Laravel 5 Eloquent hasMany relation返回数组：1 [0 =＆gt;空值]

Question

我有以下类作为模型：

class WorkOrder extends Model {
    protected $connection = 'qcmms-epdevl';
    protected $primaryKey = "workorder-id";  
    public $table = "PUB.pm-work-card";  

    public function jobs(){
        return $this->hasMany('pm-work-job', 'workorder-id', 'workorder-id');
    }
}

class WorkJobs extends model {
    protected $connection = 'qcmms-epdevl';
    protected $table = "PUB.pm-work-job";
    protected $primaryKey = "workjob-id";
}
(*) There is a field "workorder-id" in this table.

WorkorderController如下：

class WorkorderController extends Controller {

    private $repo;
    public function __construct(WorkOrderRepository $repo)
    {
        $this->repo = $repo;
    }

    public function artisan()
    {
        $workorders = $this->repo->getArtisanRecords();
        foreach ($workorders as $workorder){
            $data = array($workorder->jobs);
             app('debugbar')->warning($data);  
        }
     }
}

WorkorderRepository是这样的：

class WorkOrderRepository
{
    public function __construct(WorkOrderModel $workOrderModel)
    {
        $this->model = $workOrderModel;
    }
    public function getArtisanRecords()
    {
        $user = \Auth::user()->getAttribute('emp-id');
        return ($this->model->select(
            'pm-work-card.wo-number',
            'pm-work-card.wo-initial-date',
            'pm-work-card.emp-id',
            'pm-work-card.workorder-id',
            'pm-assets.asset-no',
            'pm-assets.asset-desc',
            'pm-employee.emp-name',
            'pm-employee.emp-surname',
            'sys-code.cde-desc',
            'pm-work-spares.qty-used'
         )

        ->join('PUB.' . 'pm-assets' , function($join)
        {
            $join->on('pm-assets.asset-number-id', '=', 'pm-work-card.asset-number-id');
        })

        ->leftjoin('PUB.' . 'pm-employee' , function($join2)
        {
            $join2->on('pm-employee.emp-id', '=', 'pm-work-card.emp-id')
            ;
        })

        ->join('PUB.' . 'sys-code' , function($join3)
        {
            $join3->on('pm-work-card.wo-status', '=', 'sys-code.tab-cde')
                ->where('sys-code.tab-no', '=', 9300);
        })

        ->leftjoin('PUB.' . 'pm-work-spares' , function($join4)
        {
            $join4->on('pm-work-spares.workorder-id', '=', 'pm-work-card.workorder-id')
            ;
        })


        ->where('pm-work-card.emp-id', '=', $user)
        ->where(function($query){
                           $query->where('pm-work-card.wo-status', '=', 'O')
                               ->orwhere('pm-work-card.wo-status', '=', 'S');
                 })
        ->orderBy('wo-number', 'desc')
        ->get());
}

我遇到的问题是$ data返回null数组，而$ workorders返回控制器中的所有正确数据。
我需要这个（移动能力）才能在没有将字段重新映射到Laravel规范的情况下工作，因为已经部署了应用程序。（使用破折号而不是下划线）
我是Laravel＆amp;的新手。 PHP和任何帮助将不胜感激。