MySQL选择内连接和联合

Question

我有这两张桌子。我有当前的玩家id_player，我想选择这个玩家的所有游戏（id_player）和他的对手信息。当前玩家和对手玩家使用相同的id_game连接。或

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

  

“向我提供当前玩家及其对手的所有单独游戏信息   并加入他们的游戏信息（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

任何人都可以提供MySQL解决方案吗？

谢谢

---

编辑： 我尝试使用这段代码，但我不确定这是最快的方法（WHERE IN），有没有办法对上面的结果进行分组？

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)

Answer 1

试一试

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