namespace NHSample2.Domain
{
  public class User
  {
      public virtual int Id { get; set; }
      public virtual string UserName { get; set; }
      public virtual string Password { get; set; }
  }
}

namespace NHSample2.Domain
{
  public class Category
  {
      public virtual int Id { get; set; }
      public virtual string CategoryName { get; set; }
  }
}

using System;

namespace NHSample2.Domain
{
  public class News
  {
      public virtual Guid Id { get; set; }
      public virtual string Subject { get; set; }
      public virtual string NewsText { get; set; }
      public virtual DateTime DateEntered { get; set; }
      public virtual Category Category { get; set; }
      public virtual User User { get; set; }
  }
}

using FluentNHibernate.Automapping;
using FluentNHibernate.Cfg;
using FluentNHibernate.Cfg.Db;
using NHibernate;
using NHibernate.Cfg;
using NHibernate.Tool.hbm2ddl;

namespace NHSample2
{
  class Config
  {
      public static Configuration GenerateMapping(IPersistenceConfigurer dbType)
      {
          var cfg = dbType.ConfigureProperties(new Configuration());

          new AutoPersistenceModel()
              .Where(x => x.Namespace.EndsWith("Domain"))
              .AddEntityAssembly(typeof(NHSample2.Domain.News).Assembly).Configure(cfg);

          return cfg;
      }

      public static void GenerateDbScript(Configuration config, string filePath)
      {
          bool script = true;//فقط اسکریپت دیتابیس تولید گردد
          bool export = false;//نیازی نیست بر روی دیتابیس هم اجرا شود
          new SchemaExport(config).SetOutputFile(filePath).Create(script, export);
      }

      public static void BuildDbSchema(Configuration config)
      {
          bool script = false;//آیا خروجی در کنسول هم نمایش داده شود
          bool export = true;//آیا بر روی دیتابیس هم اجرا شود
          bool drop = false;//آیا اطلاعات موجود دراپ شوند
          new SchemaExport(config).Execute(script, export, drop);
      }

      public static void CreateSQL2008DbPlusScript(string connectionString, string filePath)
      {
          Configuration cfg =
              GenerateMapping(
              MsSqlConfiguration
              .MsSql2008
              .ConnectionString(connectionString)
              .ShowSql()
              );
          GenerateDbScript(cfg, filePath);
          BuildDbSchema(cfg);
      }

      public static ISessionFactory CreateSessionFactory(IPersistenceConfigurer dbType)
      {
          return
             Fluently.Configure().Database(dbType)
              .Mappings(m => m.AutoMappings
                         .Add(
                             new AutoPersistenceModel()
                                 .Where(x => x.Namespace.EndsWith("Domain"))
                                 .AddEntityAssembly(typeof(NHSample2.Domain.News).Assembly))
                                 )
               .BuildSessionFactory();
      }
  }
}

using System;

namespace NHSample2
{
  class Program
  {
      static void Main(string[] args)
      {
         Config.CreateSQL2008DbPlusScript(
              "Data Source=(local);Initial Catalog=HelloNHibernate;Integrated Security = true",
              "db.sql");

          Console.WriteLine("Press a key...");
          Console.ReadKey();
      }
  }
}

  create table [Category] (
      Id INT IDENTITY NOT NULL,
     CategoryName NVARCHAR(255) null,
     primary key (Id)
  )

  create table [User] (
      Id INT IDENTITY NOT NULL,
     UserName NVARCHAR(255) null,
     Password NVARCHAR(255) null,
     primary key (Id)
  )

  create table [News] (
      Id UNIQUEIDENTIFIER not null,
     Subject NVARCHAR(255) null,
     NewsText NVARCHAR(255) null,
     DateEntered DATETIME null,
     Category_id INT null,
     User_id INT null,
     primary key (Id)
  )

  alter table [News]
      add constraint FKE660F9E1C9CF79
      foreign key (Category_id)
      references [Category]

  alter table [News]
      add constraint FKE660F95C1A3C92
      foreign key (User_id)

      references [User]

using System;
using FluentNHibernate.Cfg.Db;
using NHibernate;
using NHSample2.Domain;

namespace NHSample2
{
  class Program
  {
      static void Main(string[] args)
      {
          using (ISessionFactory sessionFactory = Config.CreateSessionFactory(
                  MsSqlConfiguration
                      .MsSql2008
                      .ConnectionString("Data Source=(local);Initial Catalog=HelloNHibernate;Integrated Security = true")
                      .ShowSql()
                  ))
          {
              using (ISession session = sessionFactory.OpenSession())
              {
                  using (ITransaction transaction = session.BeginTransaction())
                  {
                      //با توجه به کلیدهای خارجی تعریف شده ابتدا باید گروه‌ها را اضافه کرد
                      Category ca = new Category() {  CategoryName = "Sport" };
                      session.Save(ca);
                      Category ca2 = new Category() { CategoryName = "IT" };
                      session.Save(ca2);
                      Category ca3 = new Category() { CategoryName = "Business" };
                      session.Save(ca3);

                      //سپس یک کاربر را به دیتابیس اضافه می‌کنیم
                      User u = new User() {  Password = "123$5@1", UserName = "VahidNasiri" };
                      session.Save(u);

                      //اکنون می‌توان یک خبر جدید را ثبت کرد

                      News news = new News()
                      {
                          Category = ca,
                          User = u,
                          DateEntered = DateTime.Now,
                          Id = Guid.NewGuid(),
                          NewsText = "متن خبر جدید",
                          Subject = "عنوانی دلخواه"
                      };
                      session.Save(news);

                      transaction.Commit(); //پایان تراکنش
                  }
              }
          }

          Console.WriteLine("Press a key...");
          Console.ReadKey();
      }
  }
}

using System.Linq;
using NHibernate;
using NHibernate.Linq;
using NHSample2.Domain;

namespace NHSample2
{
  class NewsContext : NHibernateContext
  {
      public NewsContext(ISession session)
         : base(session)
     { }

     public IOrderedQueryable<News> News
     {
         get { return Session.Linq<News>(); }
     }

     public IOrderedQueryable<Category> Categories
     {
         get { return Session.Linq<Category>(); }
     }

     public IOrderedQueryable<User> Users
     {
         get { return Session.Linq<User>(); }
     }
  }
}

using System;
using FluentNHibernate.Cfg.Db;
using NHibernate;
using System.Linq;
using NHSample2.Domain;

namespace NHSample2
{
  class Program
  {
      static void Main(string[] args)
      {
          using (ISessionFactory sessionFactory = Config.CreateSessionFactory(
                  MsSqlConfiguration
                      .MsSql2008
                      .ConnectionString("Data Source=(local);Initial Catalog=HelloNHibernate;Integrated Security = true")
                      .ShowSql()
                  ))
          {
              using (ISession session = sessionFactory.OpenSession())
              {
                  using (ITransaction transaction = session.BeginTransaction())
                  {
                      using (NewsContext db = new NewsContext(session))
                      {
                          var query = from x in db.Users
                                      where x.UserName == "VahidNasiri"
                                      select x;

                          //اگر چیزی یافت شد
                          if (query.Any())
                          {
                              User vahid = query.First();
                              //نمایش اطلاعات کاربر
                              Console.WriteLine("Id: {0}, UserName: {0}", vahid.Id, vahid.UserName);
                              //به روز رسانی نام کاربر
                              vahid.UserName = "Vahid";
                              session.Update(vahid);

                              transaction.Commit(); //پایان تراکنش
                          }
                      }
                  }
              }
          }

          Console.WriteLine("Press a key...");
          Console.ReadKey();
      }
  }
}

      using FluentNHibernate.Conventions.Helpers;

      public static Configuration GenerateMapping(IPersistenceConfigurer dbType)
      {
          var cfg = dbType.ConfigureProperties(new Configuration());

          new AutoPersistenceModel()
          .Conventions.Add()
              .Where(x => x.Namespace.EndsWith("Domain"))
               .Conventions.Add(
                 PrimaryKey.Name.Is(x => "ID"),
                 DefaultLazy.Always(),
                 ForeignKey.EndsWith("ID"),
                 Table.Is(t => "tbl" + t.EntityType.Name)                 
                 )
              .AddEntityAssembly(typeof(NHSample2.Domain.News).Assembly)
              .Configure(cfg);

          return cfg;
      }

using FluentNHibernate.Conventions;
using FluentNHibernate.Conventions.Instances;

namespace NHSample2.Conventions
{
  class MyStringLengthConvention : IPropertyConvention
  {
      public void Apply(IPropertyInstance instance)
      {
          instance.Length(500);
      }
  }
}

      public static Configuration GenerateMapping(IPersistenceConfigurer dbType)
      {
          var cfg = dbType.ConfigureProperties(new Configuration());

          new AutoPersistenceModel()
          .Conventions.Add()
              .Where(x => x.Namespace.EndsWith("Domain"))
               .Conventions.Add<MyStringLengthConvention>()
              .AddEntityAssembly(typeof(NHSample2.Domain.News).Assembly)
              .Configure(cfg);

          return cfg;
      }

   [DataContract]
    public class Book
    {
        [DataMember]
        public int Code { get; set; }

        [DataMember]
        public string Title { get; set; }
    }

using System;
using System.Collections.Generic;
using System.Linq.Expressions;
using System.ServiceModel;

namespace WcfLambdaExpression
{
    [ServiceContract]
    public interface IBookService
    {
        [OperationContract]
        IEnumerable<Book> GetByExpression( Expression<Func<Book, bool>> expression );
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;

namespace WcfLambdaExpression
{    
    public class BookService : IBookService
    {        
        public BookService()
        {
            ListOfBook = new List<Book>();
        }

        public List<Book> ListOfBook 
        {
            get;
            private set;
        }

        public IEnumerable<Book> GetByExpression( Expression<Func<Book, bool>> expression )
        {
            ListOfBook.AddRange( new Book[] 
            {
                new Book(){Code = 1 , Title = "Book1"},
                new Book(){Code = 2 , Title = "Book2"},
                new Book(){Code = 3 , Title = "Book3"},
                new Book(){Code = 4 , Title = "Book4"},
                new Book(){Code = 5 , Title = "Book5"},
            } );

            return ListOfBook.AsQueryable().Where( expression );
        }       
    }
}

Type 'System.Linq.Expressions.Expression`1[System.Func`2[WcfLambdaExpression.Book,System.Boolean]]' cannot be serialized. 
Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute.  
If the type is a collection, consider marking it with the CollectionDataContractAttribute.  
See the Microsoft .NET Framework documentation for other supported types

[ServiceContract]
    public interface IBookService
    {
        [OperationContract]
        IEnumerable<Book> GetByExpression( XElement expression );
    }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Xml.Linq;

namespace WcfLambdaExpression
{
    public class BookService : IBookService
    {
        public BookService()
        {
            ListOfBook = new List<Book>();
        }

        public List<Book> ListOfBook
        {
            get;
            private set;
        }

        public IEnumerable<Book> GetByExpression( XElement expression )
        {
            ListOfBook.AddRange( new Book[] 
            {
                new Book(){Code = 1 , Title = "Book1"},
                new Book(){Code = 2 , Title = "Book2"},
                new Book(){Code = 3 , Title = "Book3"},
                new Book(){Code = 4 , Title = "Book4"},
                new Book(){Code = 5 , Title = "Book5"},
            } );

             Common.ExpressionSerializer serializer = new Common.ExpressionSerializer();

            return ListOfBook.AsQueryable().Where( serializer.Deserialize( expression ) as Expression<Func<Book, bool>> );
        }
    }