diff --git a/application/libraries/FiltersLib.php b/application/libraries/FiltersLib.php
index a4703bf7d..638fc7251 100644
--- a/application/libraries/FiltersLib.php
+++ b/application/libraries/FiltersLib.php
@@ -264,7 +264,7 @@ class FiltersLib
 	 */
 	public function generateDatasetQuery($query, $filters)
 	{
-		$datasetQuery = null;
+		$datasetQuery = 'SELECT * FROM ('.$query.') '.self::DATASET_TABLE_ALIAS;
 
 		// If the given query is valid and the parameter filters is an array
 		if (!empty(trim($query)) && $filters != null && is_array($filters))
@@ -287,7 +287,7 @@ class FiltersLib
 
 			if ($where != '') // if the SQL where clause was built
 			{
-				$datasetQuery = 'SELECT * FROM ('.$query.') '.self::DATASET_TABLE_ALIAS.' WHERE '.$where;
+				$datasetQuery .= ' WHERE '.$where;
 			}
 		}
 
diff --git a/application/models/system/Filters_model.php b/application/models/system/Filters_model.php
index eb81dbb32..20ab6419e 100644
--- a/application/models/system/Filters_model.php
+++ b/application/models/system/Filters_model.php
@@ -13,7 +13,7 @@ class Filters_model extends DB_Model
 	}
 
 	/**
-	 *
+	 * Loads a filter by its app, dataset_name and filter_kurzbz
 	 */
 	public function getFilterList($app, $dataset_name, $filter_kurzbz)
 	{
@@ -24,7 +24,6 @@ class Filters_model extends DB_Model
 			'app' => $app,
 			'dataset_name' => $dataset_name,
 			'person_id' => null,
-			'default_filter' => false,
 			'array_length(description, 1) >' => 0,
 			'filter_kurzbz ILIKE' => $filter_kurzbz
 		);
@@ -33,7 +32,7 @@ class Filters_model extends DB_Model
 	}
 
 	/**
-	 *
+	 * Loads a custom filter by its app, dataset_name and the uid of the owner
 	 */
 	public function getCustomFiltersList($app, $dataset_name, $uid)
 	{
@@ -50,12 +49,4 @@ class Filters_model extends DB_Model
 
 		return $this->loadWhere($filterParametersArray);
 	}
-
-	/**
-	 *
-	 */
-	public function deleteCustomFilter($filter_id)
-	{
-		return $this->delete($filter_id);
-	}
 }