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How to access specific intermediate table in case of multiple ManyToMany relationships in Laravel Eloquent relationship

I have a model Product, and the same product can be sold by multiple supermarkets and outlets, so I define two BelongsToMany relationships for them:

class Product extends Model
{
    public function supermarkets(): BelongsToMany
    {
        return $this->belongsToMany(
            Supermarket::class,
            'product_supermarket',
            'product_id',
            'supermarket_id'
        );
    }

    public function outlets(): BelongsToMany
    {
        return $this->belongsToMany(
            Outlet::class,
            'outlet_product',
            'product_id',
            'outlet_id'
        );
    }
}

Then in the Supermarket model I define a BelongsToMany relastionship to Products model, since one supermarket can sell many different products.

class Supermarket extends Model
{
    public function products(): BelongsToMany
    {
        return $this->belongsToMany(
            Product::class,
            'product_supermarket',
            'supermarket_id',
            'product_id'
        );
    }
}

If I want to access the intermediate table product_supermarket, I can:

foreach ($supermarket->products as $product) {
    echo $product->pivot->created_at;
}

However, we see that Product model has two BelongsToMany defined in its class. So what will property pivot be like in such a case? How can I access the intermediate table product_supermarket or outlet_product specifically?

I read the official documentation of Laravel but found nothing about it metioned in it: https://laravel.com/docs/11.x/eloquent-relationships

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    I've figured it out. So if you want to return a specific intermediate table by 'pivot', you need to get the related model instances from the model that this intermediate table is bounded to. For example:

    $outlet = AppModelsOutlet::find(1);
foreach($outlet->products as $product) 
{ 
   echo $product->pivot; // access the outlet_product table
}

$supermarket = AppModelsSupermarket::find(1);
foreach($supermarket->products as $product) 
{ 
   echo $product->pivot; // access the product_supermarket table
}

  2. 0

    You can use https://laravel.com/docs/11.x/eloquent-relationships#customizing-the-pivot-attribute-name to alias the pivot attribute name for each relationship you have.

    class Supermarket extends Model
{
    public function products(): BelongsToMany
    {
        return $this->belongsToMany(
            Product::class,
            'product_supermarket',
            'supermarket_id',
            'product_id'
        )->as('supermarkets_pivot');
    }
}

    and the reverse if you need it.

    class Product extends Model
{
    public function supermarkets(): BelongsToMany
    {
        return $this->belongsToMany(
            Supermarket::class,
            'product_supermarket',
            'product_id',
            'supermarket_id'
        )->as('supermarkets_pivot');
    }

    public function outlets(): BelongsToMany
    {
        return $this->belongsToMany(
            Outlet::class,
            'outlet_product',
            'product_id',
            'outlet_id'
        )->as('outlets_pivot');
    }
}

    Then you can access each one by it’s pivot alias outlets_pivot or supermarkets_pivot I also recommend to eager load those relationships since you are already looping through all of them to avoid n+1 query if you are querying multiple supermarkets.

    Also note that

    foreach ($supermarket->products as $product) {
    echo $product->pivot->created_at;
}

    the pivot here will always be the pivot related to the product and supermarket.

    foreach ($outlet->products as $product) {
    echo $product->pivot->created_at;
}

    and here it will always be for the outlets and products.
    So you might not need the alias in most cases.

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