diff --git a/Sources/dafl_project_flutter/lib/controller/controller.dart b/Sources/dafl_project_flutter/lib/controller/controller.dart
index 835b87a..7a9ea57 100644
--- a/Sources/dafl_project_flutter/lib/controller/controller.dart
+++ b/Sources/dafl_project_flutter/lib/controller/controller.dart
@@ -12,12 +12,14 @@ import '../persistence/searcher.dart';
 class Controller{
   static Controller? _this;
 
-  static Saver? saver = DatabaseSaver();
-  static Loader? loader = DatabaseLoader();
+  static Saver saver = DatabaseSaver();
+  static Loader loader = DatabaseLoader();
   static Searcher _searcher = DatabaseSearcher();
 
+
   User currentUser = User("", "");
 
+
   factory Controller(){
     if (_this == null) _this = Controller._();
     return _this!;
@@ -26,11 +28,11 @@ class Controller{
   Controller._();
 
   void save(User userToSave){
-    saver?.save(userToSave);
+    saver.save(userToSave);
   }
 
   void load(String username, String password) async{
-    currentUser =  await loader?.load(username, password) as User;
+    currentUser =  await loader.load(username, password) as User;
   }
 
   User createUser(String username, String password){
@@ -43,16 +45,16 @@ class Controller{
 
   void changeUsernameCourant(String newName){
     if(newName !=null){
-      this.currentUser?.usernameDafl = newName;
+      this.currentUser.usernameDafl = newName;
     }
   }
   void changePasswordCourant(String newPass){
     if(newPass !=null){
-      this.currentUser?.passwDafl = newPass;
+      this.currentUser.passwDafl = newPass;
     }
   }
 
   Future<bool> searchByUsername(String username) async{
-    return _searcher.searchByUsername(username);
+    return await _searcher.searchByUsername(username);
   }
 }
diff --git a/Sources/dafl_project_flutter/lib/model/user.dart b/Sources/dafl_project_flutter/lib/model/user.dart
index 22bcb95..864f018 100644
--- a/Sources/dafl_project_flutter/lib/model/user.dart
+++ b/Sources/dafl_project_flutter/lib/model/user.dart
@@ -61,14 +61,12 @@ class User{
 
 
 
-
-
   void addDiscovery(Music newmusic){
-    if(MyApp().controller?.currentUser?.Discovery == null){
+    if(MyApp().controller.currentUser.Discovery == null){
 
     }
     else{
-      MyApp().controller.currentUser?.Discovery.add(newmusic);
+      MyApp().controller.currentUser.Discovery.add(newmusic);
     }
 
 
diff --git a/Sources/dafl_project_flutter/lib/model/user_creator.dart b/Sources/dafl_project_flutter/lib/model/user_creator.dart
deleted file mode 100644
index 07029e6..0000000
--- a/Sources/dafl_project_flutter/lib/model/user_creator.dart
+++ /dev/null
@@ -1,8 +0,0 @@
-import 'user.dart';
-
-class UserCreator{
-
-  User? createUser(int id, String username){
-
-  }
-}
\ No newline at end of file
diff --git a/Sources/dafl_project_flutter/lib/persistence/.logs/.gitkeep b/Sources/dafl_project_flutter/lib/persistence/.logs/.gitkeep
deleted file mode 100644
index e69de29..0000000
diff --git a/Sources/dafl_project_flutter/lib/persistence/.logs/logs.txt b/Sources/dafl_project_flutter/lib/persistence/.logs/logs.txt
deleted file mode 100644
index f589036..0000000
--- a/Sources/dafl_project_flutter/lib/persistence/.logs/logs.txt
+++ /dev/null
@@ -1,5 +0,0 @@
-postgres
-mdpDaflBd
-89.83.54.48
-BD-DaflMusic
-
diff --git a/Sources/dafl_project_flutter/lib/persistence/database_saver.dart b/Sources/dafl_project_flutter/lib/persistence/database_saver.dart
index d8385a5..25ab875 100644
--- a/Sources/dafl_project_flutter/lib/persistence/database_saver.dart
+++ b/Sources/dafl_project_flutter/lib/persistence/database_saver.dart
@@ -6,6 +6,8 @@ import '../model/user.dart';
 
 class DatabaseSaver extends Saver{
 
+
+  // Save user in the database
   @override
   void save(User userToSave) async{
     final connection = await DatabaseConnexion.initConnexion();
@@ -13,7 +15,11 @@ class DatabaseSaver extends Saver{
     connection.execute('insert into utilisateur (username, password) values (@username, @password)',
         { 'id' : '',
           'username': userToSave.usernameDafl,
-          'password' : userToSave.passwDafl}).then((_) {});
+          'password' : userToSave.passwDafl})
+
+          .whenComplete(() {
+            connection.close();
+          });
   }
 
 }
\ No newline at end of file
diff --git a/Sources/dafl_project_flutter/lib/persistence/database_searcher.dart b/Sources/dafl_project_flutter/lib/persistence/database_searcher.dart
index af15b59..612b19b 100644
--- a/Sources/dafl_project_flutter/lib/persistence/database_searcher.dart
+++ b/Sources/dafl_project_flutter/lib/persistence/database_searcher.dart
@@ -2,24 +2,24 @@ import 'package:dafl_project_flutter/persistence/database_connexion.dart';
 
 import 'searcher.dart';
 
-class DatabaseSearcher extends Searcher{
 
+
+class DatabaseSearcher extends Searcher{
   Future<bool> searchUser(String? username, String? password) async { return true; }
 
 
+
+  // Search an user in the database by username
   @override
-  Future<bool> searchByUsername(String? username) async{
+  Future<bool> searchByUsername(String? usernameToSearch) async{
     final connection = await DatabaseConnexion.initConnexion();
-    bool isHere  = true;
 
-    connection.query('select * from utilisateur where username = $username').toList().then((rows) {
-      if(rows.isEmpty){
-        isHere = false;
-      }
-    }).whenComplete(() {
-      print('close');
-    });
+    bool queryResult = await connection.query('select * from utilisateur where username = @username',{ 'username' : usernameToSearch})
+        .toList()
+        .then((rows) { return rows.isEmpty; });
+
 
-    return isHere;
+    return queryResult;
   }
+
 }
diff --git a/Sources/dafl_project_flutter/lib/views/pages/sign_in/p_sign_in.dart b/Sources/dafl_project_flutter/lib/views/pages/sign_in/p_sign_in.dart
index ea0700d..958f632 100644
--- a/Sources/dafl_project_flutter/lib/views/pages/sign_in/p_sign_in.dart
+++ b/Sources/dafl_project_flutter/lib/views/pages/sign_in/p_sign_in.dart
@@ -1,6 +1,5 @@
 import 'dart:ui';
 import 'package:dafl_project_flutter/model/user.dart';
-import 'package:dafl_project_flutter/views/pages/main/p_main.dart';
 import 'package:flutter/material.dart';
 import 'package:page_transition/page_transition.dart';
 import '../../../main.dart';
diff --git a/Sources/dafl_project_flutter/lib/views/pages/sign_up/p_sign_up.dart b/Sources/dafl_project_flutter/lib/views/pages/sign_up/p_sign_up.dart
index 70b9afb..569336b 100644
--- a/Sources/dafl_project_flutter/lib/views/pages/sign_up/p_sign_up.dart
+++ b/Sources/dafl_project_flutter/lib/views/pages/sign_up/p_sign_up.dart
@@ -307,7 +307,6 @@ class _SignUpPageState extends State<SignUpPage> {
     else if(! await MyApp().controller.searchByUsername(username)){
       Notify(0, context);
     }
-
     if(password == "" || confirmPassword == ""){
       Notify(4, context);
     }