Question

据我所知，当映射组件的所有属性在数据库中为空时，NHibernate会将组件设置为null。但是，在以下情况下，如果多对一项 LevelOfInvolvement 为null，则组件将设置为null，尽管组件的所有其他属性都不 null。

更改数据库中 LevelOfInvolvement 列的值将导致组件为null或不为null，无论其他字段的值如何。

这是完整的maping：

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="NHS.WebTeam.LPTInvolvementHub.Activity, NHS.WebTeam.LPTInvolvementHub" table="[Activity]" lazy="false" optimistic-lock="version" where="Deleted=0" >
    <id name="ID" type="Int32" column="ID" unsaved-value="0">
      <generator class="hilo">
        <param name="table">NHibernateHiLo</param>
        <param name="column">NextValue</param>
        <param name="max_lo">100</param>
      </generator>
    </id>

    <version name="Version"/>
    <property name="Deleted" />
    <property name="LastUpdateBy" />
    <property name="LastUpdateDate" />

    <many-to-one name="Service" column="ServiceID"></many-to-one>
    <property name="Title"></property>
    <property name="Abstract"></property>
    <property name="ProposedDate"></property>
    <property name="DueDate"></property>
    <property name="ActualDate"></property>
    <property name="Rationale"></property>
    <many-to-one name="PreAssessment" column="PreAssessmentID"></many-to-one>
    <many-to-one name="PostAssessment" column="PostAssessmentID"></many-to-one>

    <component name="InvolvementChecklist">
      <property name="Impact" column="InvolvementChecklist_Impact"></property>
      <property name="RewardsAndRecognition" column="InvolvementChecklist_RewardsAndRecognition"></property>
      <property name="Training" column="InvolvementChecklist_Training"></property>
      <property name="LogisticalIssues" column="InvolvementChecklist_LogisticalIssues"></property>
      <property name="Feedback" column="InvolvementChecklist_Feedback"></property>
      <property name="DueRegard" column="InvolvementChecklist_DueRegard"></property>
      <property name="SupportRequiredFromTheTeam" column="InvolvementChecklist_SupportRequiredFromTheTeam"></property>
      <property name="QualityAssurance" column="InvolvementChecklist_QualityAssurance"></property>
      <property name="NonComplianceReason" column="InvolvementChecklist_NonComplianceReason"></property>
      <many-to-one name="LevelOfInvolvement" column="InvolvementChecklist_LevelOfInvolvementID"></many-to-one>
    </component>

  </class>
</hibernate-mapping>

加载实体的代码很简单：

entity = NHibernateSession.Load(persitentType, id);

我正在使用NHibernate版本3.3.1

这似乎是一个相对简单的映射，但我找不到任何有类似问题的人的参考。

Answer 1

除了在所有组件成员都为null时返回null，我相信如果任何非可空成员为null，NHibernate也会将组件视为null。默认情况下，<many-to-one>映射会创建一个不可为空的成员，我认为这会导致您看到的行为。尝试更改LevelOfInvolement映射以允许空值：

<many-to-one 
    name="LevelOfInvolvement" 
    column="InvolvementChecklist_LevelOfInvolvementID" 
    not-null="false" />

NHibernate组件在多对一NULL时加载为null，尽管有几个非null属性

1 个答案: