diff --git a/includes/class-QueryEventUser.php b/includes/class-QueryEventUser.php
index d7578be..1748402 100644
--- a/includes/class-QueryEventUser.php
+++ b/includes/class-QueryEventUser.php
@@ -1,80 +1,84 @@
 <?php
 # Linux Day Torino website - classes
 # Copyright (C) 2016, 2017, 2018, 2019 Valerio Bozzolan, Linux Day Torino contributors
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 // load dependent traits
 class_exists( 'QueryEvent', true );
 class_exists( 'QueryUser',  true );
 
 /**
  * Class able to query a QueryEventUser
  */
 trait QueryEventUserTrait {
 
 	use QueryEventTrait;
 	use QueryUserTrait;
 
-	/*
-	 * Univoque User ID column name
-	 *
-	 * Used from EventUserTrait.
-	 *
-	 * @var
-	 */
-	protected $USER_ID = 'event_user.user_ID';
-
-	/*
-	 * Univoque Event ID column name
-	 *
-	 * Used from EventUserTrait.
-	 *
-	 * @var
-	 */
-	protected $EVENT_ID = 'event_user.event_ID';
-
 	/**
 	 * Limit to a specific EventUser
 	 *
 	 * @param $event_user EventUser
 	 * @return self
 	 */
 	public function whereEventUser( $event_user ) {
 		return $this->whereEvent( $event_user )
 		            ->whereUser(  $event_user );
 	}
 
+	/**
+	 * Order by the EventUser order field
+	 *
+	 * @return self
+	 */
+	public function orderByEventUserOrder() {
+		return $this->orderBy( EventUser::ORDER );
+	}
 }
 
 /**
  * Query an EventUser
  */
 class QueryEventUser extends Query {
 
 	use QueryEventUserTrait;
 
+	/**
+	* Univoque User ID column name
+	 */
+	protected $USER_ID = 'event_user.user_ID';
+
+	/*
+	 * Univoque Event ID column name
+	 *
+	 * Used from EventUserTrait.
+	 *
+	 * @var
+	 */
+	protected $EVENT_ID = 'event_user.event_ID';
+
 	/**
 	 * Constructor
 	 */
 	public function __construct( $db = null ) {
 
 		// set database connection and default result class
 		parent::__construct( $db, EventUser::class );
 
 		// set the default table
 		$this->from( EventUser::T );
 	}
 
 }