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Nhibernate学习起步之many-to-one篇（转）

發布時間：2023/12/9 编程问答 46 豆豆

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1.???? 學習目的:

通過進一步學習nhibernate基礎知識，在實現單表CRUD的基礎上，實現兩表之間one-to-many的關系.

2.???? 開發環境+必要準備

開發環境: windows 2003,Visual studio .Net 2005,Sql server 2005 developer edition

必要準備: 學習上篇文章單表操作???

3．對上篇文章中部分解釋

?1）在User.hbm.xml中class節點中有一個lazy的屬性，這個屬性用于指定是否需要延遲加載（lazy loading），在官方文檔中稱為:lazy fecting.可以說延遲加載是nhibernate最好的特點，因為它可以在父類中透明的加載子類集合，這對于many-to-one的業務邏輯中，真是方便極了。但是有些時候，父類是不需要攜帶子類信息的。這時候如果也加載，無疑對性能是一種損失。在映射文件的class節點中可以通過配置lazy屬性來指定是否支持延遲加載，這就更靈活多了。?

?2) 在User.hbm.xml中generate節點，代表的是主鍵的生成方式，上個例子中的”native”根據底層數據庫的能力選擇identity,hilo,sequence中的一個，比如在MS Sql中，使我們最經常使用的自動增長字段，每次加1.?

3) 在NHibernateHelper.cs中，創建Configuration對象的代碼：new Configuration().Configure(@"E:\myproject\nhibernatestudy\simle1\NHibernateStudy1\NhibernateSample1\hibernate.cfg.xml")；因為我是在單元測試中調試，所以將絕對路徑的配置文件傳遞給構造函數。如果在windows app或者web app可以不用傳遞該參數。?

4．實現步驟

?1）確定實現的業務需求：用戶工資管理系統

?2) 打開上篇文章中的NHibernateStudy1解決方案。向項目NhibernateSample1添加類Salary;代碼如下

Salary.cs
using?System;
using?System.Collections.Generic;
using?System.Text;

namespace?NhibernateSample1
{
????public?partial?class?Salary
????{
????????int?_id;
????????User?_user;
????????int?_year;
????????int?_month;
????????int?_envy;
????????decimal?_money;
????????/**////?<summary>
????????///?工資編號
????????///?</summary>
????????public?virtual?int?Id
????????{
????????????get
????????????{
????????????????return?_id;
????????????}
????????????set
????????????{
????????????????_id?=?value;
????????????}
????????}
????????/**////?<summary>
????????///?雇員
????????///?</summary>
????????public?virtual?User?Employee
????????{
????????????get
????????????{
????????????????return?_user;
????????????}
????????????set
????????????{
????????????????_user?=?value;
????????????}
????????}
????????/**////?<summary>
????????///?年度
????????///?</summary>
????????public?int?Year
????????{
????????????get
????????????{
????????????????return?_year;
????????????}
????????????set
????????????{
????????????????_year?=?value;
????????????}
????????}
????????/**////?<summary>
????????///?月份
????????///?</summary>
????????public?int?Month
????????{
????????????get
????????????{
????????????????return?_month;
????????????}
????????????set
????????????{
????????????????_month?=?value;
????????????}
????????}
????????/**////?<summary>
????????///?季度
????????///?</summary>
????????public?int?Envy
????????{
????????????get
????????????{
????????????????return?_envy;
????????????}
????????????set
????????????{
????????????????_envy?=?value;
????????????}
????????}
????????/**////?<summary>
????????///?工資
????????///?</summary>
????????public?decimal?Money
????????{
????????????get
????????????{
????????????????return?_money;
????????????}
????????????set
????????????{
????????????????_money?=?value;
????????????}
????????}
????}
}

3) 更改User.cs,在User里面添加SalaryList屬性：

User.cs
?1private?System.Collections.IList?_salaryList;
?2?/**////?<summary>
?3????????///?工資列表
?4????????///?</summary>
?5????????public?System.Collections.IList?SalaryList
?6????????{
?7????????????get
?8????????????{
?9????????????????return?_salaryList;
10????????????}
11????????????set
12????????????{
13????????????????_salaryList?=?value;
14????????????}
15????????} 4）修改User.hbm.xml，加入bag節點
User.hbm.xml
<bag?name="SalaryList"?table="Salary"?inverse="true"?lazy="true"?cascade="all">
??????<key?column="Id"/>
??????<one-to-many?class="NhibernateSample1.Salary,NhibernateSample1"></one-to-many>
????</bag>
?5）編寫類Salary的映射文件:Salary.hbm.xml
Salary.hbm.xml
<?xml?version="1.0"?encoding="utf-8"??>
<hibernate-mapping?xmlns="urn:nhibernate-mapping-2.2">
??<class?name="NhibernateSample1.Salary,NhibernateSample1"?table="Salary"?lazy="false">
????<id?name="Id"?column="Id"?unsaved-value="0">
??????<generator?class="native"?/>
????</id>
????<property?name="Year"?column="Year"?type="Int32"?not-null="true"></property>
????<property?name="Month"??column="Month"??type="Int32"?not-null="true"></property>
????<property?name="Envy"??column="Envy"??type="Int32"?not-null="true"></property>
????<property?name="Money"??column="Money"??type="Decimal"?not-null="true"></property>
????<many-to-one?name="Employee"?column="Uid"?not-null="true"></many-to-one>
??</class>
</hibernate-mapping> 6）編寫CRUD類
UserSalaryFixure.cs
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?UserSalaryFixure
????{
????????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.SalaryList?=?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?Salary?CreateSalary(User?u,?int?year,int?month,int?envy,decimal?money)
????????{
????????????Salary?item?=?new?Salary();
????????????item.Year?=?year;
????????????item.Money?=?money;
????????????item.Envy?=?envy;
????????????item.Month?=?month;
????????????item.Employee?=?u;
????????????u.SalaryList.Add(item);
????????????ISession?session?=?_sessions.OpenSession();
????????????ITransaction?tx?=?null;

????????????try
????????????{
????????????????tx?=?session.BeginTransaction();
????????????????session.Update(u);
????????????????tx.Commit();
????????????}
????????????catch?(HibernateException?e)
????????????{
????????????????if?(tx?!=?null)?tx.Rollback();
????????????????throw?e;
????????????}
????????????finally
????????????{
????????????????session.Close();
????????????}
????????????return?item;
????????}
????????public?Salary?CreateSalary(int?uid,int?year,?int?month,?int?envy,?decimal?money)
????????{
????????????Salary?item?=?new?Salary();
????????????item.Year?=?year;
????????????item.Money?=?money;
????????????item.Envy?=?envy;
????????????item.Month?=?month;
????????????
????????????ISession?session?=?_sessions.OpenSession();
????????????ITransaction?tx?=?null;
????????????try
????????????{
????????????????tx?=?session.BeginTransaction();
????????????????User?u?=?(User)session.Load(typeof(User),?uid);
????????????????item.Employee?=?u;
????????????????u.SalaryList.Add(item);
????????????????tx.Commit();
????????????}
????????????catch?(HibernateException?e)
????????????{
????????????????if?(tx?!=?null)?tx.Rollback();
????????????????throw?e;
????????????}
????????????finally
????????????{
????????????????session.Close();
????????????}
????????????return?item;
????????}
????????public?Salary?GetSalary(int?salaryID)
????????{
????????????ISession?session?=?_sessions.OpenSession();
????????????ITransaction?tx?=?null;
????????????try
????????????{
????????????????tx?=?session.BeginTransaction();
????????????????Salary?item?=?(Salary)session.Load(typeof(Salary),
????????????????????salaryID);???????????????
????????????????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?UpdateSalary(int?salaryID,?decimal?money)
????????{
????????????ISession?session?=?_sessions.OpenSession();
????????????ITransaction?tx?=?null;
????????????try
????????????{
????????????????tx?=?session.BeginTransaction();
????????????????Salary?item?=?(Salary)session.Load(typeof(Salary),
????????????????????salaryID);
????????????????item.Money?=?money;
????????????????tx.Commit();
????????????}
????????????catch?(HibernateException?e)
????????????{
????????????????if?(tx?!=?null)?tx.Rollback();
????????????????throw?e;
????????????}
????????????finally
????????????{
????????????????session.Close();
????????????}
????????}

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

????}
}
7) 編寫單元測試類：UnitTest1.cs
UnitTest1.cs
using?System;
using?System.Text;
using?System.Collections.Generic;
using?Microsoft.VisualStudio.TestTools.UnitTesting;
using?NhibernateSample1;

namespace?TestProject1
{
????/**////?<summary>
????///?UnitTest1?的摘要說明
????///?</summary>
????[TestClass]
????public?class?UnitTest1
????{
????????public?UnitTest1()
????????{
????????????//
????????????//?TODO:?在此處添加構造函數邏輯
????????????//
????????}
????????NhibernateSample1.UserSalaryFixure?usf?=?new?UserSalaryFixure();
????????其他測試屬性#region?其他測試屬性
????????//
????????//?您可以在編寫測試時使用下列其他屬性:
????????//
????????//?在運行類中的第一個測試之前使用?ClassInitialize?運行代碼
????????//?[ClassInitialize()]
????????//?public?static?void?MyClassInitialize(TestContext?testContext)?{?}
????????//
????????//?在類中的所有測試都已運行之后使用?ClassCleanup?運行代碼
????????//?[ClassCleanup()]
????????//?public?static?void?MyClassCleanup()?{?}
????????//
????????//?在運行每個測試之前使用?TestInitialize?運行代碼?
????????//?[TestInitialize()]
????????//?public?void?MyTestInitialize()?{?}
????????//
????????//?在運行每個測試之后使用?TestCleanup?運行代碼
????????//?[TestCleanup()]
????????//?public?void?MyTestCleanup()?{?}
????????//
????????#endregion

????????[TestMethod]
????????public?void?Test1()
????????{
????????????usf.Configure();
????????????usf.ExportTables();
????????????User?u?=?usf.CreateUser(Guid.NewGuid().ToString(),?"ds");
????????????Assert.IsTrue(u.Id>0);
????????????Salary?s?=?usf.CreateSalary(u,?2007,?3,?1,?(decimal)8000.00);
????????????Assert.IsTrue(s.Id?>?0);
????????????Salary?s1?=?usf.CreateSalary(u.Id,?2007,?3,?1,?(decimal)7500);
????????????Assert.IsTrue(s1.Id>0);
????????????usf.UpdateSalary(s1.Id,?(decimal)6000);
????????????s1?=?usf.GetSalary(s1.Id);
????????????Assert.IsTrue(s1.Money?==?(decimal)6000);
????????????usf.Delete(s1.Id);
????????????s1?=?usf.GetSalary(s1.Id);
????????????Assert.IsNull(s1);
????????????User?u1?=?usf.GetUser(1);
????????????Assert.IsTrue(u1.SalaryList.Count>0);
????????}

????}
}
加載測試元數據，直到Test()通過。
總結：通過進一步學習nhiberate，發現ORM框架真是非常強大。今天先到這里。明天繼續。
項目文件:/Files/jillzhang/simple2.rar

轉載于:https://www.cnblogs.com/erichzhou/archive/2007/03/29/692949.html

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