hibernate/hibernate-orm · error · UnsupportedOperationException

"Dialect does not support aggregateCustomWriteExpressionRend

Error message

"Dialect does not support aggregateCustomWriteExpressionRenderer: " + getClass().getName()

What it means

Error ""Dialect does not support aggregateCustomWriteExpressionRenderer: " + getClass().getName()" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/dialect/aggregate/AggregateSupportImpl.java:78

	@Override
	public boolean preferSelectAggregateMapping(int aggregateSqlTypeCode) {
		// By default, assume the driver supports this and prefer selecting the aggregate column
		return true;
	}

	@Override
	public boolean preferBindAggregateMapping(int aggregateSqlTypeCode) {
		// By default, assume the driver supports this and prefer binding the aggregate column
		return true;
	}

	@Override
	public WriteExpressionRenderer aggregateCustomWriteExpressionRenderer(
			SelectableMapping aggregateColumn,
			SelectableMapping[] columnsToUpdate,
			TypeConfiguration typeConfiguration) {
		throw new UnsupportedOperationException( "Dialect does not support aggregateCustomWriteExpressionRenderer: " + getClass().getName() );
	}

	@Override
	public List<AuxiliaryDatabaseObject> aggregateAuxiliaryDatabaseObjects(
			Namespace namespace,
			String aggregatePath,
			AggregateColumn aggregateColumn,
			List<Column> aggregatedColumns) {
		return Collections.emptyList();
	}

	@Override
	public int aggregateComponentSqlTypeCode(int aggregateColumnSqlTypeCode, int columnSqlTypeCode) {
		return switch (aggregateColumnSqlTypeCode) {
			case JSON -> columnSqlTypeCode == ARRAY ? JSON_ARRAY : columnSqlTypeCode;
			case SQLXML -> columnSqlTypeCode == ARRAY ? XML_ARRAY : columnSqlTypeCode;
			default -> columnSqlTypeCode;
		};

View on GitHub (pinned to fad1729dce)

Solutions

1. Use a dialect with aggregate support.
2. Avoid custom aggregate mappings on this database.

When it happens

Trigger: Triggered when the application calls a Hibernate dialect feature that the configured database dialect cannot provide: Dialect does not support aggregateCustomWriteExpressionRenderer.

Common situations: Common when running against a database whose dialect lacks this capability, when a mapping or HQL/Criteria query requests unsupported functionality, or when the wrong dialect is configured for the database in use. Error: Dialect does not support aggregateCustomWriteExpressionRenderer.

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/5c28f2a11862fbda. Report an issue: GitHub.