(C#) ASP.NET GridView Control - DataSet,DataTable,TableRows

<%@ Import Namespace="System.Data"%>
<%@ Import Namespace="System.Data.OleDb"%>
<%@ Page Language="C#" Debug="true" %>
<script runat="server">

    void Page_Load(object sender,EventArgs e)
	{
		DataTable dt;

		//*** DataSet To DataTable ***//
		dt = CreateDsToDt();
		
		//*** DataTable ***//
		//dt = CreateDataTable();

		//*** DataSet ***//
		//DataSet ds;
		//ds = CreateDataSet();
		//dt = ds.Tables[0]; //*** Convert DataSet to DataTable ***//

		//*** TableRows ***//
		//dt = DataTableRows();

		//*** BindData to GridView ***//
		myGridView.DataSource = dt;
		myGridView.DataBind();
    }
	

	
	//*** DataTable ***//
	protected DataTable CreateDataTable()
	{
        System.Data.OleDb.OleDbConnection objConn = new System.Data.OleDb.OleDbConnection();
		System.Data.OleDb.OleDbDataAdapter dtAdapter = new System.Data.OleDb.OleDbDataAdapter();
		DataTable dt = new DataTable();
       
       
		String strConnString;
		strConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + 
		Server.MapPath("database/mydatabase.mdb")+";Jet OLEDB:Database Password=;";
		objConn = new System.Data.OleDb.OleDbConnection(strConnString);
		objConn.Open();

		String strSQL;
		strSQL = "SELECT * FROM customer";
		
		dtAdapter = new System.Data.OleDb.OleDbDataAdapter(strSQL, objConn);
		dtAdapter.Fill(dt);

		dtAdapter = null;

		objConn.Close();
		objConn = null;

		return dt; //*** Return DataTable ***//

	}

	//*** DataSet ***//
	protected DataSet CreateDataSet()
	{
        System.Data.OleDb.OleDbConnection objConn = new System.Data.OleDb.OleDbConnection();
		System.Data.OleDb.OleDbCommand objCmd = new System.Data.OleDb.OleDbCommand(); 
        System.Data.OleDb.OleDbDataAdapter dtAdapter = new System.Data.OleDb.OleDbDataAdapter();
       
		DataSet ds= new DataSet();
		String strConnString,strSQL;

		strConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + 
		Server.MapPath("database/mydatabase.mdb")+";Jet OLEDB:Database Password=;";
		
		strSQL = "SELECT * FROM customer ";
		objConn.ConnectionString = strConnString;

		objCmd.Connection = objConn;
		objCmd.CommandText = strSQL;
		objCmd.CommandType = CommandType.Text;

		dtAdapter.SelectCommand = objCmd;

		dtAdapter.Fill(ds);

		dtAdapter = null;
		objConn.Close();
		objConn = null;

		return ds;   //*** Return DataSet ***//
		
	}

	//*** DataSet to DataTable ***//
	protected DataTable CreateDsToDt()
	{
        System.Data.OleDb.OleDbConnection objConn = new System.Data.OleDb.OleDbConnection();
		System.Data.OleDb.OleDbCommand objCmd = new System.Data.OleDb.OleDbCommand();
        System.Data.OleDb.OleDbDataAdapter dtAdapter = new System.Data.OleDb.OleDbDataAdapter();
       
		DataSet ds = new DataSet();
		DataTable dt;
		String strConnString,strSQL;


		strConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + 
		Server.MapPath("database/mydatabase.mdb")+";Jet OLEDB:Database Password=;";
		strSQL = "SELECT * FROM customer";

		objConn.ConnectionString = strConnString;

		objCmd.Connection = objConn;
		objCmd.CommandText = strSQL;
		objCmd.CommandType = CommandType.Text;

		dtAdapter.SelectCommand = objCmd;

		dtAdapter.Fill(ds);
		dt = ds.Tables[0];

		dtAdapter = null;
		objConn.Close();
		objConn = null;

		return dt;   //*** Return DataTable ***//
		
	}


	
	//*** TableRows (DataTable) ***//
	protected DataTable DataTableRows()
	{
        DataTable dt = new DataTable();
        DataRow dr;
		
		//*** Column ***//
        dt.Columns.Add("CustomerID");
        dt.Columns.Add("Name");
        dt.Columns.Add("Email");
        dt.Columns.Add("CountryCode");
        dt.Columns.Add("Budget");
        dt.Columns.Add("Used");
		
		//*** Rows ***//
		dr = dt.NewRow();
        dr["CustomerID"] = "C001";
        dr["Name"] = "Win Weerachai";
        dr["Email"] = "[email protected]";
        dr["CountryCode"] = "TH";
        dr["Budget"] = "1000000";
        dr["Used"] = "600000";
        dt.Rows.Add(dr);

		//*** Rows ***//
		dr = dt.NewRow();
        dr["CustomerID"] = "C002";
        dr["Name"] = "John Smith";
        dr["Email"] = "[email protected]";
        dr["CountryCode"] = "EN";
        dr["Budget"] = "2000000";
        dr["Used"] = "800000";
        dt.Rows.Add(dr);

		//*** Rows ***//
		dr = dt.NewRow();
        dr["CustomerID"] = "C003";
        dr["Name"] = "Jame Born";
        dr["Email"] = "[email protected]";
        dr["CountryCode"] = "US";
        dr["Budget"] = "3000000";
        dr["Used"] = "600000";
        dt.Rows.Add(dr);
		
		//*** Rows ***//
		dr = dt.NewRow();
        dr["CustomerID"] = "C004";
        dr["Name"] = "Chalee Angel";
        dr["Email"] = "[email protected]";
        dr["CountryCode"] = "US";
        dr["Budget"] = "4000000";
        dr["Used"] = "100000";
        dt.Rows.Add(dr);

		return dt; //*** Return DataTable ***//
	}

</script>
<html>
<head>
<title>ThaiCreate.Com ASP.NET - GridView</title>
</head>
<body>
	<form id="form1" runat="server">
	<asp:GridView id="myGridView" runat="server">
	</asp:GridView>	
	</form>
</body>
</html>