hibernate/hibernate-orm · error · UnsupportedOperationException

Temporal unit not supported [{}]

Error message

Temporal unit not supported [{}]

What it means

DateTruncEmulation (used by TruncFunction when the dialect lacks native date_trunc) formats the datetime with format() and pads the trailing components; it implements only YEAR, MONTH, DAY, HOUR, MINUTE and SECOND. Requesting any other TemporalUnit — WEEK, QUARTER, MILLISECOND, EPOCH, NATIVE... — hits the default branch and throws UnsupportedOperationException at query compilation.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/dialect/function/DateTruncEmulation.java:102

				break;
			case DAY:
				pattern = "yyyy-MM-dd";
				literal = " 00:00:00";
				break;
			case HOUR:
				pattern = "yyyy-MM-dd HH";
				literal = ":00:00";
				break;
			case MINUTE:
				pattern = "yyyy-MM-dd HH:mm";
				literal = ":00";
				break;
			case SECOND:
				pattern = "yyyy-MM-dd HH:mm:ss";
				literal = null;
				break;
			default:
				throw new UnsupportedOperationException( "Temporal unit not supported [" + temporalUnit + "]" );
		}
		final var datetime = arguments.get( 0 );
		final var formatExpression =
				queryEngine.getSqmFunctionRegistry()
						.getFunctionDescriptor( "format" )
						.generateSqmExpression(
								asList(
										datetime,
										new SqmFormat( pattern, nodeBuilder.getStringType(), nodeBuilder )
								),
								null,
								queryEngine
						);
		final SqmExpression<?> formattedDatetime;
		if ( literal != null ) {
			formattedDatetime =
					queryEngine.getSqmFunctionRegistry()
							.getFunctionDescriptor( "concat" )

View on GitHub (pinned to fad1729dce)

Solutions

1. Use one of the supported units (YEAR, MONTH, DAY, HOUR, MINUTE, SECOND)
2. Compute week/quarter truncation differently: e.g. arithmetic on extract(year/month) or a native query for that DB
3. Extend the dialect: subclass and register a custom date_trunc/trunc descriptor that renders week/quarter SQL for your database

Example fix

// before (HANA / emulated date_trunc)
session.createQuery("select trunc(e.ts, WEEK) from Event e"); // -> UnsupportedOperationException

// after
session.createQuery("select trunc(e.ts, DAY) from Event e"); // supported unit

Set<TemporalUnit> SUPPORTED = EnumSet.of(YEAR, MONTH, DAY, HOUR, MINUTE, SECOND);
if (!SUPPORTED.contains(unit) && dialectLacksNativeDateTrunc(dialect)) {
    throw new IllegalArgumentException("date_trunc unit " + unit + " unsupported on " + dialect);
}

boolean isEmulationSupportedUnit(TemporalUnit u) {
    return u == YEAR || u == MONTH || u == DAY || u == HOUR || u == MINUTE || u == SECOND;
}

catch (UnsupportedOperationException e) {
    // fall back to a native query for exotic units on this dialect
    return runNativeWeekTruncation(session, ts);
}

When it happens

Trigger: HQL like 'select trunc(e.ts, WEEK)' or date_trunc('week', ts) emulation on a dialect using DateTruncEmulation; extract/trunc with temporal units such as quarter, millisecond, or week on those dialects (commonly SAP HANA, which routes TruncFunction through toDateFunction emulation).

Common situations: Writing portable HQL on PostgreSQL (week works natively) and running the same query on HANA/other DB in CI or production; upgrading Hibernate and having previously-ignored units now validated strictly.

Related errors

• Unrecognized field:
• unrecognized field: {unit}
• Unrecognized field: {unit}
• Emulation of function chr() supports only integer literals,
• NATIVE is not a legal field for extract()

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/c086f4e4ece9abd1. Report an issue: GitHub.