Creating/Developing/Performing NHibernate Applications Using Asp.Net C# Linq CRUD Operations O/R mapper

Posted by on December 4, 2010 Leave a comment (0) Go to comments

We allready discussed the key interfaces for creating nhibernate asp.net application in http://aspdotnetcodesonline.com/asp-net/creatingdevelopingperforming-crud-operations-using-nhibernate-c-asp-net-linq-or-mapper-1/

Open file and create a new console application and named it NHibernate1,

In this demonstartion,i am going to access a database table and performing all the CRUD operation,Here i used the 3 main emp table columns are FirstName,
DeptName,Manager.

In main.cs,

using System;
using System.Collections.Generic;
using System.Reflection;
using System.Linq;
using NHibernate;
using NHibernate.Cfg;
using NHibernate.Cfg.ConfigurationSchema;
using System.Data.SqlClient;
 
namespace NHibernate1
{
    public class Emp
    {
        virtual public int id { get; set; }
        virtual public string FirstName { get; set; }
        virtual public string DeptName { get; set; }
        virtual public string Manager { get; set; }
 
        virtual public string DisplayEmp()
        {
            return "FirstName: '" + FirstName + "' Department Name: " + DeptName + " Manager: " + Manager + ".";
        }
    }
 
    public class Program
    {
        private static void Main()
        {
            Emp James = new Emp { FirstName = "James", DeptName = "Cat", Manager = "Peter" };
            Console.WriteLine(James.DisplayEmp());
 
            //let's save James to the database
            try
            {
                using (ISession session = OpenSession())
                {
                    using (ITransaction transaction = session.BeginTransaction())
                    {
                        session.Save(James);
                        transaction.Commit();
                    }
                    Console.WriteLine("Saved James to the database");
                }
            }
            catch (Exception e) { Console.WriteLine(e); }
 
            //let's read all the Emps in the database
            using (ISession session = OpenSession())
            {
                IQuery query = session.CreateQuery("FROM Emp");
                IList<Emp> Emps = query.List<Emp>();
                Console.Out.WriteLine("Emps.Count = " + Emps.Count);
                Emps.ToList().ForEach(p => Console.WriteLine(p.DisplayEmp()));
            }
 
            //let's update our Emp in the database
            using (ISession session = OpenSession())
            {
                using (ITransaction transaction = session.BeginTransaction())
                {
                    IQuery query = session.CreateQuery("FROM Emp WHERE FirstName = 'James'");
                    Emp Emp = query.List<Emp>()[0];
                    Emp.FirstName = "Jerold";
                    transaction.Commit();
                }
 
            }
 
            //let's read all the Emps in the database (again)
            using (ISession session = OpenSession())
            {
                IQuery query = session.CreateQuery("FROM Emp");
                IList<Emp> Emps = query.List<Emp>();
                Console.Out.WriteLine("Emps.Count = " + Emps.Count);
                Emps.ToList().ForEach(p => Console.WriteLine(p.DisplayEmp()));
            }
 
            //let's delete our Emp from the database
            using (ISession session = OpenSession())
            {
                using (ITransaction transaction = session.BeginTransaction())
                {
                    IQuery query = session.CreateQuery("FROM Emp WHERE FirstName = 'Jerold'");
                    Emp Emp = query.List<Emp>()[0];
                    session.Delete(Emp);
                    transaction.Commit();
                }
 
            }
        }
 
        static ISessionFactory SessionFactory;
        static ISession OpenSession()
        {
            if (SessionFactory == null) //not threadsafe
            { //SessionFactories are expensive, create only once
                Configuration configuration = new Configuration();
                configuration.AddAssembly(Assembly.GetCallingAssembly());
                SessionFactory = configuration.BuildSessionFactory();
            }
            return SessionFactory.OpenSession();
        }
    }
}