Unable to save custom order attribute

Question

I've created a custom order attribute in my extension's setup script like this:

$setup->addAttribute('order', 'my_custom_attribute', array(
    'type' => 'varchar',
    'input' => 'text',
    'label' => 'My Custom Attribute',
    'global' => 0,
    'visible' => 1,
    'required' => 0,
    'user_defined' => 1,
    'default' => '',
    'visible_on_front' => 0,
));

When I look into eav_attribute table in the DB after running this script I can see that a new entry has been created with the options listed above and assigned to the entity_type_id of 4, which is the sales/order entity model in this installation.

Now when I do the following, I get an empty result:

$order = Mage::getModel('sales/order')->load(90);
$order->setData('my_custom_attribute', 'test');
$order->save();

$order = Mage::getModel('sales/order')->load(90);
echo $order->getData('my_custom_attribute'); // NULL

Is there a step that I'm missing here?

Answer 1

You are probably using wrong class during setup. You need to make sure that $setup is instance of Mage_Sales_Model_Resource_Setup class. I'm not sure but you are probably using Mage_Eav_Model_Entity_Setup.

If there is no my_custom_attribute row in sales_flat_order table you are probably using wrong setup class. You can also remove my_custom_attribute from eav_attribute table.

Answer 2

Your code works fine for me. If you used that exact code then you're missing a quote after attribute in your attribute name.

$setup->addAttribute('order', 'my_custom_attribute, array(

The only other thing would be to make sure the order ID exists.

Here is the full install script I used to install your attribute:

<?php

require_once('app/Mage.php');
Mage::app()->setCurrentStore(Mage::getModel('core/store')->load(Mage_Core_Model_App::ADMIN_STORE_ID));

$installer = new Mage_Sales_Model_Mysql4_Setup;
$installer->addAttribute('order', 'my_custom_attribute', array(
    'type' => 'varchar',
    'input' => 'text',
    'label' => 'My Custom Attribute',
    'global' => 0,
    'visible' => 1,
    'required' => 0,
    'user_defined' => 1,
    'default' => '',
    'visible_on_front' => 0,
));

$installer->endSetup();