hibernate/hibernate-orm · error · IllegalStateException

JSON not supported!

Error message

JSON not supported!

What it means

Error "JSON not supported!" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/dialect/aggregate/OracleAggregateSupport.java:433

				return aggregateParentAssignmentExpression + "." + columnExpression;
		}
		throw new IllegalArgumentException( "Unsupported aggregate SQL type: " + aggregateColumnTypeCode );
	}

	private String jsonCustomWriteExpression(
			String customWriteExpression,
			SelectableMapping column,
			TypeConfiguration typeConfiguration) {
		switch ( jsonSupport ) {
			case OSON:
			case MERGEPATCH:
			case QUERY_AND_PATH:
			case QUERY:
				StringBuilderSqlAppender sqlAppender = new StringBuilderSqlAppender();
				appendJsonWriteExpression( sqlAppender, () -> sqlAppender.appendSql( customWriteExpression ), column.getJdbcMapping(), typeConfiguration );
				return sqlAppender.toString();
		}
		throw new IllegalStateException( "JSON not supported!" );
	}

	public void appendJsonWriteExpression(
			SqlAppender sqlAppender,
			Runnable renderFunction,
			JdbcMapping jdbcMapping,
			TypeConfiguration typeConfiguration) {
		final int sqlTypeCode = jdbcMapping.getJdbcType().getDefaultSqlTypeCode();
		switch ( sqlTypeCode ) {
			case CLOB:
				sqlAppender.append( "to_clob(" );
				renderFunction.run();
				sqlAppender.append( ")" );
				break;
			case UUID:
				sqlAppender.append( "regexp_replace(lower(rawtohex(" );
				renderFunction.run();
				sqlAppender.append( ")),'^(.{8})(.{4})(.{4})(.{4})(.{12})$','\\1-\\2-\\3-\\4-\\5')" );

View on GitHub (pinned to fad1729dce)

Solutions

1. Enable JSON support / upgrade Oracle.
2. Avoid JSON aggregate mappings.

When it happens

Trigger: Triggered when the application calls a Hibernate dialect feature that the configured database dialect cannot provide: JSON not supported!.

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: JSON not supported!.

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/0b90bd0c35543198. Report an issue: GitHub.