[6.x] Call to a member function getCreatedAtColumn() on string

[maguilar92]

• Laravel Version: 6.4.1
• PHP Version: 7.3.1
• Database Driver & Version: Mysql 5.6

Description:

When using sync on relationship with using pivot class Call to a member function getCreatedAtColumn() on string is throwed.

Steps To Reproduce:

• As on my case, create a many to many relationship in mysql, for example products, categories and product_category with timestamps.

• Create the following models:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Category extends Model
{
    protected $table = 'categories';
    protected $guarded = ['id'];
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
    protected $table = 'products';
    protected $guarded = ['id'];

    public function categories()
    {
        return $this->belongsToMany(Category::class, (new ProductCategory)->getTable())
            ->using(ProductCategory::class)
            ->withTimestamps();
    }
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Relations\Pivot;

class ProductCategory extends Pivot
{
    protected $table = 'product_category';
    public $pivotParent = Product::class;
    protected $foreignKey = 'product_id';
    protected $relatedKey = 'category_id';
}

• Attempt to sync product with categories:

$product = new Product();
$product->save();
$category = new Category();
$category->save();
$product->categories()->sync([$category->id]);

Exception trace:

Error : Call to a member function getCreatedAtColumn() on string
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/AsPivot.php:222
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/AsPivot.php:211
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/AsPivot.php:45
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/AsPivot.php:76
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Model.php:1077
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithPivotTable.php:499
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithPivotTable.php:642
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithPivotTable.php:330
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithPivotTable.php:309
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithPivotTable.php:282
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithPivotTable.php:257
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithPivotTable.php:167
 /var/www/jet8-core/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithPivotTable.php:119

[staudenmeir]

You can't override the $pivotParent property like that, it needs to be a Model instance and is set by Laravel.

[maguilar92]

@staudenmeir I will prove now what you comment but in laravel 5.5 that works fine.

[maguilar92]

@staudenmeir I proved removing $pivotParent and all works fine now! Thank you so much.