Laravel 4：为什么我不能在laravel代码中使用别名

Question

这是我的代码：

public function getReports()
        {   


            $reports=DB::table('reports')
            ->select(array('*',DB::raw('reports.id','reports.departmentID','reports.officerID','reports.created_at','reports.report','reports.title','department.name','posts.name AS pname')))
            ->leftjoin('department','reports.departmentID','=','department.id')
            ->leftjoin('posts','reports.postID','=','posts.id')             
            ->leftjoin('users','reports.officerID','=','users.id')
            ->leftjoin('events','events.id','=','reports.eventID')
            ->orderBy('reports.id','DESC')
            ->get();

            $reportsArray=array();
            foreach($reports as $row)
            {
                $reportsArray[]=array(
                    'id'=>$row->id,
                    'report'=>$row->report,
                    'title'=>$row->title,
                    'departmentName'=>$row->name,               
                    'created_at'=>$row->created_at,
                    'post'=>$row->pname,
                    );
            }

            return View::make('reports.reports')
            ->with('reports',$reportsArray);

        }

加载视图时出现以下错误：未定义属性：stdClass :: $ pname 这基本上是一个问题，因为我需要在许多实例中使用别名。当我尝试对任何列使用列别名时，错误基本相同。任何人都可以看到我的代码存在问题吗？

我的模特：

class Report extends Eloquent
{
 protected $table = 'reports';  
protected $fillable= array(
'title','reportDate',,'departmentID','date','eventID','officerID','postID‌​',
);
 }