How to solve "SQLSTATE[42S22]: Column not found: 1054 Unknown column 'email' in 'where clause'"

Question

I am trying to extend the sales order grind in Magento in order to show Product Name, SKU, And Billing email. I've had to use an Observer since there is a module currently rewriting the Grid. I have the columns I need but I am unable to search them without getting this error.

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

Here is my Observer

public function salesOrderGridCollectionLoadBefore($observer)
    {
        $collection = $observer->getOrderGridCollection();

        $select = $collection->getSelect();

        if(Mage::getStoreConfig('sales/ordergrid/postcode'))
        {
            $select->joinLeft(array(
                    'sfoa'=>'sales_flat_order_address'),
                    'main_table.entity_id = sfoa.parent_id AND sfoa.address_type="billing"',
                    array(
                        'sfoa.postcode',
                        'sfoa.email',

                    )
                );
        }

        if(Mage::getStoreConfig('sales/ordergrid/skus')||(Mage::getStoreConfig('sales/ordergrid/items')))
        {

            $select->join(array(
                        'item'=>$collection->getTable('sales/order_item')),
                    'item.order_id=`main_table`.entity_id AND item.product_type="simple"',
                    array(
                        'skus' => new Zend_Db_Expr('group_concat(item.sku SEPARATOR ", ")'),
                        'name' => new Zend_Db_Expr('group_concat(item.name SEPARATOR ", ")')
                         )
                     );
        }

        if(Mage::getStoreConfig('sales/ordergrid/payment'))
        {
            $select->joinLeft(array(
                        'payment' => $collection->getTable('sales/order_payment')),
                    'payment.parent_id=main_table.entity_id', 
                    array(
                        'payment_method' => 'method'
                         )
                    );
        }

        if(Mage::getStoreConfig('sales/ordergrid/coupon'))
        {
            $select->joinLeft('sales_flat_order',
                    'main_table.entity_id = sales_flat_order.entity_id',
                    array(
                        'coupon_code'
                         )
                    );
        }

        $select->group('main_table.entity_id');

        // Fix for ambiguous 'created at' columns. With extended/rewrite approach we can use:
        //      $collection->addFilterToMap('created_at', 'main_table.created_at');
        // However, with event observer something more creative has to be used to fix the query:

        if ($where = $select->getPart('where')) {
            foreach ($where as $key=> $condition) {
                if (strpos($condition, 'created_at')) {
                    $new_condition = str_replace("created_at", "main_table.created_at", $condition);
                    $where[$key] = $new_condition;
                }
            }
            $select->setPart('where', $where);
        }

        //Mage::log($select->__toString());

    }

    // This adds the mass action button

    public function beforeBlockToHtml(Varien_Event_Observer $observer)
    {
        $block = $observer->getEvent()->getBlock();
        if ($block instanceof Mage_Adminhtml_Block_Sales_Order_Grid) {
            $this->_modifySalesOrderGrid($block);
            $block->getMassactionBlock()->addItem('export', array(
                        'label' => 'Download CSV',
                        'url' => $block->getUrl('*/*/massExportAction'),
                ));
        }
    }

    protected function _removeColumn(Mage_Adminhtml_Block_Sales_Order_Grid $block, $columnName)
    {
        $columns = $block->getColumns();
        unset($columns[$columnName]);        
        $this->_mutateProtectedProperty($block, '_columns', $columns);
    }

    protected function _mutateProtectedProperty($object, $propertyName, $value)
    {
        $reflection = new ReflectionClass($object);
        $property = $reflection->getProperty($propertyName);
        $property->setAccessible(true);
        $property->setValue($object, $value);        
    }

    protected function _callProtectedMethod($object, $methodName)
    {
        $reflection = new ReflectionClass($object);
        $method = $reflection->getMethod($methodName);
        $method->setAccessible(true);
        return $method->invoke($object);
    }

    protected function _modifySalesOrderGrid(Mage_Adminhtml_Block_Sales_Order_Grid $grid)
    {

        $this->_removeColumn($grid, 'shipping_name');
        $this->_removeColumn($grid, 'base_grand_total');
        $this->_removeColumn($grid, 'grand_total');

        $grid->sortColumnsByOrder();
        $this->_callProtectedMethod($grid, '_prepareCollection');                

    }

Answer 1

Solved it...

Needed to add this to the layout.xml in order to filter

    <action method="addColumnAfter" ifconfig="sales/ordergrid/email">
        <columnId>email</columnId>
        <arguments>
            <header>Email</header>
            <index>email</index>
            <type>text</type>
            **<filter_index>sfoa.email</filter_index>**
            <width>80px</width>
        </arguments>
        <after>created_at</after>
    </action>