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From Craig L Russell <Craig.Russ...@Sun.COM>
Subject Re: Fetch Groups
Date Mon, 13 Aug 2007 22:31:13 GMT
clearFetchGroups actually clears everything, including the default  
fetch group (according to the JDO specification).  If you want to  
reset to the default fetch group, setFetchGroups("default") should work.

Craig

On Aug 13, 2007, at 2:32 PM, Patrick Linskey wrote:

> ... so maybe the clearFetchGroups() is causing the implicit fetching
> of the primitives in Address to be disabled. What happens if you call
> resetFetchGroups() before setting things up instead?
>
> -Patrick
>
> On 8/13/07, Pinaki Poddar <ppoddar@bea.com> wrote:
>>> I thought the clear*() operations were to remove any custom
>> fetchgroups that were added to > the plan, and left default alone.
>>
>> clearFetchGroups() clears all the fetch groups. Does the  
>> documentation
>> say otherwise?
>>
>>
>> Pinaki Poddar
>> 972.834.2865
>>
>> -----Original Message-----
>> From: Joe Grassel [mailto:jgrassel@mac.com]
>> Sent: Monday, August 13, 2007 4:17 PM
>> To: dev@openjpa.apache.org
>> Subject: Re: Fetch Groups
>>
>> 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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>
>
> -- 
> Patrick Linskey
> 202 669 5907

Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!


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