I am trying to use a FetchGroup to retrieve a path of relationships.
Can a fetchGroup be defined across multiple Entities?
My application has DeptBean, EmpBean, ProjectBean with a relationship
from DeptBean to EmpBean named "emps" and a relationship from EmpBean
to ProjectBean named "projects". All relationship defined or
defaulted to LAZY.
When retrieving DeptBean, I want the related EmpBeans and in turn
their related ProjectBeans to be eagerly retrieved.
What I tried was
@Entity
@FetchGroup (name="detail", attributes={
@FetchAttribute(name="emps" ,recursionDepth=2})
public class DeptBean{
@OneToMany
Collection<EmpBean> emps
...
@Entity
@FetchGroup (name="detail", attributes = {
@FetchAttribute (name="tasks", recursionDepth=2)})
public class EmpBean {
...
@OneToMany
Collection<ProjectBean> projects;
I then add "details" to the FetchPlan for the query
select d from DeptBean d where d.location='CA'
and maxFetchDepth was set to 4 in the persistence.xml
I find that the EmpBeans related via "emps" are retrieved but not
"projects". I could not find any way to go deeper than one level
using a FetchGroup. The only way I found to get "projects" to be
fetched on a query returning DeptBean was to define the relationships
as EAGER, but then this made the relationship EAGER all the time which
is not what I want.
