hibernate/hibernate-orm · error · UnsupportedOperationException

This is not supported yet!

Error message

This is not supported yet!

What it means

Error "This is not supported yet!" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/query/specification/internal/ProjectionSpecificationImpl.java:69

	@Override
	public <X> Element<X> select(@Nonnull SingularAttribute<T, X> attribute) {
		final int position = specifications.size();
		specifications.add( (select, root) -> root.get( attribute ) );
		return tuple -> cast( attribute.getJavaType(), tuple[position] );
	}

	@Nonnull
	@Override
	public <X> Element<X> select(@Nonnull Path<T, X> path) {
		final int position = specifications.size();
		specifications.add( (select, root) -> (SqmPath<X>) path.path( root ) );
		return tuple -> cast( path.getType(), tuple[position] );
	}

	@Nonnull
	@Override
	public QuerySpecification<Object[]> restrict(@Nonnull Restriction<? super Object[]> restriction) {
		throw new UnsupportedOperationException( "This is not supported yet!" );
	}

	@Nonnull
	@Override
	public SelectionQuery<Object[]> createQuery(@Nonnull EntityHandler entityHandler) {
		return entityHandler.unwrap( SharedSessionContract.class )
				.createQuery( buildCriteria( entityHandler.getCriteriaBuilder() ) );
	}

	@Nonnull
	@Override
	public CriteriaQuery<Object[]> buildCriteria(@Nonnull CriteriaBuilder builder) {
		var impl = (SelectionSpecificationImpl<T>) selectionSpecification;
		// TODO: handle HQL, existing criteria
		final var tupleQuery =
				(SqmSelectStatement<Object[]>)
						builder.createQuery(Object[].class);
		final var root = tupleQuery.from( impl.getResultType() );

View on GitHub (pinned to fad1729dce)

Solutions

1. This projection specification operation is not supported yet. Use an explicit projection query.

When it happens

Trigger: A code path that Hibernate has not implemented is exercised: This is not supported yet!

Common situations: Using newer/edge API features (certain projections, specifications, fetch mementos, composite-path native mappings, null keys in key-based pagination) that are present but not yet implemented.

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/1f33931d5e5693bd. Report an issue: GitHub.