加入三个联结表

Question

我想弄明白这个问题时头疼！

我有三张桌子 -球员 -团队 -游戏

具有两列的三个联结表。 -player_teams -teams_games -player_games

我需要列出游戏中的所有玩家（例如：Game_id = 变量中的 111）未分配到团队（在此游戏中）。我称他们为孤儿玩家

基本上获取游戏中的团队，获取他们的球员并反向匹配 Games_players。或者我想反过来。

我试了两天都不行！

谢谢！

/J p.s 在我发布这篇文章之后，我已经走到这一步了，但它似乎很复杂！

SELECT * from players
JOIN
(SELECT DISTINCT games_players.player_id from games_players
Left JOIN
(Select team_players.player_id p1 from team_players 
inner join (Select * from games_teams where games_teams.game_id = :P1) AS tm1 ON team_players.team_id = tm1.team_id) As f1
On games_players.player_id = f1.p1
where p1 is null) as q1
on players.player_id = q1.player_id

Answer 1

由于给出了比赛，您可以只看比赛中的球员和比赛中的球队球员：

select *
from players
where player_id in
(
  select player_id
  from player_games
  where game_id = 111
)
and player_id not in
(
  select pt.player_id
  from player_teams pt
  join teams_games tg using (team_id)
  where tg.game_id = 111
);

加入三个联结表

Joining three junction tables

mysql

sql

junction-table