Missing options for some attributes like 'SKU' or 'NAME'

Question

I found that sku is not being displayed in product listing nor product view page. I checked and found that the template is checking whether to display the attribute by using:

$_product->getResource()->getAttribute('sku')->getUsedInProductListing()

Which results with null for sku but not for, lets say, description. I found out that more attributes have very short list of options (name also has this problem).

I have dumped the $_data in Varien_Object and for sku it is suprisingly short:

array (
  'attribute_id' => '68',
  'entity_type_id' => '4',
  'attribute_code' => 'sku',
  'attribute_model' => 'catalog/resource_eav_attribute',
  'backend_model' => 'catalog/product_attribute_backend_sku',
  'backend_type' => 'static',
  'backend_table' => NULL,
  'frontend_model' => NULL,
  'frontend_input' => 'text',
  'frontend_label' => 'SKU',
  'frontend_class' => NULL,
  'source_model' => NULL,
  'is_required' => '1',
  'is_user_defined' => '0',
  'default_value' => NULL,
  'is_unique' => '1',
  'note' => NULL,
  'store_label' => 'Product code',
)

However, the same dump for description attribute has much more options:

array (
  'attribute_id' => '66',
  'entity_type_id' => '4',
  'attribute_code' => 'description',
  'attribute_model' => 'catalog/resource_eav_attribute',
  'backend_model' => NULL,
  'backend_type' => 'text',
  'backend_table' => NULL,
  'frontend_model' => NULL,
  'frontend_input' => 'textarea',
  'frontend_label' => 'Description',
  'frontend_class' => NULL,
  'source_model' => NULL,
  'is_required' => '0',
  'is_user_defined' => '0',
  'default_value' => NULL,
  'is_unique' => '0',
  'note' => NULL,
  'frontend_input_renderer' => NULL,
  'is_global' => '0',
  'is_visible' => '1',
  'is_searchable' => '1',
  'is_filterable' => '0',
  'is_comparable' => '1',
  'is_visible_on_front' => '0',
  'is_html_allowed_on_front' => '1',
  'is_used_for_price_rules' => '0',
  'is_filterable_in_search' => '0',
  'used_in_product_listing' => '0',
  'used_for_sort_by' => '0',
  'is_configurable' => '1',
  'apply_to' => NULL,
  'is_visible_in_advanced_search' => '0',
  'position' => '0',
  'is_wysiwyg_enabled' => '1',
  'is_used_for_promo_rules' => '0',
  'entity_type' => 
  Mage_Eav_Model_Entity_Type::__set_state(array(
     '_attributes' => NULL,
     '_attributesBySet' => 
    array (
    ),
     '_sets' => NULL,
     '_eventPrefix' => 'core_abstract',
     '_eventObject' => 'object',
     '_resourceName' => 'eav/entity_type',
     '_resource' => NULL,
     '_resourceCollectionName' => 'eav/entity_type_collection',
     '_cacheTag' => false,
     '_dataSaveAllowed' => true,
     '_isObjectNew' => NULL,
     '_data' => 
    array (
      'entity_type_id' => '4',
      'entity_type_code' => 'catalog_product',
      'entity_model' => 'catalog/product',
      'attribute_model' => 'catalog/resource_eav_attribute',
      'entity_table' => 'catalog/product',
      'value_table_prefix' => NULL,
      'entity_id_field' => NULL,
      'is_data_sharing' => '1',
      'data_sharing_key' => 'default',
      'default_attribute_set_id' => '4',
      'increment_model' => NULL,
      'increment_per_store' => '0',
      'increment_pad_length' => '8',
      'increment_pad_char' => '0',
      'additional_attribute_table' => 'catalog/eav_attribute',
      'entity_attribute_collection' => 'catalog/product_attribute_collection',
    ),
     '_hasDataChanges' => true,
     '_origData' => NULL,
     '_idFieldName' => 'entity_type_id',
     '_isDeleted' => false,
     '_oldFieldsMap' => 
    array (
    ),
     '_syncFieldsMap' => 
    array (
    ),
  )),
)

Any ideas why this happens? I am using Magento 1.9.1.0

Answer 1

The difference in values is because the SKU and the Description are attributes with different back-end models. The SKU is a Static attribute, its value is stored directly in the catalog_product_entity table. The description is a text attribute its values are stored in the catalog_product_entity_text table.

If you switch the Used in Product Listing to yes the below snippet will return a value of 1.

used in product listing can be found in Catalog-> Attributes->Manage Attribute under the Frontend properties of the selected attribute

$_product->getResource()->getAttribute('sku')->getUsedInProductListing()