sorry for the inconvenience as caused.
here is my code:
using System;
using System.IO;
using System.Data;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Northwind.Tutorial.DatabaseSpecific;
using Northwind.Tutorial.EntityClasses;
using Northwind.Tutorial.FactoryClasses;
using Northwind.Tutorial.HelperClasses;
using Northwind.Tutorial.RelationClasses;
using Northwind.Tutorial.TypedViewClasses;
using Northwind.Tutorial;
using DevExpress.XtraGrid.Views.Card;
using DevExpress.XtraEditors.Repository;
using SD.LLBLGen.Pro.ORMSupportClasses;
namespace NorthwindConsole
{
	public partial class SecondViewer : Form
	{
		private DataAccessAdapter DAA;
		public SecondViewer()
		{
			InitializeComponent();
			DataLoad();
    }
    private void DataLoad()
    {
        DAA = new DataAccessAdapter();
        PatientEntity patient = new PatientEntity();
        BookingEntity booking = new BookingEntity();
        DAA.FetchEntity(booking);
    }
    private void button1_Click(object sender, EventArgs e)
    {
        IPrefetchPath2 path= new PrefetchPath2((int)EntityType.PatientEntity);
        path.Add(PatientEntity.PrefetchPathBookings);
        EntityCollection<PatientEntity> patients = new EntityCollection<PatientEntity>();
        IRelationPredicateBucket bucket = new RelationPredicateBucket();
        bucket.Relations.Add(PatientEntity.Relations.BookingEntityUsingPatient_ID);
        bucket.PredicateExpression.Add(PatientFields.Surname == "Andersen");
        bucket.PredicateExpression.Add(BookingFields.Duration > 15);
        SortExpression sorter = new SortExpression();
            sorter.Add(PatientFields.FirstName | SortOperator.Ascending);
            DAA.FetchEntityCollection(patients, bucket, 0, sorter, path);                               // syntax - DAA.FetchEntityCollection(ec,rpb,0,prefetchpath)
    }
    private void SecondViewer_FormClosing(object sender, FormClosingEventArgs e)
    {
        try
        {
            DAA.CloseConnection();
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }
    }
    private void button2_Click(object sender, EventArgs e)
    {
        this.Close();
    }
    private void button3_Click(object sender, EventArgs e)
    {
        this.Hide();
        Viewer v = new Viewer();
        v.Show();
    }
    private void SecondViewer_Load(object sender, EventArgs e)
    {
        var entity = new BookingEntity();
            DAA.FetchEntity(entity);
        bookingEntityBindingSource.DataSource = entity;
        //gridControl2.DataSource = bookingEntityBindingSource;
    }
          }
}