@amut, It may not fail executing the query, but the results returned are incorrect. If joining an entity without following a path – here: “thingStats” – hibernate treats it (appropriatedly, I think) like a cross-join, and the SQL generated is:

select t1_0.THING_PK 
from Thing t1_0 
left join ThingStats t2_0 on true 
where t2_0.THING_FK is null or t2_0.REJECTED_COUNT=0

Note the on true. However, if you add the join criteria explicitly (I changed the name to ts2 to avoid confusion with Thing.thingStats):

select thing from Thing thing 
left join ThingStats ts2 on ts2.thingPk = thing.pk
where ts2 is null or (ts2.rejectedCount = 0 and ts2.thingPk = thing.pk

It works. Here’s the generated SQL:

select t1_0.THING_PK 
from Thing t1_0 
left join ThingStats t2_0 on t2_0.THING_FK=t1_0.THING_PK 
where t2_0.THING_FK is null or (t2_0.REJECTED_COUNT=0 and t2_0.THING_FK=t1_0.THING_PK)

But I think as a workaround, simply testing the attribute, as I indicated previously, is simpler (and easier to understand).