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From Joe Grassel <jgras...@mac.com>
Subject Re: Fetch Groups
Date Mon, 13 Aug 2007 20:06:28 GMT
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
>
>

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