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From Hugi Thordarson <h...@karlmenn.is>
Subject Re: Expression to look for objects with an empty to-many relationship?
Date Fri, 24 Jul 2015 16:56:55 GMT
Indeed :). I’ve been looking at the Expression classes for a while now and they look a little
daunting. Any recommendations on where to start? Is there a developer guide or an annotated
example implementation somewhere?

- hugi



> On 24. júl. 2015, at 15:59, Andrus Adamchik <andrus@objectstyle.org> wrote:
> 
> Classic open source - "scratch your own itch" :) 
> 
> 
>> On Jul 24, 2015, at 6:54 PM, Hugi Thordarson <hugi@karlmenn.is> wrote:
>> 
>> Thanks Andrus, we’ll revert to EJBQL for now.
>> 
>> Looks like an excellent opportunity to try and implement my first Expression class
:)
>> 
>> - hugi
>> 
>> 
>> 
>>> On 24. júl. 2015, at 15:36, Andrus Adamchik <andrus@objectstyle.org> wrote:
>>> 
>>> We should add it. For now OUTER JOIN should do the trick:
>>> 
>>> "a.paintingArray+ = null"
>>> 
>>> Also EJBQL syntax supports "IS [NOT] EMPTY" :
>>> 
>>> "SELECT a FROM Artist a WHERE a.paintingArray IS EMPTY"
>>> 
>>> Andrus
>>> 
>>>> On Jul 24, 2015, at 5:51 PM, Hugi Thordarson <hugi@karlmenn.is> wrote:
>>>> 
>>>> Hi all.
>>>> Does Cayenne have an Expression class that allows searching for objects with
an empty to-many relationships? If not, any pointers towards a sensible approach?
>>>> 
>>>> Cheers,
>>>> - hugi
>>>> 
>>>> // Hugi Thordarson
>>>> // http://www.loftfar.is/ <http://www.loftfar.is/>
>>>> // s. 895-6688
>>>> 
>>>> 
>>>> 
>>> 
>> 
> 


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