zoukankan      html  css  js  c++  java
  • Hibernate QBC

    QBC查询:

      Query By Criteria

      使用面向对象的方式查询

      和HQL单表查询相似,但不包含别名查询和具名查询

        1 全表查询

       Criteria ce = session.createCriteria(Customer.class);
      List<Customer> list = ce.list();
      
      
    for(Customer customer : list) {     System.out.println(customer);   }

      2 条件查询

      Criteria ce = session.createCriteria(Order.class);
      ce.add(Restrictions.eq("orderno", "111"));
        List<Order> list = ce.list();

      Criteria ce = session.createCriteria(Order.class);
      ce.add(Restrictions.and(
        Restrictions.like("orderno", "%111%"),
        Restrictions.like("productName", "%手机%")

      ));
       
      List<Order> list = ce.list();

       3 分页查询

       Criteria ce = session.createCriteria(Order.class);
     
    //分页   ce.setFirstResult(0);   ce.setMaxResults(5);   
      List
    <Order> list = ce.list();

      4 查询排序

      Criteria ce = session.createCriteria(Order.class);
                
      ce.addOrder(org.hibernate.criterion.Order.desc("id"));
                
      List<Order> list = ce.list();

      5 聚合查询

      Criteria ce = session.createCriteria(Order.class);
                
      /*ce.setProjection(Projections.rowCount());
      Long count = (Long)ce.uniqueResult();*/
                
      ce.setProjection(Projections.max("id"));
      Integer count = (Integer)ce.uniqueResult();
                
      System.out.println(count);

      6 投影查询

       Criteria ce = session.createCriteria(Order.class);
        
      ProjectionList pList
    = Projections.projectionList();   pList.add(Property.forName("orderno"));   pList.add(Property.forName("productName"));   ce.setProjection(pList);   List<Object[]> list = ce.list();   for(Object[] order : list) {      for(Object column : order) {         System.out.print(column);         System.out.print(" ");      }     System.out.println();   }
  • 相关阅读:
    Source Insight 安装使用
    size_t和ssize_t
    jquery ui autoComplete自动完成
    一个php类 Autoloader
    php register_shutdown_function
    mysql concat和group_concat
    nginx反向代理
    6.关于QT中的内存管理,动态的制作,动态库的调用,静态库的制作
    Sublime Text2 按shift键选择不了的问题
    javascript--瀑布流
  • 原文地址:https://www.cnblogs.com/roxy/p/7611733.html
Copyright © 2011-2022 走看看