How to get a list of skus in magento - magento

Question

How to get a list of skus whiout using the looping in magento.
Example: I am using below code with my conditons.
$productsCollection = Mage::getModel('catalog/product')->getCollection()
->addAttributeToSelect('sku');
Now I want to result as array('A001','A002'....) etc.
I don't want to iterate (loop) the product collection.
Please suggest.

Answer 1

If you want to retrieve the collection in that way, you will have to loop through the collection and retrieve the sku.
$skus = array();
foreach ($productsCollection as $product) {
$skus[] = $product->getSku();
}
If you don't want that, you can just use a simple query because the SKU is kept in the catalog_product_entity table.
$conn = Mage::getSingleton('core/resource')->getConnection('core_write');
$table = 'catalog_product_entity';
$q = "SELECT sku FROM {$table}";
$list = $conn->fetchOneFieldAll($q, 'sku');

Answer 2

Retrieve the read connection you should use ->getConnection('core_read') not ->getConnection('core_write'). Whole codes is below which runs faster.
$resource = Mage::getSingleton('core/resource');
$readConnection = $resource->getConnection('core_read');
$skus = $readConnection->fetchCol('SELECT sku FROM `catalog_product_entity`');
foreach ($skus as $sku) {
echo $sku;
}