And I did say that this is indeed a problem assuming you are right, and I have no reason to believe you are not.  In fact I can see how that would happen.  Yes all based on Hibernate internals. So I am not trying to blow you off as "this is not a bug". I think it is a bug.  I'm just saying I do not yet know what to do about it. On Wed, Feb 7, 2018 at 12:41 PM Steve Ebersole <steve(a)hibernate.org <mailto:steve@hibernate.org>> wrote: Yes, I understood the situation. I'm saying that in your query you should just be able to switch to use named parameters (prefixed with `:`, rather than `?`) as a workaround On Wed, Feb 7, 2018 at 11:21 AM Laurent Almeras <laurent.almeras(a)laposte.net <mailto:laurent.almeras@laposte.net>> wrote: Hi, Thanks for this insight ; but as I stated (and this is a correction of the assumptions of my first email) in my second email, it seems that the wrong query (with mixed positional and named parameters) is built in hibernate inside layers (and not in QueryDSL). I get rid of my QueryDSL query and replace it with raw JPQL query : ============================         Query query = getEntityManager().createQuery("select queuedTaskHolder\n" +                 "from QueuedTaskHolder queuedTaskHolder\n" +                 "where queuedTaskHolder.status in (?1) and queuedTaskHolder.queueId = ?2\n" +                 "order by queuedTaskHolder.id asc").setParameter(1, ImmutableList.of(TaskStatus.CANCELLED, TaskStatus.COMPLETED)).setParameter(2, "queue");         return query.getResultList(); ============================ And it fails with the very same message : ============================ Cannot define positional and named parameterSpecs : select queuedTaskHolder from org.iglooproject.jpa.more.business.task.model.QueuedTaskHolder queuedTaskHolder where queuedTaskHolder.status in (:x1_0, :x1_1) and queuedTaskHolder.queueId = ?2 order by queuedTaskHolder.id asc     at org.hibernate.hql.internal.ast.HqlSqlWalker.generatePositionalParameter(HqlSqlWalker.java:1094)     at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.parameter(HqlSqlBaseWalker.java:3463) ============================ It used to work with Hibernate 5.2.x ; and by reading JPQL spec (not sure if this is the right version - https://docs.oracle.com/html/E13946_01/ejb3_langref.html#ejb3_langref_in ) it seems that " IN (?param) " is a valid syntax. I agree that mixed query may not be supported, but even if positional parameter queries bring nothing more than named parameters ones, there are also required for JPA compliance ? Can you say me if I made some wrong assumptions ? If not, is it usefull I provide some minimal test-case ? *Side-note:* same query written with named parameters is OK (as expected): ============================         Query query = getEntityManager().createQuery("select queuedTaskHolder\n" +         "from QueuedTaskHolder queuedTaskHolder\n" +         "where queuedTaskHolder.status in (:statuses) and queuedTaskHolder.queueId = :queue\n" +         "order by queuedTaskHolder.id asc").setParameter("statuses", ImmutableList.of(TaskStatus.CANCELLED, TaskStatus.COMPLETED)).setParameter("queue", "queue");         return query.getResultList(); ============================ Thanks, Le 07/02/2018 à 17:30, Steve Ebersole a écrit : > Yes, I can see this being a problem. Its caused by some very > old, fulgy code in how "list-valued parameters" are handled > internally. > > I'm not sure the best way to deal with this. Unfortunately > reverting this is not possible - its necessary for JPA > compliance.  The simple workaround of course is to use named > parameters yourself.  Honestly JPA's notion of "positional" > parameters is nonsensical since they are not positional - the > ordinals can repeat and can appear in any order... nothing > particularly positional about that.  In fact they are really > nothing more than named parameters that happen to use > int-valued labels. > > Longer term 6.0 will address this because it changes that > "old, fulgy" internal code - but those same changes are not > possibly in 5.3. > >