NH表关系一对多分析

nhibernate 表之间的几种关系不易把握,现根据个人学习,总结如下,共同学习,提高,

完整代码参见我的资源[NHibernateTestExampleforSqlServer20110109]

若有错误,请指出,

不甚感谢!

 

a.实体:

public class Parent

    {

        public Parent()

        {

            children = new HashedSet();

        }

        private Guid id;

        private ISet children;

 

        public virtual Guid Id

        {

            get { return id; }

            set { id = value; }

        }

 

        public virtual ISet Children

        {

            get { return children; }

            set { children = value; }

        }

}

 

  public class Child

     {

         public Child()

         {

         }

         public virtual Guid  Id { get; set; }

         public virtual string Name { get; set; }

         public virtual Parent Parent { get; set; }

     }

b.映射:

  <class name="Parent">

    <id name="Id">

      <generator class="guid" />

    </id>   

   

    <!--由child控制,不生生更新语句,和一对一差不多-->

    <set name ="Children" inverse="true" lazy="true">

     

    <!--由parent控制,将产生更新语句-->

    <!--<set name="Children" lazy="true">-->

      <key column="parent_id"/>

      <one-to-many class="Child"/>

    </set>

  </class>

 

<class name="Child">

    <id name="Id">

      <generator class="guid" />

    </id>

    <property name="Name"/>

    <many-to-one name="Parent" class="Parent" column="parent_id"></many-to-one>

  </class>

c.测试代码:

  /// <summary>

        /// 一对多,inverse设置是否产生第三语句的问题

        /// </summary>

        [Test]

        public void CreateInitialDataOnetoMany()

        {

            #region 仅保存parent表,主动权在child

            using (ISession session = _sessionFactory.OpenSession())

            using (ITransaction transaction = session.BeginTransaction())

            {

                Parent p = new Parent();

                Child c = new Child();

                p.Children.Add(c);

                c.Parent = p;

                session.Save(p);

                session.Save(c);

                transaction.Commit();

            }

            #endregion

        }

d.总结: