6 eclipselink-orm.xml Schema Reference

This chapter describes how you can use EclipseLink's native metadata XML file, eclipselink-orm.xml, to override mappings defined in the JPA configuration file (orm.xml) and to provide extended ORM features.

Note:

Using the eclipselink-orm.xml mapping file enables many EclipseLink advanced features, but it may prevent the persistence unit from being portable to other JPA implementations.

The eclipselink-orm.xml file defines object-relational mapping metadata for EclipseLink. It has the same basic structure as the orm.xml file, which makes it more intuitive, requires minimum configuration, and makes it easy to override.

For more information, see:

Section 12.2 "XML Overriding Rules" in the JPA Specification
http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Basic_JPA_Development/Configuration/JPA/orm.xml

The schema for EclipseLink is eclipselink_orm_X_X.xsd where X_X is the current EclipseLink version number (such as 2_4 for 2.4). All EclipseLink schemas are available from http://wiki.eclipse.org/EclipseLink/XSDs.

This chapter includes the following sections:

Overriding and Merging

6.1 Overriding and Merging

To override the orm.xml file's mapping, you must define the META-INF/eclipselink-orm.xml file in the project. When both orm.xml and eclipselink-orm.xml are specified, the contents of eclipselink-orm.xml will override orm.xml and any other JPA mapping file specified in the persistence unit. If there are overlapping specifications in multiple ORM files, the files are merged if they are no conflicting entities.

Note:

The order of files defined in persistence.xml does not define the order of their processing. The files are processed, merged, and overridden as determined by the rules.

See the following sections for more information:

Rules for Overriding and Merging
Examples of Overriding and Merging

6.1.1 Rules for Overriding and Merging

EclipseLink provides specific overriding and merging rules for the following elements defined in the orm.xml file:

Persistence Unit Metadata
Entity Mappings
Mapped Superclasses
Entity override and merging rules
Embeddable

6.1.1.1 Persistence Unit Metadata

In eclipselink-orm.xml, a persistence-unit-metadata element merges or overrides the values of existing persistence-unit-metadata specification as defined in Table 6-1.

Table 6-1 Overriding and Merging Persistence Unit Metadata

entity-mappings/ persistence-unit-metadata	Rule	Description
`xml-mapping-metadata- complete`	Full override	If specified, the complete set of mapping metadata for the persistence unit is contained in the XML mapping files for the persistence unit.
`persistence-unit-defaults/ schema`	Full override	If a `schema` setting exists, then the `eclipselink-orm.xml` `schema` setting overrides the existing setting or creates a new `schema` setting.
`persistence-unit-defaults/ catalog`	Full override	If a `catalog` setting exists, then the `eclipselink-orm.xml` `catalog` setting overrides the existing setting or creates a new `catalog` setting
`persistence-unit-defaults/ access`	Full override	If an `access` setting exists, then the `eclipselink-orm.xml` `access` setting overrides the existing setting, or creates a new `access` setting.
`entity-mappings/persistence-unit-metadata/persistence-unit-defaults/cascade- persist`	Full override	If a `cascade-persist` setting exists, then the `eclipselink-orm.xml` `cascade-persist` setting overrides the existing setting or creates a new `cascade-persist` setting.
`entity-mappings/persistence-unit-metadata/persistence-unit-defaults/entity- listeners`	Merge	If an `entity-listeners` exists, then the `eclipselink-orm.xml` `entity-listeners` will be merged with the list of all `entity-listeners` from the persistence unit

6.1.1.2 Entity Mappings

Entities, embeddables and mapped superclasses are defined within the entity-mappings section. The eclipselink-orm.xml entities, embeddables and mapped superclasses are added to the persistence unit as defined in Table 6-2.

Table 6-2 Overriding and Merging Entity Mappings

`entity-mappings/`	Rule	Description
`package`	None	The `package` element specifies the package of the classes listed within the subelements and attributes of the same mapping file only. It is only applicable to those entities that are fully defined within the `eclipselink-orm.xml` file, else its usage remains local and is same as described in the JPA specification.
`catalog`	None	The `catalog` element applies only to the subelements and attributes listed within the `eclipselink-orm.xml` file that are not an extension to another mapping file. Otherwise, the use of the catalog element within the `eclipselink-orm.xml` file remains local and is same as described in the JPA specification.
`schema`	None	The schema element applies only to the subelements and attributes listed within the `eclipselink-orm.xml` file that are not an extension to another mapping file. Otherwise, the use of the schema element within the `eclipselink-orm.xml` file remains local and is same as described in the JPA specification.
`access`	None	The access element applies only to the subelements and attributes listed within the `eclipselink-orm.xml` file that are not an extension to another mapping file. Otherwise, the use of the access element within the `eclipselink-orm.xml` file remains local and is same as described in the JPA specification.
`sequence-generator`	Full override	A `sequence-generator` is unique by name. The sequence-generator defined in the `eclipselink-orm.xml` will override a sequence-generator of the same name defined in another mapping file. Outside of the overriding case, an exception is thrown if two or more `sequence-generators` with the same name are defined in one or across multiple mapping files.
`table-generator`	Full override	A `table-generator` is unique by name. The table-generator defined in the `eclipselink-orm.xml` will override a table-generator of the same name defined in another mapping file. Outside of the overriding case, an exception is thrown if two or more `table-generators` with the same name are defined in one or across multiple mapping files.
`named-query`	Full override	A `named-query` is unique by name. The named-query defined in the `eclipselink-orm.xml` will override a named-query of the same name defined in other mapping files. Outside of the overriding case, an exception is thrown if two or more `named-querys` with the same name are defined in one or across multiple mapping file.
`named-native-query`	Full override	A `named-native-query` is unique by name. The `named-native-query` defined in the `eclipselink-orm.xml` will override a `named-native-query` of the same name defined in other mapping files. Outside of the overriding case, an exception is thrown if two or more `named-native-querys` with the same name are defined in one or across multiple mapping files.
`sql-result-set-mapping`	Full override	A `sql-result-set-mapping` is unique by name. The sql-result-set-mapping defined in the `eclipselink-orm.xml` will override a `sql-result-set-mapping` of the same name defined in other mapping files. Outside of the overriding case, an exception is thrown if two or more `sql-result-set-mapping` entities with the same name are defined in one or across multiple mapping files.

6.1.1.3 Mapped Superclasses

A mapped-superclass can be defined completely, or with specific elements to provide extensions to a mapped-superclass from another mapping file. Table 6-3 lists individual override and merging rules:

Table 6-3 Overriding and Merging Mapped Superclasses

`entity-mappings/mapped-superclass`	Rule	Description
`id-class`	Full override	If an `id-class` exists, then the `eclipselink-orm.xml` `id-class` setting overrides the existing setting, or creates a new `id-class` setting.
`exclude-default- listeners`	Full override	If an `exclude-default-listeners` exists, then the `eclipselink-orm.xml` `exclude-default-listeners` setting will be applied. If the `exclude-default-listeners` setting is not specified, it will not override an existing setting, that is essentially turning it off.
`exclude-superclass- listeners`	Full override	If an `exclude-superclass-listeners` setting exists, then the `eclipselink-orm.xml` `exclude-superclass-listeners` setting will be applied. If exclud`e-superclass-listen`ers setting is not specified, it will not override an existing setting, that is essentially turning it off.
`entity-listeners`	Merge and full override	If an `entity-listeners` setting exists, then the `eclipselink-orm.xml` `entity-listeners` setting will override and merge with an existing setting, or creates a new `entity-listeners` setting all together. Note: An entity listener override must be complete. All lifecycle methods of that listener must be specified and no merging of individual lifecycle methods of an entity listener is allowed. The class name of the listener is the key to identify the override.
`pre-persist`	Full override	If a `pre-persist` setting exists, then the `eclipselink-orm.xml` `pre-persist` setting overrides the existing setting, or creates a new `pre-persist` setting.
`post-persist`	Full override	If a `post-persist` setting exists, then the `eclipselink-orm.xml` `post-persist` setting overrides the existing setting, or creates a new `post-persist` setting.
`pre-remove`	Full override	If a pre-remove setting exists, then the eclipselink-orm.xml's pre-remove setting overrides the existing setting, or creates a new pre-remove setting.
`post-remove`	Full override	If a post-remove setting exists, then the eclipselink-orm.xml's post-remove setting overrides the existing setting, or creates a new post-remove setting.
`pre-update`	Full override	If a pre-update setting exists, then the eclipselink-orm.xml's pre-update setting overrides the existing setting, or creates a new pre-update setting.
`post-update`	Full override	If a post-update setting exists, then the eclipselink-orm.xml's post-update setting overrides the existing setting, or creates a new post-update setting.
`post-load`	Full override	If a post-load setting exists, then the eclipselink-orm.xml's post-load setting overrides the existing setting, or creates a new post-load setting.
`attributes`	Merge and mapping level override	If the `attribute` settings (such as `id`, `embedded-id`, `basic`, `version`, `many-to-one`, `one-to-many`, or `one-to-one`) exist at the mapping level, then the `eclipselink-orm.xml` attributes merges or overrides the existing settings, else creates new attributes.
`class`	None
`access`	Full override	If an access setting exists, then the eclipselink-orm.xml's access setting overrides the existing setting, or creates a new access setting. It also overrides the default class setting.
`metadata-complete`	Full override	If a metadata-complete setting exists, then the eclipselink-orm.xml's metadata-complete setting will be applied. If metadata-complete setting is not specified, it will not override an existing setting, that is essentially turning it off.

6.1.1.4 Entity override and merging rules

An entity can be defined completely, or with specific elements to provide extensions to an entity from another mapping file. The following table lists individual override and merging rules:

Table 6-4 Overriding and Merging Entities

entity-mappings/entity	Rule	Description
`table`	Full override	The table definition overrides any other table setting (with the same name) for this entity. There is no merging of individual table values.
`secondary-table`	Full override	The secondary-table definition overrides another secondary-table setting (with the same name) for this entity. There is no merging of individual secondary-table(s) values.
`primary-key-join-column`	Full override	The primary-key-join-column(s) definition overrides any other primary-key-join-column(s) setting for this entity. There is no merging of the primary-key-join-column(s). The specification is assumed to be complete and these primary-key-join-columns are the source of truth.
`id-class`	Full override	If an id-class setting exists, then the eclipselink-orm.xml's id-class setting overrides the existing setting, or creates a new id-class .
`inheritance`	Full override	If an inheritance setting exists, then the eclipselink-orm.xml's inheritance setting overrides the existing setting, or creates a new inheritance setting.
`discriminator-value`	Full override	If a discriminator-value setting exists, then the eclipselink-orm.xml's discriminator-value setting overrides the existing setting, or creates a new discriminator-value setting.
`discriminator-column`	Full override	If a discriminator-column setting exists, then the eclipselink-orm.xml's discriminator-column setting overrides the existing setting, or creates a new discriminator-column setting.
`sequence-generator`	Full override	A sequence-generator is unique by name. The sequence-generator defined in eclipselink-orm.xml overrides sequence-generator of the same name defined in other mapping files. Outside of the overriding case, an exception is thrown if two or more sequence-generators with the same name are defined in one or across multiple mapping files.
`table-generator`	Full override	A table-generator is unique by name. The table-generator defined in eclipselink-orm.xml overrides table-generator of the same name defined in other mapping files. Outside of the overriding case, an exception is thrown if two or more table-generators with the same name are defined in one or across multiple mapping files.
`named-query`	Merge and full override	A named-query is unique by name. The named-query defined in eclipselink-orm.xml overrides any named-query of the same name defined in other mapping files. Outside of the overriding case, an exception is thrown if two or more `named-query` elements with the same name are defined in one or across multiple mapping files.
`named-native-query`	Merge and full override	A named-native-query is unique by name. The named-native-query defined in eclipselink-orm.xml overrides named-native-query of the same name defined in other mapping files. Outside of the overriding case, an exception is thrown if two or more named-native-query elements with the same name are defined in one or across multiple mapping files.
`sql-result-set-mapping`	Merge and full override	A sql-result-set-mapping is unique by name. sql-result-set-mapping defined in eclipselink-orm.xml overrides sql-result-set-mapping of the same name defined in other mapping files. Outside of the overriding case, an exception is thrown if two or more sql-result-set-mapping elements with the same name are defined in one or across multiple mapping files.
`exclude-default-listeners`	Full override	If an exclude-default-listeners setting exists, then the eclipselink-orm.xml's exclude-default-listeners setting will be applied. If an exclude-default-listeners setting is not specified, it will not override an existing setting, that is essentially turning it off.
`exclude-superclass-listeners`	Full override	If an exclude-superclass-listeners setting exists, then the eclipselink-orm.xml's exclude-superclass-listeners setting will be applied. If an exclude-superclass-listeners setting is not specified, it will not override an existing setting, that is essentially turning it off.
`entity-listeners`	Full override	If an entity-listeners setting exists, then the eclipselink-orm.xml's entity-listeners setting will override and merge with an existing setting, or creates a new entity-listeners setting all together. Note: An entity listener override must be complete. All lifecycle methods of that listener must be specified and no merging of individual lifecycle methods of an entity listener is allowed. The class name of the listener is the key to identify the override.
`pre-persist`	Full override	If a pre-persist setting exists, then the eclipselink-orm.xml's pre-persist setting overrides the existing setting, or creates a new pre-persist setting.
`post-persist`	Full override	If a post-persist setting exists, then the eclipselink-orm.xml's post-persist setting overrides the existing setting, or creates a new post-persist setting.
`pre-remove`	Full override	If a pre-remove setting exists, then the eclipselink-orm.xml's pre-remove setting overrides the existing setting, or creates a new pre-remove setting.
`post-remove`	Full override	If a post-remove setting exists, then the eclipselink-orm.xml's post-remove setting overrides the existing setting, or creates a new post-remove setting.
`pre-update`	Full override	If a pre-update setting exists, then the eclipselink-orm.xml's pre-update setting overrides the existing setting, or creates a new pre-update setting.
`post-update`	Full override	f a post-update setting exists, then the eclipselink-orm.xml's post-update setting overrides the existing setting, or creates a new post-update setting.
`post-load`	Full override	If a post-load setting exists, then the eclipselink-orm.xml's post-load setting overrides the existing setting, or creates a new post-load setting.
`attributes`	Merge and mapping level override	If the attribute settings (id, embedded-id, basic, version, many-to-one, one-to-many, one-to-one) exist at the mapping level, then the eclipselink-orm.xml's attributes merges or overrides the existing settings, else creates new attributes.
`association-override`	Merge and mapping level override	If an association-override setting exists, then the eclipselink-orm.xml's association-override setting overrides the existing setting, or creates a new association-override setting.
`name`	Full override	If a name setting exists, then the eclipselink-orm.xml's name setting overrides the existing setting, or creates a new name setting.
`class`	None
`access`	Full override	If an access setting exists, then the eclipselink-orm.xml's access setting overrides the existing setting, or creates a new access setting. It also overrides the default class setting
`metadata-complete`	Full override	If a metadata-complete setting exists, then the eclipselink-orm.xml's metadata-complete setting will be applied. If a metadata-complete setting is not specified, it will not override an existing setting, that is essentially turning it off.

6.1.1.5 Embeddable

An embeddable can be defined wholly or may be defined so as to provide extensions to an embeddable from another mapping file. Therefore, we will allow the merging of that class' metadata. Table 6-4 lists the individual override rules Embeddable classes.

Table 6-5 Overriding and Merging Embeddable Classes

entity-mappings/ embeddable	Rule	Description
`attributes`	Override and merge	If the attribute settings (id, embedded-id, basic, version, many-to-one, one-to-many, one-to-one, many-to-many, embedded, transient) exist at the mapping level, then the eclipselink-orm.xml's attributes merges or overrides the existing settings, or creates new attributes.
`class`	None
`access`	Full override	If an access setting exists, then the eclipselink-orm.xml's access setting overrides the existing setting, or creates a new access setting. It also overrides the default class setting.
`metadata-complete`	Full override	If a metadata-complete setting exists, then the eclipselink-orm.xml's metadata-complete setting will be applied. If a metadata-complete setting is not specified, it will not override an existing setting, that is essentially turning it off.