If I understand correctly, the goal is to match artists that must have
painting that are ALL with the same color. So I think the second OR
would match artists that have SOME painting of matching color, and
some of a different color.
But I guess the important thing here is that Andrey and me showed 2
new capabilities of Cayenne 3.0 that would help with a number of non-
trivial queries.
Andrus
On Jan 10, 2010, at 2:08 PM, Andrey Razumovsky wrote:
> Or you can use left joins:
> ExpressionFactory.matchExp("paintingsArray+.color",
> null).orExp(ExpressionFactory.matchExp("paintingsArray+.color",
> blue));
>
> 2010/1/10 Andrus Adamchik <andru..bjectstyle.org>
>
>> This requires Cayenne 3.0 and EJBQLQuery with subquery. Something
>> like this
>> might work:
>>
>> new EJBQLQuery(
>> "SELECT a FROM Artist a " +
>> "WHERE NOT EXISTS " +
>> "(SELECT p FROM Painting p WHERE p.color <> 'XYZ')";
>>
>> Andrus
>>
>>
>> On Jan 7, 2010, at 2:32 AM, Mark Fraser wrote:
>>
>> Suppose I have an Artists table and a Paintings table with the
>> usual setup
>>> of the Artist class having a PAINTINGS_ARRAY property. Suppose
>>> further
>>> that
>>> the painting has a "color" property that can be a string or null.
>>>
>>> How would I build an Expression such that I get back the Artists
>>> that have
>>> either no paintings or only paintings with a specific color value
>>> (or a
>>> null
>>> color value)?
>>>
>>> I am using Cayenne 2.0.4 in case that matters.
>>>
>>> TIA
>>>
>>
>>
>
>
> --
> Andrey
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