Question

我如何在NHibernate中映射以下内容？
我的实体和ERD如下。我知道如何映射多对多关系，但不知道如何将连接表ReportTargets映射到Datapoint表。您会注意到没有ReportTargets实体模型，因为它不是严格意义上的域实体。这里最好的解决方案是什么？我是一个NHibernate新手所以请轻松请... :)谢谢

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Answer 1

由于MarketReport.Targets有一个连接表，请将其映射为多对多。

<class name="MarketReport">
  <id column="reportid" />
  <bag name="ReportTargets" table="reporttargets">
    <key column="marketreportid"/>
    <many-to-many column="targetid" class="Target"/>
  </bag>
</class>

<class name="Target">
  <id column="targetid" />
  <bag name="DataPoints" inverse="true">
    <key column="targetid"/>
    <one-to-many class="DataPoint"/>
  </bag>
</class>

<class name="DataPoint">
  <id column="datapointid" />
</class>

根据您最近的评论，您希望获得ternary association或component collection。我已经包含了两个映射。

<class name="MarketReport">
    <id column="reportid" />
    <map name="ReportTargets" table="reporttargets">
        <key column="marketreportid"/>
        <index-many-to-many column="targetid" class="Target"/>
        <many-to-many column="datapointid" class="DataPoint"/>
    </map>
</class>

<class name="MarketReport">
    <id column="reportid" />
    <bag name="ReportTargets" table="reporttargets">
        <key column="marketreportid"/>
        <composite-element class="ReportTarget">
            <many-to-one name="Target" column="targetid"/>
            <many-to-one name="DataPoint" column="datapointid"/>
        </composite-element>
    </bag>
</class>

<class name="Target">
    <id column="targetid" />
</class>

<class name="DataPoint">
    <id column="datapointid" />
</class>

如何通过连接表映射一对多关系？

1 个答案: