NHibernate开发入门
首先，我们了解一下ORM是什么？
ORM指对象关系映射（英语：Object Relational Mapping，简称ORM，或O/RM，或O/R mapping），是一种程序技术，用于实现面向对象编程语言里不同类型系统的数据之间的转换。从效果上说，它其实是创建了一个可在编程语言里使用的“虚拟对象数据库”。
其次，我们需要了解.NET领域ORM框架有哪些？
在.NET平台下，关于数据持久层框架非常多，以下是主要的5种：
1．NHibernate
2．NBear
3．Castle ActiveRecord
4．iBATIS.NET
5．DAAB 微软
使用过Java的朋友都不会对Hibernate陌生。由于之前的Java经历，所以我直接选择NHibernate作为ORM框架首选。那么NHibernate是什么？
NHibernate是一个面向.NET环境的对象/关系数据库映射工具。对象/关系数据库映射（object/relational mapping，ORM）这个术语表示一种技术，用来把对象模型表示的对象映射到基于SQL的关系模型数据结构中去。
下面，我们做一个简单的NHibernate Demo。创建项目WinForm窗体项目，命名为CRMdemo，以下是解决方案截图：
解决方案项目截图
获取NHibernate
NHibernate下载地址
https://sourceforge.net/projects/nhibernate/files/NHibernate/4.0.3.GA/NHibernate-4.0.3.GA-bin.zip/download
NHibernate项目地址
https://sourceforge.net/projects/nhibernate/
为了方便，下载后将NHibernate-4.0.3.GA-bin.zip解压缩至解决方案根目录下
添加NHibernate Dll引用
添加引用
NHibernate-4.0.3.GA-bin\Required_Bins\NHibernate.dll
NHibernate-4.0.3.GA-bin\Required_Bins\Iesi.Collections.dll
NHibernate-4.0.3.GA-bin\Tests\log4net.dll
NHibernate-4.0.3.GA-bin\Tests\NHibernate.DomainModel.dll
NHibernate-4.0.3.GA-bin\Tests\nunit.framework.dll
配置hibernate.cfg.xml
复制NHibernate-4.0.3.GA-bin\Configuration_Templates\MSSQL.cfg.xml至bin\Debug下，重命名为hibernate.cfg.xml，并做如下配置
<!-- This is the System.Data.dll provider for SQL Server --> <hibernate-configuration xmlns="urn:nhibernate-configuration-2.2" > <session-factory name="CRMDemo.Hibernate"> <property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property> <property name="connection.connection_string"> Server=Your-PC\SQLEXPRESS;initial catalog=crm;Integrated Security=SSPI </property> <property name="dialect">NHibernate.Dialect.MsSql2008Dialect</property> <mapping assembly="CRMDemo"/> </session-factory> </hibernate-configuration>
在MSSQL中创建一张演示表employee
创建员工表employee
CREATE TABLE [dbo].[employee]( [id] [int] IDENTITY(1,1) NOT NULL, [name] [nvarchar](50) NULL, [age] [nchar](10) NULL, [gender] [nchar](10) NULL, [email] [nvarchar](100) NULL, [phonenum] [nvarchar](50) NULL, CONSTRAINT [PK_employee] PRIMARY KEY CLUSTERED ( [id] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY]
创建Employee.cs类
public class Employee { public virtual int id { get; set; } public virtual string name { get; set; } public virtual int age { get; set; } public virtual string gender { get; set; } public virtual string email { get; set; } public virtual string phonenum { get; set; } }
创建映射文件Employee.hbm.xml，其中字段名称必须和类属性名称一致，区分大小写。
<?xml version="1.0" ?> <!-- * By huiyaosoft.com * build date 2015-4-12 10:10 --> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-lazy="false"> <class name="CRMDemo.Employee, CRMDemo" discriminator-value="0" table="employee" > <id name="id" type="int" unsaved-value="null"> <column name="id" length="4" sql-type="4" not-null="true" unique="true" index="PK_employee"/> <generator class="native" /> <!-- unsaved-value used to be null and generator was increment in h2.0.3 --> </id> <property name="name" type="String"> <column name="name" length="50" sql-type="nvarchar" not-null="false"/> </property> <property name="email" type="String"> <column name="email" length="50" sql-type="nvarchar" not-null="false"/> </property> <property name="gender" type="String"> <column name="gender" length="10" sql-type="nchar" not-null="false"/> </property> <property name="phonenum" type="String"> <column name="phonenum" length="50" sql-type="nvarchar" not-null="false"/> </property> <property name="age" type="int"> <column name="age" length="4" sql-type="int" not-null="false"/> </property> </class> </hibernate-mapping>
设置Employee.hbm.xml为嵌入的资源
增删改查代码
添加命名空间
using NHibernate; using NHibernate.Cfg;
查询操作，CreateQuery或CreateSqlQuery
Configuration cfg = new Configuration(); cfg.Configure(); ISessionFactory factory = cfg.BuildSessionFactory(); ISession session = factory.OpenSession(); IQuery query = session.CreateQuery("from Employee"); IList<Employee> eList = query.List<Employee>(); foreach (Employee item in eList) { this.textBox1.AppendText(string.Format("id:{0},name:{1},email:{2}\r\n", item.id, item.name, item.email)); } //ISQLQuery query = session.CreateSQLQuery("select * from employee").AddEntity(typeof(Employee)); //IList<Employee> eList = query.List<Employee>(); //foreach (Employee item in eList) //{ // Console.WriteLine("id:{0},name:{1},email:{2}\r\n", item.id, item.name, item.email); //} session.Close(); factory.Close();
增加操作session.Save(Entity)
Configuration cfg = new Configuration(); cfg.Configure(); ISessionFactory factory = cfg.BuildSessionFactory(); ISession session = factory.OpenSession(); ITransaction trans = session.BeginTransaction(); Employee ee = new Employee(); ee.age = 31; ee.name = "李四"; ee.email = "zhang@163.com"; ee.phonenum = "1358111111"; ee.gender = "男"; session.Save(ee); trans.Commit(); session.Close(); factory.Close(); this.textBox1.AppendText("已增加一条记录\r\n");
修改操作session.Save(Entity)
Configuration cfg = new Configuration(); cfg.Configure(); ISessionFactory factory = cfg.BuildSessionFactory(); ISession session = factory.OpenSession(); ITransaction trans = session.BeginTransaction(); IQuery query = session.CreateQuery("from Employee where id = :id").SetString("id","1"); IList<Employee> eList = query.List<Employee>(); foreach (Employee item in eList) { this.textBox1.AppendText("查询到一条记录\r\n"); this.textBox1.AppendText(string.Format("id:{0},name:{1},email:{2}\r\n", item.id, item.name, item.email)); item.email = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"); session.Save(item); } trans.Commit(); query = session.CreateQuery("from Employee where id = :id").SetString("id", "1"); eList = query.List<Employee>(); foreach (Employee item in eList) { this.textBox1.AppendText("修改后记录\r\n"); this.textBox1.AppendText(string.Format("id:{0},name:{1},email:{2}\r\n", item.id, item.name, item.email)); } session.Close(); factory.Close();
删除操作session.Delete(Entity)
Configuration cfg = new Configuration(); cfg.Configure(); ISessionFactory factory = cfg.BuildSessionFactory(); ISession session = factory.OpenSession(); ITransaction trans = session.BeginTransaction(); IQuery query = session.CreateQuery("from Employee where name = :name").SetString("name", "李四"); IList<Employee> eList = query.List<Employee>(); foreach (Employee item in eList) { this.textBox1.AppendText("查询记录\r\n"); this.textBox1.AppendText(string.Format("id:{0},name:{1},email:{2}\r\n", item.id, item.name, item.email)); session.Delete(item); } trans.Commit(); query = session.CreateQuery("from Employee where name = :name").SetString("name", "李四"); eList = query.List<Employee>(); foreach (Employee item in eList) { this.textBox1.AppendText("删除后记录\r\n"); } session.Close(); factory.Close();
来源：http://www.huiyaosoft.com/html/nhibernate.htm
本项目演示例子点击下载
