title: How to add SKU in Order Grid Page
body: <p>I have already seen many examples on this for how to do it. But all the examples are for a different version of Magento. And none of them worked in my case. My version is 1.4.0.0rc-1. Yes I know this should not be in a production environment but unfortunately this is the case in here.</p>
  
  <p>The problem is _prepareCollection() function in Mage/Adminhtml/Block/Sales/Order/Grid.php class is different than all the other example I have seen. So not sure how to do it. </p>
  
  <p>This is how the code for that function: </p>
  
  <pre><code>protected function _prepareCollection()
  {
      $collection = Mage::getResourceModel('sales/order_collection')
          -&gt;addAttributeToSelect('*')
          -&gt;joinAttribute('sku','sales_flat_order_item', null, null, 'left')
          -&gt;joinAttribute('billing_firstname', 'order_address/firstname', 'billing_address_id', null, 'left')
          -&gt;joinAttribute('billing_lastname', 'order_address/lastname', 'billing_address_id', null, 'left')
          -&gt;joinAttribute('shipping_firstname', 'order_address/firstname', 'shipping_address_id', null, 'left')
          -&gt;joinAttribute('shipping_lastname', 'order_address/lastname', 'shipping_address_id', null, 'left')
          -&gt;addExpressionAttributeToSelect('billing_name',
              'CONCAT({{billing_firstname}}, " ", {{billing_lastname}})',
              array('billing_firstname', 'billing_lastname'))
          -&gt;addExpressionAttributeToSelect('shipping_name',
              'CONCAT({{shipping_firstname}},  IFNULL(CONCAT(\' \', {{shipping_lastname}}), \'\'))',
              array('shipping_firstname', 'shipping_lastname'));
      $this-&gt;setCollection($collection);
      return parent::_prepareCollection();
  }
  </code></pre>
  
  <p>I tried to add a left join but it didn't work. This is what I have tried right before the setCollection statement:</p>
  
  <pre><code>$collection-&gt;getSelect()-&gt;join('sales_flat_order_item', 'order_id=entity_id',    array('name'=&gt;'name', 'sku' =&gt;'sku'), null,'left');
  </code></pre>
  
  <p>But it is printing out the following error:</p>
  
  <pre><code>SELECT `e`.*, `_table_billing_address_id`.`value` AS `billing_address_id`, `_table_billing_firstname`.`value` AS `billing_firstname`, `_table_billing_lastname`.`value` AS `billing_lastname`, `_table_shipping_address_id`.`value` AS `shipping_address_id`, `_table_shipping_firstname`.`value` AS `shipping_firstname`, `_table_shipping_lastname`.`value` AS `shipping_lastname`, CONCAT(_table_billing_firstname.value, " ", _table_billing_lastname.value) AS `billing_name`, CONCAT(_table_shipping_firstname.value,  IFNULL(CONCAT(' ', _table_shipping_lastname.value), '')) AS `shipping_name`, `sales_flat_order_item`.`name`, `sales_flat_order_item`.`sku` FROM `sales_order` AS `e`
   LEFT JOIN `sales_order_int` AS `_table_billing_address_id` ON (_table_billing_address_id.entity_id = e.entity_id) AND (_table_billing_address_id.attribute_id='112')
   LEFT JOIN `sales_order_entity_varchar` AS `_table_billing_firstname` ON (_table_billing_firstname.entity_id = _table_billing_address_id.value) AND (_table_billing_firstname.attribute_id='202')
   LEFT JOIN `sales_order_entity_varchar` AS `_table_billing_lastname` ON (_table_billing_lastname.entity_id = _table_billing_address_id.value) AND (_table_billing_lastname.attribute_id='204')
   LEFT JOIN `sales_order_int` AS `_table_shipping_address_id` ON (_table_shipping_address_id.entity_id = e.entity_id) AND (_table_shipping_address_id.attribute_id='113')
   LEFT JOIN `sales_order_entity_varchar` AS `_table_shipping_firstname` ON (_table_shipping_firstname.entity_id = _table_shipping_address_id.value) AND (_table_shipping_firstname.attribute_id='202')
   LEFT JOIN `sales_order_entity_varchar` AS `_table_shipping_lastname` ON (_table_shipping_lastname.entity_id = _table_shipping_address_id.value) AND (_table_shipping_lastname.attribute_id='204')
   INNER JOIN `sales_flat_order_item` ON order_id=entity_id WHERE (e.entity_type_id = '11') ORDER BY `e`.`created_at` desc, `e`.`created_at` desc LIMIT 20
  </code></pre>
  
  <p>Can someone please help me on how to solve this? And for your info, the SKU field is in the "Sales_flat_order_item" table.</p>