Is there a way to add a custom Attribute (DB-Column, whatever) to product attribute sets?
I tried the following but it I get the error 'Wrong Entity ID':
/** @var Mage_Catalog_Model_Resource_Setup $this */
$this->addAttribute('eav/entity_attribute_set', 'pim_id', array(
'group' => 'General Information',
'input' => 'text',
'type' => 'text',
'label' => 'PIM ID',
'backend' => '',
'visible' => false,
'required' => false,
'is_unique' => true,
'visible_on_front' => false,
'global' => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_GLOBAL,
));