Using column aliases in Sales Order Grid field

Question

I'm trying to add two fields (Shipping Postcode and Billing Postcod) to Magento 1.7CE's backend Sales grid.

I'm doing this by overriding Mage_Adminhtml_Block_Sales_Order_Grid::setCollection(...) to join the table with sales/order_address.

public function setCollection($collection){
    parent::setCollection($collection);
    $collection->getSelect()->join(
        array('address_shipping' => $collection->getTable("sales/order_address")),
        'main_table.entity_id = address_shipping.parent_id AND address_shipping.address_type = "shipping"',
        array('postcode')
    );
    $collection->getSelect()->join(
        array('address_billing' => $collection->getTable("sales/order_address")),
        'main_table.entity_id = address_billing.parent_id AND address_billing.address_type = "billing"',
        array('postcode')
    );
}

And Mage_Adminhtml_Block_Sales_Order_Grid::_prepareColumns(...) to add the columns to Sales Grid.

protected function _prepareColumns(){
    $this->addColumn('shipping_postcode', array(
        'header' => Mage::helper('sales')->__('Shipping Postcode'),
        'index' => 'postcode',
    ));
    $this->addColumn('billing_postcode', array(
        'header' => Mage::helper('sales')->__('Billing Postcode'),
        'index' => 'postcode',
    ));
    return parent::_prepareColumns();
}

The issue is that both times I need to select postcode field from sales/order_address table which results in SQL error

SQLSTATE[23000]: Integrity constraint violation: 1052 Column 'postcode' in order clause is ambiguous

I have tried to use MySQL's AS alias to differentiate between two postcodes, by modifying setCollection(...) to pass array('shipping_postcode'=>'postcode') and array('billing_postcode'=>'postcode') as well as changing _prepareColumns(...) to say 'index' => 'shipping_postcode' and 'index' => 'billing_postcode'. This resulted in another SQL error

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'shipping_postcode' in 'where clause'

How can I achieve having both columns in the Sales Grid?

Answer 1

let try this first code

public function setCollection($collection){
    parent::setCollection($collection);
    $collection->getSelect()->join(
        array('address_shipping' => $collection->getTable("sales/order_address")),
        'main_table.entity_id = address_shipping.parent_id AND address_shipping.address_type = "shipping"',
        array('address_shipping.postcode as shippingpostcode')
    );

    $collection->getSelect()->join(
        array('address_billing' => $collection->getTable("sales/order_address")),
        'main_table.entity_id = address_billing.parent_id AND address_billing.address_type = "billing"',
        array('address_billing.postcode as billingpostcode')
    );
}

Second _prepareColumns() is here,

protected function _prepareColumns(){
     $this->addColumn('shippingpostcode', array(
        'header' => Mage::helper('sales')->__('Shipping Postcode'),
        'index' => 'shippingpostcode',
        'filter_index' => 'address_shipping.postcode'
     ));

    $this->addColumn('billingpostcode', array(
        'header' => Mage::helper('sales')->__('Billing Postcode'),
        'index' => 'billingpostcode',
        'filter_index' => 'address_billing.postcode'  
    ));

return parent::_prepareColumns();

}

if you want to know more about 'filter_index', comment in/out in this, then try sorting in your grid for post code column. You will see different result. If you remove filter_index, error in sorting.

Answer 2

Before return parent::_prepareCollection(); You should create a join:

$collection->getSelect()->joinLeft(array('billing'=>'sales_flat_order_address'),
        'main_table.entity_id = billing.parent_id AND billing.address_type="billing"',array('billing.postcode AS bp'));

And in the method _prepareColumns paste:

$this->addColumn('bp', array(
            'header' => Mage::helper('sales')->__('Billing Postcode'),
            'index' => 'bp',
            'width' => '60px',
            'filter_index'  => 'billing.postcode'
        ));