hibernate/hibernate-orm · error · NonUniqueResultException

Query did not return a unique result: " + resultCount + " re

Error message

Query did not return a unique result: " + resultCount + " results were returned

What it means

Error "Query did not return a unique result: " + resultCount + " results were returned" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/query/ResultListTransformer.java:68

	 * {@link NonUniqueResultException} otherwise.
	 *
	 * @param <T> The result list element type
	 *
	 * @since 7.3
	 */
	static <T> ResultListTransformer<T> uniqueResultTransformer() {
		return resultList ->
				switch ( resultList.size() ) {
					case 0, 1 -> resultList;
					default -> {
						final var first = resultList.get( 0 );
						for ( int i = 1; i < resultList.size(); i++ ) {
							final T current = resultList.get( i );
							if ( !Objects.equals( first, current )
									// also consider case of multiple select items in an Object[]
									&& !( first instanceof Object[] array
											&& !Arrays.equals( array, (Object[]) current ) ) ) {
								throw new NonUniqueResultException( resultList.size() );
							}
						}
						yield List.of( first );
					}
				};
	}
}

View on GitHub (pinned to fad1729dce)

Solutions

1. Add restricting criteria so the query returns at most one row.
2. Use getResultList() if multiple results are valid.

When it happens

Trigger: A runtime precondition of the Hibernate API is violated.

Common situations: Occurs when application code or configuration does not satisfy the documented contract of the API being called.

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/efdd472a33616e0e. Report an issue: GitHub.