new file mode 100644
--- /dev/null
+++ b/classes/bfw/DBInterface.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace bfw {
+    interface DBInterface {
+
+        /* fetch methods */
+        public function fetch($table, $cond);
+
+        public function fetchAll($table, $cond);
+
+        /* find methoden */
+        public function find($table, $id);
+
+        public function findAll($table, $sys);
+
+        public function findByField($table, $field, $value);
+
+        function findAllByField($table, $field, $value);
+
+        /* Abfrage Methoden */
+        public function query($sql);
+
+        /* Persistence Methods */
+        public function persist($table, $array);
+
+        public function store($table, $id, $array);
+
+        public function delete($table, $id);
+
+        /* PK Management */
+        public function getLastInsertedId();
+    }
+}
\ No newline at end of file