JPA Criteria API - Add days to DATE using ORACLE - oracle

Question

I'm trying to use JPA Criteria API to filter a date between a specific range.
The problem is that I don't have directly the date in my entity, I obtain the date using a date field and adding a number of days (which are in another field) to this date .
I look around and I saw some responses which recommends to calculate the date in java before pass it to criteria builder, but the problem is that I don't know the number of days to add because it depends on the days in a specific column of the table.
The simplified table OBJECT has a field CREATION_DATE of type date and EXPIRATION_DAYS which is a number. I want to filter by a range of possible expiration date, I get the expiration date of each element in OBJECT table adding EXPIRATION_DAYS to CREATION_DATE, the SQL query is:
select * from OBJECT
where CREATION_DATE + EXPIRATION_DAYS
between to_date('01/01/2018','dd/MM/yyyy') and to_date('01/02/2018','dd/MM/yyyy')
In CriteriaBuilder I make some attempts, but I think the best approach I try to use is the follow:
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Object> criteria = criteriaBuilder.createQuery(Object.class);
List<Predicate> predicates...
predicates.add(criteriaBuilder.between(
criteriaBuilder.function("AddDate", Date.class, Object.get("creationDate"), criteriaBuilder.literal("day"), Object.get("expirationDays")),
dateInit, dateEnd));
criteria.where(predicates.toArray(new Predicate[]{}));
...
TypedQuery<Object> query = entityManager.createQuery(criteria);
return query.getResultList();
I use function("addDate"...) method, the problem is that I thought JPA implementation translate "addDate" to specific database vendor but it's not, because it's throwing the following exception which is pretty clear:
javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.4.v20160829-44060b6): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLSyntaxErrorException: ORA-00904: "ADDDATE": invalid identifier
And the query trace:
(AddDate(t0.CREATION_DATE, ?, t0.EXPIRATION_DAYS) BETWEEN ? AND ?)).
How can I achieve this using ORACLE as a database? Or there is a better approach?

Answer 1

In Hibernate seems that there is the #Formula annotation which provides the functionality I'm looking for, however there is no such thing in JPA neither in specific implementation I'm using(eclipselink).
I want to avoid the necessity of declare a specific function, but unfortunately I do it this way, first I declare the function ADD_DAYS in Oracle as follows:
create or replace function ADD_DAYS(dateValue DATE, daysValue NUMBER)
return DATE is
begin
return dateValue + daysValue;
end;
Then I call this function using function method of criteriaBuilder, and passing as parameters the function name, the type of object returned by the oracle function, and the two arguments I define, the column with the date, and the column with the days to add:
criteriaBuilder.function("ADD_DAYS", Date.class, Object.get("creationDate"), Object.get("expirationDays"))