$ids = array(240, 12, 400);
$res = $modx->getCollection('modResource', array( 'id:IN' => $ids ));
$ids = '240,12,400'; $classname = 'modResource'; $c = $modx->newQuery($classname); $c->where(array('id:IN' => explode(',',$ids))); $c->sortby('FIELD(modResource.id, ' . $ids . ')'; $res = $modx->getCollection($classname, $c);