第一种是使用高级查询DetachedCriteria实现,代碼如下:
String alias = "user_"; //查詢時的table別名 DetachedCriteria dc = DetachedCriteria.forClass(User.class,alias); ProjectionList pList = Projections.projectionList(); pList.add(Projections.property(alias + "." + "id").as("id")); pList.add(Projections.property(alias + "." + "name").as("name")); pList.add(Projections.property(alias + "." + "age").as("age")); pList.add(Projections.property(alias + "." + "sex").as("sex")); dc.setProjection(pList); dc.setResultTransformer(Transformers.aliasToBean(User.class)); resultList = memberService.findByDetached(dc).size();
通過HQL语句查询
String hql = "select new Link(id,name) from Link"; Query query = session.createQuery(hql); //默认查询出来的list里存放的是一个Object对象,但是在这里list里存放的不再是默认的Object对象了,而是Link对象了 List<Link> links = query.list(); for(Link link : links){ String id = link.getId(); String name = link.getName(); System.out.println(id + " : " + name); }
第三种方式是通过HQL语句实现,类似SQL,方法如下:
String hql = "select id,name from Link"; Query query = session.createQuery(hql); //默认查询出来的list里存放的是一个Object数组,还需要转换成对应的javaBean。 List<Object[]> links = query.list(); for(Object[] link : links){ String id = link[0]; String name = link[1]; System.out.println(id + " : " + name); }