/** * @param EMongoCriteria $criteria * @param string $group * @return array */ public function findAllIds(EMongoCriteria $criteria = null, $group = '') { $id = property_exists($this, 'id') ? 'id' : '_id'; $select = [$id]; if ($group) { array_push($select, $group); } $cursor = $this->findAllAsArray($criteria->select($select)); return $group ? ArrayHelper::groupByAttribute($cursor, $group, $id) : ArrayHelper::pickAttribute($cursor, $id, false); }