I'm trying to get a report using Criteria and ProjectionList, and I'm pretty new using this through hibernate. So I have this model:
private Long _userId;
private Category _category;
private Long _companyId;
private Double _amount;
private Date _date;
And I building the query using this:
public List sumPaymentsByUserCategoryPeriod(Category category, Long userId,Integer period){
GregorianCalendar from = new GregorianCalendar();
from.add(Calendar.MONTH, -period);
List<CategoryAmount> resultDTO= new ArrayList<CategoryAmount>();
Criteria criteria = getSession().createCriteria(Payment.class);
criteria.add(Restrictions.eq("_category", category));
criteria.add(Restrictions.eq("_userId",userId));
criteria.add(Restrictions.between("_date", from.getTime(), new Date()));
ProjectionList projectionList = Projections.projectionList();
projectionList.add(Projections.sum("_amount"));
projectionList.add(Projections.groupProperty("_date"));
criteria.setProjection(projectionList);
return criteria.list();
}
Basically this method receive a Category and a userId to filter the payments records and a period, who will indicate how many months from now to back I want to sum. How can I get the sum result grouped by months?
Any help or tip I'll appreciate it!