Named JPQL Query and Native SQL Query produce different SUMs

Question

i'm dealing with the following scenario:

The Entity Class:

@NamedQuery(
    name = "Table.getSum",
    query = "SELECT SUM(s.price) FROM Table s WHERE 
        (s.openingDate >= :openingDate AND s.closingDate <= :closingDate)"
)

The EJB:

    Calendar openingDate = new GregorianCalendar(year, 1, 1, 0, 0, 0);
    Calendar closingDate = new GregorianCalendar(year, 12, 31, 23, 59, 59);

    BigDecimal salePriceSum = em.createNamedQuery("Table.getSum", BigDecimal.class)
            .setParameter("openingDate", openingDate)
            .setParameter("closingDate", closingDate)
            .getSingleResult();

The native SQL Query:

SELECT SUM(price) FROM Table WHERE openingDate >= 'YYYY-01-01T00:00:00' AND closingDate <= 'YYYY-12-31T23:59:59'

But the two sums are of by a significant amount. That drives me crazy. How can that be?

I'm using hibernate 4.3.7 with wildfly 8.2.0 and the current mariadb on centos 7.

Thank you very much for any suggestion.

Answer 1

month parameter in the constructor for GregorianCalendar is zero-based, that probably is messing up your results. From the docs:

month - the value used to set the MONTH calendar field in the calendar. Month value is 0-based. e.g., 0 for January.