hibernate/hibernate-orm · error · IllegalArgumentException

Unsupported aggregate SQL type: {}

Error message

Unsupported aggregate SQL type: {}

What it means

Error "Unsupported aggregate SQL type: {}" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/dialect/aggregate/SQLServerAggregateSupport.java:201

								"cast('<Collection>'+cast(" + xmlColumn + XML_QUERY_SEPARATOR + parentXmlPartExpression + "/" + columnExpression + "/*') as nvarchar(max))+'</Collection>' as xml)"
						);
					case BINARY:
					case VARBINARY:
					case LONG32VARBINARY:
					case BLOB:
						// We encode binary data as hex, so we have to decode here
						return template.replace(
								placeholder,
								"convert(" + getCastTypeName( column, typeConfiguration ) + "," + xmlColumn + ".value('(" + parentXmlPartExpression + "/" + columnExpression + "/text())[1]','nvarchar(max)'),2)"
						);
					default:
						return template.replace(
								placeholder,
								xmlColumn + ".value('(" + parentXmlPartExpression + "/" + columnExpression + "/text())[1]','" + getCastTypeName( column, typeConfiguration ) + "')"
						);
				}
		}
		throw new IllegalArgumentException( "Unsupported aggregate SQL type: " + aggregateColumnTypeCode );
	}

	@Override
	public String aggregateComponentAssignmentExpression(
			String aggregateParentAssignmentExpression,
			String columnExpression,
			int aggregateColumnTypeCode,
			Column column) {
		switch ( aggregateColumnTypeCode ) {
			case JSON:
			case JSON_ARRAY:
				if ( jsonSupportLevel == JsonSupportLevel.NONE ) {
					break;
				}
			case SQLXML:
			case XML_ARRAY:
				// For JSON/XML we always have to replace the whole object
				return aggregateParentAssignmentExpression;

View on GitHub (pinned to fad1729dce)

Solutions

1. Map the aggregate column with a supported SQL type (JSON).
2. Avoid the unsupported aggregate type on SQL Server.

When it happens

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

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 (SQL Server).

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/473aaf1998492330. Report an issue: GitHub.