it wont UPDATE

I have written this code, it works perfectly but it wont edit (update) the selected data. have I missed something.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.OleDb;

namespace Registry
{
    public partial class Form10 : Form
    {
        private OleDbConnection connection = new OleDbConnection();
        public Form10()
        {
            InitializeComponent();
        connection.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\fredhope\Desktop\Registry Access\registry.accdb;
Persist Security Info=False;";
        load_table();
        }
        void load_table()
        {
            try
            {
                connection.Open();
                OleDbCommand command = new OleDbCommand();
                command.Connection = connection;
               // string query = "select * from registry";
                string query = "select ID,siku,sfnumber,shelf,raw,column from registry";
                command.CommandText = query;

                OleDbDataAdapter da = new OleDbDataAdapter(command);
                DataTable dt = new DataTable();
                da.Fill(dt);
                dataGridView1.DataSource = dt;

                connection.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error " + ex);
            }
        }
        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                connection.Open();
                OleDbCommand command = new OleDbCommand();
                command.Connection = connection;
                string query = "UPDATE [registry] SET [siku]='" + dateTimePicker1.Text + "',[shelf]='" + txt_shelf.Text + "',[raw]='" + txt_raw.Text + "',[column]='" + txt_column.Text + "' where [sfnumber]='" + txt_sfnumber + "'";
                MessageBox.Show(query);
                command.CommandText = query;

                command.ExecuteNonQuery();
                MessageBox.Show("Data Edited Successful");
                connection.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error " + ex);
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Form4 m = new Form4();
            m.Show();
            Form10 f = new Form10();
            this.Visible = false;
            this.Hide();
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            try
            {
                connection.Open();
                OleDbCommand command = new OleDbCommand();
                command.Connection = connection;
                string query = "select * from [registry] where [sfnumber]='"+comboBox1.Text+"'";
                command.CommandText = query;

                OleDbDataReader reader = command.ExecuteReader();
                while (reader.Read())
                {
                  //  dateTimePicker1.Text = reader["siku"].ToString();
                 //   txt_sfnumber.Text = reader["sfnumber"].ToString();
                 //   txt_casezone.Text = reader["casezone"].ToString();
                 //   txt_casetype.Text = reader["casetype"].ToString();
                //    txt_appellant.Text = reader["appellant"].ToString();
               //     txt_respondant.Text = reader["respondant"].ToString();
               //     txt_shelf.Text = reader["shelf"].ToString();
              //      txt_raw.Text = reader["raw"].ToString();
              //      txt_column.Text = reader["column"].ToString();
                   //other way
                    string dateTimePicker1 = reader["siku"].ToString();
                    string sfnumber = reader["sfnumber"].ToString();
                    string casezone = reader["casezone"].ToString();
                    string casetype = reader["casetype"].ToString();
                    string appellant = reader["appellant"].ToString();
                    string respondant = reader["respondant"].ToString();
                    string shelf = reader["shelf"].ToString();
                    string raw = reader["raw"].ToString();
                    string column = reader["column"].ToString();
                }

                connection.Close();
            }
            catch(Exception ex)
            {
                MessageBox.Show("Error  " + ex);
            }
        }
    }
}