JPAQueryFactory NVL function

Question

I am using this JPAQueryFactory .select to get the data

queryFactory.select(
            Projections.bean(detailDTO.class,
                    qEmpcate.id,
                    qEmcate.date.as("completeDate"),
                    qEmpcate.status,                       
                    qCete_name
                   ))
            .from(qEmpcate)
            .leftJoin(qCete).on(qCete.id.eq(qEmpcate.cete_id))
            .fetch();

complete date is sometimes NULL and it causes error in other components. In SQL I would fix it simply by using something like NVL(qEmcate.date,'') but I am quite new to JPAQueryFactory (Spring boot in general) and I realized it wouldnt be that easy. JPAQueryFactory doesnt recognize NVL and COALESCE is not working for me. Is there any other function in JPAQueryFactory that replaces NULL values with some String ?

Thank you for help.