laravel如何實現不同數據庫的模型進行關聯

假設模型Replenishment和模型Product要關聯，並且模型Replenishment和模型Product的表是在不同數據庫

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Replenishment extends Model
{
    protected $fillable = ['g_code'];
    public $table = 'replenishment';
    protected $connection = "mm"; //config/database.php中的connections數組中的
    public function product(){
        $connection = 'mysql';//config/database.php中的connections數組中的

        return $this->setConnection($connection)->belongsTo(Product::class,'g_code','code');//Product::class就是要關聯的模型，g_code和code是關聯字段
    } 
}