此内容没有您所选择的语言版本。

18.2. XML Mapping Metadata


18.2.1. About XML Mapping Metadata

A range of Hibernate mapping elements accept the node attribute. This lets you specify the name of an XML attribute or element that holds the property or entity data. The format of the node attribute must be one of the following:
  • "element-name": map to the named XML element
  • "@attribute-name": map to the named XML attribute
  • ".": map to the parent element
  • "element-name/@attribute-name": map to the named attribute of the named element
For collections and single valued associations, there is an additional embed-xml attribute. If embed-xml="true", the default, the XML tree for the associated entity (or collection of value type) will be embedded directly in the XML tree for the entity that owns the association. Otherwise, if embed-xml="false", then only the referenced identifier value will appear in the XML for single point associations and collections will not appear at all.
Do not leave embed-xml="true" for too many associations, since XML does not deal well with circularity.
<class name="Customer" 
        table="CUSTOMER" 
        node="customer">
        
    <id name="id" 
            column="CUST_ID" 
            node="@id"/>
            
    <map name="accounts" 
            node="." 
            embed-xml="true">
        <key column="CUSTOMER_ID" 
                not-null="true"/>
        <map-key column="SHORT_DESC" 
                node="@short-desc" 
                type="string"/>
        <one-to-many entity-name="Account"
                embed-xml="false" 
                node="account"/>
    </map>
    
    <component name="name" 
            node="name">
        <property name="firstName" 
                node="first-name"/>
        <property name="initial" 
                node="initial"/>
        <property name="lastName" 
                node="last-name"/>
    </component>
    
    ...
    
</class>
Copy to Clipboard Toggle word wrap
In this case, the collection of account ids is embedded, but not the actual account data. The following HQL query:
from Customer c left join fetch c.accounts where c.lastName like :lastName
Copy to Clipboard Toggle word wrap
would return datasets such as this:
<customer id="123456789">
    <account short-desc="Savings">987632567</account>
    <account short-desc="Credit Card">985612323</account>
    <name>
        <first-name>Gavin</first-name>
        <initial>A</initial>
        <last-name>King</last-name>
    </name>
    ...
</customer>
Copy to Clipboard Toggle word wrap
If you set embed-xml="true" on the <one-to-many> mapping, the data might look more like this:
<customer id="123456789">
    <account id="987632567" short-desc="Savings">
        <customer id="123456789"/>
        <balance>100.29</balance>
    </account>
    <account id="985612323" short-desc="Credit Card">
        <customer id="123456789"/>
        <balance>-2370.34</balance>
    </account>
    <name>
        <first-name>Gavin</first-name>
        <initial>A</initial>
        <last-name>King</last-name>
    </name>
    ...
</customer>
Copy to Clipboard Toggle word wrap
返回顶部
Red Hat logoGithubredditYoutubeTwitter

学习

尝试、购买和销售

社区

关于红帽文档

通过我们的产品和服务,以及可以信赖的内容,帮助红帽用户创新并实现他们的目标。 了解我们当前的更新.

让开源更具包容性

红帽致力于替换我们的代码、文档和 Web 属性中存在问题的语言。欲了解更多详情,请参阅红帽博客.

關於紅帽

我们提供强化的解决方案,使企业能够更轻松地跨平台和环境(从核心数据中心到网络边缘)工作。

Theme

© 2025 Red Hat