select column magento
===

I was wondering how you can select columns. Above you can see the sql I wanna write in the controller. But I want to do this the wright way. Like other sql statements in magento.

I tried to add ->columns('o.sku AS  SKU') but this didn't work.

Any ideas? Thanks in advance!
    
    //sql
    $readresult="SELECT o.name AS  'Product', o.sku AS  'SKU', c.entity_id AS  'Order', c.customer_email AS  'Email', c.customer_firstname AS  'Voornaam', c.customer_lastname AS  'Achternaam', c.customer_middlename AS  'Tussenvoegsel', o.product_options AS 'Options', a.telephone AS  'Telefoon', a.postcode AS  'Postcode', a.street AS  'Street', a.city AS  'City', c.increment_id AS 'Bestelnr' FROM magento_sales_flat_order AS c INNER JOIN magento_sales_flat_order_item AS o ON c.entity_id = o.order_id INNER JOIN magento_sales_flat_order_address AS a ON a.parent_id = c.entity_id WHERE o.product_id =".$product." GROUP BY c.entity_id ORDER BY o.sku;";


    //THE MAGENTO WAY!
    $resource = Mage::getSingleton('core/resource');
    $read = $resource->getConnection('core_read');
    $o = $resource->getTableName('magento_sales_flat_order');
    $o_item = $resource->getTableName('magento_sales_flat_order_item');
    $o_address = $resource->getTableName('magento_sales_flat_order_address');
    $select = $read->select()->from(array('c'=>$o))
        ->join(array('o'=>$o_item), 'c.entity_id = o.order_id', array(o.sku AS  'SKU'))
        ->join(array('a'=>$o_address), 'a.parent_id = c.entity_id', array())
        ->where('o.product_id', $product)
        ->group('c.entity_id')
        ->order('o.sku');