Finds all parents of a given term ID.
$tid: A taxonomy term ID.
An array of term objects which are the parents of the term $tid, or an empty array if parents are not found.
function taxonomy_get_parents($tid) {
$parents =& drupal_static(__FUNCTION__, array());
if ($tid && !isset($parents[$tid])) {
$query = db_select('taxonomy_term_data', 't');
$query
->join('taxonomy_term_hierarchy', 'h', 'h.parent = t.tid');
$query
->addField('t', 'tid');
$query
->condition('h.tid', $tid);
$query
->addTag('taxonomy_term_access');
$query
->orderBy('t.weight');
$query
->orderBy('t.name');
$tids = $query
->execute()
->fetchCol();
$parents[$tid] = taxonomy_term_load_multiple($tids);
}
return isset($parents[$tid]) ? $parents[$tid] : array();
}