DataBase-Finding总分

Question

我有15个级别，每个级别都由2 rounds组成。现在，我要找到max score用户在round1 and round2中获得的总成绩并计算出来。同样的方法，直到他玩了多少级别。最后，通过计算所有级别的分数得出总结果。

任何人都可以帮我找到使用MySQL的总分..！

我尝试了这段代码：

    SELECT *, (classifica_score + MAX2) AS TOTAL FROM(

    SELECT IFNULL( MAX(XX1.classifica_score), 0) AS classifica_score, XX1.classifica_level, XX1.classifica_round, XX1.fb_id,
    (SELECT IFNULL( MAX(TC1.classifica_score), 0) FROM tab_classifica AS TC1 WHERE TC1.classifica_round = 2 AND TC1.fb_id = XX1.fb_id) AS MAX2
      FROM tab_classifica AS XX1 WHERE XX1.classifica_round=1 
    GROUP BY XX1.classifica_level, XX1.classifica_round, XX1.fb_id

UNION ALL 

SELECT IFNULL( MAX(XX2.classifica_score),0) AS classifica_score, XX2.classifica_level, XX2.classifica_round, XX2.fb_id,
(SELECT IFNULL( MAX(TC2.classifica_score),0) FROM tab_classifica AS TC2 WHERE TC2.classifica_round = 1 AND TC2.fb_id = XX2.fb_id ) AS MAX1
  FROM tab_classifica AS XX2 WHERE XX2.classifica_round=2
GROUP BY XX2.classifica_level, XX2.classifica_round, XX2.fb_id


 ) AS TAB 

我的Db结构如下

classifica_id----- fb_id---classifica_nome----classifica_level----classifica_round---classifica_score