hibernate/hibernate-orm · error · IllegalOutputTypeException

Cannot treat ResultSetOutput as UpdateCountOutput

Error message

Cannot treat ResultSetOutput as UpdateCountOutput

What it means

Error "Cannot treat ResultSetOutput as UpdateCountOutput" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/procedure/ResultSetOutput.java:26

/// Models a [java.sql.ResultSet] as an Output.
///
/// @author Steve Ebersole
public interface ResultSetOutput<T> extends Output {
	/// Consume the underlying [java.sql.ResultSet] and return the resulting List.
	List<T> getResultList();

	/// Consume the underlying [java.sql.ResultSet] with the expectation that there is just a single result.
	Object getSingleResult();

	@Override
	default ResultSetOutput<?> asResultSetOutput() {
		return this;
	}

	@Override
	default UpdateCountOutput asUpdateCountOutput() {
		throw new IllegalOutputTypeException( "Cannot treat ResultSetOutput as UpdateCountOutput" );
	}
}

View on GitHub (pinned to fad1729dce)

Solutions

1. Check the output type before casting: use outputs.getCurrent() instanceof UpdateCountOutput.
2. Consume result-set outputs before expecting an update count.

When it happens

Trigger: An API operation is invoked on an object that does not support it.

Common situations: Using query/procedure/proxy APIs beyond their supported feature set (e.g. scrolling, locking, unwrapping a procedure call).

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/edfa7fbefb075803. Report an issue: GitHub.