hibernate/hibernate-orm · error · UnsupportedOperationException

Function root does not have an entity type. Use getReference

Error message

Function root does not have an entity type. Use getReferencedPathSource() instead.

What it means

SqmFunctionRoot is a query root derived from a function call (Hibernate 7 function roots / set-returning functions in the FROM clause). It has no entity metamodel identity, so the JPA Root.getModel() contract, which promises an SqmEntityDomainType, throws UnsupportedOperationException; the message points you to getReferencedPathSource() (also exposed as getResolvedModel()) for the actual path source.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/query/sqm/tree/spi/domain/SqmFunctionRoot.java:99

		final SqmPathSource<?> pathSource =
				function.getType().getSubPathSource( CollectionPart.Nature.INDEX.getName() );
		//noinspection unchecked
		final SqmPathSource<Long> indexPathSource = (SqmPathSource<Long>) pathSource;
		return resolvePath( indexPathSource.getPathName(), indexPathSource );
	}

	@Override
	public <X> X accept(SemanticQueryWalker<X> walker) {
		return walker.visitRootFunction( this );
	}

	// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	// JPA

	@Nonnull
	@Override
	public SqmEntityDomainType<E> getModel() {
		throw new UnsupportedOperationException( "Function root does not have an entity type. Use getReferencedPathSource() instead." );
	}

	@Override
	public String getEntityName() {
		throw new UnsupportedOperationException( "Function root does not have an entity type. Use getReferencedPathSource() instead." );
	}

	@Override
	public SqmPathSource<E> getResolvedModel() {
		return getReferencedPathSource();
	}

	@Override
	@Nonnull
	public SqmCorrelatedRoot<E> createCorrelation() {
		throw new UnsupportedOperationException();
	}

View on GitHub (pinned to fad1729dce)

Solutions

1. Replace getModel() with getResolvedModel()/getReferencedPathSource(), which works for both entity and function roots
2. Guard generic code: if (root instanceof SqmFunctionRoot) skip entity-specific handling such as getModel()/getEntityName()
3. If you truly need the entity type, obtain it from the function's return type (referenced path source's path type) instead

Example fix

// before
SqmRoot<?> root = ...; // may be a function root
String name = root.getModel().getHibernateEntityName(); // throws on SqmFunctionRoot

// after
if (root instanceof SqmFunctionRoot<?> fr) {
    SqmPathSource<?> src = fr.getReferencedPathSource(); // no entity metamodel exists
} else {
    String name2 = root.getModel().getHibernateEntityName();
}

static SqmPathSource<?> referencedSource(SqmRoot<?> root) {
    // works for entity roots and function roots alike
    return root instanceof SqmFunctionRoot<?> fr
        ? fr.getReferencedPathSource()
        : root.getModel();
}

try {
    SqmEntityDomainType<?> t = root.getModel();
} catch (UnsupportedOperationException e) {
    // function root has no entity type: fall back to getReferencedPathSource()
    SqmPathSource<?> src = ((SqmFunctionRoot<?>) root).getReferencedPathSource();
}

When it happens

Trigger: Calling getModel() on a root created for a function in the FROM clause, e.g. 'from unnest(...) u' / json_table roots, through generic criteria-inspection code, query transformers, or libraries that assume every SqmRoot is entity-backed.

Common situations: Spring Data JPA / Blaze-Persistence / reporting tooling calling getModel() or getEntityName() on arbitrary roots; custom query copy/rewrite utilities iterating over query roots; adoption of Hibernate 7 function roots in codebases with generic criteria infrastructure.

Related errors

• MappedSuperclassType cannot be used to create an SqmPath - t
• LHS cannot be null for a sub-navigable reference - {}
• Not correlated
• Could not interpret attribute '%s' of basic-valued path '%s'
• Boolean expression does not support max()

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/bc9a15208e4d5b7e. Report an issue: GitHub.