Help: HasManyDeep for Polymorphic many-to-many

[Aniket-IN]

Hi,

First of all thank you so much for this awesome package. I need a lil help.

I've Order model and Order hasMany OrderItem and Shipment like this:

    // Order model
    public function items()
    {
        return $this->hasMany(OrderItem::class);
    }
    public function shipments()
    {
        return $this->hasMany(Shipment::class);
    }

And items and shipments has Cancel whcih is a polymorphic many to many relation.

    // Item and Shipment model
    public function cancels()
    {
        return $this->morphToMany(Cancel::class, 'cancelable');
    }

Now, I want to aceess all cancels directly from Order. Is that possible?

---

I've tried something like this:

    // Order model
    public function cancels()
    {
        return $this->hasManyDeep(
            Cancel::class,
            [OrderItem::class, 'cancelables'],
            [null, ['cancelable_type', 'cancelable_id'], 'id'],
            [null, null, 'cancel_id']
        );
    }

It works but returns cancels those are through OrderItem, but I want to get all cancels via OrderItem and Shipment together.

In addition, the current setup returns same Cancel multiple times, cause same Cancel belongs to many OrderItem.

Thank you so much in advance :)

[staudenmeir]

Hi @Aniket-IN,

This is actually not something the package can do: It (only) allows you to concatenate/chain relationships (A -> B -> C) but not to merge them – that's a different (and more complicated) topic. I also created a package for this: https://github.com/staudenmeir/laravel-merged-relations

Combine both packages:

use Staudenmeir\LaravelMergedRelations\Facades\Schema;

Schema::createMergeView(
    'all_cancels',
    [(new Order)->itemCancels(), (new Order)->shipmentCancels()]
);

class Order extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;
    use \Staudenmeir\LaravelMergedRelations\Eloquent\HasMergedRelationships;

    public function itemCancels()
    {
        return $this->hasManyDeep(
            Cancel::class,
            [OrderItem::class, 'cancelables'],
            [null, ['cancelable_type', 'cancelable_id'], 'id'],
            [null, null, 'cancel_id']
        );
    }

    public function shipmentCancels()
    {
        return $this->hasManyDeep(
            Cancel::class,
            [Shipment::class, 'cancelables'],
            [null, ['cancelable_type', 'cancelable_id'], 'id'],
            [null, null, 'cancel_id']
        );
    }

    public function allCancels()
    {
        return $this->mergedRelationWithModel(Cancel::class, 'all_cancels');
    }
}

Order::find($id)->allCancels;

In addition, the current setup returns same Cancel multiple times, cause same Cancel belongs to many OrderItem.

If the allCancels relationship itself works, try creating the view with createMergeViewWithoutDuplicates() instead of createMergeView(). I'm not totally sure if that works in your case, but we'll find another solution if it doesn't.

[Aniket-IN]

Thank you @staudenmeir ,

This is exactly what I wanted, Honestly I'm a noob and had no idea about SQL Views.

Now I gotta learn more about SQL Views :)

So, just to confirm here's what I did:

• Created a new migration with php artisan make:migration create_order_cancels_view

  // this is the migration file
  return new class extends Migration
  {
  public function up()
  {
      \Staudenmeir\LaravelMergedRelations\Facades\Schema::createMergeViewWithoutDuplicates(
          'order_cancels',
          [(new Order)->itemCancels(), (new Order)->shipmentCancels()]
      );
  }
  
  public function down()
  {
      \Staudenmeir\LaravelMigrationViews\Facades\Schema::dropViewIfExists('order_cancels');
  }
  };

• Ran the migration with php artisan migrate
• Pasted your code for Order model as it is.

as you suggested using createMergeViewWithoutDuplicates is not returning and duplicated results :)

And it works as expected. I can not thank you enough.