Consulta C#:'System.InvalidOperationException' | Informações adicionais:A conexão deve ser válida e aberta

connectionString = @"server=localhost;database=" + lbDatabase.SelectedItem.ToString() + ";userid=root;password=;";

    string query = "SELECT order_id FROM orders WHERE id = 1";

    MySqlConnection connect = new MySqlConnection(connectionString);


    MySqlCommand cmd = new MySqlCommand(query, connect);

    connect.Open();

    reader = cmd.ExecuteReader();

 /*Do Whatever You Want To Do Here */

connect.Close();