magento 订单order 增加栏目

 protected function _prepareCollection() {
        $this->setDefaultLimit(200);
        $collection = Mage::getResourceModel($this->_getCollectionClass());
        $collection->getSelect()->joinLeft(array('d' => 'customer_entity'), 'main_table.customer_id = d.entity_id', array('d.group_id'));
        $collection->getSelect()->joinLeft(array('c' => 'customer_group'), 'd.group_id = c.customer_group_id', array('c.customer_group_code'));
        $collection->getSelect()->joinLeft(array('f' => 'sales_flat_shipment_track'), 'main_table.entity_id = f.order_id', array('f.track_number'));
        $collection->getSelect()->joinLeft('sales_flat_order_address', 'main_table.entity_id = sales_flat_order_address.parent_id', array('telephone', 'city', 'postcode', 'country_id'))->where("sales_flat_order_address.address_type =  'billing'");
        $collection->getSelect()->reset(Zend_Db_Select::GROUP);
        $this->setCollection($collection);

        return parent::_prepareCollection();
    }

    protected function _prepareColumns() {

        $this->addColumn('real_order_id', array(
            'header' => Mage::helper('sales')->__('Order #'),
            'width' => '80px',
            'type' => 'text',
            'index' => 'increment_id',
            'filter_index' => 'main_table.increment_id',
        ));

        if (!Mage::app()->isSingleStoreMode()) {
            $this->addColumn('store_id', array(
                'header' => Mage::helper('sales')->__('Purchased From (Store)'),
                'index' => 'store_id',
                'type' => 'store',
                'store_view' => true,
                'display_deleted' => true,
            ));
        }
        $this->addColumn('customer_group_code', array(
            'header' => Mage::helper('sales')->__('Customer Group Id'),
            'index' => 'customer_group_code',
            'type' => 'text',
            'filter_index' => 'c.customer_group_code',
        ));
        $this->addColumn('track_number', array(
            'header' => Mage::helper('sales')->__('Track Number'),
            'index' => 'track_number',
            'type' => 'text',
            'filter_index' => 'f.track_number'
        ));

<pre name="code" class="php">class namespace_module_Model_Resource_Order_Collection
    extends Mage_Sales_Model_Resource_Order_Collection
{
    public function getSelectCountSql()
{   
    $this->_renderFilters();
    $countSelect = clone $this->getSelect();
    $countSelect->reset(Zend_Db_Select::ORDER);
    $countSelect->reset(Zend_Db_Select::LIMIT_COUNT);
    $countSelect->reset(Zend_Db_Select::LIMIT_OFFSET);
    $countSelect->reset(Zend_Db_Select::COLUMNS);

    // Count doesn't work with group by columns keep the group by 
    if(count($this->getSelect()->getPart(Zend_Db_Select::GROUP)) > 0) {
        $countSelect->reset(Zend_Db_Select::GROUP);
        $countSelect->distinct(true);
        $group = $this->getSelect()->getPart(Zend_Db_Select::GROUP);
        $countSelect->columns("COUNT(DISTINCT ".implode(", ", $group).")");
    } else {
        $countSelect->columns('COUNT(*)');
    }
    return $countSelect;
}
}