MySQL的SELECT加入，按组或东西

Question

我不能在正确的轨道与此上得到的，任何帮助，将不胜感激

我有一个表

+---+----------+---------+-----------+ 
|id | match_id | team_id | player_id | 
+---+----------+---------+-----------+ 
| 1 |  9 |  10 |   5 | 
| 2 |  9 |  10 |   7 | 
| 3 |  9 |  10 |   9 | 
| 4 |  9 |  11 |  12 | 
| 5 |  9 |  11 |  15 | 
| 6 |  9 |  11 |  18 | 
+---+----------+---------+-----------+ 

我想选择这些有其中，在match_id和双方团队的ID，因此产量将

+---------+-------+------+---------+---------+ 
| MATCHID | TEAMA | TEAMB| PLAYERA | PLAYERB | 
+---------+-------+------+---------+---------+  
|  9 | 10 | 11 |  5 |  12 | 
|  9 | 10 | 11 |  7 |  15 | 
|  9 | 10 | 11 |  9 |  18 | 
+---------+-------+------+---------+---------+ 

它可能很简单，但我卡住了..

在此先感谢

p.s.似乎要忘记我的第一篇文章列，遗憾

Answer 1

我想你需要：

SELECT 
    a.match_id, a.team_id AS TeamA, b.team_id AS teamB, 
    a.player_id AS PlayerA, b.player_id AS PlayerB 
FROM PLayer AS a 
    INNER JOIN Player AS b ON a.match_id = b.match_id 
WHERE a.team_id < b.team_id 

虽然这会给你的每对选手每场比赛，即

+---------+-------+------+---------+---------+ 
| MATCHID | TEAMA | TEAMB| PLAYERA | PLAYERB | 
+---------+-------+------+---------+---------+  
|  9 | 10 | 11 |  5 |  12 | 
|  9 | 10 | 11 |  5 |  15 | 
|  9 | 10 | 11 |  5 |  18 | 
|  9 | 10 | 11 |  7 |  12 | 
|  9 | 10 | 11 |  7 |  15 | 
|  9 | 10 | 11 |  7 |  18 | 
|  9 | 10 | 11 |  9 |  12 | 
|  9 | 10 | 11 |  9 |  15 | 
|  9 | 10 | 11 |  9 |  18 | 
+---------+-------+------+---------+---------+ 

要限制它进一步，你需要一个标准来确定球员应该配对。

Answer 2

我认为重新设计数据库会更好。

Answer 3

select MatchA.id as MATCHID, MatchA.team_id as TEAMA, MatchB.team_id as TEAMB, MatchA.player_id as PLAYERA, MatchB.player_id as PLAYERB 
from Match as MatchA, match as MatchB 
where MatchA.id = MatchB.id and MatchA.team_id < MatchB.team_id