Quoting Michael Bouschen <[EMAIL PROTECTED]>:
> The following query groups the class A instances by the strings in their
> string collection:
> Query q = pm.newQuery(A.class);
> q.declareVariables("java.lang.String str");
> q.setFilter("this.stringCol.contains(str)");
> q.setGrouping("str");
> q.setResult("str");
> This results in an exception:
> JDOUserException: Unable to find the field "str" in the candidate
> class. It is possible that this field is a field in a subclass, but it
> is illegal to reference fields directly when they are in a subclass.
>
The query should work, but grouping on a literal has not a lot of sense. The
compiler should ignore the grouping.
> I get a different exception when adding an aggregate to the result clause
> q.setResult("str, count(this)");
> JDOUserException: Unconstrained variable referenced: str
>
Should work again.
> The behavior is different when iterating a collection of pc instances:
> Query q = pm.newQuery(A.class);
> q.declareVariables("model.B b");
> q.setFilter("this.bCol.contains(b)");
> q.setGrouping("b");
> q.setResult("count(this), b");
> This results in:
> JDOUserException: The result clause has a field expression
> "UnboundVariable "UNBOUND_B.ID"" that doesnt appear in the grouping. Any
> result specification has to be present in the grouping when grouping is
> specified.
>
And should work too.
