hibernate select 查询方式总结

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1. 查询整个映射对象所有字段(查询整个映射对象所有字段,填充到List<User>中)

List<User> result = hibernateTemplate.executeFind(new HibernateCallback(){public Object doInHibernate(Session session)throws HibernateException, SQLException {Query query = session.createQuery("from User as u");List<User> result = query.list();return result;}});return result;

2. 查询单个字段，(查询整个映射对象单一字段,填充到List<String>中)

List<User> result = hibernateTemplate.executeFind(new HibernateCallback(){public Object doInHibernate(Session session)throws HibernateException, SQLException {Query query = session.createQuery("select name from User as u");List<String> result = query.list();return result;}});return result;

3. 查询多个字段，(查询整个映射对象多个字段,返回Object[],可以new两个ArrayList,不常使用)

List result = hibernateTemplate.executeFind(new HibernateCallback(){public Object doInHibernate(Session session)throws HibernateException, SQLException {Query query = session.createQuery("select name,pass,registeredTime from User as u");List result = query.list();return result;}});return result;

遍历这个Object数组

List name = new ArrayList();for (int i = 0; i < result.size(); i++) {Object[] objArray = (Object[])result.get(i);for(Object obj : objArray){name.add(obj);}}

4. 查询多个字段，(查询整个映射对象多个字段,通过select new com.bict.entity.User()，必须加包名，返回自定义的类User,可以填充到模板,常使用)

List<User> result = hibernateTemplate.executeFind(new HibernateCallback(){public Object doInHibernate(Session session)throws HibernateException, SQLException {Query query = session.createQuery("select new com.bict.entity.User(u.id,u.name,u.pass,u.registeredTime) from User as u");query.setFirstResult((pageNum - 1) * Pagination.PAGESIZE);query.setMaxResults(Pagination.PAGESIZE);List<User> result = query.list();return result;}});return result;}

实体类有带参数的构造方法，并且参数与查询的字段对应，Date类型引用java.util.Date