getConnection()->addColumn($this->getTable('sales_order'), 'shipping_tax_refunded', 'decimal(12,4) NULL'); $installer->getConnection()->addColumn($this->getTable('sales_order'), 'base_shipping_tax_refunded', 'decimal(12,4) NULL'); $installer->addAttribute('order', 'shipping_tax_refunded', array('type'=>'static')); $installer->addAttribute('order', 'base_shipping_tax_refunded', array('type'=>'static'));