How do I update a column in database with the new user inputs?

private void button1_Click(object sender, EventArgs e)
        {
            /*VirtualPet.Popup popup = new VirtualPet.Popup();
            popup.UpdatePopup();*/
            SqlCeConnection conn = new SqlCeConnection("Data Source=E:\\Project Final_Year\\Project Final\\MyProject\\ERU Implementation\\VirtualPetedit\\VirtualPet\\MyDB.sdf");
            string query = "UPDATE Events SET (event_name='" + this.textBox2.Text + "', event_description='" + this.richTextBox1.Text + "', event_type='" + this.comboBox1.SelectedItem + "', date='" + this.dateTimePicker1.Value + "', time='" + this.textBox3.Text +"')  WHERE event_id = " + textBox1.Text + ";";
            SqlCeCommand cmd = new SqlCeCommand(query, conn);
            try
            {
                conn.Open();
                SqlCeCommand command = new SqlCeCommand(query, conn);
                command.ExecuteNonQuery();
                VirtualPet.Popup popup = new VirtualPet.Popup();
                popup.UpdatePopup();
                conn.Close();
                //command.Parameters.AddWithValue("@EI", textBox4.Text);  
            }
            catch (Exception err)
            {
                MessageBox.Show(err.Message);
            }
        }