<?php

//total instanciation 
include_once( 'phpsimpledb.class.php' );
Global $oBDD;
$oBDD = new PHPSIMPLEDB();

//creation and loading of the collection of "users"
$oUsers_col = $oBDD->getCollection( "users" );
$oUsers_col->load( array( "level > 80" ) );

//update of the “users” of the collection
foreach( $oUsers_col->getObjects() as $oUser ){
    $oUser->setData_field( "level", 1 );
    $oUser->save();
}

?>