Limit inside WhereHas

Question

So I want to get requests which have last status equal to given status I've tried with first() but it gives me an error and limit is not working

$requests = Request::whereHas('requestStatus', function ($query) use ($status) {
            return $query->where('status',$status)->orderBy('updated_at', 'desc')->limit(1);
        })->get();

Controller

    public function listByStatus($status)
    {   

        $requests = Request::whereHas('requestStatus', function ($query) use ($status) {
        return $query->where('status',$status)->orderBy('updated_at', 'desc')->limit(1);
    })->get();


        return view('admin.request.list',compact('requests','status'));
    }

Model Request

public function requestStatus()
{
    return $this->hasMany('App\RequestStatus');
} 

Migration RequestStatus

Schema::create('request_status', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('request_id')->unsigned();;
    $table->foreign('request_id')->references('id')->on('requests');
    $table->string('status');
    $table->string('image')->nullable();
    $table->timestamps();
});

Answer 1

Try this:

$requests = Request::select('requests.*')
    ->join('request_status', 'requests.id', 'request_status.request_id')
    ->where('request_status.status', $status)
    ->where('request_status.id', function($query) {
        $query->select('id')
            ->from('request_status')
            ->whereColumn('request_id', 'requests.id')
            ->orderByDesc('updated_at')
            ->limit(1);
    })
    ->get();

Answer 2

To avoid N+1 problem you can use the power of the collections :

$requests = Request::whereHas('requestStatus', function ($query) use ($status) {
            return $query->where('status',$status)->orderBy('updated_at', 'desc');
        })->get()
          ->map(function($request) {
                $request->setRelation('requestStatus', $request->requestStatus->take(1));
                return $request;
            });