(PECL mongo >= 0.9.0)
MongoDBRef::get — Fetches the object pointed to by a reference
Database to use.
Reference to fetch.
Returns the document to which the reference refers or
NULL if the document does not exist (the reference is broken).
Пример #1 MongoCollection::createDBRef() example
// get $person out of the db
$person = $people->findOne();
// dereference the address
$address = MongoDBRef::get($people->db, $person['address']);