hibernate/hibernate-orm · error · HibernateException

merge requested with id not matching id of passed entity

Error message

merge requested with id not matching id of passed entity

What it means

Error "merge requested with id not matching id of passed entity" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/event/internal/DefaultMergeEventListener.java:561

		else {
			return target;
		}
	}

	@Nullable
	private static Object getDetachedEntityId(
			@Nonnull MergeEvent event,
			@Nullable Object originalId,
			@Nonnull EntityPersister persister) {
		final var source = event.getSession();
		final Object id = event.getRequestedId();
		if ( id == null ) {
			return originalId;
		}
		else {
			// check that entity id = requestedId
			if ( !persister.getIdentifierType().isEqual( id, originalId, source.getFactory() ) ) {
				throw new HibernateException( "merge requested with id not matching id of passed entity" );
			}
			return id;
		}
	}

	@Nonnull
	private static Object unproxyManagedForDetachedMerging(
			@Nonnull Object incoming,
			@Nonnull Object managed,
			@Nonnull EntityPersister persister,
			@Nonnull EventSource source) {
		if ( isHibernateProxy( managed ) ) {
			return assertInitialized( managed );
		}

		if ( isPersistentAttributeInterceptable( incoming )
				&& persister.getBytecodeEnhancementMetadata().isEnhancedForLazyLoading() ) {

View on GitHub (pinned to fad1729dce)

Solutions

1. Do not change the id of the entity being merged to a value different from the one requested.
2. Pass the entity whose id matches the id used to look up the managed copy.

When it happens

Trigger: Thrown when a merge is explicitly given an id that differs from the id of the passed entity instance.

Common situations: Typical situations: copy/paste of ids between entities; wrong entity passed together with an id from another instance.

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/df9912fda0b3ddaa. Report an issue: GitHub.