cakePHP返回重复记录

出于某种原因，cakePHP给了我一个结果的两个副本。谁能告诉我为什么以及如何修复它？现在这没什么大不了的，但是一旦我为一个玩家获得了多个游戏组，那么文件下载量就会增加

以下是模型代码：

        $this->recursive = -1;
        return $this->find('all', array(
            'order' => array(
                'PlaygroupActivity.timestamp DESC'
            ), 
            'limit' => $limit, 
            'joins' => array(
                array(
                    'table' => 'playgroup_players', 
                    'alias' => 'PlaygroupPlayers', 
                    'type' => 'inner', 
                    'foreignKey' => false, 
                    'conditions'=> array('PlaygroupPlayers.playgroup_id = Playgroup.id', 'PlaygroupPlayers.player_id'=>$id) 
                ),
                array(
                    'table' => 'playgroup_activities', 
                    'alias' => 'PlaygroupActivity', 
                    'type' => 'inner', 
                    'foreignKey' => false, 
                    'conditions'=> array('PlaygroupActivity.playgroup_id = Playgroup.id') 
                )
            ),
            'contain'=> array('PlaygroupActivity')
        ));

结果是：

{
   "data":[
      {
         "Playgroup":{
            "id":"3",
            "name":"South Florida Redemption",
            "email":null,
            "email_username":null,
            "email_password":null,
            "tag":null,
            "description":null,
            "avatar_url":null,
            "city":null,
            "state":null
         },
         "PlaygroupActivity":[
            {
               "id":"3",
               "text":"FINAL RESULTS OF THE FLORIDA STATE TOURNAMENT ",
               "timestamp":"2011-11-02 00:13:33",
               "playgroup_id":"3",
               "timeSince":"1320210813000"
            }
         ]
      },
      {
         "Playgroup":{
            "id":"2",
            "name":"Redemption Springfield",
            "email":null,
            "email_username":null,
            "email_password":null,
            "tag":null,
            "description":null,
            "avatar_url":null,
            "city":null,
            "state":null
         },
         "PlaygroupActivity":[
            {
               "id":"2",
               "text":"Due to bad weather, our Redemption meet today will be canceled.",
               "timestamp":"2011-02-01 14:16:21",
               "playgroup_id":"2",
               "timeSince":"1296591381000"
            },
            {
               "id":"1",
               "text":"Remember we have a meet Tuesday, February 1rst at the Greene County Library Station at 6:30pm.",
               "timestamp":"2011-01-28 23:01:57",
               "playgroup_id":"2",
               "timeSince":"1296277317000"
            }
         ]
      },
      {
         "Playgroup":{
            "id":"2",
            "name":"Redemption Springfield",
            "email":null,
            "email_username":null,
            "email_password":null,
            "tag":null,
            "description":null,
            "avatar_url":null,
            "city":null,
            "state":null
         },
         "PlaygroupActivity":[
            {
               "id":"2",
               "text":"Due to bad weather, our Redemption meet today will be canceled.",
               "timestamp":"2011-02-01 14:16:21",
               "playgroup_id":"2",
               "timeSince":"1296591381000"
            },
            {
               "id":"1",
               "text":"Remember we have a meet Tuesday, February 1rst at the Greene County Library Station at 6:30pm.",
               "timestamp":"2011-01-28 23:01:57",
               "playgroup_id":"2",
               "timeSince":"1296277317000"
            }
         ]
      }
   ],
   "status":200
}

---

为find（）引入'fields'键，列出返回结果中需要的所有字段，包括'DISTINCT Playgroup.id'

和使用连接-GROUP BY sql语句最适合我删除相同数据的多次出现：

$this->find('all', array('group' => 'Playgroup.id', 'join' => etc....));

---

对于我来说，字段添加不起作用，但对于分页添加：

$this->paginate = array_merge_recursive($this->paginate, array('group' => '`Vehicle`.`id`'));//for duplicate removal

---

奥列格斯方法也会起作用；我正在使用两个的组合来连接。不要！真不敢相信我居然没想到groupBY！请注意，尽管这在某些MySQL设置中可能有效（我所说的“工作”是指不会导致错误），但这不是一个正确的查询，结果是未定义的。在GROUPBY子句中，需要指定所有非聚合字段。这也意味着你可能不会，在某些时候也不会，得到你想要的结果。现在，如果你想每个玩家只有一个游戏组，你需要指定哪一个！