6.2. 集合映射( Collection mappings )

用于映射集合类的Hibernate映射元素取决于接口的类型。比如, <set> 元素用来映射Set类型的属性。

<class name="Product">
    <id name="serialNumber" column="productSerialNumber"/>
    <set name="parts">
        <key column="productSerialNumber" not-null="true"/>
        <one-to-many class="Part"/>
    </set>
</class>

除了&lt;set&gt;,还有&lt;list&gt;, &lt;map&gt;, &lt;bag&gt;, &lt;array&gt;&lt;primitive-array&gt; 映射元素。&lt;map&gt;具有代表性:

<map
    name="propertyName"
    table="table_name"
    schema="schema_name"
    lazy="true|extra|false"
    inverse="true|false"
    cascade="all|none|save-update|delete|all-delete-orphan|delete-orphan"
    sort="unsorted|natural|comparatorClass"
    order-by="column_name asc|desc"
    where="arbitrary sql where condition"
    fetch="join|select|subselect"
    batch-size="N"
    access="field|property|ClassName"
    optimistic-lock="true|false"
    mutable="true|false"
    node="element-name|."
    embed-xml="true|false"
>

    <key .... />
    <map-key .... />
    <element .... />
</map>