Relationship Update Can't Write in Database

[mikehsieh0305]

Can Update but relationship can't connect

 private function bindEventFeaturesProperty()
    {
        Lodata::getEntitySet('EventFeatures')
            ->discoverRelationship('Events')
            ->discoverRelationship('EventImages');

        Lodata::getEntityType('EventFeature')
            ->getProperty('geometry_scope')
            ->setType($this->odataTypes['polygon']);
    }

    private function bindEventImagesProperty()
    {
        Lodata::getEntitySet('EventImages')
            ->discoverRelationship('EventFeatures');
    }

Another question when i use remove can't support changed