OpenJPA
  1. OpenJPA
  2. OPENJPA-255

Inconsistent behavior during merge with cascade=none

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Minor Minor
    • Resolution: Fixed
    • Affects Version/s: 0.9.7, 1.0.0
    • Fix Version/s: 1.1.0
    • Component/s: kernel
    • Labels:
      None

      Description

      Suppose you have 2 entities, A and B, with a unidirectional one-to-one relation from A to B and cascade=none. Persist A, B1 and B2, where A.b == B1. Later change A.b to B2 and merge, the operation may or may not succeed, depending on the following conditions:

      • If both A and B2 is detached, merge succeeds.
      • If both A and B2 is attached, iow managed in the same entity manager, merge succeeds.
      • If A is detached and B2 is managed as above, merge fails with 'encountered new object ...' exception.

      (It doesn't matter if the objects are versioned or not.)

      The latter case is a rather typical usecase involving a detached context, where the server application unmarshalls a user-modified domain object, creates an entity manager and further modifies that object before invoking merge (such as setting A.b depending on values of other fields). There are two workarounds for the issue: merge twice (merge/set server managed fields/merge), or explicitly detach all such relation objects before calling merge, but obviously neither is desirable.

      Looking at the code, it all boils down to AttachStrategy.getReference(...) method. This method is invoked whenever a relation with cascade=none is encountered during merge operation (and only for that case). Yet this method assumes that the object must be detached or it will throw the mentioned exception --I don't see the logic behind that assumption.

      Attached a testcase demonstrating that behaviour, and a possible fix for it --based on the premise that the above assumption is not correct. If that's not the case, I'd appreciate if someone can point me in the right direction as to why cascade=none on any type of relation field requires a detached object.

      1. openjpa-jira-255.patch
        10 kB
        Gokhan Ergul
      2. openjpa-jira-231-255-new.patch
        19 kB
        Xiaoqin Feng

        Issue Links

          Activity

          Hide
          Gokhan Ergul added a comment -

          Testcase and fix attached.

          Show
          Gokhan Ergul added a comment - Testcase and fix attached.
          Hide
          Adish Abnave added a comment -

          How do i use the patched attached here? I am trying to build OpenJPA with the patched code but getting maven Build error.Can some one send me or let me know where i can get an openJpa jar with the patched code ?

          Show
          Adish Abnave added a comment - How do i use the patched attached here? I am trying to build OpenJPA with the patched code but getting maven Build error.Can some one send me or let me know where i can get an openJpa jar with the patched code ?
          Hide
          Xiaoqin Feng added a comment -

          I added TestNoCascadeOneToOneMerge.java based on the test case provided in this bug.
          The attached patch includes both tests and fixes for open-231 and open-255.

          Show
          Xiaoqin Feng added a comment - I added TestNoCascadeOneToOneMerge.java based on the test case provided in this bug. The attached patch includes both tests and fixes for open-231 and open-255.
          Hide
          Patrick Linskey added a comment -

          Hi,

          The recent patch is somewhat corrupted; can you recreate and re-post?

          Show
          Patrick Linskey added a comment - Hi, The recent patch is somewhat corrupted; can you recreate and re-post?
          Hide
          Xiaoqin Feng added a comment -

          openjpa-255 is already fixed by openjpa-419 on openjpa1.1.x branch. I think my recent added openjpa-jira-231-255-new.patch is not needed for this issue.
          But fix for openjpa-231 on openjpa1.1.x and openjpa head will be different. I will attach patch to openjpa-231.

          Show
          Xiaoqin Feng added a comment - openjpa-255 is already fixed by openjpa-419 on openjpa1.1.x branch. I think my recent added openjpa-jira-231-255-new.patch is not needed for this issue. But fix for openjpa-231 on openjpa1.1.x and openjpa head will be different. I will attach patch to openjpa-231.

            People

            • Assignee:
              Unassigned
              Reporter:
              Gokhan Ergul
            • Votes:
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              Dates

              • Created:
                Updated:
                Resolved:

                Development