diff --git a/lib/db.php b/lib/db.php
new file mode 100644
index 00000000..8e5ed5ba
--- /dev/null
+++ b/lib/db.php
@@ -0,0 +1,26 @@
+<?php
+/**
+ * ownCloud - Documents App
+ *
+ * @author Victor Dubiniuk
+ * @copyright 2013 Victor Dubiniuk victor.dubiniuk@gmail.com
+ *
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ */
+
+namespace OCA\Documents;
+
+class Db {
+	/**
+	 * Build placeholders for the query with variable input data 
+	 * @param Array $array data
+	 * @return String string of '?' placeholders matching the number of elements in array
+	 */
+	public function buildPlaceholders($array){
+		$count = count($array);
+		$placeholders = array_fill(0, $count, '?');
+		$stmt = implode(', ', $placeholders);
+		return $stmt;
+	}
+}
\ No newline at end of file
diff --git a/lib/member.php b/lib/member.php
index e3fc8df8..07a36c87 100644
--- a/lib/member.php
+++ b/lib/member.php
@@ -12,7 +12,7 @@
 
 namespace OCA\Documents;
 
-class Member {
+class Member extends Db{
 
 	const ACTIVITY_THRESHOLD = 60; // 10 Minutes
 	
@@ -46,8 +46,7 @@ class Member {
 			return array();
 		}
 		
-		$placeholders = array_fill(0, $memberCount, '?');
-		$stmt = implode(', ', $placeholders);
+		$placeholders = self::buildPlaceholders($ids);
 		$query = \OCP\DB::prepare('SELECT * FROM `*PREFIX*documents_member` WHERE `member_id` IN (' . $stmt . ')');
 		$result = $query->execute($ids);
 		return $result->fetchAll();
diff --git a/lib/session.php b/lib/session.php
index da291ef5..85d9e762 100644
--- a/lib/session.php
+++ b/lib/session.php
@@ -11,7 +11,7 @@
 
 namespace OCA\Documents;
 
-class Session {
+class Session extends Db{
 	
 	public static function add($genesis, $hash, $fileId){
 		$query = \OCP\DB::prepare('
@@ -86,9 +86,8 @@ class Session {
 		if (!is_array($fileIds)){
 			$fileIds = array($fileIds);
 		}
-		$fileIdCount = count($fileIds);
-		$placeholders = array_fill(0, $fileIdCount, '?');
-		$stmt = implode(', ', $placeholders);
+		
+		$stmt = self::buildPlaceholders($fileIds);
 		$query = \OCP\DB::prepare('SELECT * FROM `*PREFIX*documents_session` WHERE `file_id` IN (' . $stmt .')');
 		$result = $query->execute($fileIds);
 		$sessions = $result->fetchAll();
@@ -99,13 +98,15 @@ class Session {
 	}
 	
 	public static function getInfoByFileid($fileIds){
-		$fileIdCount = count($fileIds);
-		if (!$fileIdCount || !is_array($fileIds)){
+		if (!is_array($fileIds)){
+			return array();
+		}
+		
+		$stmt = self::buildPlaceholders($fileIds);
+		if (!$stmt){
 			return array();
 		}
 		
-		$placeholders = array_fill(0, $fileIdCount, '?');
-		$stmt = implode(', ', $placeholders);
 		$query = \OCP\DB::prepare('
 			SELECT `s`.*, COUNT(`m`.`member_id`) AS `users`
 			FROM `*PREFIX*documents_session` AS `s`
@@ -114,8 +115,7 @@ class Session {
 			WHERE `s`.`file_id` IN (' . $stmt .')
 			GROUP BY `m`.`es_id`
 			');
-		$result = $query->execute($fileIds
-		);
+		$result = $query->execute($fileIds);
 		
 		$info = $result->fetchAll();
 		if (!is_array($info)){
diff --git a/lib/storage.php b/lib/storage.php
index 59b07096..870d9dd3 100755
--- a/lib/storage.php
+++ b/lib/storage.php
@@ -40,5 +40,20 @@ class Storage {
 		
 		return $list;
 	}
+	
+	/**
+	 * @brief Copy files to trash bin
+	 * @param array
+	 *
+	 * This function is connected to the delete signal of OC_Filesystem
+	 * to copy the file to the trash bin
+	 */
+	public static function onDelete($params) {
+
+		if ( \OCP\App::isEnabled('files_trashbin') ) {
+			$path = $params['path'];
+			Trashbin::move2trash($path);
+		}
+	}
 
 }