yii relations求救 [ 未指定版本 ]

数据库是 mysql myisam 

现有已表 train 培训表

train_people 参加培训的人员表

一个train对应多个 train_people 通过 train的主键 train_id关联的 train_people 里面也有个train_id

在Train model里面

public function relations()
{
// NOTE: you may need to adjust the relation name and the related
// class name for the relations automatically generated below.
return array(
'people'=>array(self::HAS_MANY, 'TrainPeople', 'train_id'),
);
}

这样写的

查询语句

$model = new Train();
        $model_user = new User();
        $criteria = new CDbCriteria;
        //$criteria->condition = "";
        $criteria->order = 'add_time DESC';
        $criteria->select = '*';
        $count = $model->count($criteria);
        $pager = new CPagination($count);
        $pager->pageSize = 10;
        $pager->applyLimit($criteria);
        $lists = $model->with('people')->findAll($criteria);
        var_dump($lists->people);
结果为 空 数据库里我添加数据了 请问这是什么情况