hibernate/hibernate-orm · error · MappingException

Mixed inheritance strategies not supported

Error message

Mixed inheritance strategies not supported

What it means

Error "Mixed inheritance strategies not supported" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/boot/model/source/internal/hbm/EntityHierarchySourceImpl.java:366

	}

	@Override
	public InheritanceType getHierarchyInheritanceType() {
		return hierarchyInheritanceType;
	}

	@Override
	public RootEntitySourceImpl getRoot() {
		return rootEntitySource;
	}

	public void processSubclass(SubclassEntitySourceImpl subclassEntitySource) {
		final InheritanceType inheritanceType = Helper.interpretInheritanceType( subclassEntitySource.jaxbEntityMapping() );
		if ( hierarchyInheritanceType == InheritanceType.NO_INHERITANCE ) {
			hierarchyInheritanceType = inheritanceType;
		}
		else if ( hierarchyInheritanceType != inheritanceType ) {
			throw new MappingException( "Mixed inheritance strategies not supported", subclassEntitySource.getOrigin() );
		}

		collectedEntityNames.add( subclassEntitySource.getEntityNamingSource().getEntityName() );
	}


	protected JaxbHbmRootEntityType entityElement() {
		return rootEntitySource.jaxbEntityMapping();
	}

	@Override
	public IdentifierSource getIdentifierSource() {
		return identifierSource;
	}

	@Override
	public VersionAttributeSource getVersionAttributeSource() {
		return versionAttributeSource;

View on GitHub (pinned to fad1729dce)

Solutions

1. Use a single inheritance strategy (table-per-class, joined, or union-subclass) throughout the entity hierarchy in the hbm.xml mappings.

Example fix

Use a single inheritance strategy (table-per-class, joined, or union-subclass) throughout the entity hierarchy in the hbm.xml mappings.

When it happens

Trigger: An hbm.xml / orm.xml mapping document violates a mapping rule during bootstrap.

Common situations: Legacy XML mappings with invalid combinations (column+formula, mixed inheritance, missing identifiers, bad extends references).

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/0a14530b41318402. Report an issue: GitHub.