Hibernate查询数据的几种方式以及HQL用法及参数的几种使用方法

Hibernate查询数据的几种方式

/**
* 第一种查询：利用query接口与HQL语句
* 1.如果查询所有字段，则list中的元素为POJO对象
* 2.如果查询若干字段，则list中的元素为对象数组
* 3.如果想返回若干字段的对象，则需要通过 new TUser(username,email)方式
*/

public void query(){
	Session session = null;
	Query query = null;
	String hql = null;
	try {
		session = HibernateSessionFactory.getSession();
		hql="From TUser user where user.suser='admin'";
		query = session.createQuery(hql);
		List list = query.list();
		for (Iterator iter = list.iterator(); iter.hasNext();) {
			TUser user = (TUser) iter.next();
			System.out.println("----Query---");
			System.out.println("-Suser-="+user.getSuser());
			System.out.println("-Name--="+user.getName());
			System.out.println("-Email-="+user.getEmail());
		}
	} catch (Exception e) {
		e.printStackTrace();
	}finally{
		HibernateSessionFactory.closeSession();
	}
}

/**
* 第二种查询：利用criteria接口
*/

public void criteria(){
	Session session = null;
	Criteria criteria = null;
	try {
		session = HibernateSessionFactory.getSession();
		criteria = session.createCriteria(TUser.class);
		criteria.add(Restrictions.isNotNull("suser"));
		criteria.add(Restrictions.ilike("name", "%T%"));
		criteria.addOrder(Order.desc("nation"));
		List list = criteria.list();
		for (Iterator iter = list.iterator(); iter.hasNext();) {
			TUser user = (TUser) iter.next();
			System.out.println("----Criteria---");
			System.out.println("-Suser-="+user.getSuser());
			System.out.println("-Name--="+user.getName());
			System.out.println("-Email-="+user.getEmail());
			System.out.println("-Nation="+user.getNation());
		}
	} catch (Exception e) {
		e.printStackTrace();
	}finally{
		HibernateSessionFactory.closeSession();
	}
}

/**
* 第三种查询：利用SQLQuery接口，即原生SQL
* 1.如果查询所有字段，要加入标量设置query.addEntity(TUser.class);
* 2.如果查询若干字段，则集合中数据为对象数组
*/

public void nativeSql() {
	Session session =null;
	Query query = null;
	String sql = null;
	try {
		session = HibernateSessionFactory.getSession();
		sql = "select suser,name,email,nation from t_user";
		query = session.createQuery(sql);
		List list = query.list();
		for (Iterator iter = list.iterator(); iter.hasNext();) {
			Object[] obj = (Object[]) iter.next();
			System.out.println("-Suser-="+obj[0]);
			System.out.println("-Name--="+obj[1]);
			System.out.println("-Email-="+obj[2]);
			System.out.println("-Nation="+obj[3]);
		}
	} catch (Exception e) {
		e.printStackTrace();
	}finally{
		HibernateSessionFactory.closeSession();
	}
}

/**
* 第四种查询：查询单个对象，注意get和load方法的区别
*/

public void getOrLoad(){
	Session session = null;
	try {
		session = HibernateSessionFactory.getSession();
		TUser user = (TUser)session.load(TUser.class, "test1");
		System.out.println("-Suser-="+user.getSuser());
		System.out.println("-Name--="+user.getName());
		System.out.println("-Email-="+user.getEmail());
		System.out.println("-Nation="+user.getNation());
	} catch (Exception e) {
		e.printStackTrace();
	}finally{
		HibernateSessionFactory.closeSession();
	}
}

HQL用法及参数的几种使用方法

/**
*按参数位置绑定
*/

public void batchUpdate() {
	Session session = null;
	Transaction transaction = null;
	Query query = null;
	String hql ="update TUser set name='阿德' where suser=:user";
	try {
		session = HibernateSessionFactory.getSession();
		transaction =session.beginTransaction();
		query = session.createQuery(hql);
		query.setString("user", "test9");
		int i = query.executeUpdate();
		transaction.commit();
		System.out.println("--update--"+i);
	} catch (Exception e) {
		e.printStackTrace();
		transaction.rollback();
	}finally{
		HibernateSessionFactory.closeSession();
	}
}

/**
*按参数位置绑定
*/

public void batchDelete() {
	Session session = null;
	Transaction transaction = null;
	Query query = null;
	String hql = "delete from t_user suser=:user";
	try {
		session = HibernateSessionFactory.getSession();
		transaction = session.beginTransaction();
		query = session.createQuery(hql);
		query.setString("user", "test11");
		int i = query.executeUpdate();
		transaction.commit();
		System.out.println("--delete--"+i);
	} catch (Exception e) {
		e.printStackTrace();
		transaction.rollback();
	}finally{
		HibernateSessionFactory.closeSession();
	}
}

/*
*使用setProperties方法
*/

public void queryUsers() {
	Session session = null;
	Transaction transaction = null;
	Query query = null;
	String hql =null;
	try {
		session = HibernateSessionFactory.getSession();
		hql = "from TUser where suser=:user";
		transaction = session.beginTransaction();
		query = session.createQuery(hql);
		TUser user = new TUser();
		user.setSuser("test1");
		query.setProperties(user);
		List list = query.list();
		for (Iterator iter = list.iterator(); iter.hasNext();) {
			Object[] obj = (Object[]) iter.next();
			System.out.println("-Suser-="+obj[0]);
			System.out.println("-Name--="+obj[1]);
			System.out.println("-Email-="+obj[2]);
			System.out.println("-Nation="+obj[3]);
		}
	} catch (Exception e) {
		e.printStackTrace();
		transaction.rollback();
	}finally{
		HibernateSessionFactory.closeSession();
	}
}