Hibernate criteria interface setprojection method: sets the projection column of the query
•
Java
setProjection(Projection projection)
Example 1
Criteria criteria = session.createCriteria(UserForm.class); //示例化Criteria对象 criteria.setProjection(Projections.id()); //设置查询列 list = criteria.list(); //执行查询 Iterator it = list.iterator(); //获取查询结果迭代器 while(it.hasNext()){ //循环遍历查询结果 System.out.println(it.next()); }
Example 2
Criteria criteria = session.createCriteria(UserForm.class); //示例化Criteria对象 criteria.setProjection(Projections.projectionList() .add(Projections.id()) .add(Projections.property("username")) //查询数据表全部用户ID和用户名 ); List list = criteria.list(); //获取查询结果 Iterator it = list.iterator(); //获取查询结果迭代器 while(it.hasNext()){ //循环遍历迭代器 Object[] o = (Object[])it.next(); System.out.println("ID:"+o[0]+"用户名:"+o[1]); }
Example 3
Criteria criteria = session.createCriteria(OrderForm.class); //获取Criteria示例 criteria.setProjection(Projections.sum("money")); //设置查询列 double sumMoney = (Double)criteria.uniqueResult(); //获取订单信息表总金额 System.out.println("合计金额:"+sumMoney);
The content of this article comes from the network collection of netizens. It is used as a learning reference. The copyright belongs to the original author.
THE END
二维码