*, 'opponent' status
FROM    game_player c
        INNER JOIN
        (
            SELECT  a.*
            FROM    game aa
                    INNER JOIN game_player bb
                        ON aa.id_game = bb.id_game
            WHERE   bb.id_player = @player_ID
        ) d ON c.id_game = d.id_game AND c.id_player <> @player_ID
ORDER   BY id_game, status

【讨论】：