Laravel eloquent find（）返回找不到自定义主键

I have set in my model a custom primary key as:

protected $primaryKey = 'id_player';

It is set as the primary key on MySql

But If I do a

$rows = DB::table("players")->find($playerId);

It returns no items (but it exists).

Players Model

 namespace App;
 use Illuminate\Database\Eloquent\Model;

 class Players extends Model{
    protected $primaryKey = 'id_player';
 }

PlayersController

namespace App\Http\Controllers\Players;

use Illuminate\Http\Request;
use App\Http\Controllers\Controller;
use App\Players;
use Illuminate\Support\Facades\DB;

class PlayersController extends Controller{
   ...
   ...
}

I'm new on Laravel, what I'm missing?

You are querying from the table.

If you want to use Model primaryKey, you need to access from the Model eloquent

//Supposing your Model Name is User

$row = App\User::find($playerId);

This will work:

$rows = DB::table("players")->where('id_player', $playerId)->first();