Assign category_ids to Product by using updateAttributes in Magento

Question

I'm trying to set category_ids to a product by using following code:

<?php
Mage::getSingleton('catalog/product_action')->updateAttributes(
    array($product->getId()), 
    array("category_ids"=>$this->convertCategories($prod['categories']))
    ,0
);
?> 

Unfortunatly script exits with an exception: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'attribute_id' in 'where clause'

Some hints? I don't want to use $product->setCategoryIds()->save() since it's much more longer in execution.

Thanks in advance.

Answer 1

In the end I've had to slightly modify one of magento function and make a workaround:

/**
* Updates product categories
*
* @param Mage_Catalog_Model_Product $product
* @param array $categoryIds
* @return MagentoImporter
*/
protected function updateCategories(&$product, $categoryIds)
{
    /** @var Varien_Db_Adapter_Pdo_Mysql **/
    $dbw = Mage::getSingleton('core/resource')->getConnection('core_write');
    $productCategoryTable = Mage::getSingleton('core/resource')->getTableName('catalog/category_product');

    $oldCategoryIds = $product->getCategoryIds();

    $insert = array_diff($categoryIds, $oldCategoryIds);
    $delete = array_diff($oldCategoryIds, $categoryIds);

    if (!empty($insert)) {
        $data = array();
        foreach ($insert as $categoryId) {
            if (empty($categoryId)) {
                continue;
            }
            $data[] = array(
                'category_id' => (int)$categoryId,
                'product_id'  => (int)$product->getId(),
                'position'    => 1
            );
        }
        if ($data) {
            $ris = $dbw->insertMultiple($productCategoryTable, $data);
        }
    }
    if (!empty($delete)) {
        foreach ($delete as $categoryId) {
            $where = array(
                'product_id = ?'  => (int)$product->getId(),
                'category_id = ?' => (int)$categoryId,
            );
            $ris = $dbw->delete($productCategoryTable, $where);
        }
    }
    return $this;
}

Thanks bixi for pointing out fact about category_ids, the strange thing is that although it's not an attribute there is an entry in eav_attribute table called category_ids, and magento is loading attribute model with this code, but crashing when trying to save attribute. Maybe it would be better to remove category_ids attribute at all, so people wouldn't think that its' a bug.

About indexes: probably I will need to reindex all data, just in case after using my function, it's not a big deal since product saving by using updateAttributes went from 9sec to 0.75.

Answer 2

You can't use updateAttributes() when dealing with categories (a category isn't an attribute). You'll have to deal with the models (catalog/product) ...

It's slow because of the indexes generation (if your indexes are on "Update On Saves") and depending of your catalog configuration (are your categories all "is_anchor" == true ?) All that is slow but needed ..