create custom collection in magento

Question

We have a table with delivery dates and i want to add it to the adminhtml in sales/order/grid. The problem that i have is that the left join examples dont work for me and im out of options.

Mage/Adminhtml/Block/Sales/Order/Grid.php

The method im trying now is to create a custom query in _prepareCollection()

    $resource = Mage::getSingleton('core/resource');
    $readConnection = $resource->getConnection('core_read');

    $query = 'SELECT * FROM mage_sales_flat_order_grid
              left join mage_aw_deliverydate_delivery
              on mage_sales_flat_order_grid.entity_id =  
              mage_aw_deliverydate_delivery.order_id';

    $collection = $readConnection->fetchAll($query);

   //$collection = Mage::getResourceModel($this->_getCollectionClass());
   //$this->setCollection($collection);
   return parent::_prepareCollection();

Then i add this column code in _prepareColumns()

    $this->addColumn('delivery_date', array(
        'header' => 'delivery_date',
        'index' => 'delivery_date',
        'type' => 'datetime',
        'width' => '100px',
    ));

I dont even see the new column when i look at the orders grid in the backoffice.

Any help is appreciated!

Answer 1

If you want to add the anthor table

protected function _prepareCollection()
    {
        $collection = Mage::getResourceModel($this->_getCollectionClass());

       $collection->getSelect()->joinLeft('aw_deliverydate_delivery', 'main_table.entity_id = aw_deliverydate_delivery.order_id',array('*' ) );
        $this->setCollection($collection);
        return parent::_prepareCollection();
    }

And the below code in _prepareColumns()

 $this->addColumn('aw_deliverydate_delivery', array(
            'header' => Mage::helper('sales')->__('Delivery Date '),
            'index' => 'aw_deliverydate_delivery',
            'type' => 'datetime',
            'width' => '100px',

        ));