How achieve batch update data

Question

hi all,
I am trying to achieve batch update data, but failed to achieve, give correction, the code is as follows
thank in advance.
 public partial class UpdateTranData : Form
  {
  public UpdateTranData()
  {
  InitializeComponent();
  }
  SqlDataAdapter adapter;
  DataSet ds;
  string connectionString = @"data source=StudentDB;initial catalog=MYDB;user=sa;password=PASSWORD;";
  SqlConnection sqlCnn;
  SqlCommand sqlCmd;
  string sql = null;
  private void UpdateTranData_Load(object sender, EventArgs e)
  {
  sql="SELECT *FROM TRAN_INFO";
  sqlCnn = new SqlConnection(connectionString);
  sqlCnn.Open();
  adapter = new SqlDataAdapter(sql, sqlCnn);// specifing SQL statement and Database connection
  ds = new DataSet();//creating instance of DataSet
  adapter.Fill(ds); //filling DataSet
  dataGridView1.DataSource = ds.Tables[0];//Binding DataGridView with DataSet
 
  }
 
  private void btnUpdate_Click(object sender, EventArgs e)
  {
 
  SqlCommandBuilder scb = new SqlCommandBuilder(adapter);
  if (MessageBox.Show("Are you sure?","Warning",MessageBoxButtons.YesNo,MessageBoxIcon.Warning)==DialogResult.Yes)
  {
  try
  {
  adapter.Update(ds.Tables[0]);
  sqlCnn.Close();
  MessageBox.Show("Data updated successful!");
 
  }
  catch (Exception)
  {
  MessageBox.Show("Data updated defeat!");
  sqlCnn.Close();
  }
  }
  private void dataGridView1_CellMouseClick(object sender, DataGridViewCellMouseEventArgs e)
  {
  txtID.Text = dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString();
  txtStart_Station.Text = dataGridView1.Rows[e.RowIndex].Cells[1].Value.ToString();
  txtEnd_Station.Text = dataGridView1.Rows[e.RowIndex].Cells[2].Value.ToString();
 txID.Enabled = false;
   }
 }