decrement('column_name') on trashed related model

Or do it in the deleting event (or an observer), so that you don't need to add this code in every place you might delete a review

@j4wx an Observer (of itself) does not solve the question actually asked.

Of course it doesn't. That's why I replied to your existing answer with a supplement instead of posting my own.

What a bizarre statement.

Ok, Call to a member function decrement() on null suggests that the Category instance does not exist (or at least, it does not load) - do you also delete or soft-delete the category?

No the category is not softdeleted. The category is ok. The error is showed on the line in which I try to decrement the product.

And I'm doing this test following the workflow, so softdelete the product and related review and then forcedelete the review one by one.

Exactly my point; $review->category is null, why? Even when the Review is trashed, the associated Category, if (i) the foreign key is valid on categories and (ii) the referenced Category is not itself not soft-deleted, should load; but you get null

I've tried also this:

public function deletePermanentlyService(int $id) :void
    {
        $review = Review::onlyTrashed()->findOrFail($id);

        $review->forceDelete();

        if ($review->no_yes == 'yes') {

            $review->category->decrement('total_reviews');
            $review->category->decrement('total_yes');

            $product = $review->product;
            $product->decrement('total_reviews');
            $product->decrement('total_yes');

        } elseif ($review->no_yes == 'no') {

            $review->category->decrement('total_reviews');
            $review->category->decrement('total_no');

            $product = $review->product;
            $product->decrement('total_reviews');
            $product->decrement('total_no);
        }

    }

Still shows me

Call to a member function decrement() on null

I don't really understand why, yes it throws me that error but the review itself with the last method is deleted, the category is decremented, but the product which is softdeleted is not decremented.

I may think that the category has nothing to do with that...

So it is the product, and not the category giving rise to the exception.

Because the product is soft-deleted, the result of $review->product is null; you need to load the Product using withTrashed method:

$product = $review->product()->withTrashed()->first();

Still same error... strange

Edit: Sorry no same error but:

Call to a member function withTrashed() on null

Do you have (i) a product relationbship on Review; (ii) a valid product_id on the Review record?

Yes of course.

Product model:

public function reviews()
   {
       return $this->hasMany(Review::class, 'product_id', 'id');
   }

Review model:

public function product()
    {
        return $this->belongsTo(Product::class);
    }

reviews migrations:

public function up()
    {
        Schema::create('reviews', function (Blueprint $table) {
            $table->id();
            $table->unsignedBigInteger('user_id')->nullable();
            $table->unsignedBigInteger('category_id');
            $table->unsignedBigInteger('status_id');
            $table->unsignedBigInteger('product_id')->nullable();
            $table->unsignedBigInteger('content_id')->nullable();
            $table->string('title')->nullable();
            $table->text('other_content')->nullable();
            $table->string('no_yes');
            $table->string('shop_name');
            $table->string('shop_address');
            $table->string('invoice')->nullable();
            $table->string('product_origin')->nullable();
            $table->string('declined_reason')->nullable();
            $table->string('approved_by')->nullable();
            $table->softDeletes();
            $table->timestamps();

            $table->foreign('user_id')->references('id')->on('users');
            $table->foreign('category_id')->references('id')->on('categories');
            $table->foreign('status_id')->references('id')->on('statuses');
            $table->foreign('product_id')->references('id')->on('products');
            $table->foreign('content_id')->references('id')->on('contents');
        });
    }

Yes that's right. Now that I'm thinking maybe the issue will be for the category too in case that the related category would be soft-deleted to...

If I do:

dd($review->product());

It will show me:

Illuminate\Database\Eloquent\Relations\BelongsTo {#454 ▼
  #child: App\Models\Review {#1526 ▶}
  #foreignKey: "product_id"
  #ownerKey: "id"
  #relationName: "product"
  #query: Illuminate\Database\Eloquent\Builder {#560 ▶}
  #parent: App\Models\Review {#1526 ▶}
  #related: App\Models\Product {#1439 ▶}
  #withDefault: null
}

If I try to dd($review->product); it will throw the same error.

The bindings should be the product_id from the Review? : Yes.

I've tried dd(Product::onlyTrashed()->findOrFail($review->product_id)); also but the error:

No query results for model [App\Models\Product]

So I cannot even catch the product using the $review->product_id.

onlyTrashed means that the Product must be soft-deleted, whereas withTrashed means the Product might be soft-deleted. Subtle, but important difference.

Yes I know, in this case the product is soft-deleted and still is not working. I tried with withTrashed also but same error as was with onlyTrashed.

what does dd($review->category) give you?

Also, is that method used in a for loop or the like? It may appear that the category is okay, but if you are doing it in a loop maybe most are okay but some of them are not.

ps. if you may register in larachat.slack.com, there is a community it may help you more with this problem.

Like I specified before dd($review->category) it gives me same results as dd($review->product):

Call to a member function withTrashed() on null

The problem is only when a related belongsTo is soft-deleted. I managed it in a very bad way but I had no choice at the moment and I don't have time right now to go and find a better solution.

Thanks for sharing larachat.slack.com with me.