Get orders and use them in cycle magento - magento

Question

i want to get all the orders from all the customers on admin side to export them in csv, but i am having problems getting them, in the foreach below dont know why it does not convert $collection to $col and give me the instance, can you help me please?
require_once('app/Mage.php');
Mage::app('admin');
Mage::getSingleton("core/session", array("name" => "adminhtml"));
Mage::register('isSecureArea',true);
$collection = Mage::getResourceModel('sales/order_collection')
->addAttributeToSelect('*');
$min_diff = '60';
$from_date = date("Y-m-d H:i:s", strtotime("-".$min_diff." minute"));
$to_date = date("Y-m-d H:i:s");
$collection->addAttributeToFilter('updated_at', array(
'from' => $from_date,
'to' => $to_date
));
Mage::log("80",null,"ordenes.log");
foreach ($collection as $col) { //falls here Mage::log($col,null,"ordenes.log");
echo '<tr>';
echo "<td>".$col->getIncrementId()."</td>";
echo "<td>".$col->getCreatedAt()."</td>";
echo "<td>".$col->getUpdatedAt()."</td>";
echo "<td>".$col->getState()."</td>";
echo "<td>".$col->getStatus()."</td>";
echo "<td>".$col->getHpcOrderId()."</td>";
echo "<td>".$col->getHpcOrderFrom()."</td>";
echo '</tr>';
}
echo '</table>';
echo "<br />supplement order ends";

Answer 1

The Problem is in your addAttributeToFilter() filter. The collection is getting empty data.
If you remove date filter then your code is working. Or try to increase the From & To date difference.
require_once('app/Mage.php');
Mage::app('admin');
Mage::getSingleton("core/session", array("name" => "adminhtml"));
Mage::register('isSecureArea',true);
$collection = Mage::getResourceModel('sales/order_collection')
->addAttributeToSelect('*');
$min_diff = '60';
$from_date = date("Y-m-d H:i:s", strtotime("-".$min_diff." minute"));
$to_date = date("Y-m-d H:i:s");
/*$collection->addAttributeToFilter('updated_at', array(
'from' => $from_date,
'to' => $to_date
));*/
Mage::log("80",null,"ordenes.log");
foreach ($collection as $col) { //falls here Mage::log($col,null,"ordenes.log");
echo '<tr>';
echo "<td>".$col->getIncrementId()."</td>";
echo "<td>".$col->getCreatedAt()."</td>";
echo "<td>".$col->getUpdatedAt()."</td>";
echo "<td>".$col->getState()."</td>";
echo "<td>".$col->getStatus()."</td>";
echo "<td>".$col->getHpcOrderId()."</td>";
echo "<td>".$col->getHpcOrderFrom()."</td>";
echo '</tr>';
}
echo '</table>';
echo "<br />supplement order ends";