1. 查詢整個映射對象所有字段

//直接from查詢出來的是一個映射對象，即：查詢整個映射對象所有字段?? ????????String hql = "from Users";?? ????????Query query = session.createQuery(hql);?? ???????????? ????????List<Users> users = query.list();?? ????????for(Users user : users){?? ????????????System.out.println(user.getName() + " : "?+ user.getPasswd() + " : "?+ user.getId());?? ????????}?? ??? ?輸出結果為：?? name1 : password1 : 1? name2 : password2 : 2? name3 : password3 : 3?

2.查詢字段　　

//查詢其中幾個字段?? ????????String hql = " select name,passwd from Users";?? ????????Query query = session.createQuery(hql);?? ????????//默認查詢出來的list里存放的是一個Object數組?? ????????List<Object[]> list = query.list();?? ????????for(Object[] object : list){?? ????????????String name = (String)object[0];?? ????????????String passwd = (String)object[1];?? ???????????????? ????????????System.out.println(name + " : "?+ passwd);?? ????????}?? 輸出結果為：?? name1 : password1?? name2 : password2?? name3 : password3?

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3.修改默認查詢結果(query.list())不以Object[]數組形式返回，以List形式返回

//查詢其中幾個字段,添加new list(),注意list里的l是小寫的。也不需要導入包，這樣通過query.list()出來的list里存放的不再是默認的Object數組了，而是List集合了? ?????????String hql = " select new list(name,passwd) from Users";?? ????????Query query = session.createQuery(hql);?? ????????//默認查詢出來的list里存放的是一個Object數組，但是在這里list里存放的不再是默認的Object數組了，而是List集合了?? ????????List<List> list = query.list();?? ????????for(List user : list){?? ????????????String name = (String)user.get(0);?? ????????????String passwd = (String)user.get(1);?? ???????????????? ????????????System.out.println(name + " : "?+ passwd);?? ????????}?? ????????/**? ????????輸出結果為：? ?????????name1 : password1? ????????name2 : password2? ????????name3 : password3? ?????????*/?

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4.修改默認查詢結果(query.list())不以Object[]數組形式返回，以Map形式返回

//查詢其中幾個字段,添加new map(),注意map里的m是小寫的。也不需要導入包，這樣通過query.list()出來的list里存放的不再是默認的Object數組了，而是map集合了?? ????????String hql = " select new map(name,passwd) from Users";?? ????????Query query = session.createQuery(hql);?? ????????//默認查詢出來的list里存放的是一個Object數組，但是在這里list里存放的不再是默認的Object數組了，而是Map集合了?? ????????List<Map> list = query.list();?? ????????for(Map user : list){?? ????????????//一條記錄里所有的字段值都是map里的一個元素,key是字符串0,1,2,3....，value是字段值?? ????????????//如果將hql改為：String hql = " select new map(name as username,passwd as password) from Users";,那么key將不是字符串0,1,2...了，而是"username","password"了?? ????????????String name = (String)user.get("0");//get("0");是get(key),注意:0,1,2...是字符串，而不是整形?? ????????????String passwd = (String)user.get("1");?? ???????????????? ????????????System.out.println(name + " : "?+ passwd);?? ????????}?? ????????/**? ????????輸出結果為：? ?????????name1 : password1? ????????name2 : password2? ????????name3 : password3? ?????????*/?

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5.修改默認查詢結果(query.list())不以Object[]數組形式返回，以自定義類型返回

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6.條件查詢

//條件查詢，參數索引值從0開始，索引位置。通過setString,setParameter設置參數?? ????????String hql = "from Users where name=? and passwd=?";?? ????????Query query = session.createQuery(hql);?? ????????//第1種方式?? //????? query.setString(0, "name1");?? //????? query.setString(1, "password1");?? ????????//第2種方式?? ????????query.setParameter(0, "name1",Hibernate.STRING);?? ????????query.setParameter(1, "password1",Hibernate.STRING);?? ????????List<Users> list = query.list();?? ????????for(Users users : list){?? ????????????System.out.println(users.getId());?? ????????}??

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//條件查詢，自定義索引名(參數名):username,:password.通過setString,setParameter設置參數?? ????????String hql = "from Users where name=:username and passwd=:password";?? ????????Query query = session.createQuery(hql);?? ????????//第1種方式?? //????? query.setString("username", "name1");?? //????? query.setString("password", "password1");?? ????????//第2種方式,第3個參數確定類型?? ????????query.setParameter("username", "name1",Hibernate.STRING);?? ????????query.setParameter("password", "password1",Hibernate.STRING);?? ????????List<Users> list = query.list();?? ????????for(Users users : list){?? ????????????System.out.println(users.getId());?? ????????}?

　　

//條件查詢,通過setProperties設置參數?? ????????String hql = "from Users where name=:username and passwd=:password";?? ????????Query query = session.createQuery(hql);?? ????????//MyUser類的2個屬性必須和:username和:password對應?? ????????MyUser myUser = new?MyUser("name1","password1");?? ????????query.setProperties(myUser);?? ????????List<Users> list = query.list();?? ????????for(Users users : list){?? ????????????System.out.println(users.getId());?? ????????}?

　　

7.update 數據

?????????? 執行SQL語句（為什么要用SQL語句，我想是為了執行某些復雜的SQL語句吧）　

String sql="update Table set field = 'test'" Session session = HibernateSessionFactory.getSession(); session.createSQLQuery(sql).executeUpdate(); ts.commit();

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?? 執行HQL語句　　　

String hql="update Table set field = 'test'"

Session session = HiberanteSessionFactory.getSession(); Transaction ts = session.beginTransaction(); Query query = session.createQuery(hql); query.executeUpdate(); ts.commit();

轉載于:https://www.cnblogs.com/printN/p/6415377.html

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