Implemented basic structure

lib/data/dao/player_group_dao.dart

@@ -0,0 +1,40 @@
+import 'package:drift/drift.dart';
+import 'package:game_tracker/data/db/database.dart';
+import 'package:game_tracker/data/db/tables/player_group_table.dart';
+
+part 'player_group_dao.g.dart';
+
+@DriftAccessor(tables: [PlayerGroupTable])
+class PlayerGroupDao extends DatabaseAccessor<AppDatabase>
+    with _$PlayerGroupDaoMixin {
+  PlayerGroupDao(super.db);
+
+  Future<List<UserGroupData>> getAllUsersAndGroups() async {
+    return await select(userGroup).get();
+  }
+
+  Future<List<UserGroupData>> getUsersGroups(String userId) async {
+    return await (select(
+      userGroup,
+    )..where((uG) => uG.userId.equals(userId))).get();
+  }
+
+  Future<List<UserGroupData>> getGroupsUsers(String groupId) async {
+    return await (select(
+      userGroup,
+    )..where((uG) => uG.groupId.equals(groupId))).get();
+  }
+
+  Future<void> addUserToGroup(String userId, String groupId) async {
+    await into(
+      userGroup,
+    ).insert(UserGroupCompanion.insert(userId: userId, groupId: groupId));
+  }
+
+  Future<void> removeUserFromGroup(String userId, String groupId) async {
+    await (delete(
+          userGroup,
+        )..where((uG) => uG.userId.equals(userId) & uG.groupId.equals(groupId)))
+        .go();
+  }
+}