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From Chris Murphy <ch...@strandz.org>
Subject Re: Insert at a particular position in the detail list
Date Sun, 28 Sep 2008 15:04:26 GMT

That's why I was focusing only on the list being able to act like a 
list. In my application refreshing the detail list from the DB already 
keeps the ordering - and the user wouldn't care about a different 
ordering coming up for the next program invocation - as RosterSlots 
within Worker is an inherently unordered concept. Perhaps my program's 
UI design isn't perfect - and the user shouldn't be able to insert at a 
particular point in the list - but I'm not going to change that now.

The inability of the detail list to act like a list is hardly a 
show-stopper for me however - writing those special methods on the 
server and client versions of the Worker DO works fine...

- Chris

Michael Gentry wrote:
> I've never found it onerous in Cayenne (or EOF) to apply a sort
> ordering if I care about the ordering of the returned results in a
> to-many.  Maybe it is just because I understand that the List will be
> ordered, by default, in whatever sequence the database returned the
> records.  If I need to order things differently, I can do it at the
> database level or provide cover methods to order by any attribute I
> choose in memory -- even after adding new records.
>
> For the cases where an ordering is maintained in the database (by
> adding an integer column, for example), it is pretty trivial to add
> that column to order-by to your query.  And one can always create the
> query/ordering in the Modeler to ensure the ordering is always applied
> (assuming a common query).
>
> I guess I just don't see this as a problem that is in dire need of
> being "solved".  In the Hibernate training class I took, one of the
> complaints was all the different modeling options of the to-many
> relationship.  The developers I know just wanted a list of objects.
> They just wanted to call getArtists() and have it work and be simple
> to set up.  Something that could be iterated over and could be sorted
> later if they wanted, but the sorting was internal.
>
> I didn't mean for this to be a rant, but at some level you have to
> know where the ORM and DB demarcation line is.  Cayenne (and other
> ORMs) can do a lot to minimize the work done, but I think the current
> approach is great for the overwhelming majority of use-cases.  And it
> is trivial for a developer to add an integer-column to a table and
> maintain a position in it for apps that need it (like maintaining a
> queue).  Cayenne works great for that, too, with minimal code having
> to be written to support it.
>
> mrg
>
>
> On Fri, Sep 26, 2008 at 3:52 PM, Andrus Adamchik <andrus@objectstyle.org> wrote:
>   
>> That's a good point - we are trying to bridge the gap between OO and RDB
>> worlds in a best possible way. And I wish we could do a reasonable ordering
>> implementation (and without a join table). Otherwise the java.util.List
>> "contract" is indeed broken.
>>
>> Andrus
>>     
>
>
>   

-- 
Seaweed Software Pty Ltd,
http://www.strandz.org


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