Aktualizacja bazy danych SqlDataAdapter

 
    //Metoda odczytująca dane z bazy danych
    public class TADOReader
    {
        public DataTable Read(TADOConnection _connection)
        {
            DataTable dt = new DataTable();
            SqlDataAdapter adapter = new SqlDataAdapter(new SqlCommand("SELECT * FROM GroundWireDatabase", _connection.connection));
            adapter.Fill(dt);

            //Kolumna z kluczem głównym jako tylko do odczytu
            dt.Columns[0].ReadOnly = true;

            return dt;
        }
    }

    //Metoda zapisująca dane w bazie danych
    public class TADOWriter
    {
        public void Write(TADOConnection _connection, DataTable _table)
        {
            try
            {
                SqlDataAdapter adapter = new SqlDataAdapter(new SqlCommand("SELECT * FROM GroundWireDatabase",                  _connection.connection));
                SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
                adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
                adapter.DeleteCommand = builder.GetDeleteCommand(true);
                adapter.UpdateCommand = builder.GetUpdateCommand(true);
                adapter.InsertCommand = builder.GetInsertCommand(true);

                int result = adapter.Update(_table); // Zwraca liczbę <> 0
               // _table.AcceptChanges();
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }

    //Fragment klasy łączeniowej 
    public class TADOConnection
    {
        private const string DATASOURCE = @"(LocalDB)\v11.0";
        private const string INTEGRATED_SECURITY = "True";
        private const string ATTACH_DB_FILENAME = @"|DataDirectory|\IO\Database\GroundWireDatabase.mdf";
        private const string ConnectionString = "Data Source=" + DATASOURCE + 
                                                ";AttachDbFilename= " + ATTACH_DB_FILENAME +
                                                ";Integrated Security=" + INTEGRATED_SECURITY;

        public TADOConnection()
        {
            Fconnection = new SqlConnection(ConnectionString);
            Connect();
        }
    }

    //wywołania w formatce
        private void GroundWireDatabaseForm_Load(object sender, EventArgs e)
        {
            TADOReader reader = new TADOReader();
            dgGroundwire.DataSource = reader.Read(new TADOConnection());
        }

        private void btnAktualizuj_Click(object sender, EventArgs e)
        {
            TADOWriter writer = new TADOWriter();
            writer.Write(new TADOConnection(), dgGroundwire.DataSource as DataTable);
        }

 
CREATE TABLE [dbo].[GroundWireDatabase] (
    [CableID]              INT        IDENTITY (1, 1) NOT NULL,
    [Producer]             TEXT       NULL,
    [CrossSection]         FLOAT (53) NULL,
    [Radius]               FLOAT (53) NULL,
    [Resistance]           FLOAT (53) NULL,
    [MagneticConductivity] FLOAT (53) NULL,
    PRIMARY KEY CLUSTERED ([CableID] ASC)
);

int result = adapter.Update(_table); //Zwraca 1
// _table.AcceptChanges();
adapter.AcceptChanges();

 
    public class TADOWriter
    {
        private TADOConnection Connection;

        public void Write(TADOConnection _connection, DataTable _table)
        {
            foreach(DataRow row in _table.Rows)
            {
                switch(row.RowState)
                {
                    case DataRowState.Added:
                        Insert(row);
                        break;
                    case DataRowState.Deleted:
                        Delete(row);
                        break;
                    case DataRowState.Modified:
                        Update(row);
                        break;
                }
                row.AcceptChanges();
            }
        }

        private void Insert(DataRow _row)
        {
            SqlCommand cmd = new SqlCommand("INSERT INTO [GroundWireDatabase] ([Producer], [CrossSection], [Radius], [Resistance], [MagneticConductivity]) " +
                                            "VALUES (@p1, @p2, @p3, @p4, @p5)", Connection.connection);
            cmd.Parameters.AddWithValue("@p1", _row["Producer"]);
            cmd.Parameters.AddWithValue("@p2", _row["CrossSection"]);
            cmd.Parameters.AddWithValue("@p3", _row["Radius"]);
            cmd.Parameters.AddWithValue("@p4", _row["Resistance"]);
            cmd.Parameters.AddWithValue("@p5", _row["MagneticConductivity"]);

            cmd.ExecuteNonQuery();
        }

        private void Delete(DataRow _row)
        {
            SqlCommand cmd = new SqlCommand("DELETE FROM [GroundWireDatabase] WHERE [CableID] = @p1", Connection.connection);
            cmd.Parameters.AddWithValue("@p1", _row["CableID"]);

            cmd.ExecuteNonQuery();          
        }

        private void Update(DataRow _row)
        {
            SqlCommand cmd = new SqlCommand("UPDATE [GroundWireDatabase] SET [Producer] = @p1, [CrossSection] = @p2, " +
                                            "[Radius] = @p3, [Resistance] = @p4, [MagneticConductivity] = @p5 " +
                                            "WHERE [CableID] = @p6", Connection.connection);
            cmd.Parameters.AddWithValue("@p1", _row["Producer"]);
            cmd.Parameters.AddWithValue("@p2", _row["CrossSection"]);
            cmd.Parameters.AddWithValue("@p3", _row["Radius"]);
            cmd.Parameters.AddWithValue("@p4", _row["Resistance"]);
            cmd.Parameters.AddWithValue("@p5", _row["MagneticConductivity"]);
            cmd.Parameters.AddWithValue("@p6", _row["CableID"]);

            int result = cmd.ExecuteNonQuery();        
        }

        public TADOWriter()
        {
            Connection = new TADOConnection();
        }
    }