[hibernate-issues] [JIRA] (HHH-16438) Left outer joins do not work with polymorphic entities due to use of discriminator in the main query condition

Jones ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiMTVhZmI5NzBl... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16438?atlOrigin=eyJpIjoiMTVhZm... ) HHH-16438 ( https://hibernate.atlassian.net/browse/HHH-16438?atlOrigin=eyJpIjoiMTVhZm... ) Left outer joins do not work with polymorphic entities due to use of discriminator in the main query condition ( https://hibernate.atlassian.net/browse/HHH-16438?atlOrigin=eyJpIjoiMTVhZm... ) Issue Type: Bug Affects Versions: 6.2.0 Assignee: Unassigned Created: 05/Apr/2023 02:13 AM Priority: Critical Reporter: Jones ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) Given * A simple entity * A polymorphic entity When * querying the simple entity doing a left join with the polymorphic entity Then * The results will always be empty when the left joined entity is not present @Entity @Table(name = "ENTITY_B" ) public class EntityB { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "ID" ) private Integer id; @Column(name = "SOME_ID" ) private Integer someId; } @Entity @Table(name = "ENTITY_A" ) @DiscriminatorColumn(name = "DISC_COL" , discriminatorType = DiscriminatorType.INTEGER) public abstract class AbstractEntityA { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "ID" ) Integer id; } @Entity @DiscriminatorValue( "1" ) public class EntityAChildOne extends AbstractEntityA {} @Test public void hhhXXXXTest() throws Exception { try (Session s = openSession()) { Transaction tx = s.beginTransaction(); EntityB entityB = new EntityB(); s.persist(entityB); tx.commit(); } try (Session s = openSession()) { Query<EntityB> query = s.createQuery( "select b from EntityB b left outer join EntityAChildOne a1 on a1.id = b.someId" , EntityB.class); List<EntityB> actual = query.list(); assertThat(actual).hasSize(1); } } java.lang.AssertionError: Expected size:<1> but was:<0> in: <[]> at org.hibernate.bugs.ORMUnitTestCase.hhhXXXXTest(ORMUnitTestCase.java:76) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:568) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56) at org.hibernate.testing.junit4.ExtendedFrameworkMethod.invokeExplosively(ExtendedFrameworkMethod.java:45) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27) at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:299) at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:293) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at java.base/java.lang.Thread.run(Thread.java:833) In hibernate 5.6.15, this example just works, because hibernate 5 completely ignores the discriminator when generating the SQL (might be a limitation or a bug), but the expected outcome for the example is kept and we get the expected result which is the single list with the entity b in it: Hibernate 5.6.15: select entityb0_.ID as id1_1_, entityb0_.SOME_ID as some_id2_1_ from MY_TABLE entityb0_ left outer join ENTITY_A entityachi1_ on ( entityachi1_.ID=entityb0_.SOME_ID ) In hibernate 6.2.0, the resulting list will always be empty, because hibernate 6 does not ignore the discriminator, but adds it to the main query criteria (this part is the wrong part). Since this is a left join, the joined entity is optional and adding the discriminator criteria to the main part of the query will result to empty when the joined entity is not present. Hibernate 6.2.0: select e1_0.ID, e1_0.SOME_ID from MY_TABLE e1_0 left join ENTITY_A e2_0 on e2_0.ID=e1_0.SOME_ID where e2_0.DISC_COL=1 A failing test scenario is to be attached ( https://hibernate.atlassian.net/browse/HHH-16438#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16438#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#100221- sha1:78e8bd6 )