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From "Patrick Linskey" <plins...@gmail.com>
Subject Re: Fetch Groups
Date Mon, 13 Aug 2007 20:36:04 GMT
What if you remove the fetch group annotations, and just set fetch
type to eager on the relation? If that, or that + @Basic, works, then
it must be a problem with our fetch group traversal application.

-Patrick

On 8/13/07, Joe Grassel <jgrassel@mac.com> wrote:
> No change:
>
> SELECT t0.EMP_TYPE, t1.id, t0.dept_id, t0.description, t0.manager_id FROM Employee t0
LEFT OUTER JOIN Address t1 ON t0.address_id = t1.id WHERE t0.id = ? [params=(int) 1]
>
> On Monday, August 13, 2007, at 03:25PM, "Patrick Linskey" <plinskey@gmail.com>
wrote:
> >Hmm. What happens if you put @Basic annotations on the fields in Address?
> >
> >-Patrick
> >
> >On 8/13/07, Joe Grassel <jgrassel@mac.com> wrote:
> >> Looks like the only query that goes out is:
> >>
> >>
> >> [main] openjpa.jdbc.SQL - <t 16515324, conn 1700554076> executing prepstmnt
1983018546 SELECT t0.EMP_TYPE, t1.id, t0.dept_id, t0.description, t0.manager_id FROM Employee
t0 LEFT OUTER JOIN Address t1 ON t0.address_id = t1.id WHERE t0.id = ? [params=(int) 1]
> >>
> >>
> >> On Monday, August 13, 2007, at 02:37PM, "Patrick Linskey" <plinskey@gmail.com>
wrote:
> >> >> Is this a bug in OpenJPA, or is a proxy object supposed to be in the
Address entity's place?
> >> >
> >> >I would expect the address data to be available.
> >> >
> >> >What SQL is produced by the find call?
> >> >
> >> >-Patrick
> >> >
> >> >On 8/13/07, Joe Grassel <jgrassel@mac.com> wrote:
> >> >> Hello, I'm writing a program that is trying to capitalize on FetchGroups,
but I'm hitting some behavior that I was not expecting, based on what I read from the manual.
> >> >>
> >> >> I have two entities, Employee and Address, as follows:
> >> >>
> >> >> @Entity
> >> >> @FetchGroups({
> >> >>         @FetchGroup(name="DescFetchGroup", attributes= {@FetchAttribute(name="description")}
),
> >> >>         @FetchGroup(name="AddressFetchGroup", attributes= {@FetchAttribute(name="address")}
)
> >> >> //...
> >> >> })
> >> >> public class Employee {
> >> >>     @Id
> >> >>     private int id;
> >> >>
> >> >> //...
> >> >>
> >> >> @Basic(fetch=FetchType.LAZY)
> >> >>     private String description;
> >> >>
> >> >>  @OneToOne(fetch=FetchType.LAZY)
> >> >>     private Address address;
> >> >>
> >> >> //...
> >> >>
> >> >> }
> >> >>
> >> >> and
> >> >>
> >> >> @Entity
> >> >> public class Address {
> >> >>     @Id
> >> >>     private int id;
> >> >>
> >> >>     private String street;
> >> >>     private String city;
> >> >>     private String state;
> >> >>     private int zip;
> >> >>
> >> >> //...
> >> >>
> >> >> public String toString()
> >> >>     {
> >> >>         StringBuffer sb = new StringBuffer();
> >> >>         sb.append("Address(id=").append(this.id).append(")");
> >> >>         sb.append(": street=").append(getStreet());
> >> >>         sb.append(": city=").append(getCity());
> >> >>         sb.append(": state=").append(getState());
> >> >>         sb.append(": zip=").append(getZip());
> >> >>
> >> >>         return new String(sb);
> >> >>     }
> >> >> }
> >> >>
> >> >> This is what I'm trying to do:
> >> >>
> >> >> // ...
> >> >> OpenJPAEntityManager oem = (OpenJPAEntityManager) em;
> >> >> oem.getFetchPlan().addFetchGroups("DescFetchGroup");
> >> >> oem.getFetchPlan().addFetchGroups("AddressFetchGroup");
> >> >>
> >> >> oem.clear();
> >> >> Employee emp = oem.find(Employee.class, 1);
> >> >> oem.clear();
> >> >>
> >> >> if (emp.getDescription() != null)
> >> >>   System.out.println("Employee description=" + emp.getDescription());
> >> >> else
> >> >>   System.out.println("Description is null");
> >> >>
> >> >> if (emp.getAddress() != null)
> >> >>   System.out.println("Employee address=" + emp.getAddress());
> >> >> else
> >> >>   System.out.println("Address is null");
> >> >>
> >> >> // ...
> >> >>
> >> >> I get the following results:
> >> >>
> >> >> Employee description=Description 1
> >> >> Employee address=Address(id=1): street=null: city=null: state=null:
zip=0
> >> >>
> >> >> It looks like an empty proxy object containing just the Address entity's
primary key is returned.  I was under the impression that with the AddressFetchGroup added
to the fetch plan, that the whole (Address) entity's persistent state would be eagerly loaded.
> >> >>
> >> >> Is this a bug in OpenJPA, or is a proxy object supposed to be in the
Address entity's place?
> >> >>
> >> >
> >> >
> >> >--
> >> >Patrick Linskey
> >> >202 669 5907
> >> >
> >> >
> >>
> >
> >
> >--
> >Patrick Linskey
> >202 669 5907
> >
> >
>


-- 
Patrick Linskey
202 669 5907

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