Question

我有两个表配置和设置，其中设置是配置的部分（子）。< / p>

我使用HibernateDaoSupport.find（）来检索配置，结果对象包含3个设置，其中一个是 null 。不是具有空值的对象，而是 null 。

根据日志，Hibernate只发现了两行：

DEBUG [org.hibernate.jdbc.ConnectionManager] - releasing JDBC connection [ (open PreparedStatements: 0, globally: 0) (open ResultSets: 0, globally: 0)]
DEBUG [org.hibernate.engine.TwoPhaseLoad] - resolving associations for [com.xx.Setting#1]
DEBUG [org.hibernate.engine.TwoPhaseLoad] - done materializing entity [com.xx.Setting#1]
DEBUG [org.hibernate.engine.TwoPhaseLoad] - resolving associations for [com.xx.Setting#2]
DEBUG [org.hibernate.engine.TwoPhaseLoad] - done materializing entity [com.xx.Setting#2]
DEBUG [org.hibernate.engine.loading.CollectionLoadContext] - 1 collections were found in result set for role: com.xx.Configuration.settings
DEBUG [org.hibernate.engine.loading.CollectionLoadContext] - collection fully initialized: [com.xx.Configuration.settings#1]
DEBUG [org.hibernate.engine.loading.CollectionLoadContext] - 1 collections initialized for role: com.xx.Configuration.settings
DEBUG [org.hibernate.loader.Loader] - done loading collection

然后

DEBUG [org.hibernate.pretty.Printer] - com.xx.Setting{dataType=TEXT, name=xx, id=1, value=xx}
DEBUG [org.hibernate.pretty.Printer] - com.xx.Configuration{settings=[null, com.xx.Setting#1, com.xx.Setting#2], id=1, bu=xx}
DEBUG [org.hibernate.pretty.Printer] - com.xx.Setting{dataType=TEXT, name=xx, id=2, value=xx}

正如您所见，它只找到2 设置，但该集合包含3。

编辑：以下是Hibernate映射

<hibernate-mapping>
  <class name="com.xx.Configuration"
         table="sf_config"
         dynamic-insert="false" dynamic-update="false"
         mutable="true" optimistic-lock="version"
         polymorphism="implicit" select-before-update="false" lazy="false">
    <id access="field" name="id">
      <generator class="native"/>
    </id>
    <natural-id>
      <property name="bu" access="field"/>
    </natural-id>

    <list access="field" name="settings" table="sf_setting" lazy="false" cascade="all-delete-orphan">
      <key>
        <column name="configId"/>
      </key>
      <list-index column="id"/>
      <one-to-many class="com.xx.Setting"/>
    </list>

    <property name="recordState" access="field"/>
  </class>
</hibernate-mapping>

<hibernate-mapping>
  <class name="com.xx.Setting"
         table="sf_setting"
         dynamic-insert="false" dynamic-update="false"
         mutable="true" optimistic-lock="version"
         polymorphism="implicit" select-before-update="false" lazy="false">
    <id access="field" name="id">
      <generator class="native"/>
    </id>

    <property name="name" access="field"/>
    <property name="value" access="field"/>
    <property name="dataType" access="field"/>
  </class>
</hibernate-mapping>

Answer 1

正如对this question的回答，问题是使用列表和列表索引：在这种情况下，子项的ID必须从0开始任何缺少的索引都会导致Hibernate为它生成一个空值。

在我的情况下，第一个孩子的id = 1，因此正在创建0的空行。

Hibernate检索额外的NULL行

1 个答案: