Skip to main content
Jump to: navigation, search

Difference between revisions of "EclipseLink/UserGuide/JPA/Basic JPA Development/Configuration/JPA/orm.xml"

m (orm.xml)
m (Replacing page with ' '''Warning See "About Object-Relational Mapping" in the [ EclipseLink Concepts Guide]'''')
(19 intermediate revisions by 3 users not shown)
Line 1: Line 1:
Use the '''orm.xml''' file to apply the metadata to the persistence unit. This metadata is a union of all the mapping files and the annotations (if there is no '''xml-mapping-metadata-complete'''  element). If you use one mapping '''orm.xml''' file for your metadata and place this file in a META-INF directory on the classpath, then you do not need to explicitly list it. The EclipseLink persistence provider will automatically search for this file ('''orm.xml''')and use it.
If you use a different name for your mapping files, or place them in a different location, you must list them in the '''mapping-file'''  element of the [[EclipseLink/UserGuide/JPA/Basic_JPA_Development/Configuration/JPA/persistence.xml|persistence.xml file]], as shown here:
<source lang="xml">
<persistence-unit name="EmployeeService">
|note=In this example, the '''orm.xml''' file is not listed -- the persistence provider finds it by default.
|previous=[[EclipseLink/UserGuide/JPA/Basic JPA Development/Configuration/JPA/Annotations|Annotations]]
|next=[[EclipseLink/UserGuide/JPA/Basic JPA Development/Configuration/JPA/Defaults|Defaults]]
|up=[[EclipseLink/UserGuide/JPA/Basic JPA Development/Configuration|Configuration]]}}
'''[[Image:Elug_draft_icon.png|Warning]] See "About Object-Relational Mapping" in the [ EclipseLink Concepts Guide]'''
==Advantages and Disadvantages of Using XML==
Some advantages of using XML instead of [[EclipseLink/UserGuide/JPA/Basic JPA Development/Configuration/JPA/Annotations|Annotations]] include:
* No coupling between the metadata and the source code
* Compliance with the existing, pre-EJB 3.0 development process
* Support in IDEs and source control systems
The main disadvantages of mapping with XML include:
*Its inherent complexitiy (when compared to annotations)
*The need for replication of the code context

Latest revision as of 11:49, 25 January 2013

Warning See "About Object-Relational Mapping" in the EclipseLink Concepts Guide

Back to the top