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双向多对多关联

nhibernate

Brandon · 技术社区 · 16 年前

我有一门课,描述如下:

public class Customer {
    public ISet<Client> Contacts { get; protected set;}
}

我要将“联系人”属性映射到下表:

CREATE TABLE user_contacts (
    user1 uuid NOT NULL,
    user2 uuid NOT NULL
)

我希望它双向映射,即当customer1添加到customer2的contacts时,customer1的contacts集合应该包含customer2(可能只有在实体重新加载之后)。我怎么能做到?

更新当然,我可以从左到右和从右到左映射集,然后在运行时合并,但它会…隐马尔可夫模型。。。不好吃…还有其他解决办法吗?无论如何,谢谢你的配合, 弗里哈德 !

1 回复 | 直到 15 年前

FryHard 16 年前

看看这个链接,了解Hibernate称之为单向的 many-to-many associations . 在 Castle ActiveRecord 我使用了hasandbelongmotorny链接,但我不确定它在nhibernate中的映射方式。

虽然稍微深入了解一下您的问题,但看起来您将双向链接客户与用户的联系人,这可能会破坏许多链接。我会举个例子,看看我能想出什么。

从ActiveRecord导出HBM文件显示

<?xml version="1.0" encoding="utf-16"?>
<hibernate-mapping  auto-import="true" default-lazy="false" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:nhibernate-mapping-2.2">
  <class name="NHibernateMapping.Customer, NHibernateMapping" table="Customer" schema="dbo">
    <id name="Id" access="property" column="Id" type="Int32" unsaved-value="0">
      <generator class="identity">
      </generator>
    </id>
    <property name="LastName" access="property" type="String">
      <column name="LastName" not-null="true"/>
    </property>
    <bag name="ChildContacts" access="property" table="user_contacts" lazy="false">
      <key column="user1" />
      <many-to-many class="NHibernateMapping.Customer, NHibernateMapping" column="user2"/>
    </bag>
    <bag name="ParentContacts" access="property" table="user_contacts" lazy="false" inverse="true">
      <key column="user2" />
      <many-to-many class="NHibernateMapping.Customer, NHibernateMapping" column="user1"/>
    </bag>
  </class>
</hibernate-mapping>

活动记录示例:

[ActiveRecord("Customer", Schema = "dbo")]
public class Customer
{
    [PrimaryKey(PrimaryKeyType.Identity, "Id", ColumnType = "Int32")]
    public virtual int Id { get; set; }

    [Property("LastName", ColumnType = "String", NotNull = true)]
    public virtual string LastName { get; set; }

    [HasAndBelongsToMany(typeof(Customer), Table = "user_contacts", ColumnKey = "user1", ColumnRef = "user2")]
    public IList<Customer> ChildContacts { get; set; }

    [HasAndBelongsToMany(typeof(Customer), Table = "user_contacts", ColumnKey = "user2", ColumnRef = "user1", Inverse = true)]
    public IList<Customer> ParentContacts { get; set; }
}

希望它有帮助!