Magento 2 – Sort Product Collection by Last Update

What about something like this:

    Mage::getResourceModel('catalog/product_collection')
        ->addAttributeToFilter('type_id', array('eq' => 'simple'))
        ->addAttributeToFilter('sku', array("notnull" => true))
        ->addFieldToFilter('visibility', Mage_Catalog_Model_Product_Visibility::VISIBILITY_NOT_VISIBLE)
        ->addFieldToFilter('status', Mage_Catalog_Model_Product_Status::STATUS_ENABLED)
        //->addAttributeToSelect('entity_id')   // you don't need this
        ->addAttributeToSelect('search_sku_textfield')
        //->addAttributeToSelect('sku')         // static attributes are always loaded
        ->addFieldToFilter('entity_id', array('gt' => $productId))
        ->addFieldToFilter('attribute_set_id', $attributeSetId)
        ->setOrder('entity_id')
        ->setPageSize(100);

If it helps anyone, this is the only way I've managed to get all products, including out of stock products, in a loop for updating the stock values.

I needed to use ->getAllIds() to get an array of all of the products IDs, and then load each product individually rather than loop through the whole collection.

$productCollection = $objectManager->create('Magento\Catalog\Model\ResourceModel\Product\CollectionFactory');
$productCollectionIds = $productCollection->create()->getAllIds();

foreach ($productCollectionIds as $productId) {
    try {
        $product = $objectManager->create('Magento\Catalog\Model\Product')->load($productId);
        // do actions with product
    } catch (Exception $e) {
        $e->getMessage();
    }
}