lib/data/dao/group_dao.dart

@@ -3,6 +3,7 @@ import 'package:tallee/data/db/database.dart';
 import 'package:tallee/data/db/tables/group_table.dart';
 import 'package:tallee/data/db/tables/player_group_table.dart';
 import 'package:tallee/data/dto/group.dart';
+import 'package:tallee/data/dto/match.dart';
 import 'package:tallee/data/dto/player.dart';
 
 part 'group_dao.g.dart';
@@ -171,6 +172,12 @@ class GroupDao extends DatabaseAccessor<AppDatabase> with _$GroupDaoMixin {
     });
   }
 
+  /// Retrieves all matches associated with the given [groupId].
+  Future<List<Match>> getGroupMatches({required String groupId}) async {
+    final matches = await db.matchDao.getAllMatches();
+    return matches.where((match) => match.group?.id == groupId).toList();
+  }
+
   /// Deletes the group with the given [id] from the database.
   /// Returns `true` if more than 0 rows were affected, otherwise `false`.
   Future<bool> deleteGroup({required String groupId}) async {

lib/data/dao/match_dao.dart

@@ -338,10 +338,10 @@ class MatchDao extends DatabaseAccessor<AppDatabase> with _$MatchDaoMixin {
     return rowsAffected > 0;
   }
 
-  /// Entfernt die Gruppen-Verknüpfung des Matches mit der gegebenen [matchId].
+  /// Removes the group association of the match with the given [matchId].
-  /// Setzt die groupId auf null.
+  /// Sets the groupId to null.
-  /// Gibt `true` zurück, wenn mehr als 0 Zeilen betroffen waren, ansonsten `false`.
+  /// Returns `true` if more than 0 rows were affected, otherwise `false`.
-  Future<bool> deleteMatchGroup({required String matchId}) async {
+  Future<bool> removeMatchGroup({required String matchId}) async {
     final query = update(matchTable)..where((g) => g.id.equals(matchId));
     final rowsAffected = await query.write(
       const MatchTableCompanion(groupId: Value(null)),

lib/presentation/views/main_menu/group_view/create_group_view.dart

@@ -190,11 +190,16 @@ class _CreateGroupViewState extends State<CreateGroupView> {
     return (success, updatedGroup);
   }
 
+  /// Removes the group association from matches that no longer belong to the edited group.
+  ///
+  /// After updating the group's members, matches that were previously linked to
+  /// this group but don't have any of the newly selected players are considered
+  /// obsolete. For each such match, the group association is removed by setting
+  /// its [groupId] to null.
   Future<void> deleteObsoleteMatchGroupRelations() async {
-    final matches = await db.matchDao.getAllMatches();
+    final groupMatches = await db.groupDao.getGroupMatches(
-    final groupMatches = matches
+      groupId: widget.groupToEdit!.id,
-        .where((match) => match.group?.id == widget.groupToEdit!.id)
+    );
-        .toList();
 
     final selectedPlayerIds = selectedPlayers.map((p) => p.id).toSet();
     final relationshipsToDelete = groupMatches.where((match) {
@@ -204,7 +209,7 @@ class _CreateGroupViewState extends State<CreateGroupView> {
     }).toList();
 
     for (var match in relationshipsToDelete) {
-      await db.matchDao.deleteMatchGroup(matchId: match.id);
+      await db.matchDao.removeMatchGroup(matchId: match.id);
     }
   }
 

lib/presentation/views/main_menu/group_view/group_detail_view.dart

@@ -194,7 +194,6 @@ class _GroupDetailViewState extends State<GroupDetailView> {
                         return CreateGroupView(
                           groupToEdit: _group,
                           onMembersChanged: () {
-                            isLoading = true;
                             _loadStatistics();
                           },
                         );
@@ -248,10 +247,8 @@ class _GroupDetailViewState extends State<GroupDetailView> {
 
   /// Loads statistics for this group
   Future<void> _loadStatistics() async {
-    final matches = await db.matchDao.getAllMatches();
+    isLoading = true;
-    final groupMatches = matches
+    final groupMatches = await db.groupDao.getGroupMatches(groupId: _group.id);
-        .where((match) => match.group?.id == _group.id)
-        .toList();
 
     setState(() {
       totalMatches = groupMatches.length;

test/db_tests/aggregates/match_test.dart

@@ -308,13 +308,12 @@ void main() {
       expect(fetchedMatch.winner!.id, testPlayer5.id);
     });
 
-    // Tests for removeMatchGroup
     test(
       'removeMatchGroup removes group from match with existing group',
       () async {
         await database.matchDao.addMatch(match: testMatch1);
 
-        final removed = await database.matchDao.deleteMatchGroup(
+        final removed = await database.matchDao.removeMatchGroup(
           matchId: testMatch1.id,
         );
         expect(removed, isTrue);
@@ -323,7 +322,6 @@ void main() {
           matchId: testMatch1.id,
         );
         expect(updatedMatch.group, null);
-        // Andere Felder bleiben unverändert
         expect(updatedMatch.game.id, testMatch1.game.id);
         expect(updatedMatch.name, testMatch1.name);
         expect(updatedMatch.notes, testMatch1.notes);
@@ -335,10 +333,9 @@ void main() {
       () async {
         await database.matchDao.addMatch(match: testMatchOnlyPlayers);
 
-        final removed = await database.matchDao.deleteMatchGroup(
+        final removed = await database.matchDao.removeMatchGroup(
           matchId: testMatchOnlyPlayers.id,
         );
-        // Update sollte trotzdem eine Zeile betreffen
         expect(removed, isTrue);
 
         final updatedMatch = await database.matchDao.getMatchById(
@@ -349,7 +346,7 @@ void main() {
     );
 
     test('removeMatchGroup on non-existing match returns false', () async {
-      final removed = await database.matchDao.deleteMatchGroup(
+      final removed = await database.matchDao.removeMatchGroup(
         matchId: 'non-existing-id',
       );
       expect(removed, isFalse);