Insert & display data to access database

public partial class Form1 : Form
    {
        private OleDbConnection connection;
         private string connectionString = @"Provider=Microsoft.JET.OLEDB.4.0;Data Source=..\..\..\Database.mdb;";
        private int currentStationIndex = 0;
        private List<object> uniqueStations;
        private DataTable allData;

        public Form1()
        {
            InitializeComponent();
            Text = "Data Entry";
            //dataGridView1.ColumnCount = 2;
           // dataGridView1.RowCount = 12;
            connection = new OleDbConnection(connectionString);
            LoadAllRecords();

        }
        private void LoadAllRecords()
        {
            try
            {
                using (OleDbCommand cmd = new OleDbCommand("SELECT * FROM TableName ORDER BY Station", connection))
                {
                    OleDbDataAdapter adapter = new OleDbDataAdapter(cmd);
                    allData = new DataTable();
                    adapter.Fill(allData);

                    // Get unique stations
                    uniqueStations = allData.AsEnumerable()
                        .Select(row => row.Field<object>("Station"))
                        .Distinct()
                        .ToList();
                }
                DisplayCurrentStation();
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Error loading records: {ex.Message}\n\nStack Trace: {ex.StackTrace}");
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                using (OleDbCommand cmd = new OleDbCommand("INSERT INTO TableName (Station, Offset, Elevation) VALUES (@Station, @Offset, @Elevation)", connection))
                {
                    connection.Open();

                    for (int i = 0; i < dataGridView1.Rows.Count - 1; i++)
                    {
                        cmd.Parameters.Clear();
                        cmd.Parameters.AddWithValue("@Station", textBox1.Text);
                        cmd.Parameters.AddWithValue("@Offset", dataGridView1.Rows[i].Cells[0].Value ?? DBNull.Value);
                        cmd.Parameters.AddWithValue("@Elevation", dataGridView1.Rows[i].Cells[1].Value ?? DBNull.Value);
                        cmd.ExecuteNonQuery();
                    }

                    MessageBox.Show("Data saved successfully!");

                    // Increase station by the interval
                    double currentStation = double.Parse(textBox1.Text);
                    double interval = double.Parse(textBox2.Text);
                    textBox1.Text = (currentStation + interval).ToString();

                    // Clear the DataGridView
                    dataGridView1.Rows.Clear();

                    // Reload records
                    LoadAllRecords();
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Error saving data: {ex.Message}\n\nStack Trace: {ex.StackTrace}");
            }
            finally
            {
                if (connection.State == ConnectionState.Open)
                    connection.Close();
            }
        }
        private void button2_Click(object sender, EventArgs e)
        {
            // Show previous station
            if (currentStationIndex > 0)
            {
                currentStationIndex--;
                DisplayCurrentStation();
            }
            else
            {
                MessageBox.Show("You are at the beginning of the stations.");
            }
        }
        private void button3_Click(object sender, EventArgs e)
        {
            // Show next station
            if (currentStationIndex < uniqueStations.Count - 1)
            {
                currentStationIndex++;
                DisplayCurrentStation();
            }
            else
            {
                MessageBox.Show("You have reached the end of the stations.");
            }
        }
        private void DisplayCurrentStation()
        {
            if (uniqueStations.Count > 0 && currentStationIndex >= 0 && currentStationIndex < uniqueStations.Count)
            {
                object currentStation = uniqueStations[currentStationIndex];
                textBox1.Text = currentStation.ToString();
                var stationData = allData.AsEnumerable()
                    .Where(row => row.Field<object>("Station") == currentStation)
                    .Select(row => new {
                        Offset = row.Field<double>("Offset"),
                        Elevation = row.Field<double>("Elevation")
                    }).ToList();
                dataGridView1.DataSource = stationData;
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // dataGridView1.AutoGenerateColumns = true;
            dataGridView1.Columns[0].Width = 140;
            dataGridView1.Columns[1].Width = 140;
        }
    }