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/ExistsProjectionSpecificationImpl.java:41

import java.util.Collections;
import java.util.List;
import java.util.Map;

/**
 * @author Gavin King
 */
public class ExistsProjectionSpecificationImpl<T> implements SimpleProjectionSpecification<T,Boolean>, JpaTypedQueryReference<Boolean> {

	private final SelectionSpecification<T> selectionSpecification;

	public ExistsProjectionSpecificationImpl(@Nonnull SelectionSpecification<T> specification) {
		this.selectionSpecification = specification;
	}

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

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

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

View on GitHub (pinned to fad1729dce)

Solutions

1. This exists-projection specification operation is not supported yet. Use an explicit exists subquery instead.

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/cae6489e2254db9c. Report an issue: GitHub.