menu.addMenuItem ("Show tables", [&] (ConsoleMenu& menu) {
        ConsoleMenu showTables;

        showTables.addMenuItem ("Books", [&] (ConsoleMenu) {
            system ("cls");
            db.showBooks();
            cin.get();
        });

        showTables.addMenuItem ("Clients", [&] (ConsoleMenu) {
            system ("cls");
            //db.showBooks();
            cin.get();
        });

        showTables.addMenuItem ("Back", [] (ConsoleMenu& menn) {menn.quit();});

        showTables.run();
    });