EntityManager 查询指定字段

@PersistenceContext

private EntityManager em;

@Override

public User findUserByAccount(String account) {

User user = new User();

if(account != null){

String sql = "select user_id,create_time,create_user_id,update_time,update_user_id,account,avatar,name,password,role_id from user ORDER BY user_id ASC";

Query query = em.createNativeQuery(sql,User.class); 

user = (User) query.getSingleResult(); //获取单个结果

List<User> list = query.getResultList(); //获取结果集

}

return user;

}