php - 为什么这个PHP activerecord关联不起作用？

为什么这个密码坏了？这应该行得通，但不行。
我有三张桌子：

applications
   id, name
subjects
   id, name
application_subjects
   application_id, subject_id, notes

这些是我的模型：

<? # Application.php
 class Application extends ActiveRecord\Model
 {
  static $has_many = array(
     array('application_subjects'),
     array('subjects', 'through' => 'application_subjects')
  );
 }
?>

<? # Subject.php
 class Subject extends ActiveRecord\Model
 {
 }
?>

<? # ApplicationSubject.php
  class ApplicationSubject extends ActiveRecord\Model
  {
    static $has_many = array(
       array("subjects")
    );
  }
?>

以下是访问模型的代码：

$app = Application::find_by_id(1); # this brings up a valid application record

foreach($app->subjects as $s) {
   echo $s->name;
}

但当我运行代码时，我得到：

Fatal error: Uncaught exception 'ActiveRecord\HasManyThroughAssociationException' with message
'Could not find the association application_subjects in model Application'

最佳答案

似乎ApplicationSubject是一个连接模型。
如果是，请考虑以下设置…

class Application extends ActiveRecord\Model
{
  static $has_many = array(
    array('application_subjects'),
    array('subjects', 'through' => 'application_subjects')
  );
}

class Subject extends ActiveRecord\Model
{
  static $has_many = array(
    array('application_subjects'),
    array('applications', 'through'=> 'application_subjects')
  );
}

class ApplicationSubject extends ActiveRecord\Model
{
  static $belongs_to = array(
    array('application'),
    array('subject')
  );
}