Question

当我保存新报告时，NHibernate会插入报告，忽略发布并尝试插入UserPublication。然而，SQL然后抱怨违反FK约束。它就像NHibernate一样认为发布是新的，即使数据库中不存在该行。

将实体关系视为：报告可以有很多出版物（出版物属于报告）出版物可以有许多UserPublications（UserPublications属于出版物）

任何想法我做错了什么？提前谢谢。

这是映射：

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true">
<class name="Model.Report, Model" table="Report" lazy="true">
  <id name="Id" access="property" column="ReportID">
    <generator class="assigned"></generator>
  </id>    
  <property name="DeleteUnread" access="property" />
  <property name="Description" access="property" />
  <property name="Name" access="property" />    
  <bag name="Publications" access="property" lazy="true" cascade="all-delete-orphan">
    <key column="ReportID"/>
    <one-to-many class="Model.Publication, Model"/>        
  </bag>
</class>  
</hibernate-mapping>

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true">
  <class name="Model.Publication, Model" table="Publication" lazy="true">
    <id name="Id" access="property" column="PublicationID">    
      <generator class="assigned"></generator>
    </id>  
    <property name="CreatedOn" access="property" />
    <property name="FileExtension" access="property" /> 
    <property name="IsDownloaded" access="property" />
    <property name="ToBeDownloaded" access="property" />
    <property name="Name" access="property"/>  
    <bag name="UserPublications" access="property" lazy="true" cascade="all-delete-orphan">    
      <key column="PublicationID"></key>
      <one-to-many class="Model.UserPublication, Model" />
    </bag>
    <many-to-one name="Report" class="Model.Report, Model" lazy="false" column="ReportID" not-null="true" cascade="none">
    </many-to-one>
  </class>
</hibernate-mapping>

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true">
  <class name="Model.UserPublication, Model" table="UserPublication" lazy="true">
    <id name="Id" access="property" column="UserPublicationID">
      <generator class="native"></generator>
    </id>
    <property name="IsFlaggedForDeletion" access="property" column="IsFlaggedForDeletion" />
    <property name="HasBeenRead" access="property" column="HasBeenRead" />
    <property name="DateReceived" access="property" column="DateReceived" />
    <property name="MustRead" access="property" column="MustRead" />
    <property name="ShowToolbar" access="property" column="ShowToolbar" />
    <property name="MaxAge" access="property" column="MaxAge" />
    <property name="FeedId" access="property" column="FeedId" />
    <property name="CanEdit" access="property" column="CanEdit" />    
    <many-to-one name="User" access="property" column="ClientUserID" class="Model.ClientUser, Model" not-null="true" cascade="none">      
    </many-to-one>
    <many-to-one name="Publication" access="property" class="Model.Publication, Model" column="PublicationID" not-null="true" cascade="none">      
    </many-to-one>
</class>

Answer 1

我认为问题是发布的id是一个指定的id，因此NHibernate无法识别何时应该插入一个发布。刷新会话时，首先插入所有插入的对象，然后更新所有更新的对象，然后删除所有已删除的对象。所以我认为这将在这里发生：您保存一个包含userpublications的发布的报告。因为发布了id NHibernate假定它必须更新并忽略它，但UserPublication id是本机的，NHibernates知道何时应该插入它并尝试插入它因此发生FK违规。要解决此问题，您可以向发布添加版本属性，以便NHibernate可以根据其版本值插入它。

Answer 2

Publication类中的UserPublications包具有错误的键元素。它应该是：

<key column="PublicationID"/>

Answer 3

这很有效。我将unsaved-value属性设置为“any”。

我认为不会有任何重复。

<id name="Id" access="property" column="PublicationID" unsaved-value="any">    
  <generator class="assigned"></generator>
</id>

NHibernate没有将父插入数据库

3 个答案: