Update

private void button3_Click(object sender, EventArgs e)

        {

            String s = "data source=ACER-PC\\SQLEXPRESS;database = hr;integrated security = SSPI";

            SqlConnection c = new SqlConnection(s);

            try {

                if (textBox1.Text == ""){

                    MessageBox.Show("Enter Id To Update");

                } else

                {

     SqlCommand cmdupdate = new SqlCommand("Update tblEmployees SET name='" + textBox2.Text + "' where id=" + textBox1.Text + "", c);

                    c.Open();

                    cmdupdate.CommandType = CommandType.Text;

                    cmdupdate.ExecuteNonQuery();

                    MessageBox.Show("Data Updated");

                }

            }

            catch (Exception ex){

                MessageBox.Show(ex.Message);

            }

            finally{

                if (c.State == ConnectionState.Open){

                    c.Close();

                }            }        }    }}