Adding custom columns in order grid (Magento 1.7.0.0) - magento

Question

I'm having this problem with adding custom columns in the order grid in Magento 1.7.0.0 and I was hoping you'd be able to give me a hand in here.
Basically I followed this guide http://www.atwix.com/magento/customize-orders-grid/ which explained I had to make a local version of /app/code/core/Mage/Adminhtml/Block/Sales/Order/Grid.php and make a couple of changes to have the extra columns I want. By following said guide, it said that I had to edit the function _prepareCollection() to add this line (specifying the fields I want to extract in the array)
$collection->getSelect()->join('magento_sales_flat_order_address', 'main_table.entity_id = magento_sales_flat_order_address.parent_id',array('telephone', 'email'));
Before
return parent::_prepareCollection();
And add the two columns in _prepareColumns() like this:
$this->addColumn('telephone', array(
'header' => Mage::helper('sales')->__('Telephone'),
'index' => 'telephone',
));
$this->addColumn('email', array(
'header' => Mage::helper('sales')->__('Email'),
'index' => 'email',
));
And that was it, apparently... Or maybe not, since it throws the following error when I do that:
Item (Mage_Sales_Model_Order) with the same id "XXXX" already exist
To which the solution, according to the comments underneath, was to add the following line in _prepareCollection before $this->setCollection($collection):
$collection->getSelect()->group('main_table.entity_id');
After adding the line, the Order Grid now shows the Email and Phone columns just like I want it, but turns out the pagination stopped working, it only shows the most recent 20 and it says "Pages 1 out of 1", "2 records found" on top. I can't seem to figure out why this is happening and every comment I see around doesn't go beyond the last instruction above. What could possibly be the cause of this issue?
I assume it could be replicated since I haven't made any other modifications of this model.

Answer 1

Alright, solved it. This is what I did:
Inspired by this answer https://stackoverflow.com/a/4219386/2009617, I made a copy of the file lib/Varien/Data/Collection/Db.php, placed it under app/core/local/Varien/Data/Collection/Db.php and copied the modifications suggested on that answer to fix the group select count error that was giving me problems above. So far it seemed to work.
However, there was a problem in the rows, when I clicked on the orders it said the Order "no longer exists", so I checked the actual url and turns out the order_id in the url was the same as the "entity_id" in the order_address table, which didn't correspond with the actual associative id of the order (parent_id). After tweaking for a long time with the MySQL query, I realized the issue was in the functions called by the _prepareColumns() and getRowUrl() functions in the /app/code/local/Mage/Adminhtml/Block/Sales/Order/Grid.php I made, since they were retrieving the wrong Id. So I made the following changes:
In _prepareColumns(), within the code corresponding to the Action column, I changed the 'getter' to 'getParentId', like this:
if (Mage::getSingleton('admin/session')->isAllowed('sales/order/actions/view')) {
$this->addColumn('action',
array(
'header' => Mage::helper('sales')->__('Action'),
'width' => '50px',
'type' => 'action',
//~ 'getter' => 'getId',
'getter' => 'getParentId',
'actions' => array(
array(
'caption' => Mage::helper('sales')->__('View'),
'url' => array('base'=>'*/sales_order/view'),
'field' => 'order_id',
)
),
'filter' => false,
'sortable' => false,
'index' => 'stores',
'is_system' => true,
));
}
And in the getRowUrl() function, I changed the $row statement within the getUrl() function like this:
public function getRowUrl($row)
{
if (Mage::getSingleton('admin/session')->isAllowed('sales/order/actions/view')) {
//~ return $this->getUrl('*/sales_order/view', array('order_id' => $row->getId()));
return $this->getUrl('*/sales_order/view', array('order_id' => $row->getParentId()));
}
return false;
}
And now it works like a charm. I hope this helps somebody else.

Answer 2

The problem is in query. Instead of this query:
$collection->getSelect()->join('magento_sales_flat_order_address', 'main_table.entity_id = magento_sales_flat_order_address.parent_id',array('telephone', 'email'));
You should use this:
$collection->getSelect()->join('sales_flat_order_address', 'main_table.entity_id = sales_flat_order_address.parent_id AND sales_flat_order_address.address_type = "shipping" ',array('telephone', 'email'));
In the table sales_flat_order_address, parent_id is duplicated. The first is for billing and the second one is for shipping. So you just need to select one of this: billing or shipping. This values are in column address_type...

Answer 3

Try using filter_index in the addColumn function:
$this->addColumn('telephone', array(
'header' => Mage::helper('sales')->__('Telephone'),
'index' => 'telephone',
'filter_index' => 'tablename.telephone'
));
You can find out the table name with printing out the sql query:
var_dump((string)$collection->getSelect())