diff --git a/NestedSetQuery.php b/NestedSetQuery.php
new file mode 100644
index 0000000..52befba
--- /dev/null
+++ b/NestedSetQuery.php
@@ -0,0 +1,40 @@
+<?php
+/**
+ * @link https://github.com/creocoder/nested-set-behavior-2
+ * @copyright Copyright (c) 2013 Alexander Kochetov
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace creocoder\yii\behaviors;
+
+use yii\base\Behavior;
+use yii\db\ActiveRecord;
+use yii\db\ActiveQuery;
+
+/**
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ */
+class NestedSetQuery extends Behavior
+{
+	/**
+	 * @var ActiveQuery the owner of this behavior.
+	 */
+	public $owner;
+	public $hasManyRoots = false;
+	public $rootAttribute = 'root';
+	public $leftAttribute = 'lft';
+	public $rightAttribute = 'rgt';
+	public $levelAttribute = 'level';
+
+	/**
+	 * Named scope. Gets root node(s).
+	 * @param ActiveQuery $query.
+	 * @return ActiveRecord the owner.
+	 */
+	public function roots($query)
+	{
+		/** @var $modelClass ActiveRecord */
+		$modelClass=$this->owner->modelClass;
+		$query->andWhere($modelClass::getDb()->quoteColumnName($this->leftAttribute) . '=1');
+	}
+}