Category has many manufacturers from product brands

[Stelios Eglezos]

I honestly tried everything before writing an issue but i couldn't find a solution.
In sort:

I'm trying to grab manufacturers from product categories and the only connection is through the product brand

Category→ many to many → Product→ has one → Brand→ has one → Manufacturer

Inside category.php model

  public function manufacturers() {
      return $this->hasManyDeep(Manufacturer::class, ['category_product', Product::class], [Brand::class],
      [
          'category_id', // Foreign key on the "category_product" table.
          'id', // Foreign key on the "products" table (local key).
          'manufacturer_id', // Foreign key on the "brands" table.
          'id' // Foreign key on the "manufacturers" table.
      ],
      [
          'id', // Local key on the "categories" table.
          'product_id', // Local key on the "category_product" table (foreign key).
          'id' // Local key on the "products" table,
          'id' // Local key on the "brands" table,
      ]
      );
  }

What am i doing wrong?

[Jonas Staudenmeir]

Hi @Stelikas,

['category_product', Product::class], [Brand::class]

Is this a typo or are passing two separate arrays here? It should be ['category_product', Product::class, Brand::class].

If that's not the issue, please share the migrations (local and foreign keys) of all tables involved in this relationship.

[Stelios Eglezos]

Hello @staudenmeir thanks for responding.

I changed the code as below:

public function manufacturers() {
      return $this->hasManyDeep(Manufacturer::class, ['category_product', Product::class, Brand::class],
      [
          'category_id',
          'brand_id',
          'manufacturer_id',
          'id'
      ],
      [
          'id',
          'product_id',
          'id',
          'id'
      ]
      );
  }

As of the tables:

category
--id

category_product
--category_id
--product_Id

product
--id
--brand_id

brand
--id
--manufacturer_id

manufacturer
--id

[Jonas Staudenmeir]

Use this relationship:

public function manufacturers() {
    return $this->hasManyDeep(
        Manufacturer::class,
        ['category_product', Product::class, Brand::class],
        [
            'category_id',
            'id',
            'id',
            'id',
        ],
        [
            'id',
            'product_id',
            'brand_id',
            'manufacturer_id',
        ]
    );
}

[Stelios Eglezos]

@staudenmeir I actually tried this and it displays a manufacturer two times.

[Jonas Staudenmeir]

There must be multiple paths from the category through the category_product table to this manufacturer (possibly with different products and/or brands). The query result is correct, but they are also ways to only get unique manufacturers.

What does your query look like in this case?

[Devstack]

@staudenmeir you can add ->distinct(); at the end of your relationship