hibernate/hibernate-orm · error · IllegalArgumentException

Unrecognized member mapping type: {}

Error message

Unrecognized member mapping type: {}

What it means

Error "Unrecognized member mapping type: {}" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/query/results/internal/jpa/EntityBuilder.java:113

				if ( !identifierFetchHandler.handleMember( embeddedMapping ) ) {
					if ( attributeMapping instanceof EmbeddableValuedModelPart modelPart ) {
						attributeFetchBuilders.put(
								embeddedMapping.name(),
								new CompleteFetchBuilderEmbeddableValuedModelPart(
										rootPath.append( attributeMapping.getPartName() ),
										modelPart,
										extractColumnNames( embeddedMapping, modelPart )
								)
						);
					}
					else {
						throw new IllegalArgumentException( "Not an embedded attribute: "
								+ attributeMapping.getNavigableRole().getFullPath() );
					}
				}
			}
			else {
				throw new IllegalArgumentException( "Unrecognized member mapping type: "
							+ memberMapping.getClass().getName() );
			}
		}

		this.identifierFetchBuilder = identifierFetchHandler.buildFetchBuilder();
	}

	private static List<String> extractColumnNames(
			EmbeddedMapping<?, ?> embeddedMapping,
			EmbeddableValuedModelPart modelPart) {
		final var columnNames = new String[modelPart.getJdbcTypeCount()];
		collectColumnNames( embeddedMapping, modelPart.getEmbeddableTypeDescriptor(), 0, columnNames );
		for ( int i = 0; i < columnNames.length; i++ ) {
			if ( columnNames[i] == null ) {
				throw new IllegalArgumentException(
						"No column name specified for embedded attribute selectable: "
								+ modelPart.getSelectable( i ).getSelectableName()
				);

View on GitHub (pinned to fad1729dce)

Solutions

1. The member mapping type is not recognized. Use a supported member mapping (column, formula, ...).

When it happens

Trigger: A JPA result mapping for an embedded/identifier attribute is invalid: Unrecognized member mapping type: <value>

Common situations: @SqlResultSetMapping/@MappingElement definitions referencing non-embedded attributes, missing column names, or duplicate member mappings.

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/8f395d0c53ff9df4. Report an issue: GitHub.