HHH-19565 @SQLRestriction should not be applied to a @manytoone

At least not when mapped to a foreign key association.

If we apply such a restriction, we will set the FK to null
when the entity is updated, resulting in data loss.

Note that this was the historical and correct behavior right
up until Hibernate 6.2. Some recent tests are asserting a
different and dangerous behavior, so I'm changing those tests.

Author: gavinking

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/internal/ToOneAttributeMapping.java

@@ -2091,10 +2091,12 @@ public TableGroupJoin createTableGroupJoin(
 							creationState
 					) );
 
+					final EntityMappingType associatedEntityMappingType = getAssociatedEntityMappingType();
+
 					// Note specifically we only apply `@Filter` restrictions that are applyToLoadByKey = true
 					// to make the behavior consistent with lazy loading of an association
-					if ( getAssociatedEntityMappingType().getEntityPersister().hasFilterForLoadByKey() ) {
-						getAssociatedEntityMappingType().applyBaseRestrictions(
+					if ( associatedEntityMappingType.getEntityPersister().hasFilterForLoadByKey() ) {
+						associatedEntityMappingType.applyBaseRestrictions(
 								join::applyPredicate,
 								tableGroup,
 								true,
@@ -2104,22 +2106,28 @@ public TableGroupJoin createTableGroupJoin(
 								creationState
 						);
 					}
-					getAssociatedEntityMappingType().applyWhereRestrictions(
-							join::applyPredicate,
-							tableGroup,
-							true,
-							creationState
-					);
-					if ( getAssociatedEntityMappingType().getSuperMappingType() != null && !creationState.supportsEntityNameUsage() ) {
-						getAssociatedEntityMappingType().applyDiscriminator( null, null, tableGroup, creationState );
+					// @SQLRestriction should not be applied when joining FK association,
+					// because that would result in us setting the FK to null when the
+					// owning entity is updated, that is, to data loss.
+					// But we'll let it apply on the TARGET side of a @OneToOne
+					if ( sideNature == ForeignKeyDescriptor.Nature.TARGET ) {
+						associatedEntityMappingType.applyWhereRestrictions(
+								join::applyPredicate,
+								tableGroup,
+								true,
+								creationState
+						);
+					}
+					if ( associatedEntityMappingType.getSuperMappingType() != null && !creationState.supportsEntityNameUsage() ) {
+						associatedEntityMappingType.applyDiscriminator( null, null, tableGroup, creationState );
 					}
 
-					final SoftDeleteMapping softDeleteMapping = getAssociatedEntityMappingType().getSoftDeleteMapping();
+					final SoftDeleteMapping softDeleteMapping = associatedEntityMappingType.getSoftDeleteMapping();
 					if ( softDeleteMapping != null ) {
 						// add the restriction
 						final TableReference tableReference = lazyTableGroup.resolveTableReference(
 								navigablePath,
-								getAssociatedEntityMappingType().getSoftDeleteTableDetails().getTableName()
+								associatedEntityMappingType.getSoftDeleteTableDetails().getTableName()
 						);
 						join.applyPredicate( softDeleteMapping.createNonDeletedRestriction(
 								tableReference,

hibernate-core/src/test/java/org/hibernate/orm/test/inheritance/join/AttributeJoinWithRestrictedJoinedInheritanceTest.java

@@ -66,7 +66,8 @@ public void testLeftJoinWithDiscriminatorFiltering(SessionFactoryScope scope) {
 			).getResultList();
 			assertEquals( 2, resultList.size() );
 			assertResult( resultList.get( 0 ), 1, 11, 11, "child_a_1", SubChildEntityA1.class );
-			assertResult( resultList.get( 1 ), 2, 21, null, null, null );
+			// @SQLRestriction should not be applied when joining FK association
+			assertResult( resultList.get( 1 ), 2, 21, 21, "child_a_2", SubChildEntityA2.class );
 		} );
 	}
 

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/where/WhereAnnotationAndJoinedInheritanceTest.java

@@ -79,7 +79,8 @@ public void testCriteriaQuery(EntityManagerFactoryScope scope) {
 
 					// the child
 					List<PrimaryObject> resultList = entityManager.createQuery( query ).getResultList();
-					assertThat( resultList.size() ).isEqualTo( 0 );
+					// @SQLRestriction should not be applied when joining FK association
+					assertThat( resultList.size() ).isEqualTo( 1 );
 				}
 		);
 	}
@@ -124,7 +125,8 @@ public void testCriteriaQuery2(EntityManagerFactoryScope scope) {
 									root.get( "child" ).get( "data" ), DELETED_CHILD ) );
 
 					List<PrimaryObject> resultList = entityManager.createQuery( query ).getResultList();
-					assertThat( resultList.size() ).isEqualTo( 0 );
+					// @SQLRestriction should not be applied when joining FK association
+					assertThat( resultList.size() ).isEqualTo( 1 );
 
 					builder = entityManager.getCriteriaBuilder();
 					query = builder.createQuery( PrimaryObject.class );