I was trying to execute a JPA Criteria Query using Hibernate 6 calling the datediff function, but it seems that due to the cast to SqmDurationUnit in TimestampdiffFunction->TimestampdiffFunctionReturnTypeResolver I’m unable to supply a temporal unit that will be accepted.

Given an entityManager the following demonstrates it when it throws an exception with the failed cast:

CriteriaBuilder cb = entityManager.getCriteriaBuilder();
		
Expression<Long> dateDiffFunc = cb.function("DATEDIFF", Long.class, 
	criteriaBuilder.literal(TemporalUnit.MINUTE), criteriaBuilder.currentDate(), criteriaBuilder.currentDate());
		
CriteriaQuery<Long> cr = cb.createQuery(Long.class)
	.select(dateDiffFunc);
				
entityManager.createQuery(cr).getResultList();

Caused by: java.lang.ClassCastException: class org.hibernate.query.sqm.tree.expression.SqmLiteral cannot be cast to class org.hibernate.query.sqm.tree.expression.SqmDurationUnit
at org.hibernate.dialect.function.TimestampdiffFunction$TimestampdiffFunctionReturnTypeResolver.resolveFunctionReturnType(TimestampdiffFunction.java:133)