hibernate/hibernate-orm · error · IllegalArgumentException

"Unsupported aggregate SQL type: " + aggregateSqlTypeCode

Error message

"Unsupported aggregate SQL type: " + aggregateSqlTypeCode

What it means

Error ""Unsupported aggregate SQL type: " + aggregateSqlTypeCode" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/dialect/aggregate/H2AggregateSupport.java:195

	public boolean requiresAggregateCustomWriteExpressionRenderer(int aggregateSqlTypeCode) {
		switch ( aggregateSqlTypeCode ) {
			case JSON:
				return true;
		}
		return false;
	}

	@Override
	public WriteExpressionRenderer aggregateCustomWriteExpressionRenderer(
			SelectableMapping aggregateColumn,
			SelectableMapping[] columnsToUpdate,
			TypeConfiguration typeConfiguration) {
		final int aggregateSqlTypeCode = aggregateColumn.getJdbcMapping().getJdbcType().getDefaultSqlTypeCode();
		switch ( aggregateSqlTypeCode ) {
			case JSON:
				return jsonAggregateColumnWriter( aggregateColumn, columnsToUpdate );
		}
		throw new IllegalArgumentException( "Unsupported aggregate SQL type: " + aggregateSqlTypeCode );
	}

	private WriteExpressionRenderer jsonAggregateColumnWriter(
			SelectableMapping aggregateColumn,
			SelectableMapping[] columns) {
		return new RootJsonWriteExpression( aggregateColumn, columns );
	}

	interface JsonWriteExpression {
		void append(
				SqlAppender sb,
				String path,
				SqlAstTranslator<?> translator,
				AggregateColumnWriteExpression expression);
	}
	private static class AggregateJsonWriteExpression implements JsonWriteExpression {
		private final LinkedHashMap<String, JsonWriteExpression> subExpressions = new LinkedHashMap<>();

View on GitHub (pinned to fad1729dce)

Solutions

1. Map the aggregate with a supported SQL type.
2. Avoid the unsupported aggregate type on H2.

When it happens

Trigger: Triggered when the application calls a Hibernate dialect feature that the configured database dialect cannot provide: Unsupported aggregate SQL type (H2).

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: Unsupported aggregate SQL type (H2).

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/209cddd79341aa11. Report an issue: GitHub.