Nhibernate系列学习之（二） 简单增删改查

实例中解决方案简单的创建三层架构，符合开发过程中最简单的运用；

1：首先在数据库中创建一个表T_School，脚本如下：

USE [TestDb]
GO
/****** 对象:  Table [dbo].[T_School]    脚本日期: 03/01/2014 19:45:45 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[T_School](
    [ID] [uniqueidentifier] NOT NULL,
    [SchoolName] [nvarchar](255) COLLATE Chinese_PRC_CI_AS NULL,
    [BuildDate] [datetime] NULL,
    [Address] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL,
    [IsSenior] [bit] NULL,
    [StudentNum] [int] NULL
) ON [PRIMARY]

2：创建实体层Model,实体中的字段还以virtual进行修饰

namespace Wujy.ModelLibrary.Entity
{
    public class SchoolModel
    {
        /// <summary>
        /// ID
        /// </summary>
        public virtual Guid ID
        {
            get;
            set;
        }
        /// <summary>
        /// SchoolName
        /// </summary>
        public virtual string SchoolName
        {
            get;
            set;
        }
        /// <summary>
        /// BuildDate
        /// </summary>
        public virtual DateTime? BuildDate
        {
            get;
            set;
        }
        /// <summary>
        /// Address
        /// </summary>
        public virtual string Address
        {
            get;
            set;
        }
        /// <summary>
        /// 高级
        /// </summary>
        public virtual bool IsSenior
        {
            get;
            set;
        }
        /// <summary>
        /// 人数
        /// </summary>
        public virtual int? StudentNum
        {
            get;
            set;
        }        
    }
}

2.1 此处还增加NHibernate需要的XML映射文件，以实体名+hbm.xml结尾并且还要设置其生成操作为"嵌入的资源";其中Class中的name是指实体类的完整名及类库名称，代码如下

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Maticsoft" namespace="Maticsoft">
  <class name="Wujy.ModelLibrary.Entity.SchoolModel, Wujy.ModelLibrary" table="T_School">
    <id name="ID" column="ID" type="Guid"></id>
    <property name="SchoolName" column="SchoolName" type="string"  />
    <property name="BuildDate" column="BuildDate" type="DateTime"  />
    <property name="Address" column="Address" type="string"  />
    <property name="IsSenior" column="IsSenior" type="bool"  />
    <property name="StudentNum" column="StudentNum" type="int"  />
  </class>
</hibernate-mapping>

3：创建一个类库作为DAL层，此处我们引用NHibernate两个DLL，分别为NHibernate.dll及Iesi.Collection.dll;此处创建一个帮助类NHibernateHelper用于ISessionFactory；

using NHibernate;
using NHibernate.Cfg;

namespace Wujy.DalLibrary.DalHelp
{
    public class NHibernateHelper
    {
        private ISessionFactory _sessionFactory;
        public NHibernateHelper()
        {
            _sessionFactory = GetSessionFactory();
        }
        private ISessionFactory GetSessionFactory()
        {
            return (new Configuration()).Configure().BuildSessionFactory();
        }
        public ISession GetSession()
        {
            return _sessionFactory.OpenSession();
        }
    }
}

3.1：创建类SchoolDal并把一些操作的代码写入，如查不用transaction.Commit()则要运和isession.Flush()否则无法执行SQL就没有效果：

using Wujy.ModelLibrary.Entity;
using NHibernate;
using Wujy.DalLibrary.DalHelp;

namespace Wujy.DalLibrary
{
    public class SchoolDal
    {
        private ISession isession;

        public SchoolDal()
        {
            isession = new NHibernateHelper().GetSession();
        }

        public void Add(SchoolModel model)
        {
            //如查不用transaction.Commit()则要运和isession.Flush()否则无法执行SQL就没有效果
            //ITransaction transaction = isession.BeginTransaction();
            //isession.Save(model);
            //transaction.Commit();
            isession.Save(model);
            isession.Flush();
        }

        public bool Update(SchoolModel model)
        {
            try
            {
                isession.Update(model);
                isession.Flush();
                return true;
            }
            catch (Exception ex)
            {
                return false;
            }
            finally
            {
                isession.Close();
            }
        }

        public bool Delete(SchoolModel model)
        {
            try
            {
                isession.Delete(model);
                isession.Flush();
                return true;
            }
            catch (Exception ex)
            {
                return false;
            }
            finally
            {
                isession.Close();
            }
        }

        public SchoolModel GetSchoolById(Guid ID)
        {
            return isession.Get<SchoolModel>(ID);
        }

        public IList<SchoolModel> GetSchoolList()
        {
            IList<SchoolModel> list = null;
            list = isession.QueryOver<SchoolModel>().List();
            return list;
        }
    }
}

4：因为本实例重点是对NHibernate运用，对于逻辑层就简单的引用；代码也很简单：

using Wujy.ModelLibrary.Entity;
using Wujy.DalLibrary;

namespace Wujy.BllLibrary
{
    public class SchoolBll
    {
        public static void Add(SchoolModel model) 
        {
            new SchoolDal().Add(model);
        }

        public static bool Update(SchoolModel model)
        {
            return new SchoolDal().Update(model);
        }

        public static bool Delete(SchoolModel model)
        {
            return new SchoolDal().Delete(model);
        }

        public static SchoolModel GetSchoolById(Guid ID)
        {
            return new SchoolDal().GetSchoolById(ID);
        }

        public static IList<SchoolModel> GetSchoolList()
        {
            return new SchoolDal().GetSchoolList();
        }
    }
}

5：WebUI除简单调用BLL层外，另一个比较重要是NHibernate连接数据库的配置文件，其中其属性复制到输出目录改为"始终复制"；Hibernate.cfg.xml内容：

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
  <session-factory name="NHibernateConfig">
    <property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property>
    <property name="connection.connection_string">Server=localhost;uid=sa;password=admin;database=TestDb</property>
    <property name="dialect">NHibernate.Dialect.MsSql2005Dialect</property>
    <property name="command_timeout">10</property>
    <mapping assembly="Wujy.ModelLibrary"/><!--表示映射Wujy.ModelLibrary实体程序集下的所有类,就不用一个个去映射-->
  </session-factory>
</hibernate-configuration>