What causes "Tuple size mismatch" in hibernate/hibernate-orm?

Fix the query so both tuple sides have the same number of elements

hibernate/hibernate-orm · error · IllegalArgumentException

Tuple size mismatch

Error message

Tuple size mismatch

What it means

Because IRIS lacks row-value constructor syntax, InterSystemsIRISSqlAstTranslator.emulateTupleComparisonSelections() expands a tuple comparison such as (a, b) = (x, y) into component-wise AND/OR expressions. It first asserts the left-hand select items and right-hand tuple have the same arity; a mismatch throws IllegalArgumentException('Tuple size mismatch') during SQL generation.

Source

Thrown at hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/InterSystemsIRISSqlAstTranslator.java:81

		if ( operator == ComparisonOperator.EQUAL || operator == ComparisonOperator.NOT_EQUAL ) {
			emulateTupleComparisonSelections( lhsSelections, rhsTuple, operator );
		}
		else {

			super.renderTupleComparisonStandard( lhsSelections, rhsTuple, operator );
		}
	}

	@SuppressWarnings("unchecked")
	protected void emulateTupleComparisonSelections(
			List<SqlSelection> lhsSelections,
			SqlTuple rhsTuple,
			ComparisonOperator operator
	) {
		final List<Expression> rhsExpressions = (List<Expression>) rhsTuple.getExpressions();

		if ( lhsSelections.size() != rhsExpressions.size() ) {
			throw new IllegalArgumentException( "Tuple size mismatch" );
		}

		final String joiner = ( operator == ComparisonOperator.EQUAL ) ? " and " : " or ";

		appendSql( OPEN_PARENTHESIS );
		for ( int i = 0; i < lhsSelections.size(); i++ ) {
			if ( i > 0 ) {
				appendSql( joiner );
			}

			lhsSelections.get( i ).getExpression().accept( this );
			appendSql( operator.sqlText() );
			rhsExpressions.get( i ).accept( this );
		}
		appendSql( CLOSE_PARENTHESIS );
	}

	@Override

View on GitHub (pinned to fad1729dce)

Solutions

Fix the query so both tuple sides have the same number of elements
Replace the tuple comparison with explicit scalar comparisons combined by AND/OR
If your query looks valid, upgrade Hibernate — a tuple reaching this code with mismatched arity is worth reporting as a bug with a reproducer

Example fix

// before - arity mismatch (3 vs 2)
"select o from Order o where (o.a, o.b, o.c) = (1, 2)"

// after - match arity, or compare scalars explicitly
"select o from Order o where (o.a, o.b, o.c) = (1, 2, 3)"
// or
"select o from Order o where o.a = 1 and o.b = 2 and o.c = 3"

Defensive patterns

Strategy: try-catch

Validate before calling

// before executing, check tuple arity in the predicate you build
int columns = 2; // e.g. composite id parts
if ( values.size() != columns ) {
    throw new IllegalArgumentException(
        "tuple comparison arity mismatch: " + columns + " vs " + values.size());
}
Predicate p = cb.equal(cb.tuple(root.get("a"), root.get("b")), cb.tuple(...));

Try / catch

try {
    return session.createQuery(hql).getResultList();
} catch (IllegalArgumentException e) {
    if ( "Tuple size mismatch".equals(e.getMessage()) ) {
        // fix the literal list length to match the tuple and rebuild the query
    }
    throw e;
}

Prevention

Build tuple comparisons programmatically so both sides are zipped from one source list
Prefer explicit AND-ed scalar comparisons over row-value syntax on dialects without row constructors
Add unit tests for dynamic predicate builders that assemble tuple literals

When it happens

Trigger: An HQL tuple/row-value comparison whose sides have different arity on the IRIS dialect, e.g. '(e.a, e.b, e.c) = (1, 2)' or comparing a composite-id tuple against a list of the wrong length — a condition that should normally be rejected earlier by SQM validation but slips through to the IRIS-specific emulation.

Common situations: Hand-written tuple predicates with mismatched literals; dynamic query builders that zip columns and values from different sources; Hibernate version mismatches where an arity bug in SQM validation lets the query reach the translator.

Related errors

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/b634ba40f0628bb8. Report an issue: GitHub.