NHibernate

 

Scenario:

Use a ORM framework to work with your database.

Solution:

NHibernate is an open-source ORM framework, which is persistence layer for the .Net  based on Object-Relational Mapping Technique. It  creates a "virtual representation" of database objects within the code. 

NET Framework. It handles persisting plain .NET objects to and from an underlying relational database. Given an XML description of your entities and relationships, NHibernate automatically generates SQL for loading and storing the objects.

Object Relational Mapping (ORM) is a technique used in creating a "bridge" between object-oriented programs and, in most cases, relational databases. It solves the issues like DB does not have inheritance and the structure is diffrent between DB and classes.

NHibernate, persists the object into the relation database and can do CRUD operations, you dont have to write SQL queries, the data access logic can be contained in  the application. 

1. The XML mapping file, which can be done in the code as well.

2. Configuration file

3. POCO

They need to have atleast one id property

All properties need to be marked Virtual

//Construct a Session Factory

var sessionFactory  = Fluently.Configure()
                .Database(MsSqlConfiguration.MsSql2008.ConnectionString(sqlConnection))
                .Mappings(m => m.FluentMappings.AddFromAssemblyOf<MyContext>())
                .BuildSessionFactory();

//start a session and save data/ Flush mode could be Manual, Automatic and commit time
using (var session = NHibernateHelper.OpenSession()
Session.FlushMode = FlushMode.Manual) { 

using (var transaction = session.BeginTransaction()) { 
   var user = new User { 
	  FirstName = "Ram", 
	  LastName = "Mangal" 
   }; 
		
   session.Save(customer); 
    
   session.Flush();
   transaction.Commit();
   session.Close();  
} 

//Mapping
class UserMap : ClassMap<User> { 
      public UserMap() { 
         Id(x => x.Id); 
         Map(x => x.FirstName); 
         Map(x => x.LastName); 
         Table("User"); 
      } 
	  
//load data

using (ISession session = NHibertnateSession.OpenSession())  
      {  
       using (var tx = session.BeginTransaction())  
          {  
              /*** Using Query ***/  
              var users = session.Query<User>().ToList();  
              foreach (var user in users)  
              {  
                  //read user data
              }  
              tx.Commit();  
          }                          
        }