Magento-将新列添加到销售订单网格不起作用

我正在尝试向Magento的销售订单网格（管理>销售>订单）添加一个新列。我尝试按照此处的说明进行操作：

我已将核心文件复制到本地文件夹，以便覆盖它：

From:/public\u html/wholesale/app/code/core/Mage/Adminhtml/Block/Sales/Order/Grid.php

致：/public\u html/wholesale/app/code/local/Mage/Adminhtml/Block/Sales/Order/Grid.php

奇怪的是，无论我对其中一个文件做了什么更改，在管理方面都没有任何更改。我甚至不能让Mage:：log（）工作

一旦我克服了这个问题，我需要确保我所做的改变是正确的。我只是想知道客户的公司名称。以下是我添加的两个部分：

protected function _prepareCollection()
{
    // This line is from the original
    $collection = Mage::getResourceModel($this->_getCollectionClass());

    // This is the call where I try to bring in the extra field
    // from another sales table
    $collection->getSelect()->join(
        'sales_flat_order_address',
        'sales_flat_order.entity_id = sales_flat_order_address.parent_id',
        array('company')
    );

    // These lines are also default
    $this->setCollection($collection);
    return parent::_prepareCollection();
}

在_prepareColumns（）中：

仅供参考，我正在使用Magento 1.7.0.2，请尝试以下操作：

protected function _prepareCollection()
{
    // This line is from the original
    $collection = Mage::getResourceModel($this->_getCollectionClass());

    // Join billing 'company' field from sales_flat_order_address table 
    $collection->getSelect()->join(
        array('addressTable' => 'sales_flat_order_address'),
        'main_table.entity_id = addressTable.parent_id AND addressTable.address_type = "billing"',
        array('billing_company'=>'company')
    );

    // These lines are also default
    $this->setCollection($collection);
    return parent::_prepareCollection();
}

protected function filterBillingCompany($collection, $column) {
    $val = (string)trim($column->getFilter()->getValue());
    if ($val != "") {
        $collection->getSelect()->where("addressTable.company LIKE '%{$val}%'");
    }
    return $this;
}

在_prepareColumns（）中：

protected function _prepareCollection()
{
    // This line is from the original
    $collection = Mage::getResourceModel($this->_getCollectionClass());

    // Join billing 'company' field from sales_flat_order_address table 
    $collection->getSelect()->join(
        array('addressTable' => 'sales_flat_order_address'),
        'main_table.entity_id = addressTable.parent_id AND addressTable.address_type = "billing"',
        array('billing_company'=>'company')
    );

    // These lines are also default
    $this->setCollection($collection);
    return parent::_prepareCollection();
}

protected function filterBillingCompany($collection, $column) {
    $val = (string)trim($column->getFilter()->getValue());
    if ($val != "") {
        $collection->getSelect()->where("addressTable.company LIKE '%{$val}%'");
    }
    return $this;
}

$this->addColumn('company', array(
    'header' => Mage::helper('sales')->__('Company'),
    'index' => 'billing_company',
    'filter_condition_callback' => array($this, 'filterBillingCompany'),
));