Check if belongsToMany relation exists

HasPivotTrait.php

<?php
namespace App\Traits;

use Illuminate\Database\Eloquent\Model;

trait HasPivotTrait
{
    /**
     * 检查多对多关系是否存在.
     *
     * @param string $relation
     * @param Model  $model
     *
     * @return bool
     */
    public function hasPivot(string $relation, Model $model)
    {
        return (bool) $this->{$relation}()->wherePivot($model->getForeignKey(), $model->{$model->getKeyName()})->count();
    }
}