使用NHibernate3.0來建構自己的ORM架構(一)

1. Library檔案

  需要的dll檔案如下：

  FluentNHibernate.dll (*)

  NHibernate.ByteCode.Castle.dll (*)

  NHibernate.dll (*)

  Remotion.Data.Linq.dll

  Antlr3.Runtime.dll

  Castle.Core.dll

  Iesi.Collections.dll

2. 建立Hibernate通路通用類

using System;

using System.Collections.Generic;

using FluentNHibernate.Cfg;

using FluentNHibernate.Cfg.Db;

using NHibernate;

using NHibernate.Cfg;

using NHibernate.Tool.hbm2ddl;

using NHibernate.Linq;

using System.Linq;

namespace CsharpTrainer.NHibernate3

{

    public class NHibernateDb<TMap> : IDisposable

    {

        private string connString;

        private ISessionFactory sessFactory;

        private ISession session;

        public ISessionFactory SessionFactory

        {

            get { return sessFactory; }

            set { sessFactory = value; }

        }

        public ISession Session

            get { return session; }

            set { session = value; }

        public void Dispose()

            session.Dispose();

        public NHibernateDb(string pStr)

            connString = pStr;

            sessFactory = CreateSessionFactory();

            session = sessFactory.OpenSession();

        ~NHibernateDb()

            try

            {

                Dispose();

            }

            catch 

                Console.WriteLine("Exception: session dispose failed!");

        private ISessionFactory CreateSessionFactory()

            return Fluently.Configure()

                .Database(MsSqlConfiguration

                              .MsSql2008

                              .ConnectionString(connString))

                .Mappings(m => m.FluentMappings

                                   .AddFromAssemblyOf<TMap>())

                .BuildSessionFactory();

        private void CreateSchema(Configuration cfg)

            var schemaExport = new SchemaExport(cfg);

            schemaExport.Drop(false, true);

            schemaExport.Create(false, true);

        public void CreateDatabase()

            Fluently.Configure()

                .Database(MsSqlConfiguration.MsSql2008.ConnectionString(connString))

                .Mappings(m => m.FluentMappings.AddFromAssemblyOf<TMap>())

                .ExposeConfiguration(CreateSchema)

                .BuildConfiguration();

    }

}

3. 建立表格對應的實體類

  我們以Northwind資料庫的Employees表格為例

namespace CsharpTrainer.NHibernate3.Entities

    public class Employees

        public virtual int EmployeeID { get; set; }

        public virtual string LastName { get; set; }

        public virtual string FirstName { get; set; }

        public virtual string Title { get; set; }

        public virtual DateTime BirthDate { get; set; }

        public virtual string Address { get; set; }

        public virtual string City { get; set; }

        public virtual string Region { get; set; }

        public virtual string Country { get; set; }

        public virtual string Notes { get; set; }

        public override string ToString()

            string format = "Employee ID: {0}\nLast Name: {1}\n"

                          + "First Name: {2}\nTitle: {3}\nBirth Date: {4}\n"

                          + "Address: {5}\nCity: {6}\nRegion: {7}\nCountry: {8}\n"

                          + "Notes: {9}\n";

            return string.Format(format, EmployeeID, LastName, FirstName,

                                    Title, BirthDate, Address, City, Region, Country, Notes);

4. 建立映射關系(映射類)

  EmployeeMap Class:

using FluentNHibernate.Mapping;

using CsharpTrainer.NHibernate3.Entities;

namespace CsharpTrainer.NHibernate3.Mapping

    public class EmployeeMap : ClassMap<Employees>

        public EmployeeMap()

            Id(x => x.EmployeeID, "EmployeeID");

            Map(x => x.LastName)

                .Length(20)

                .Not.Nullable();

            Map(x => x.FirstName)

                .Length(10)

            Map(x => x.Title)

                .Length(30);

            Map(x => x.BirthDate);

            Map(x => x.Address)

                .Length(60);

            Map(x => x.City)

                .Length(15);

            Map(x => x.Region)

            Map(x => x.Country)

            Map(x => x.Notes);

5. 用戶端查詢代碼

  查詢所有的員工，按照LastName排序

public void Run()

            string connStr = ConfigurationManager.ConnectionStrings["NorthwindConnStr"].ConnectionString;

                NHibernateDb<EmployeeMap> db = new NHibernateDb<EmployeeMap>(connStr);

                ISessionFactory factory = db.SessionFactory;

                using (var session = factory.OpenSession())

                {

                    var employees = session.QueryOver<Employees>()

                                    .OrderBy(a => a.LastName).Asc

                                    .List();

                    Console.WriteLine("All Employees Below:");

                    foreach (var employee in employees)

                    {

                        Console.WriteLine(employee);

                    }

                }

            catch (Exception ex)

                Console.WriteLine("Exception: " + ex.ToString());