Drupal 7 - EntityFieldPropertyQuery class

EntityFieldPropertyQuery.php

<?php
/**
 * @file
 * Contains class EntityFieldPropertyQuery.
 */

/**
 * EntityFieldQuery class allowing for base table properties to be returned.
 */
class EntityFieldPropertyQuery extends EntityFieldQuery {
  /**
   * An array of properties to include in the returned entity stubs.
   *
   * @var array
   */
  protected $properties = array();

  /**
   * Adds a property to include in each returned entity stub.
   *
   * @param string $property_name
   *   The entity's property to include in returned entity stubs.
   *
   * @return CiscoCoreEntityFieldPropertyCondition
   *   Returns this instance.
   */
  public function addProperty($property_name) {
    $this->properties[$property_name] = $property_name;
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  function finishQuery($select_query, $id_key = 'entity_id') {
    $entity_info = entity_get_info($this->entityConditions['entity_type']['value']);
    foreach ($this->properties as $property_name) {
      if (!in_array($property_name, $entity_info['schema_fields_sql']['base table'])) {
        throw new EntityFieldQueryException(t('Entity property %property does not exist in base table.', array('%property' => $property_name)));
      }
      $select_query->addField($entity_info['base table'], $property_name, $property_name);
    }

    foreach ($this->tags as $tag) {
      $select_query->addTag($tag);
    }

    foreach ($this->metaData as $key => $object) {
      $select_query->addMetaData($key, $object);
    }

    $select_query->addMetaData('entity_field_query', $this);

    if ($this->range) {
      $select_query->range($this->range['start'], $this->range['length']);
    }

    if ($this->count) {
      return $select_query->countQuery()->execute()->fetchField();
    }

    $return = array();
    foreach ($select_query->execute() as $partial) {
      $bundle = isset($partial->bundle) ? $partial->bundle : NULL;
      $entity = entity_create_stub_entity($partial->entity_type, array($partial->entity_id, $partial->revision_id, $bundle));

      foreach ($this->properties as $property_name) {
        if (isset($partial->{$property_name})) {
          $entity->{$property_name} = $partial->{$property_name};
        }
      }

      $return[$partial->entity_type][$partial->{$id_key}] = $entity;
      $this->ordered_results[] = $partial;
    }

    return $return;
  }
}

Example:

$query = new EntityFieldPropertyQuery();
$nodes = $query->entityCondition('entity_type', 'node')
  ->addProperty('uid')
  ->execute();
foreach ($nodes['node'] as $node) {
  print $node->uid;
}