hibernate groupby

Question

我想知道如何在hibernate中創建groupby。 我的代碼如下，但它不能正常工作，請告訴我如何做到這一點：

Session session = getSession(); 
Criteria c = session.createCriteria(CardLog.class); 
c.add(Restrictions.ge(CARD_PUNCHING_TIME, todaysDate)); 
c.setProjection(Projections.groupProperty(USER_ID)); 
c.addOrder(Order.desc(USER_ID)); 
cardLogList = c.list();     
System.out.println("----------------" + cardLogList); 

Answer 1

我認爲你必須使用類似這樣的

Session session = getSession(); 
Criteria c = session.createCriteria(CardLog.class); 
c.add(Restrictions.ge("bean property todaydate", todaysDate)); 
c.setProjection(Projections.groupProperty("bean property userId")); 
c.addOrder(Order.desc("bean property userId")); 
cardLogList = c.list();     
System.out.println("----------------" + cardLogList);