HibernateHQL语句使用总结

1. 查询整个映射对象所有字段 //直接from查询出来的是一个映射对象，即：查询整个映射对象所有字段 String hql = from Users ; Query query = session.createQuery(hql); ListUsers users = query.list(); for (Users user : users){ System.out.println(use

1. 查询整个映射对象所有字段

//直接from查询出来的是一个映射对象，即：查询整个映射对象所有字段 <code class="java spaces"><code class="java plain">String hql = <code class="java string">"from Users"<code class="java plain">; <code class="java spaces"><code class="java plain">Query query = session.createQuery(hql); <code class="java spaces"><code class="java spaces"><code class="java plain">List<users> users = query.list(); <code class="java spaces"><code class="java keyword">for<code class="java plain">(Users user : users){ <code class="java spaces"><code class="java plain">System.out.println(user.getName() + <code class="java string">" : " <code class="java plain">+ user.getPasswd() + <code class="java string">" : " <code class="java plain">+ user.getId()); <code class="java spaces"><code class="java plain">} <code class="java spaces"><code class="java spaces"><code class="java plain">输出结果为： <code class="java plain">name1 : password1 : <code class="java value">1 <code class="java plain">name2 : password2 : <code class="java value">2 <code class="java plain">name3 : password3 : <code class="java value">3

2.查询字段　　

//查询其中几个字段 <code class="java spaces"><code class="java plain">String hql = <code class="java string">" select name,passwd from Users"<code class="java plain">; <code class="java spaces"><code class="java plain">Query query = session.createQuery(hql); <code class="java spaces"><code class="java comments">//默认查询出来的list里存放的是一个Object数组 <code class="java spaces"><code class="java plain">List<object> list = query.list(); <code class="java spaces"><code class="java keyword">for<code class="java plain">(Object[] object : list){ <code class="java spaces"><code class="java plain">String name = (String)object[<code class="java value">0<code class="java plain">]; <code class="java spaces"><code class="java plain">String passwd = (String)object[<code class="java value">1<code class="java plain">]; <code class="java spaces"><code class="java spaces"><code class="java plain">System.out.println(name + <code class="java string">" : " <code class="java plain">+ passwd); <code class="java spaces"><code class="java plain">} <code class="java plain">输出结果为： <code class="java plain">name1 : password1 <code class="java plain">name2 : password2 <code class="java plain">name3 : password3

3.修改默认查询结果(query.list())不以Object[]数组形式返回，以List形式返回

//查询其中几个字段,添加new list(),注意list里的l是小写的。也不需要导入包，这样通过query.list()出来的list里存放的不再是默认的Object数组了，而是List集合了 <code class="java spaces"><code class="java plain">String hql = <code class="java string">" select new list(name,passwd) from Users"<code class="java plain">; <code class="java spaces"><code class="java plain">Query query = session.createQuery(hql); <code class="java spaces"><code class="java comments">//默认查询出来的list里存放的是一个Object数组，但是在这里list里存放的不再是默认的Object数组了，而是List集合了 <code class="java spaces"><code class="java plain">List<list> list = query.list(); <code class="java spaces"><code class="java keyword">for<code class="java plain">(List user : list){ <code class="java spaces"><code class="java plain">String name = (String)user.get(<code class="java value">0<code class="java plain">); <code class="java spaces"><code class="java plain">String passwd = (String)user.get(<code class="java value">1<code class="java plain">); <code class="java spaces"><code class="java spaces"><code class="java plain">System.out.println(name + <code class="java string">" : " <code class="java plain">+ passwd); <code class="java spaces"><code class="java plain">} <code class="java spaces"><code class="java preprocessor">/** <code class="java spaces"><code class="java preprocessor">输出结果为： <code class="java spaces"><code class="java preprocessor">name1 : password1 <code class="java spaces"><code class="java preprocessor">name2 : password2 <code class="java spaces"><code class="java preprocessor">name3 : password3 <code class="java spaces"><code class="java preprocessor">*/

4.修改默认查询结果(query.list())不以Object[]数组形式返回，以Map形式返回

//查询其中几个字段,添加new map(),注意map里的m是小写的。也不需要导入包，这样通过query.list()出来的list里存放的不再是默认的Object数组了，而是map集合了 <code class="java spaces"><code class="java plain">String hql = <code class="java string">" select new map(name,passwd) from Users"<code class="java plain">; <code class="java spaces"><code class="java plain">Query query = session.createQuery(hql); <code class="java spaces"><code class="java comments">//默认查询出来的list里存放的是一个Object数组，但是在这里list里存放的不再是默认的Object数组了，而是Map集合了 <code class="java spaces"><code class="java plain">List<map> list = query.list(); <code class="java spaces"><code class="java keyword">for<code class="java plain">(Map user : list){ <code class="java spaces"><code class="java comments">//一条记录里所有的字段值都是map里的一个元素,key是字符串0,1,2,3....，value是字段值 <code class="java spaces"><code class="java comments">//如果将hql改为：String hql = " select new map(name as username,passwd as password) from Users";,那么key将不是字符串0,1,2...了，而是"username","password"了 <code class="java spaces"><code class="java plain">String name = (String)user.get(<code class="java string">"0"<code class="java plain">);<code class="java comments">//get("0");是get(key),注意:0,1,2...是字符串，而不是整形 <code class="java spaces"><code class="java plain">String passwd = (String)user.get(<code class="java string">"1"<code class="java plain">); <code class="java spaces"><code class="java spaces"><code class="java plain">System.out.println(name + <code class="java string">" : " <code class="java plain">+ passwd); <code class="java spaces"><code class="java plain">} <code class="java spaces"><code class="java preprocessor">/** <code class="java spaces"><code class="java preprocessor">输出结果为： <code class="java spaces"><code class="java preprocessor">name1 : password1 <code class="java spaces"><code class="java preprocessor">name2 : password2 <code class="java spaces"><code class="java preprocessor">name3 : password3 <code class="java spaces"><code class="java preprocessor">*/

5.修改默认查询结果(query.list())不以Object[]数组形式返回，以自定义类型返回

6.条件查询

//条件查询，参数索引值从0开始，索引位置。通过setString,setParameter设置参数 <code class="java spaces"><code class="java plain">String hql = <code class="java string">"from Users where name=? and passwd=?"<code class="java plain">; <code class="java spaces"><code class="java plain">Query query = session.createQuery(hql); <code class="java spaces"><code class="java comments">//第1种方式 <code class="java comments">// query.setString(0, "name1"); <code class="java comments">// query.setString(1, "password1"); <code class="java spaces"><code class="java comments">//第2种方式 <code class="java spaces"><code class="java plain">query.setParameter(<code class="java value">0<code class="java plain">, <code class="java string">"name1"<code class="java plain">,Hibernate.STRING); <code class="java spaces"><code class="java plain">query.setParameter(<code class="java value">1<code class="java plain">, <code class="java string">"password1"<code class="java plain">,Hibernate.STRING); <code class="java spaces"><code class="java plain">List<users> list = query.list(); <code class="java spaces"><code class="java keyword">for<code class="java plain">(Users users : list){ <code class="java spaces"><code class="java plain">System.out.println(users.getId()); <code class="java spaces"><code class="java plain">}

//条件查询，自定义索引名(参数名):username,:password.通过setString,setParameter设置参数 <code class="java spaces"><code class="java plain">String hql = <code class="java string">"from Users where name=:username and passwd=:password"<code class="java plain">; <code class="java spaces"><code class="java plain">Query query = session.createQuery(hql); <code class="java spaces"><code class="java comments">//第1种方式 <code class="java comments">// query.setString("username", "name1"); <code class="java comments">// query.setString("password", "password1"); <code class="java spaces"><code class="java comments">//第2种方式,第3个参数确定类型 <code class="java spaces"><code class="java plain">query.setParameter(<code class="java string">"username"<code class="java plain">, <code class="java string">"name1"<code class="java plain">,Hibernate.STRING); <code class="java spaces"><code class="java plain">query.setParameter(<code class="java string">"password"<code class="java plain">, <code class="java string">"password1"<code class="java plain">,Hibernate.STRING); <code class="java spaces"><code class="java plain">List<users> list = query.list(); <code class="java spaces"><code class="java keyword">for<code class="java plain">(Users users : list){ <code class="java spaces"><code class="java plain">System.out.println(users.getId()); <code class="java spaces"><code class="java plain">}

//条件查询,通过setProperties设置参数 <code class="java spaces"><code class="java plain">String hql = <code class="java string">"from Users where name=:username and passwd=:password"<code class="java plain">; <code class="java spaces"><code class="java plain">Query query = session.createQuery(hql); <code class="java spaces"><code class="java comments">//MyUser类的2个属性必须和:username和:password对应 <code class="java spaces"><code class="java plain">MyUser myUser = <code class="java keyword">new <code class="java plain">MyUser(<code class="java string">"name1"<code class="java plain">,<code class="java string">"password1"<code class="java plain">); <code class="java spaces"><code class="java plain">query.setProperties(myUser); <code class="java spaces"><code class="java plain">List<users> list = query.list(); <code class="java spaces"><code class="java keyword">for<code class="java plain">(Users users : list){ <code class="java spaces"><code class="java plain">System.out.println(users.getId()); <code class="java spaces"><code class="java plain">}

7.update 数据

执行SQL语句（为什么要用SQL语句，我想是为了执行某些复杂的SQL语句吧）　

String sql=<code class="java string">"update Table set field = 'test'" <code class="java plain">Session session = HibernateSessionFactory.getSession(); <code class="java plain">session.createSQLQuery(sql).executeUpdate(); <code class="java plain">ts.commit();

执行HQL语句　　　

String hql=<code class="java string">"update Table set field = 'test'"

Session session = HiberanteSessionFactory.getSession(); <code class="java plain">Transaction ts = session.beginTransaction(); <code class="java plain">Query query = session.createQuery(hql); <code class="java plain">query.executeUpdate(); <code class="java plain">ts.commit();