Can't retrieve entity config: sales/sales_flat_order

Question

I am trying to add column existing table sales_flat_order but it's returning an error

Can't retrieve entity config: sales/sales_flat_order

my code is:

<?php
 //@var $installer Mage_Sales_Model_Entity_Setup
$installer = $this;
$installer->startSetup();
$installer->run("
ALTER TABLE `{$installer->getTable('sales/sales_flat_order')}` ADD `giftwrap` SMALLINT NULL;
ALTER TABLE `{$installer->getTable('sales/sales_flat_order')}` ADD `giftwrap_price` DECIMAIL(12,5) NULL;
");
$installer->endSetup();

can I know where I went wrong?

thanks.

Answer 1

sales_flat_order is the full name of the table and you should use alias in $installer->getTable()

If you take a look in app\code\core\Mage\Sales\etc\config.xml there is table definition

<sales_resource>
    <class>Mage_Sales_Model_Resource</class>
    <deprecatedNode>sales_mysql4</deprecatedNode>
    <entities>
       ....
       <order>
           <table>sales_flat_order</table>
       </order>
       ...
    </entities>
</sales_resource>

So $installer->getTable() should get parameter module_alias/table_alias.

In your case

module_alias = sales

table_alias = order

$installer->getTable('sales/order')

As a result it will return table name sales_flat_order.