castor

Query returns entities of wrong type for extended class hierarchies

Details

  • Type: Bug Bug
  • Status: Closed Closed
  • Priority: Critical Critical
  • Resolution: Fixed
  • Affects Version/s: 1.2
  • Fix Version/s: 1.3 rc1
  • Component/s: JDO queries
  • Labels:
    None
  • Number of attachments :
    1

Description

When executing a query for the base class of a extended class hierarchy under some conditions Castor returns entities of the wrong class.

If we have a class hierarchy with following entities:

class BaseEntity { }
class ExtendedEntity extends BaseEntity { }

According to the data in the database the query:

select o from BaseEntity o;

should return:

1. BaseEntity
2. ExtendedEntity
3. BaseEntity

but what the query returns is:

1. BaseEntity
2. ExtendedEntity
3. ExtendedEntity

Activity

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Ralf Joachim added a comment -

Final patch including test case.

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Ralf Joachim added a comment - Final patch including test case.
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Werner Guttmann added a comment -

Ralf, the problem description is just not clear to me. Can you give me a more detailed example on where things have been going wrong. I am basically just trying to understand the problem.

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Werner Guttmann added a comment - Ralf, the problem description is just not clear to me. Can you give me a more detailed example on where things have been going wrong. I am basically just trying to understand the problem.
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Ralf Joachim added a comment -

When iterating through the query results, an ExtendedEntity instance was returned even if it should have been a BaseEntity after the first ExtendedEntity..

I suggest you to take a look at the test case committed together with the patch as I do not have an idea how to describe the problem in more details. Just comment out the added line of SQLQuery and you will see the test case failing.

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Ralf Joachim added a comment - When iterating through the query results, an ExtendedEntity instance was returned even if it should have been a BaseEntity after the first ExtendedEntity.. I suggest you to take a look at the test case committed together with the patch as I do not have an idea how to describe the problem in more details. Just comment out the added line of SQLQuery and you will see the test case failing.
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Ralf Joachim added a comment -

One more try. The reason for the problem has been that SQLEngine (_engine) of SQLQuery has been changed form SQLEngine of BaseEntity to the one of ExtendedEntity when the first ExtendedEntity was returned by the query result and never got switched back to BaseEntity thereafter. This caused the query to always return ExtendedEntity instances even if it should have been a BaseEntity instance.

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Ralf Joachim added a comment - One more try. The reason for the problem has been that SQLEngine (_engine) of SQLQuery has been changed form SQLEngine of BaseEntity to the one of ExtendedEntity when the first ExtendedEntity was returned by the query result and never got switched back to BaseEntity thereafter. This caused the query to always return ExtendedEntity instances even if it should have been a BaseEntity instance.
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Werner Guttmann added a comment -

That (second comment) really makes things 100% clear. Thanks.

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Werner Guttmann added a comment - That (second comment) really makes things 100% clear. Thanks.

People

  • Assignee:
    Ralf Joachim
    Reporter:
    Ralf Joachim
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Dates

  • Created:
    Updated:
    Resolved: