C#'tan Veri Tabanına Bağlantı

C#'ta veri tabanına bağlanıp c# kodlarıyla insert, delete, update işlemlerini göstereceğim. Verileri textboxdan girdireceğiz.

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
using System.Data;
using MySql.Data.MySqlClient;

namespace veriyikay
{
	
	public partial class MainForm : Form
	{
	
		private TextBox txt1;
		private TextBox txt2;
		private TextBox txt3;
		private Button btn;
		private Button btn1;
		private Button btn2;
		
		public MainForm()
		{
			txt1=new TextBox();
			txt1.Location=new Point(16,16);
			txt2=new TextBox();
			txt2.Location=new Point(16,46);
			txt3=new TextBox();
			txt3.Location=new Point(16,76);
			btn=new Button();
			btn.Location=new Point(16,116);
			btn.Text="Kaydet";
			btn.Click+=new EventHandler(erg);
			btn1=new Button();
			btn1.Location=new Point(116,116);
			btn1.Text="Sil";
			btn1.Click+=new EventHandler(ergun);
			btn2=new Button();
			btn2.Location=new Point(216,116);
			btn2.Text="Güncelle";
			btn2.Click+=new EventHandler(ergunceliker);
	        Controls.AddRange(new Control[]{txt1,txt2,txt3,btn,btn1,btn2});
	        
		}
		private void erg(object sender, EventArgs e)
		{
			
		    string myConnString="Server=localhost;"+"Database=ergün;"+"User ID=root;"+"Password=******;";
		    MySqlConnection myConnection=new MySqlConnection(myConnString);
		    string myInsertQuery="insert into ogrenci (no,ad,soyad) values ('" + txt1.Text + "','" + txt2.Text + "','" + txt3.Text + "')";
			MySqlCommand myCommand=new MySqlCommand(myInsertQuery,myConnection);
			myConnection.Open();
	        myCommand.ExecuteNonQuery();
            myConnection.Close();
			
		}
		private void ergun(object sender, EventArgs e)
		{
		    string myConnString="Server=localhost;"+"Database=ergün;"+"User ID=root;"+"Password=******;";
		    MySqlConnection myConnection=new MySqlConnection(myConnString);
		    string myDeleteQuery="delete from ogrenci where no='" +txt1.Text + "'";
			MySqlCommand myCommand=new MySqlCommand(myDeleteQuery,myConnection);
			myConnection.Open();
	        myCommand.ExecuteNonQuery();
            myConnection.Close();
		}
		private void ergunceliker(object sender, EventArgs e)
		{
		    string myConnString="Server=localhost;"+"Database=ergün;"+"User ID=root;"+"Password=******;";
		    MySqlConnection myConnection=new MySqlConnection(myConnString);
		    string myUpdateQuery=" update ogrenci set ad='" + txt2.Text + "',soyad='"+ txt3.Text +"' where no='"+ txt1.Text +"'";
			MySqlCommand myCommand=new MySqlCommand(myUpdateQuery,myConnection);
			myConnection.Open();
	        myCommand.ExecuteNonQuery();
            myConnection.Close();
		}
	}
	    class ergün {
		public	static void Main() {
	   Application.Run(new MainForm());
		}
	}
}