CSV update products, without losing other column informations

[rob84]

Hello. I'm trying to update products with CSV import function. After creating the CSV and imported it, all works fine. Now the problem is the our suppliers update some informations in CSV 4 times a day, and i'm finding a way to update quantity in stock, and pricing. Unfortunately when I import only 2 columns (ignoring all the others), the quantiy and pricing update succesfully, but I lost all other informations. I use the key as product reference, 'cause I can't use the product ID's which is different from the supplier ID's. Now the goal is to import and update only interested columns, keeping all others information that are not imported. I found this code in adminimport.php

if (Tools::getValue('match_ref') == 1 AND $product->reference AND Product::existsRefInDatabase($product->reference))
				{
					$datas = Db::getInstance()->getRow('SELECT `date_add`, `id_product` FROM `'._DB_PREFIX_.'product` WHERE `reference` = "'.$product->reference.'"');
					$product->id = pSQL($datas['id_product']);
					$product->date_add = pSQL($datas['date_add']);
					$res = $product->update();
				} // Else If id product AND id product already in base, trying to update
				else if ($product->id AND Product::existsInDatabase((int)($product->id), 'product'))
				{
					$datas = Db::getInstance()->getRow('SELECT `date_add` FROM `'._DB_PREFIX_.'product` WHERE `id_product` = '.(int)($product->id));
					$product->date_add = pSQL($datas['date_add']);
					$res = $product->update();
				}

Can someone help ?

Thanks.

Ps: 1.4.7.3

[rob84]

If I create CSV file with only 3 columns (Reference, name, quantity in stock), and using "use key as product reference",  the problem still remain. How can I say to prestashop while importing a CSV that "if product reference already exist" and "if I select to ignore some other columns" other informations must remain the same and not drawn ?