在组合键hibernate xml中映射组合键

Question

这就是我想要做的，将一个对象映射到另一个具有相同主键的表。下面是一个示例，基本上我有一个具有组合键的对象，该对象具有另一个表的组合键，但我不知道如何包含这两个键才能创建正确的对象键。我突出显示了错误的行，它只包含键的一个属性。

  <class name="BusinessRuleObject" table="BUSINESS_RULE_OBJECTS" schema="DB">
    <composite-id name="businessRuleObjectId" class="BusinessRuleObjectId">
      <key-property name="sameIdCode" column="ID_CD" />
      **<key-many-to-one name="businessRule" class="BusinessRule" column="BUSINESS_RULE" />**
    </composite-id>
    <!-- ... STUFF GOES HERE -->
  </class>

  <class name="BusinessRule" table="BUSINESS_RULE_STRINGS" schema="DB">
    <composite-id name="businessRule2ID" class="BusinessRule2ID">
      <key-property name="sameIdCode" column="ID_CD" />
      <key-property name="businessRuleCode" column="BUSINESS_RULE" />
    </composite-id>
    <!-- TOTALLY DIFFERENT STUFF GOES HERE -->
   </class>

Answer 1

只包括复合外键businessRule的一个属性，因为<key-many-to-one只声明了一个列BUSINESS_RULE。它应该声明在您的示例中引用BUSINESS_RULE和ID_CD的组合键的两列。通过将ID_CD列添加到<key-many-to-one元素，您需要删除或重命名<key-property name="sameIdCode" column="ID_CD" />元素的列。

到businessRule对象的关联<key-many-to-one应该映射如下：

<composite-id name="businessRuleObjectId" class="BusinessRuleObjectId"> 

  <key-many-to-one name="businessRule" class="BusinessRule" >
     <column name="ID_CD" />
     <column name="BUSINESS_RULE" />
  </key-many-to-one>

</composite-id> 

Hibernate参考文档

5.1.7. composite-id

Components as composite identifiers