如何在hibernate投影结果上应用顺序

问题描述

  Criteria criteria = session.createCriteria（Student.class）; 
 ProjectionList projectionList = Projections.projectionList（）; 
 projectionList.add（Projections.groupProperty（studentId））; 
 projectionList.add（Projections.count（studentId））; 
 criteria.setProjection（projectionList）; 
 return criteria.list（）; 
  

这将返回一个对象列表，而对象有两个字段，studentId和count（studentId）。我想按count（studentId）降序排列这个列表。

目前我正在获取

  {[1,5]，[2,7]，[3,4]} 
  

我想要以获得它

  {[2,7]，[1,5]，[3,4]} 
  

解决方案：
解决了问题：

  Criteria criteria = session.createCriteria（Student.class）; 
 ProjectionList projectionList = Projections.projectionList（）; 
 projectionList.add（Projections.groupProperty（studentId））; 
 projectionList.add（Projections.alias（Projections.count（studentId），count））; 
 criteria.setProjection（projectionList）; 
 criteria.addOrder（Order.desc（（count）））; 
 return criteria.list（）; 
  

解决方案

由于没有答案接受 - 我格式化和简化你自己的解决方案有点：

  Criteria criteria = session.createCriteria（Student.class）; 
 ProjectionList projectionList = Projections.projectionList（）; 
 projectionList.add（Projections.groupProperty（studentId））; 
 projectionList.add（Projections.count（studentId），count）; 
 criteria.setProjection（projectionList）; 
 criteria.addOrder（Order.desc（（count）））; 
 return criteria.list（）; 
  

I used following hibernate criteria.

Criteria criteria = session.createCriteria(Student.class);
        ProjectionList projectionList = Projections.projectionList();
       projectionList.add(Projections.groupProperty("studentId"));
       projectionList.add(Projections.count("studentId"));
        criteria.setProjection(projectionList);
      return criteria.list();

This returns a list of objects and the objects have two fields, studentId and count(studentId). I want to sort this list by count(studentId) descending. How do I do this hibernate?

currently I am getting

{[1, 5], [2, 7], [3,4]}

I want to get it this

{[2, 7], [1, 5], [3,4]}

solution:this sloves the issue :)

  Criteria criteria = session.createCriteria(Student.class);
            ProjectionList projectionList = Projections.projectionList();
           projectionList.add(Projections.groupProperty("studentId"));
           projectionList.add( Projections.alias(Projections.count("studentId"),"count"));
            criteria.setProjection(projectionList);
           criteria.addOrder(Order.desc(("count")));
            return criteria.list();

解决方案

Since there is no answer accepted - i formatted and simplified your own solution a bit:

Criteria criteria = session.createCriteria(Student.class);
ProjectionList projectionList = Projections.projectionList();
projectionList.add(Projections.groupProperty("studentId"));
projectionList.add(Projections.count("studentId"), "count");
criteria.setProjection(projectionList);
criteria.addOrder(Order.desc(("count")));
return criteria.list();

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