On Sun, Apr 1, 2018 at 2:51 PM, Pawel Veselov <pawel.vese...@gmail.com> wrote: > Hello. > > I can't find much references to problems like this, which is > surprising. May be I'm doing something that is prohibited by the spec?
The spec OKs to use the same parameter more than once (4.6.4.2 of 2.0) > I want to re-use the same parameter twice. However, I'm seeing all > kinds of behavior except for the one I want. This is with OpenJPA > 2.4.2. This seems to be broken in OpenJPA though. Especially if sub-queries are involved. I traced this as much as I could, but I don't understand the intend of the code. There are a few parameter representations. org.apache.openjpa.jdbc.kernel.exps.Param, that has an "_idx" field, defining which parameter value is actually going to be used. There is a ParameterExpressionImpl that is constructed during query evaluation, that has the "_index" field that is later used to populate the Param._idx. While stepping through things I can see: Considering query Select t1 from t1 t1 where t1.id in ( select t2.ref from t2 t2 where t2.hash = :hash_value and t2.group = :tenancy) and t1.group = :tenancy I see: 1) ParameterExpressionImpl for tenancy is assigned _index 0 2) ParameterExpressionImpl for hash_value is assigned _index 1 3) Param for hash_value (sub-query) is assigned _idx 1 4) ParameterExpressionImpl for hash_value is re-assigned to index 0 (because now it's being processed within sub-query, and index is assigned based on the current size of the parameters in the CriteriaQueryImpl object) 5) ParameterExpressionImpl for tenancy is reassigned to index 1 6) Param for tenancy (sub-query) is assigned _idx 1 (because of step #5) 7) Param for tenancy (outer query) is assigned _idx 1 (because of step #5) Param instances are one per parameter placement. ParameterExpressionImpl instances are one per parameter I wonder if the fix is just to copy the parameters into the sub-query object when it's created. Then the parameters would be found, and there indices not modified. It also seems that if I use cb.parameter() twice, the second parameter is not considered the same, even if the name is the same. I think that's also a bug. [skipped] -- With best of best regards Pawel S. Veselov
