Fastest way to assign multiple products to the same category programmatically?

Question

I am working in a process to will weekly updating a list of products and assign them to a sales category. The list could have 2000 products or more each time. Right now I am using the method assignProductToCategories from \Magento\Catalog\Api\CategoryLinkManagementInterface

foreach($updatedSalesProducts as $_sku => $_categoryIds){
   $productModel       = $this->_productRepository->get($_sku, true, \Magento\Store\Model\Store::DEFAULT_STORE_ID, true);
   $currentCategories  = $productModel->getCategoryIds();
   $_categoryIds        = array_merge($currentCategories, $_categoryIds);
   $_categoryIds        = array_unique($_categoryIds);

   $this->_categoryLinkManagementInterface->assignProductToCategories($_sku, $_categoryIds);
}

However, each product is taking around 4 seconds to update. So, in total, all the processes are taking 2 hours or more. Is there a faster way to assign the 2000 products to the same category without taking too much time?

Answer 1

Following @HamendraSunthwa comment, I tried doing it using the setPostedProducts options. The code ends something like this:

First I changed the generation of $updatedSalesProducts. Before it was a relation sku => categoryIds. Now is categoryId => sku's to has all the skus assigned to a same category. Like this:

Before:

SKU1 => [
  CategoryId1,
  CategoryId2,
  CategoryId3
]

After:

CategoryId1 => [
  SKU1,
  SKU2,
  SKU3
]

Now the code looks like this:

foreach($updatedSalesProducts as $_categoryId => $_skusArray){
  $category                 = $this->_categoryRepository->get($_categoryId);
  $originalProductPositions = $category->getProductsPosition();
  $newProductPositions      = $originalProductPositions;
  $position                 = 0;

  foreach($_skusArray as $_sku){
    $newProductPositions[$this->_productResourceModel->getIdBySku($_sku)] = $position;
    $position++;
  }

  if(count($originalProductPositions) != count($newProductPositions)){
    $category->setPostedProducts($newProductPositions);
    
    try{
      $category->save();
    }catch(\Exception $e){
      $this->_logger->info($e);
    }
  }
}

In the firsts two tests, I faced an error throw "SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry" in url_rewrite table. I deleted the records that caused the conflict, and rerun the script, and the rows were generated again, and the products were assigned to the category successfully,

Answer 2

$preparedProducts is an array should look like [product_id] => product_position

$categories can be string or array and its category id

/**
 * Assign product to categories
 */
public function assignToCategories($preparedProducts,$categories)
{
    try {
        if($preparedProducts && $categories){
            foreach($categories as $categoryId){
                $setPositionInCategory = $this->categoryRepository->get($categoryId, Store::DEFAULT_STORE_ID);
                $productPositions      = $setPositionInCategory->getProductsPosition();
                $setPositionInCategory->setPostedProducts(($preparedProducts + $productPositions));
                $setPositionInCategory->save();
            }
        }
    } catch (Exception $exception) {
        $this->messageManager->addErrorMessage(__("An error occured: %1", $exception->getMessage()));
    }
}