Then another way to achieve this is a paginated query. You'd perform a
query with 'setPageSize(...)' that retrieves ids of all objects. Then
you cache the resulting list and reuse between requests.
As a side note, 3.0M3 optimizes paginated queries substantially and
yet unreleased 3.0M4 optimizes it even more, allowing it to scale to
at least a few hundred thousands of rows:
https://issues.apache.org/cayenne/browse/CAY-999
If you have even more rows, or memory is a premium, then you'd have to
use SQLTemplate.
Andrus
On Mar 16, 2008, at 11:57 PM, Jean-François Smigielski wrote:
> Of course I can. :)
>
> In a short term, I have to provide a web application with some JSP,
> where I
> simply have to present a list of persistent and manageable objects.
> The
> table might be big, and I would present sublists (each with a bounded
> cardinlity), with http links to jump to the prev/next sublist. The
> OFFSET
> and LIMIT parameters are then known from the URL (after some sanity
> checks).
>
> Further, some Web-services will have to do the same kind of table
> listings,
> with attributes known from the request parameters.
>
> If it helps, I am pretty sure this application will use either MySQL,
> Postgresql or Apache-Derby as a DB backend.
>
> Thanks again.
>
> JFS
>
> 2008/3/16, Andrus Adamchik <andru..bjectstyle.org>:
>>
>> Specifying offset is not (yet) supported. Aside from SQLTemplate
>> there
>> are various ways to solve it depending on your requirements. So can
>> you explain how do you know which OFFSET to use, maybe there is an
>> alternative solution...
>>
>>
>> Andrus
>>
>>
>>
>> On Mar 16, 2008, at 10:10 PM, Jean-François Smigielski wrote:
>>> Hello, list!
>>>
>>> I am wondering if and how it is possible to limit the result of a
>>> SelectQuery with Cayenne 3.0.
>>>
>>> For a user interface purpose, I want to be able to present only a
>>> subset of
>>> a select on a huge table. I already use the setFetchLimit(int)
>>> method to set
>>> a LIMIT clause, but I am unable to precisely tell the OFFSET at
>>> which my
>>> subset must start. I do not find how in the online Javadoc.
>>>
>>> Any help would be appreciated, thanks a lot!
>>> Best regards,
>>>
>>> --
>>> JF Smigielski
>>
>>
>
>
> --
> JF Smigielski
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