created tables for Group, User and UserGrouo

lib/data/database.dart

@@ -0,0 +1,46 @@
+import 'package:drift/drift.dart';
+import 'package:drift_flutter/drift_flutter.dart';
+import 'package:path_provider/path_provider.dart';
+
+part 'database.g.dart';
+
+class User extends Table {
+  TextColumn get id => text()();
+  TextColumn get name => text()();
+
+  @override
+  Set<Column<Object>> get primaryKey => {id};
+}
+
+class Group extends Table {
+  TextColumn get id => text()();
+  TextColumn get name => text()();
+
+  @override
+  Set<Column<Object>> get primaryKey => {id};
+}
+
+class UserGroup extends Table {
+  TextColumn get userId => text().references(User, #id)();
+  TextColumn get groupId => text().references(Group, #id)();
+
+  @override
+  Set<Column<Object>> get primaryKey => {userId, groupId};
+}
+
+@DriftDatabase(tables: [User, Group, UserGroup])
+class AppDatabase extends _$AppDatabase {
+  AppDatabase([QueryExecutor? executor]) : super(executor ?? _openConnection());
+
+  @override
+  int get schemaVersion => 1;
+
+  static QueryExecutor _openConnection() {
+    return driftDatabase(
+      name: 'gametracker_db',
+      native: const DriftNativeOptions(
+        databaseDirectory: getApplicationSupportDirectory,
+      ),
+    );
+  }
+}