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From Joe Grassel <jgras...@mac.com>
Subject Re: Fetch Groups
Date Mon, 13 Aug 2007 21:17:17 GMT
Ok, I commented out all the @FetchGroup annotations, and commented out the lines that add the
 fetchgroups to the fetchplan.  I still had the curious behavior that my address 1:1 relationship,
now annotated explicitly as eager, was still not getting loaded, in fact it started coming
up null instead of a proxy object even.

however, after I commented out these preceding lines (they appear before adding my fetchgroups
to the plan, I probably should have included them in my code snipper earlier):

//            oem.getFetchPlan().clearFetchGroups();
//            oem.getFetchPlan().clearFields();

Then the address relationship started displaying eager behavior.  Did either or both of the
clear* operations remove the default fetch group from the plan?  If so, is that the intended
function?  I thought the clear*() operations were to remove any custom fetchgroups that were
added to the plan, and left default alone.




On Monday, August 13, 2007, at 03:36PM, "Patrick Linskey" <plinskey@gmail.com> wrote:
>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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