hibernate/hibernate-orm · error · MappingException

Association [%s] for entity [%s] references unmapped class [

Error message

Association [%s] for entity [%s] references unmapped class [%s]

What it means

Error "Association [%s] for entity [%s] references unmapped class [%s]" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/boot/model/internal/CollectionBinder.java:1633

	 */
	protected void bindOneToManySecondPass(Map<String, PersistentClass> persistentClasses) {
		if ( property == null ) {
			throw new AssertionFailure( "Null property" );
		}

		logOneToManySecondPass();

		final var oneToMany =
				new org.hibernate.mapping.OneToMany( buildingContext, getCollection().getOwner() );
		collection.setElement( oneToMany );
		oneToMany.setReferencedEntityName( getElementType().getName() );
		oneToMany.setNotFoundAction( notFoundAction );

		final String referencedEntityName = oneToMany.getReferencedEntityName();
		final var associatedClass = persistentClasses.get( referencedEntityName );
		handleJpaOrderBy( collection, associatedClass );
		if ( associatedClass == null ) {
			throw new MappingException(
					String.format( "Association [%s] for entity [%s] references unmapped class [%s]",
							propertyName, propertyHolder.getClassName(), referencedEntityName )
			);
		}
		oneToMany.setAssociatedClass( associatedClass );

		final var joins = getMetadataCollector().getJoins( referencedEntityName );
		foreignJoinColumns.setPropertyHolder( buildPropertyHolder(
				associatedClass,
				joins,
				foreignJoinColumns.getBuildingContext(),
				inheritanceStatePerClass
		) );
		foreignJoinColumns.setJoins( joins );
		final var collectionTable =
				foreignJoinColumns.hasMappedBy()
						? associatedClass.getRecursiveProperty( foreignJoinColumns.getMappedBy() )
								.getValue().getTable()

View on GitHub (pinned to fad1729dce)

Solutions

1. Map the referenced class as an entity (add @Entity and include it in the persistence unit).
2. Or fix the association target to an already-mapped class.

When it happens

Trigger: An association or reference targets a type that Hibernate has not mapped as an entity.

Common situations: Missing @Entity on the target class, the class not being scanned into the persistence unit, or a typo in the entity name.

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/378e308137ca322d. Report an issue: GitHub.