nhibernate学习之集合组合依赖

1.学习目标

   还是学习compenent的用法，上节实现了简单字段的组合，这节中将讨论两个问题：1.依赖对象有一个指向容器对象的引用。2。集合依赖

2.开发环境和必要准备

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

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3.通过parent为依赖组合对象映射一个指向容器对象的引用

  CompositeUser.cs 

public class CompositeUser

{

        int _uid;

        UserName _name;

        public int Uid

            get

                return _uid;

            }

            set

                _uid = value;

        }

        public UserName Name

                return _name;

                _name = value;

    }

  UserName.cs

 public class UserName

        private string _firstName;

        private string _lastName;

        CompositeUser _user;

        public string FirstName

                return _firstName;

                _firstName=value;

        public string LastName

                return _lastName;

                _lastName = value;

        public CompositeUser User

                return _user;

                _user = value;

映射文件:CompositeUser.hbm.xml

<?xml version="1.0" encoding="utf-8" ?>

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">

    <class name="NhibernateSample1.CompositeUser,NhibernateSample1" table="CompositeUser" lazy="false">

        <id name="Uid" column="Uid" unsaved-value="0">

            <generator class="native" />

        </id>

        <component name="Name" class="NhibernateSample1.UserName,NhibernateSample1">

            <parent name="User"></parent>

            <property name="FirstName" column="FirstName"></property>

            <property name="LastName" column="LastName"></property>

        </component>

    </class>

</hibernate-mapping>

注意parent是指向容器对象的引用

加载一个CompositeUser对象，结果如图

4. 集合组合依赖

Composite.cs

        ISet _userNames = new HashedSet();

        DateTime _birthDay = DateTime.Now;

        public ISet UserNames

                return _userNames;

                _userNames = value;

        public DateTime BirthDay

                return _birthDay;

                _birthDay = value;

UserName.cs

public class UserName

映射文件CompositeUser.hbm.xml

        <set name="UserNames" table="UserNames" lazy="true">

            <key column="Uid"/>

            <composite-element  class="NhibernateSample1.UserName,NhibernateSample1">

                <property name="FirstName" column="FirstName"></property>

                <property name="LastName" column="LastName"></property>

            </composite-element >

        </set>

        <property name="BirthDay" type="DateTime"></property>

注意：Composite可以包含集合也可以不包含集合，上面这样的配置就不包括集合，映射的属性可以选择为List,map,bag,idbag