/*

*具体操作hibernate的类

*增加,删除,修改,按ID查询,模糊查询,查询全部

**/

public class PersonOperate {

//在hibernate中所有操作都是由Session完成

public Session session = null;  

//在构造方法中实例化Session对象

public PersonOperate(){

    //找出hibernate的配置

    Configuration config = new Configuration().configure();

    //从配置中取出SessionFactory

    SessionFactory sf = config.buildSessionFactory();

    //从SessionFactory中取出Session

    this.session = sf.openSession();

}  

//操作Hibernate类的所有操作都是通过Session完成的  

//增加数据库中数据

public void insert(Person person){

    //开始事务

    Transaction tran =    session.beginTransaction();

    //执行语句

    session.save(person);

    //提交事务

    tran.commit();

    session.close();

}  

//操作Hibernate类更改数据库中的数据

public void update(Person person){

    //开始事务

    Transaction tran =    session.beginTransaction();

    //执行语句

    session.update(person);

    //提交事务

    tran.commit();

}  

/*操作Hibernate类：按ID查询

    *我们插入,修改都是对对象进行操作

    *那么我们查询的时候也应该是返回一个对象

    **/

public Person queryById(String id){

    System.out.println(id);

    Person person = null;

    //hibernate查询语句

    String hql = "FROM Person as p WHERE p.id = ?";

    Query q = session.createQuery(hql);

    q.setString(0, id);

    List list = q.list();

    Iterator iteator = list.iterator();

    if(iteator.hasNext()){

     person = (Person)iteator.next();

    }

    return person;

}  

/*操作Hibernate类：删除数据库中数据

    *hiberante2,hibernate3中通用的删除方法

    *缺点:删除数据之前要先查询一次数据,找出删除的数据对象

    *性能低下

    **/

public void delete(Person person){

    //开始事务

    Transaction tran =    session.beginTransaction();

    //执行语句

    session.delete(person);

    //提交事务

    tran.commit();

}  

//hibernate3的用法

public void delete(String id){

    //开始事务

    Transaction tran =    session.beginTransaction();

    String hql = "DELETE Person WHERE id = ?";  

    Query q = session.createQuery(hql);

    q.setString(0, id);

    //执行更新语句

    q.executeUpdate();

    //提交事务

    tran.commit();

}  

//操作Hibernate类：查询全部数据

public List queryAll(){

    List list = null;

    String hql = "FROM Person as p ";

    Query q = session.createQuery(hql);

    list = q.list();

    return list;

}  

//操作Hibernate类：模糊查询

public List queryByLike(String colnum,String value){

    List list = null;

    String hql = "FROM Person as p WHERE p."+ colnum +" like ?";

    Query q = session.createQuery(hql);

    q.setString(0, "%"+ value +"%");

    list = q.list();  

Criteria criteria = session.createCriteria(Customer.class);

Criterion c1 = Expression.like("name", "T%");

Criterion c2 = Exception.eq("age", new Long(21));

criteria.add(c1);

criteria.add(c2);

List list = criteria.list();

以上语句相当于：

    List list = session..createCriteria(Customer.class)

                .add(Expression.like("name", "T%"))

                .add(Exception.eq("age", new Long(21)))

                .list();

查询

List <User> user = session.createCriteria(User.class)

                        //必需创建一个别名，roles为user中包 含的role 的list.

                        .createAlias("roles","roles")

                        //roleId为传进来进行查询的角色ID

                        .add(Restrictions.eq("roles.id",roleId))

                        .list();