Settings is setting class in .NET you can click on project->properties->settings to generate this class. You can find this file in Debug folder that have .config extension.

Here is my Data Access class manage command from C# to MySQL database.

    public class DataAccess
    {
        static internal string GetConnectionString()
        {
            return String.Format("server={0};user id={1};Password={2};database={3}",
                Settings.Default.DbServer, Settings.Default.DbUserId, Settings.Default.DbPassword,
                Settings.Default.DbName);
        }

        static DataAccess()
        { }

        public static DataTable ExecuteSelectCommand(MySqlCommand command)
        {
            DataTable table = null;
            try
            {
                command.Connection.Open();
                MySqlDataReader reader = command.ExecuteReader();
                table = new DataTable();
                table.Load(reader);
                reader.Close();
            }
            catch (Exception ex)
            {
                System.Windows.MessageBox.Show(ex.Data.ToString());
            }
            finally
            {
                command.Connection.Close();
            }
            return table;
        }

        public static MySqlCommand CreateCommand()
        {
            string dataProviderName = Settings.Default.DbProvoderName;
            string connectionString = GetConnectionString();
            MySqlConnection conn = new MySqlConnection();
            conn.ConnectionString = connectionString;
            MySqlCommand comm = conn.CreateCommand();
            return comm;
        }

        public static int ExecuteNonQuery(MySqlCommand command)
        {
            int affectedRows = -1;
            try
            {
                command.Connection.Open();
                affectedRows = command.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                command.Connection.Close();
            }
            return affectedRows;
        }
    }

Now here’s the sample to call that DataAccess class

    public class Golongan
    {
        private int idGolongan;
        private string namaGolongan;

        public int IdGolongan
        {
            get { return idGolongan; }
            set { idGolongan = value; }
        }

        public string NamaGolongan
        {
            get { return namaGolongan; }
            set { namaGolongan = value; }
        }

        public Golongan()
        { }

        public Golongan(int idGolongan, string namaGolongan)
        {
            this.idGolongan = idGolongan;
            this.namaGolongan = namaGolongan;
        }

        public static DataTable SelectAllGolongan()
        {
            MySqlCommand command = DataAccess.CreateCommand();
            command.CommandText = "select * from golongan";
            DataTable table = DataAccess.ExecuteSelectCommand(command);
            return table;
        }

        public int InsertGolongan()
        {
            MySqlCommand commmand = DataAccess.CreateCommand();
            commmand.CommandText = "insert into golongan (golongan) " +
                                    "values(    '" + this.namaGolongan + "')";

            return DataAccess.ExecuteNonQuery(commmand);
        }

        public int UpdateGolongan()
        {
            MySqlCommand commmand = DataAccess.CreateCommand();
            commmand.CommandText =
                String.Format("update golongan set golongan = '{0}' where idgolongan = {1}",
                this.namaGolongan, this.idGolongan);

            return DataAccess.ExecuteNonQuery(commmand);
        }

        public int DeleteGolongan()
        {
            MySqlCommand commmand = DataAccess.CreateCommand();
            commmand.CommandText =
                String.Format("delete from golongan where idgolongan = {0}",
                this.idGolongan);

            return DataAccess.ExecuteNonQuery(commmand);
        }
}

Hope it’s help
Willy Achmat Fauzi