Future<Database> getDatabaseInstanace() async {
    Directory directory = await getApplicationDocumentsDirectory();

    String path = join(directory.path, "client.db");

    return await openDatabase(path, version: 1,
        onCreate: (Database db, int version) async {
      await db.execute("CREATE TABLE Client ("
          "id integer primary key,"
          "name TEXT,"
          "phone TEXT"
          ")");
    });
  }