1. 学习目的:

通过进一步学习Nhibernate基础知识，掌握用Nhiberate实现多对多的业务逻辑

2. 开发环境+必要准备

  开发环境: windows 2003,Visual studio .Net 2005,Sql server 2005 developer edition

      前期准备: 学习上两篇单表操作和many-to-one篇
 

3．对上篇文章的部分解释

当lazy=”true”，父类初始化的时候不会自动加载子类集合

 Cascade为级联操作方式，包括： 

 当inverse=”true”的时候代表由子类维护级联关系。这时候如果只往父类中添加子类，但不设定子类的父类，是不能保存子类的。

 4．多对多业务模型

    还是用户系统，1个用户职员隶属于多个部门，同时1个部门有多个不同的职员 
    用户和部门之间的数据关系图为:

5.  实现步骤:
  1)User.cs

using System;
using System.Collections.Generic;
using System.Text;

namespace NhibernateSample1
{
    public class User
    {
        private int _id;
        private string _name;
        private string _pwd;
        private System.Collections.IList _departmentsList;
        /// <summary>
        /// 编号
        /// </summary>
        public virtual int Id
        {
            get
            {
                return _id;
            }
            set
            {
                _id = value;
            }
        }

        /// <summary>
        /// 名称
        /// </summary>
        public virtual string Name
        {
            get
            {
                return _name;
            }
            set
            {
                _name = value;
            }
        }

        /// <summary>
        /// 密码
        /// </summary>
        public virtual string Pwd
        {
            get
            {
                return _pwd;
            }
            set
            {
                _pwd = value;
            }
        }
        /// <summary>
        /// 工资列表
        /// </summary>
        public System.Collections.IList DepartmentsList
        {
            get
            {
                return _departmentsList;
            }
            set
            {
                _departmentsList = value;
            }
        }
    }
}

  2)User.hbm.xml 

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="NhibernateSample1.User,NhibernateSample1" table="Users" lazy="false">
    <id name="Id" column="Id" unsaved-value="0">
      <generator class="native" />
    </id>
    <property name="Name" column="Name" type="string" length="64" not-null="true" unique="true"></property>
    <property name="Pwd"  column="Pwd"  type="string" length="64" not-null="true"></property>
    <bag name="DepartmentsList" table="Users_Departments" inverse="true" lazy="false" cascade="all">
      <key column="Id"/>
      <many-to-many class="NhibernateSample1.Departments,NhibernateSample1" column="DepID"></many-to-many>
    </bag>
  </class>
</hibernate-mapping>

  3) Departments.cs

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace NhibernateSample1
{
    public class Departments
    {
        int _depID;
        string _name;
        IList _usersList= new ArrayList();
        public virtual int DepID
        {
            get
            {
                return _depID;
            }
            set
            {
                _depID = value;
            }
        }
        public virtual string Name
        {
            get
            {
                return _name;
            }
            set
            {
                _name = value;
            }
        }
        public virtual IList UsersList
        {
            get
            {
                return _usersList;
            }
            set
            {
                _usersList = value;
            }
        }
    }
}

4) Departments.hbm.xml

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="NhibernateSample1.Departments,NhibernateSample1" table="Departments" lazy="false">
    <id name="DepID" column="DepID" unsaved-value="0">
      <generator class="native" />
    </id>
    <property name="Name" column="Name" type="string" length="64" not-null="true" unique="true"></property>   
    <bag name="UsersList" table="Users_Departments"  lazy="true" >
      <key column="DepID"/>
      <many-to-many class="NhibernateSample1.User,NhibernateSample1" column="Id"></many-to-many>
    </bag>
  </class>
</hibernate-mapping>

5) 数据操作类 

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
using NHibernate;
using NHibernate.Cfg;
using NHibernate.Tool.hbm2ddl;

namespace NhibernateSample1
{
    public  class UserDepartmentFixure
    {
        private ISessionFactory _sessions; 
        public void Configure()
        {
            Configuration cfg = GetConfiguration();      
            _sessions = cfg.BuildSessionFactory();
        }
        Configuration GetConfiguration()
        {
            string cfgPath = @"E:\my project\nhibernate study\simle 1\NHibernateStudy1\NhibernateSample1\hibernate.cfg.xml";
            Configuration cfg = new Configuration().Configure(cfgPath);
            return cfg;
        }
        public void ExportTables()
        {
            Configuration cfg = GetConfiguration();           
            new SchemaExport(cfg).Create(true, true);
        }
        public User CreateUser(String name,string pwd)
        {
            User u = new User();
            u.Name = name;
            u.Pwd = pwd;
            u.DepartmentsList = new ArrayList();

            ISession session = _sessions.OpenSession();

            ITransaction tx = null;

            try
            {
                tx = session.BeginTransaction();
                session.Save(u);
                tx.Commit();
            }
            catch (HibernateException e)
            {
                if (tx != null) tx.Rollback();
                throw e;
            }
            finally
            {
                session.Close();
            }

            return u;
        }
        public Departments CreateDepartments(User u, string name)
        {
            Departments item = new Departments();
            item.Name=name;
            u.DepartmentsList.Add(item);
            item.UsersList.Add(u);
            ISession session = _sessions.OpenSession();
            ITransaction tx = null;

            try
            {
                tx = session.BeginTransaction();
                session.Save(item);
                tx.Commit();
            }
            catch (HibernateException e)
            {
                if (tx != null) tx.Rollback();
                throw e;
            }
            finally
            {
                session.Close();
            }
            return item;
        }       
        public Departments GetDepartments(int depID)
        {
            ISession session = _sessions.OpenSession();
            ITransaction tx = null;
            try
            {
                tx = session.BeginTransaction();
                Departments item = (Departments)session.Load(typeof(Departments),
                    depID);               
                tx.Commit();
                return item;
            }
            catch (HibernateException e)
            {
                if (tx != null) tx.Rollback();
                return null;
            }
            finally
            {
                session.Close();
            }
            return null;
        }
        public User GetUser(int uid)
        {
            ISession session = _sessions.OpenSession();
            ITransaction tx = null;
            try
            {
                tx = session.BeginTransaction();
                User item = (User)session.Load(typeof(User),
                    uid);
                tx.Commit();
                return item;
            }
            catch (HibernateException e)
            {
                if (tx != null) tx.Rollback();
                return null;
            }
            finally
            {
                session.Close();
            }
            return null;
        }       

        public void Delete(int uid)
        {
            ISession session = _sessions.OpenSession();
            ITransaction tx = null;
            try
            {
                tx = session.BeginTransaction();
                Departments item = session.Load(typeof(Departments), uid) as Departments;
                session.Delete(item);
                tx.Commit();
            }
            catch (HibernateException e)
            {
                if (tx != null) tx.Rollback();
                throw e;
            }
            finally
            {
                session.Close();
            }
        }

    }
}

6)单元测试类

using System;
using System.Text;
using System.Collections.Generic;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using NhibernateSample1;

namespace TestProject1
{
    /// <summary>
    /// UnitTest1 的摘要说明
    /// </summary>
    [TestClass]
    public class UnitTest1
    {
        public UnitTest1()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }
        NhibernateSample1.UserDepartmentFixure usf = new UserDepartmentFixure();
        其他测试属性

        [TestMethod]
        public void Test1()
        {
            usf.Configure();
            usf.ExportTables();
            User u = usf.CreateUser(Guid.NewGuid().ToString(), "ds");
            Assert.IsTrue(u.Id>0);
            Departments s = usf.CreateDepartments(u, "政治部");
            Assert.IsTrue(s.DepID > 0);
            Departments s1 = usf.CreateDepartments(u, "事业部");
            Assert.IsTrue(s1.DepID > 0);         
            usf.Delete(s1.DepID);
            s1 = usf.GetDepartments(s1.DepID);
            Assert.IsNull(s1);
            User u1 = usf.GetUser(1);
            Assert.IsTrue(u1.DepartmentsList.Count>0);
        }

    }
}