NHibernate Step by Step(二) 单表操作
接着第一期，我们继续。
为了方便学习测试，从今天开始我将使用MS Test来进行测试，这样就避免了在一个Console工程里不停地添加、注释代码了。
提示：为了在VS2005IDE中获得NHibernate配置文件的代码提示，请将你的$NHibernate/src/NHibernate下的nhibernate-configuration-2.0.xsd、nhibernate-mapping-2.0.xsd拷贝到/Program Files/Microsoft Visual Studio 8/Xml/Schemas下，这样当你编辑配置文件或者映射文件时，你将得到完整的代码提示。
VS2003请拷贝到/Program Files/Microsoft Visual Studio .NET 2003/Common7/Packages/schemas/xml下。
NHibernat内部使用log4net来进行日志操作，今天我们将在配置文件中添加log4net的配置，这样我们在测试的时候将可以清楚地看到NHibernate是如何进行工作的。
应用配置文件修改如下：
<?xml version="1.0" encoding="utf-8" ?><configuration> <configSections> <section name="nhibernate" type="System.Configuration.NameValueSectionHandler, System,Version=1.0.5000.0,Culture=neutral, PublicKeyToken=b77a5c561934e089" /> <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" /> </configSections> <nhibernate> <add key="hibernate.connection.provider" value="NHibernate.Connection.DriverConnectionProvider" /> <add key="hibernate.connection.driver_class" value="NHibernate.Driver.SqlClientDriver" /> <add key="hibernate.connection.connection_string" value="Server=localhost;Initial Catalog=NHibernate;Integrated Security=SSPI" /> <add key="hibernate.connection.isolation" value="ReadCommitted"/> <add key="hibernate.dialect" value="NHibernate.Dialect.MsSql2000Dialect" /> <add key="show_sql" value="true" /> </nhibernate> <log4net> <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender" > <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%date [%thread] %-5level %logger [%ndc] - %message%newline" /> </layout> </appender> <root> <level value="ALL" /> <appender-ref ref="ConsoleAppender" /> </root> </log4net></configuration>
请注意添加：
<add key="show_sql" value="true" />
关于log4net的使用，我们这里不做详细的讲解，有兴趣的请参考如下地址：
http://logging.apache.org/log4net/
接着，我们在上次的工程组中添加一个名为Test1的测试项目，将其中的不需要的手动测试去掉。请注意：除了NHibernate/Model引用外，还需要添加如下3个引用：
log4net,System.Data,System.Xml.
修改代码如下：
using System;using System.Text;using System.Collections;using Microsoft.VisualStudio.TestTools.UnitTesting;using NHibernate;using NHibernate.Cfg;using log4net;using log4net.Config;using Test.Model;namespace Test1
{
/**//// <summary>
/// Summary description for UnitTest1
/// </summary> [TestClass] public class UnitTest1 { static ISessionFactory factory; static ILog logger; ISession session; public UnitTest1() { } Additional test attributes#region Additional test attributes [ClassInitialize()] public static void MyClassInitialize(TestContext testContext) { XmlConfigurator.Configure(); logger = LogManager.GetLogger(typeof(Test1.UnitTest1)); Configuration config = new Configuration().AddAssembly("Test.Model"); factory = config.BuildSessionFactory(); } [ClassCleanup()] public static void MyClassCleanup() { } [TestInitialize()] public void MyTestInitialize() { session = factory.OpenSession(); } [TestCleanup()] public void MyTestCleanup() { session.Close(); } #endregion }
}
我们在测试的开始对Configuration/SessionFactory/Log进行初始化。在每一个Test的开始获取一个新的session，每一个Test结束后即关闭session。
添加如下一个Get测试：
[TestMethod]public void TestRead(){ Person person = (Person)session.Get(typeof(Person), 1); Assert.IsTrue(person.Name == "Jackie Chan");}我们在前面曾经插入一条名为“Jackie Chan”的记录，现在在Test Manager中选中TestRead，运行，ok，Passed！
我们使用了session.Get来获取记录，方法如下：
object Get(Type clazz,object id);
很简单，一目了然。
我们切换到Test Results窗口，双击测试成功的TestRead方法，这时将会有一个详细的测试结果显示出来，NHibernate将使用我们指定的log4net来输出详细信息，我们仔细观察：
2006-04-15 13:52:13,000 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - opened session
2006-04-15 13:52:13,015 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - loading [Person#1]
2006-04-15 13:52:13,015 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - attempting to resolve [Person#1]
2006-04-15 13:52:13,015 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - object not resolved in any cache [Test.Model.Person#1]
2006-04-15 13:52:13,015 [AdpaterExeMgrThread1] DEBUG NHibernate.Persister.EntityPersister [(null)] - Materializing entity: Test.Model.Person#1
2006-04-15 13:52:13,078 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.BatcherImpl [(null)] - Opened new IDbCommand, open IDbCommands :1
2006-04-15 13:52:13,078 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.BatcherImpl [(null)] - Building an IDbCommand object for the SqlString: SELECT person0_.id as id0_, person0_.name as name0_ FROM Person person0_ WHERE person0_.id=:id
2006-04-15 13:52:13,093 [AdpaterExeMgrThread1] DEBUG NHibernate.Type.Int32Type [(null)] - binding '1' to parameter: 0
2006-04-15 13:52:13,093 [AdpaterExeMgrThread1] INFO NHibernate.Loader.Loader [(null)] - SELECT person0_.id as id0_, person0_.name as name0_ FROM Person person0_ WHERE person0_.id=@p0
2006-04-15 13:52:13,093 [AdpaterExeMgrThread1] DEBUG NHibernate.SQL [(null)] - SELECT person0_.id as id0_, person0_.name as name0_ FROM Person person0_ WHERE person0_.id=@p0
2006-04-15 13:52:13,093 [AdpaterExeMgrThread1] DEBUG NHibernate.SQL [(null)] - @p0 = '1'
2006-04-15 13:52:13,093 [AdpaterExeMgrThread1] DEBUG NHibernate.Connection.DriverConnectionProvider [(null)] - Obtaining IDbConnection from Driver
2006-04-15 13:52:13,859 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.BatcherImpl [(null)] - Opened Reader, open Readers :1
2006-04-15 13:52:13,859 [AdpaterExeMgrThread1] DEBUG NHibernate.Loader.Loader [(null)] - processing result set
2006-04-15 13:52:13,875 [AdpaterExeMgrThread1] DEBUG NHibernate.Loader.Loader [(null)] - result row: 1
2006-04-15 13:52:13,875 [AdpaterExeMgrThread1] DEBUG NHibernate.Loader.Loader [(null)] - Initializing object from DataReader: 1
2006-04-15 13:52:13,875 [AdpaterExeMgrThread1] DEBUG NHibernate.Loader.Loader [(null)] - Hydrating entity: Test.Model.Person#1
2006-04-15 13:52:13,906 [AdpaterExeMgrThread1] DEBUG NHibernate.Type.StringType [(null)] - returning 'Jackie Chan' as column: name0_
2006-04-15 13:52:13,906 [AdpaterExeMgrThread1] DEBUG NHibernate.Loader.Loader [(null)] - done processing result set (1 rows)
2006-04-15 13:52:13,937 [AdpaterExeMgrThread1] DEBUG NHibernate.Driver.NHybridDataReader [(null)] - running NHybridDataReader.Dispose()
2006-04-15 13:52:13,937 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.BatcherImpl [(null)] - Closed Reader, open Readers :0
2006-04-15 13:52:13,937 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.BatcherImpl [(null)] - Closed IDbCommand, open IDbCommands :0
2006-04-15 13:52:13,937 [AdpaterExeMgrThread1] DEBUG NHibernate.Loader.Loader [(null)] - total objects hydrated: 1
2006-04-15 13:52:13,953 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - resolving associations for: [Test.Model.Person#1]
2006-04-15 13:52:13,953 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - done materializing entity [Test.Model.Person#1]
2006-04-15 13:52:13,953 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - initializing non-lazy collections
2006-04-15 13:52:13,953 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - closing session
2006-04-15 13:52:13,953 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - disconnecting session
2006-04-15 13:52:13,953 [AdpaterExeMgrThread1] DEBUG NHibernate.Connection.ConnectionProvider [(null)] - Closing connection
2006-04-15 13:52:13,968 [AdpaterExeMgrThread1] DEBUG NHibernate.Impl.SessionImpl [(null)] - transaction completion
在其中，我们可以发现：
2006-04-15 13:52:13,093 [AdpaterExeMgrThread1] DEBUG NHibernate.SQL [(null)] - SELECT person0_.id as id0_, person0_.name as name0_ FROM Person person0_ WHERE person0_.id=@p0
2006-04-15 13:52:13,093 [AdpaterExeMgrThread1] DEBUG NHibernate.SQL [(null)] - @p0 = '1'
对了，就是这里，NHibernate替我们构造了一条sql语句，并添加一个参数，然后将我们在代码中赋的id值1来填充，这样，一条完整的可以执行的sql语句产生了。
请注意：在产生sql语句的前面，NHibernate构造了一个IDBCommand，然后在sql语句产生完全后，获取连接，通过一个DataReader来填充Persion对象给我们使用，这就是NHibernate替我们做的事，是不是很简单啊？（真的很简单吗？？看看源代码吧！！）
请仔细研究输出的日志。
如法炮制，我们添加另外3个Test，完成单个表的全部CRUD操作，如下完整代码：
[TestMethod] public void TestCreate() { Person person = new Person(); person.Name = "Jackie Chan"; ITransaction trans = session.BeginTransaction(); try { session.Save(person); trans.Commit(); Assert.IsTrue(person.Id > 0); } catch (Exception ex) { trans.Rollback(); Assert.Fail(ex.Message); } } [TestMethod] public void TestUpdate() { Person person = (Person)session.Get(typeof(Person), 1); person.Name = "Jet Li"; ITransaction trans = session.BeginTransaction(); try