db user\u db和table user\u table中的我的第一个实体

public class User {

    private int userId;
    private String surname;
    private String name;

    //getters setters

    public User(ResultSet resultSet){}

    public User(ResultSet resultSet) throws SQLException {
setUserId(resultSet.getInt("userId"));
        setSurname(resultSet.getString("surname"));
        setName(resultSet.getString("name"));
    }
}

它的存储库

public class UserRepository {

    @Autowired
    private DataBaseUtil dataBaseUtil;

    public User findUser (int userId) throws SQLException {
        String query = "SELECT "+
                                "surname, name, userId" +

                        "FROM "+
                                "user_db:user_table, "+
                        "WHERE "+
                                "userId = '" + userId + "'";

            User currentUser = null;
            try {
                ResultSet resultSet = dataBaseUtil.getResultSet(query);
                while (resultSet.next()) {
                    currentUser = new User(resultSet);
                }
            }
            finally {
                dataBaseUtil.closeConnection();
            }

        return currentUser;
    }

}

我的数据库util

@Service
public class DataBaseUtil {

    @Autowired
    private DataSource dataSource;

    private Connection connection;
    private Statement statement;
    private ResultSet resultSet;

    public DataBaseUtil() {}

    public DataBaseUtil getResultSet (String query) throws SQLException {
        this.connection = dataSource.getConnection();
        this.statement = connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
        this.resultSet = statement.executeQuery(query); 
        return this;
    }

    public void closeConnection() throws SQLException {     
        try (Connection connection = this.getConnection();
             Statement statement = this.getStatement();
             ResultSet resultSet = this.getResultSet()) {                       
        }
    }

    public void update(String updateQuery) throws SQLException {
        try (Connection connection = dataSource.getConnection();
             Statement statement = connection.createStatement() ){
             statement.executeUpdate(updateQuery);
        }
    }
    }

好 啊。过了一段时间。我们已经创建了一个新表-user\u detail\u table
我正在创建实体

//My 2nd entity from db user_db and user_detail_table

    public class UserDetail {

        private int userId;
        private String address;
        private String hobby;

    //setters getters

        public UserDetail(ResultSet resultSet) throws SQLException {
            setAddress(resultSet.getString("address"));
            setHobby(resultSet.getString("hobby"));
            setUserId(resultSet.getInt("userId"));
        }
    }

如果我想从user和userdetail获取数据，我应该怎么做(就像冬眠一样？我的想法：
我在用户实体中添加了userdetail字段。没关系，我想。。。这里我有问题：如果我把userrepository方法public user finduser（int userid）中的字符串查询改为

String query = "SELECT surname, name, address, hobby    
"FROM user_db:user_table AS a,  user_db:user_detail_table AS b"+
    "WHERE a.userId = b.userId AND a.userId = '" + userId + "'";

看起来不错，但如果我只需要用户详细信息数据呢？我应该创建userdetailrepository，对吗？如果我只需要用户数据…我创建新方法？然后新的表将被再次创建，我们将需要“连接”它再次到用户…我们应该如何进行实体Map。如果我只需要用户数据的话，llooks将如何处理存储库？如果我需要用户和用户详细信息数据）？
对不起，我没有明确的描述问题…我希望你能理解我想要的：正确设计。。。最佳实践。如果你对我的代码有什么意见，我会很高兴听到的。非常感谢