Using EntityFieldQuery it is pretty easy to query for entities with a given value for a specific field. But I fail to find a way to query for entities without a value for a given field. Let's say I have an optional Taxonomy Reference field on all my content type. I can query the nodes associated with a given taxonomy term using:
$query = new EntityFieldQuery();
$query->entityCondition('entity_type', 'file')
->fieldCondition('field_tags', 'tid', $tid)
->pager($limit);
$results = $query->execute();
But how would I query for all nodes not associated with any terms (ie. which have no value for the field_tags
field). I tried setting $tid
to NULL
and $query->fieldCondition('field_tags', 'tid', $all_tids, 'NOT IN')
without success.