Question

我有三张桌子：

players
------
id|name 

teams
-------
id|name 

teams_players
-------------
id|teamID|playerID

我现在想从桌面“玩家”中获取每个条目，其中players.id是例如在ID为15的团队中。换句话说：我想让每个属于特定团队的玩家（例如teamID = 15））

我尝试了加入，但失败了。

这是我到目前为止所得到的：

       "SELECT players.*
        FROM players
        JOIN teams_players
        ON teams_players.teamID = 15 
        GROUP BY players.id";

Answer 1

你的方式过于复杂。

select players.*
 from players
 join teams_players
 on players.id = teams_players.playerid
 where teams_players.teamid = 15

JOIN部分与数字15无关.15是您过滤结果的方式。

Answer 2

您可以使用多个条件加入您的表格，同时您还未在on子句中提及表格之间的关系

SELECT players.*
        FROM players
        JOIN teams_players
        ON (players.id = teams_players.playerid AND teams_players.teamID = 15 )
        GROUP BY players.id

mysql查询连接三个表

2 个答案: