Red Hat Summit Red Hat SummitApoyoConsolaDesarrolladoresIniciar una pruebaContacto

Este contenido no está disponible en el idioma seleccionado.

6.2. Collection Mappings

6.2.1. About Collection Mappings
Copiar enlace

Note

There are quite a range of mappings that can be generated for collections that cover many common relational models. We suggest you experiment with the schema generation tool so that you understand how various mapping declarations translate to database tables.
The Hibernate mapping element used for mapping a collection depends upon the type of interface. For example, a <set> element is used for mapping properties of type Set. 
<class name="Product">
    <id name="serialNumber" column="productSerialNumber"/>
    <set name="parts">
        <key column="productSerialNumber" not-null="true"/>
        <one-to-many class="Part"/>
    </set>
</class>
Copy to Clipboard Toggle word wrap
Apart from <set>, there is also <list>, <map>, <bag>, <array> and <primitive-array> mapping elements. The <map> element is representative: 
<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>
Copy to Clipboard Toggle word wrap
name: the collection property name
table (optional - defaults to property name): the name of the collection table. It is not used for one-to-many associations.
schema (optional): the name of a table schema to override the schema declared on the root element
lazy (optional - defaults to true): disables lazy fetching and specifies that the association is always eagerly fetched. It can also be used to enable "extra-lazy" fetching where most operations do not initialize the collection. This is suitable for large collections.
inverse (optional - defaults to false): marks this collection as the "inverse" end of a bidirectional association.
cascade (optional - defaults to none): enables operations to cascade to child entities.
sort (optional): specifies a sorted collection with natural sort order or a given comparator class.
order-by (optional, JDK1.4 only): specifies a table column or columns that define the iteration order of the Map, Set or bag, together with an optional asc or desc.
where (optional): specifies an arbitrary SQL WHERE condition that is used when retrieving or removing the collection. This is useful if the collection needs to contain only a subset of the available data.
fetch (optional, defaults to select): chooses between outer-join fetching, fetching by sequential select, and fetching by sequential subselect.
batch-size (optional, defaults to 1): specifies a "batch size" for lazily fetching instances of this collection.
access (optional - defaults to property): the strategy Hibernate uses for accessing the collection property value.
optimistic-lock (optional - defaults to true): specifies that changes to the state of the collection results in increments of the owning entity's version. For one-to-many associations you may want to disable this setting.
mutable (optional - defaults to true): a value of false specifies that the elements of the collection never change. This allows for minor performance optimization in some cases.
Report a bug
Volver arriba
Red Hat logoGithubredditYoutubeTwitter

Aprender

Pruebe, compre y venda

Comunidades

Acerca de la documentación de Red Hat

Ayudamos a los usuarios de Red Hat a innovar y alcanzar sus objetivos con nuestros productos y servicios con contenido en el que pueden confiar. Explore nuestras recientes actualizaciones.

Hacer que el código abierto sea más inclusivo

Red Hat se compromete a reemplazar el lenguaje problemático en nuestro código, documentación y propiedades web. Para más detalles, consulte el Blog de Red Hat.

Acerca de Red Hat

Ofrecemos soluciones reforzadas que facilitan a las empresas trabajar en plataformas y entornos, desde el centro de datos central hasta el perímetro de la red.

Theme

© 2025 Red Hat