How can I get all related entities of a node programmatically?

Question

I am writing some drush scripts and find myself needing to get related entities (nodes) of the current node. However I can only find info for constructing views that do this.

Can anyone tell me is there a programmatic way to pull all entities that relate to the current nid with a filter on the entity type?

Ultimately I need to get a list of node ids that relate to the current node id.

The relationship depend on the relation module.

Answer 1

Like this, you will get all the referenced items of the node being displayed.

  $current_path = explode('/', $_GET['q']);
  if ($current_path[0] == 'node' && is_numeric($nid = $current_path[1])) {
    $field = 'my_field';
    $bundle = 'my_bundle';
    $query = db_query("SELECT {$field}_target_id FROM field_data_{$field} WHERE entity_id = :nid AND bundle = :bundle",
      array(
        ':nid' => $nid,
        ':bundle' => $bundle,
      )
    );
    foreach($query as $row) {
      $target_ids[] = $row->{$field . "_target_id"};
    }
    $nodes = node_load_multiple($target_ids);
  }

If you have more entity reference fields, you have to expand the query (with more joins) according to your fields.