Hibernate中三種常用的數據庫查詢

HQL查詢:

public List<User> getUserByNameAndAge(String name, Integer age) {
	Session session = getSession();
	//from後面是對象，不是表名
	String FIND_USER_BY_ID = "from User where name=:name and age=:age";
	Query query = session.createQuery(FIND_USER_BY_ID).setString(
			"name", name).setInteger("age", age);
	return query.list();
}

對象化查詢Criteria方法:

public User getUserById(Long id) {
	Criteria criteria = getSession().createCriteria(User.class);
	criteria.add(Restrictions.eq("id", id));
	return (User)criteria.uniqueResult();
}

SQL查詢:

public User getUserById(Long id) {
		
	String sql = "select Id, Name, Age from User where Id=:Id";
	SQLQuery query = getSession().createSQLQuery(sql);
	
	//設置參數
	query.setParameter("Id", id);
	
	//設置查詢列的類型
	query.addScalar("Id", new org.hibernate.type.LongType());
	query.addScalar("Name", new org.hibernate.type.StringType());
	query.addScalar("Age", new org.hibernate.type.IntegerType());
	
	//設置查詢結果的對象類型
	query.setResultTransformer(Transformers.aliasToBean(User.class));
	
	return (User)query.uniqueResult();
}