使用Laravel雄辩的关系(一对多）返回NULL

当我使用Laravel雄辩关系（一对多）时，结果为NULL。我在"work_hour"表中设置了数据，其中"workers_id"的值为2，"workers"表中有一行的id为2我遵循了文件"Laravel关系"

我的模式如下：

public function up()
    {
        Schema::create('work_hour', function($table){
            $table->increments('id');
            $table->integer('worked_hour');
            $table->time('worked_from');
            $table->time('worked_to');
            $table->integer('workers_id')->unsigned();
            $table->foreign('workers_id')->references('id')->on('workers');
            $table->integer('workday_id');
            $table->integer('offer_id');
        });
    }

PS：列workday_id，offer_id还没有设置为外部！

型号如下：

class Worker extends Eloquent{
    protected $fillable = ['first_name', 'last_name'];
}
class Workhour extends Eloquent{
    protected $table    = 'work_hour';
    public function worker(){
        return $this->belongsTo('Worker','workers_id');
    }
}

控制器PS：我在SO上搜索了同样的问题，我尝试了一些意见，然后我评论了

class WorkerController extends BaseController {
    protected $table    = 'workers';
....
    public function show($id){
        $worker     = Worker::find($id);
    //  $workhour   = Workhour::where('workers_id','=',$worker->id)->get(); 
    // casting the result: works $workhour->toArray()
    //  $workhour   = Worker::find($id)->with('workhour')->get(); 
    //Call to undefined method Illuminate'Database'Query'Builder::workhour()
    //  $workhour   = Worker::with('workhour')->where('id',2)->get(); 
    //Call to undefined method Illuminate'Database'Query'Builder::workhour()
    $workhour   = Worker::find($id)->workhour; 
    // null
        dd($workhour);
        return View::make('worker.show',['worker' => $worker,'workhour'=>$workhour]);
    }
    public function workhour(){
      return $this->hasMany('Workhour','workers_id');
    }

}

我用"…/public/worker/2"（Laravel 4）来称呼"showblade.php"我做错了什么？