Sorry for the late reply, but I've been busy. Adding the "addPrefetch"
method to the query did solve the problem in my case.
The DataContexts are in different JVMs so that might be the reason. I
don't think the problem exists within the same JVM. I'm not entirely
sure because I've recently changed the program to use one DataContext
bound to the thread. I don't remember any problems within one JVM before
that though. And the relationship is 2-way.
Thanks a lot for the help,
Peter
Bryan Lewis wrote:
> I've come across the same behavior, I think. I have three Oracle tables,
> Employee, Role, and a join table EmployeeRole. Employee has a 1-to-many
> relationship "roles"; it's a flattened relationship
> Employee->Employee_Role and Employee_Role->Role.
>
> The first query for a list of employees works fine. I can see from the
> SQL logging that the employees are fetched and then each employee's
> roles are fetched.
>
> When the query is repeated, only the employees are refetched. If some
> other user session (in another browser -- same localhost-server JVM,
> different DataContext) has changed an employee's roles, the change is
> not seen in the first session.
>
> I tried adding query.addPrefetch("employeeRoles.role") but that didn't
> help. I tried invalidateObjects() and query.setRefreshingObjects(true).
>
> Other details:
> * There is a corresponding reverse relationship Role.employees.
> * A simpler 1-to-1 relationship didn't have any trouble.
> * I'm using version 1.1M6.
>
> HTH,
> Bryan
>
>
> Andrus Adamchik wrote:
>
>> Hi Peter,
>>
>> Does this happen in different DataContexts in the same JVM? Cayenne
>> should handle this case, but there is still some room for mistake when
>> automatic refresh can't be done properly. If you have any more details
>> on that, I'd appreciate it (e.g. is there Object2.getObject1()
>> relationship?).
>>
>> To explicitly deal with this problem you can use prefetching in the
>> query, e.g.:
>>
>> query.addPrefetch("object2s");
>>
>> Also, as far as cache policies are concerned, they are not related to
>> this case. Cache policies deal with caching *lists* of objects, not
>> the objects themselves.
>>
>> Andrus
>>
>>
>> On Sep 2, 2004, at 9:37 AM, Peter Backx wrote:
>>
>>> I'm currently using Cayenne (1.1B2) with MySQL for a 3 table database
>>> with a few relationships. The database itself is changed by different
>>> programs concurrently and when I try to update the view in one
>>> program it works ok for basic objects, however if objects were added
>>> to a 1-to-many relationship these don't seem to be updated.
>>>
>>> Maybe to make it more clear: I have Object1 that has a 1-to-many
>>> relationship with Object2. If I get Object1 through a query the first
>>> time everything works ok and Object1.getObject2s() works fine.
>>> However if new Object2's are added to that relationship (from another
>>> thread/program/DataContext) and I perform a new query to get Object1
>>> I still get the old list of Object2's. So I don't see the newly added
>>> relationships.
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