diff -r 6eede6088d41 -r 3f30adba1c63 src/main/java/de/uapcore/lightpit/modules/UsersModule.java
--- a/src/main/java/de/uapcore/lightpit/modules/UsersModule.java	Sun Dec 20 11:06:25 2020 +0100
+++ b/src/main/java/de/uapcore/lightpit/modules/UsersModule.java	Mon Dec 21 18:29:34 2020 +0100
@@ -32,7 +32,7 @@
 import de.uapcore.lightpit.Constants;
 import de.uapcore.lightpit.HttpMethod;
 import de.uapcore.lightpit.RequestMapping;
-import de.uapcore.lightpit.dao.DaoProvider;
+import de.uapcore.lightpit.dao.DataAccessObject;
 import de.uapcore.lightpit.entities.User;
 import de.uapcore.lightpit.viewmodel.UsersEditView;
 import de.uapcore.lightpit.viewmodel.UsersView;
@@ -61,11 +61,9 @@
     }
 
     @RequestMapping(method = HttpMethod.GET)
-    public void index(HttpServletRequest req, HttpServletResponse resp, DaoProvider dao) throws SQLException, ServletException, IOException {
-        final var userDao = dao.getUserDao();
-
+    public void index(HttpServletRequest req, HttpServletResponse resp, DataAccessObject dao) throws SQLException, ServletException, IOException {
         final var viewModel = new UsersView();
-        viewModel.setUsers(userDao.list());
+        viewModel.setUsers(dao.listUsers());
         setViewModel(req, viewModel);
         setContentPage(req, "users");
 
@@ -73,11 +71,10 @@
     }
 
     @RequestMapping(requestPath = "edit", method = HttpMethod.GET)
-    public void edit(HttpServletRequest req, HttpServletResponse resp, DaoProvider dao) throws SQLException, ServletException, IOException {
+    public void edit(HttpServletRequest req, HttpServletResponse resp, DataAccessObject dao) throws SQLException, ServletException, IOException {
 
         final var viewModel = new UsersEditView();
-        viewModel.setUser(findByParameter(req, Integer.class, "id",
-                dao.getUserDao()::find).orElse(new User(-1)));
+        viewModel.setUser(findByParameter(req, Integer.class, "id", dao::findUser).orElse(new User(-1)));
 
         setViewModel(req, viewModel);
         setContentPage(req, "user-form");
@@ -86,7 +83,7 @@
     }
 
     @RequestMapping(requestPath = "commit", method = HttpMethod.POST)
-    public void commit(HttpServletRequest req, HttpServletResponse resp, DaoProvider dao) throws ServletException, IOException {
+    public void commit(HttpServletRequest req, HttpServletResponse resp, DataAccessObject dao) throws ServletException, IOException {
 
         User user = new User(-1);
         try {
@@ -96,12 +93,10 @@
             getParameter(req, String.class, "lastname").ifPresent(user::setLastname);
             getParameter(req, String.class, "mail").ifPresent(user::setMail);
 
-            final var userDao = dao.getUserDao();
             if (user.getId() > 0) {
-                // TODO: unused return value
-                userDao.update(user);
+                dao.updateUser(user);
             } else {
-                userDao.save(user);
+                dao.insertUser(user);
             }
 
             setRedirectLocation(req, "./teams/");