removed comment

lib/data/dao/game_dao.dart

@@ -65,7 +65,6 @@ class GameDao extends DatabaseAccessor<AppDatabase> with _$GameDaoMixin {
 
   /// Adds a new [Game] to the database.
   /// Also adds associated players and group if they exist.
-  /// If a game, player, or group already exists, it will be replaced.
   Future<void> addGame({required Game game}) async {
     await db.transaction(() async {
       await into(gameTable).insert(

lib/data/dao/group_game_dao.dart

@@ -11,12 +11,14 @@ class GroupGameDao extends DatabaseAccessor<AppDatabase>
   GroupGameDao(super.db);
 
   /// Associates a group with a game by inserting a record into the
-  /// [GroupGameTable]. If there is already group associated to the game,
-  /// it will be replaced.
+  /// [GroupGameTable].
   Future<void> addGroupToGame({
     required String gameId,
     required String groupId,
   }) async {
+    if (await gameHasGroup(gameId: gameId)) {
+      throw Exception('Game already has a group');
+    }
     await into(groupGameTable).insert(
       GroupGameTableCompanion.insert(groupId: groupId, gameId: gameId),
       mode: InsertMode.insertOrReplace,