From Eclipsepedia  Jump to: navigation, search  Starting with
[[EclipseLink/Release/2.1.0|EclipseLink 2.1.0] EclipseLink has
introduced the concept of an AttributeGroup that can be used
configure the use of partial entities in fetch, load, copy, and
merge operations. This example illustrates how this
functionality can be used.   AttributeGroup Types and Operations
The FetchGroup which has existed in EclipseLInk for a number of
releases defines which attributes should be fetched (selected
from the database) when the entity is retrieved as the result of
a query execution. The inclusion of relationship attributes in a
FetchGroup only determines if the attribute's required columns
should be fetched and populated. In the case of a lazy fetch
type the inclusion of the attribute simply means that its proxy
will be created to enable lazy loading when accessed. To force a
relationship mapping to be populated when using a FetchGroup on
a query the attribute must be included in the group and must
either be FetchType.E