Mike Conner ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=62fe3d3... ) *commented* on HHH-16080 ( https://hibernate.atlassian.net/browse/HHH-16080?atlOrigin=eyJpIjoiZjdkZD... ) Re: UnknownTableReferenceException with JPQL query of Entity with unidirectional OneToOne mapping ( https://hibernate.atlassian.net/browse/HHH-16080?atlOrigin=eyJpIjoiZjdkZD... ) @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). ( https://hibernate.atlassian.net/browse/HHH-16080#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16080#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100214- sha1:634fa42 )