ReadAllQuery on Aggregate Entities

Question

Hi, I am struggling with implementing a ReadAllQuery in a situation with a table and an aggregated table representing it's primary key fields.
e.g.
@Entity
TheTable {
SOME COLUMNS;
@Entity
TheTable_PK{
PRIMARY KEY COLUMNS
So far I have been using ReadAllQuery and setting the reference class in the usual way. However, I can't work out from experimenting and reading the documentation how I do this with aggregated tables.
It works fine using a NativeQuery and buliding the query up that way, but that doesn't fit in with my framework.
Any advice gratefully received.
Patrick

Answer 1

Aggregates / Embeddables are not independent objects, so you cannot query them directly. You must query for their parent, if you want just the aggregates, you could then collect them up.
You can also query the embeddables directly with JPQL using their parent context, i.e. "Select TheTable.thePrimaryKey from TheTable". In the EclipseLink DatabaseQuery API, this would be a ReportQuery, not a ReadAllQuery, that selects the embeddable.
See,
http://en.wikibooks.org/wiki/Java_Persistence/Embeddables#Querying
James : http://www.eclipselink.org