Question

I am looking for a solution to storing product attributes with each order. Essentially I have a need for storing a unique item lot number for each product that can then be searched on the front end to find out which orders contained products from a specific lot. My initial thought was to do this with product attributes and store the attribute with each product in an order.

Does anybody have a better solution or can point me in the right direction for implementing this solution?

Edit: Still looking for a solution to this

Answer 1

I agree the lot number should be a product attribute but you don’t need to store it twice. Just join it with order table when you later need it – That way the information is kept up to date (unless you want to know what it was at the time of ordering, in which case this is all wrong).

Unfortunately the order tables are flattened, not EAV, so don’t handle attributes so well. The collection’s joinAttribute() method is a stub. You can get around that with this query patterns library (self promotion disclaimer; I’m using it here because I wrote the attribute functions and don’t want to redo the work) and then extending it with a class specific to you.

class Knectar_Select_Product_Lot extends Knectar_Select_Product
{
    public function __construct()
    {
        parent::__construct();
        $this->joinAttribute('lots', 'catalog_product', 'lot_number',
            'products.entity_id', 0, 'lot_number'
        );
    }

    public static function enhance(Varien_Db_Select $select, $tableName, $condition, $columns = null, $type = self::LEFT_JOIN)
    {
        $select->_join(
            $type,
            array($tableName => new self()),
            $condition,
            $columns ? $columns : 'lot_number'
        );
    }
}

The enhance() function does the hard bit, you only need to call it and filter by it’s column.

$orderItems = Mage::getResourceModel('sales/order_item_collection');
Knectar_Select_Product_Lot::enhance($orderItems->getSelect, 'lots', 'lots.product_id = main_table.product_id');
$orderItems->addFieldToFilter('lot_number', 'ABC123');

If you are using the collection in an admin grid then it’s column filters will do addFieldToFilter() for you.