hibernate/hibernate-orm · error · IllegalArgumentException

null key for collection: {}

Error message

null key for collection: {}

What it means

Error "null key for collection: {}" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/persister/collection/mutation/AuditCollectionRowMutationHelper.java:62

		this.auditTableName = auditTableName;
		this.changesetIdMapping = changesetIdMapping;
		this.modificationTypeMapping = modificationTypeMapping;
		this.indexColumnIsSettable = indexColumnIsSettable;
		this.elementColumnIsSettable = elementColumnIsSettable;
		this.indexIncrementer = indexIncrementer;
		this.useServerTransactionTimestamps = useServerTransactionTimestamps;
	}

	void bindInsertValues(
			PersistentCollection<?> collection,
			Object key,
			Object rowValue,
			int rowPosition,
			ModificationType modificationType,
			SharedSessionContractImplementor session,
			JdbcValueBindings jdbcValueBindings) {
		if ( key == null ) {
			throw new IllegalArgumentException( "null key for collection: " + mutationTarget.getRolePath() );
		}

		decomposeRowIdentity(
				collection,
				key,
				rowValue,
				rowPosition,
				session,
				jdbcValueBindings,
				ParameterUsage.SET
		);

		if ( !useServerTransactionTimestamps ) {
			jdbcValueBindings.bindValue(
					session.getCurrentChangesetIdentifier(),
					auditTableName,
					changesetIdMapping.getSelectionExpression(),
					ParameterUsage.SET

View on GitHub (pinned to fad1729dce)

Solutions

1. Ensure the collection's owner entity is loaded and its key is set before triggering collection row mutation (e.g. do not flush orphan audit collections).

When it happens

Trigger: Thrown when mutating an audit collection row with a null collection key, indicating the owner entity has no identifier value.

Common situations: See trigger scenarios.

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/36c9947294e10a7e. Report an issue: GitHub.