Hibernate查询笔记.doc

Hibernate查询 -李孟锋（2008-10-29）*HQL查询*一：新建一个java普通项目：HibSelectDemo二：添加Hibernian支持：给项目导入Hibernate兼容：在项目上右键MyEclipseAdd Hibernate Capabilities：点击下一步（Next），填写数据源的id和选择数据库驱动：点击下一步（Next），勾选中Create SessionFactory class：三：DB Browser视窗打开数据库连接：四：在之前建好的User表上右键Hibernate Reverse Engineering（Hibernate反向工程）：五：点击Browse，选择我们这个项目下的src包即可六：之后勾选Hibernate mapping文件，Java Data Object：点击下一步（Next），选择id生成器为identity：点击完成（Finish）。七：新建UserDAO.javapublic class UserDAO public List search() /查询所有Session session = HibernateSessionFactory.getSession();/ 获得session对象;String hql = from User;/ from:类似于SQL语句,User:实体类名，而不是数据库表名Query query = session.createQuery(hql);/ 执行hqlreturn query.list();/ 返回结果八：运行Mian.javapublic class Mian public static void main(String args) UserDAO userdao = new UserDAO();List list = userdao.search();Iterator it = list.iterator();while (it.hasNext() User user = (User) it.next();System.out.println(用户名： + user.getUserName();结果：九：属性查询：修改UserDAO.javapublic class UserDAO public List search() /属性查询Session session = HibernateSessionFactory.getSession();/ 获得session对象;String hql = select us.id,us.userName from User as us;Query query = session.createQuery(hql);/ 执行hqlreturn query.list();/ 返回结果十：运行Mian.javapublic class Mian public static void main(String args) UserDAO userdao = new UserDAO();List list = userdao.search();Iterator it = list.iterator();while (it.hasNext() /每条数据封装为一个Object数组Object arr = (Object ) it.next();/返回的是Object数组System.out.println(用户名： + arr1);结果：十一：参数查询：修改UserDAO.javapublic class UserDAO public List search() /参数查询Session session = HibernateSessionFactory.getSession();/ 获得session对象;String hql = select us.id,us.userName from User us where us.userName like ?;Query query = session.createQuery(hql);/ 执行hqlquery.setString(0, %lmf%);return query.list();/ 返回结果也可：“：参数名”方式public class UserDAO public List search() /参数查询Session session = HibernateSessionFactory.getSession();/ 获得session对象; String hql = select us from User us where us.userName like ：name;Query query = session.createQuery(hql);/ 执行hqlquery.setString(name, %lmf%);return query.list();/ 返回结果十二：运行Mian.javapublic class Mian public static void main(String args) UserDAO userdao = new UserDAO();List list = userdao.search();Iterator it = list.iterator();while (it.hasNext() /每条数据封装为一个Object数组Object arr = (Object ) it.next();/返回的是Object数组System.out.println(用户名： + arr1);结果：十三：关联查询：Hql=select us from User us,Book bk where bk.us=us;十四：分页查询：修改UserDAO.javapublic class UserDAO public List search(int pageNo,int pageSize) /分页查询Session session = HibernateSessionFactory.getSession();/ 获得session对象;String hql = from User us order by us.id asc;Query query = session.createQuery(hql);/ 执行hqlint firstResultIndex=pageSize*(pageNo-1);query.setFirstResult(firstResultIndex);query.setMaxResults(pageSize);return query.list();/ 返回结果运行Mian.javapublic class Mian public static void main(String args) UserDAO userdao = new UserDAO();/得到每页5条数据时第2页数据List list = userdao.search(2,5);Iterator it = list.iterator();while (it.hasNext() User user = (User) it.next();System.out.println(用户名： + user.getUserName();结果：十五：统计函数：修改UserDAO.javapublic class UserDAO public Long search() /统计函数Session session = HibernateSessionFactory.getSession();/ 获得session对象;String hql = select count(us) from User us;Query query = session.createQuery(hql);/ 执行hql Long count= (Long) query.uniqueResult();return count;/ 返回结果运行Mian.javapublic class Mian public static void main(String args) UserDAO userdao = new UserDAO();userdao.search();System.out.println(数量： + userdao.search();结果：*Criteria查询*十六：修改UserDAO.javapublic class UserDAO public List search(User user) / Criteria查询Session session = HibernateSessionFactory.getSession();/ 获得session对象;Criteria c = session.createCriteria(User.class);if (user != null) if (user.getUserName() != null) c.add(Restrictions.like(userName, user.getUserName(),MatchMode.ANYWHERE);/c.add（）;/继续添加条件return c.list();/ 返回结果运行Mian.javapublic class Mian public static void main(String args) UserDAO userdao = new Use