title: Laravel One to many relation with custom primary key not working
body: <p>I am trying to implement one to many relation in laravel
  My tables have custom primary key name not id</p>
  
  <p>I have set <code>$primartKey</code> attribute as well but the relations doesnot seem to work.</p>
  
  <pre><code>activities
  |act_ID|act_acc_ID|.........
  
  categories
  |acc_ID|.......
  </code></pre>
  
  <p>Here are my Models</p>
  
  <pre><code>class Adventure extends \Eloquent {
  
  
      /**
       * @var string $table the name of the table
       */
      protected $table = 'activities';
  
      /**
       * @var string $primaryKey the primary key of the table
       */
      protected $primaryKey = 'act_ID';
  
      /**
       * @var bool timestamps updated_at and created_at columns flag
       */
      public $timestamps = false;
  
      /**
       *
       */
      public function category(){
          $this-&gt;belongsTo('Category','act_acc_ID');
      }
  }
  
  
  class Category extends \Eloquent {
  
      /**
       * @var string $table the name of the table
       */
      protected $table = 'categories';
  
      /**
       * @var string $primaryKey the primary key of the table
       */
      protected $primaryKey = 'acc_ID';
  
      /**
       * @var bool timestamps updated_at and created_at columns flag
       */
      public $timestamps = false;
  
      public function adventures(){
          $this-&gt;hasMany('Adventure','act_acc_ID');
      }
  }
  </code></pre>
  
  <p>Now when ever i try to access categories from adventure or adventures from categories i get </p>
  
  <blockquote>
    <p>Relationship method must return an object of type
    Illuminate\Database\Eloquent\Relations\Relation</p>
  </blockquote>
  
  <p>What am i doing wrong here ??
  There are plenty adventures whose category is 15 so i try
  I try <code>Categories::find(15)-&gt;adventures</code> also tried <code>Categories::find(15)-&gt;adventures()</code></p>