mySQL平均值的所有最大值

Question

我有这样的表格分数。

然后我使用查询来获得最大或最高平均值

    SELECT stud_num, assess_type, MAX(average) FROM score 
    WHERE assess_type = "general" OR assess_type = "professional" 
    OR assess_type = "specialization"
    GROUP BY stud_num, assess_type;

结果是，

但我想为每个ID添加每个最大值并获得平均值。 像学生＃1 = 70 + 80/3，学生＃2 = 62.5 + 76 + 72/3等 可以在一个查询中执行此操作吗？

欲望输出

stud_num | average
1           50      //avg of general, prof, special
2           71.5
3           72.16

Answer 1

这必须解决您的问题。试一试：

SELECT stud_num
     , (SUM(max_average)/3) as final_average
     , access_type 
  FROM 
     ( SELECT stud_num
            , access_type
            , MAX(average) as max_average 
         from score 
        where access_type IN ('general', 'professional', 'specialization') 
        GROUP 
           BY stud_name
            , access_type
      ) as temp_score 
  GROUP 
     BY stud_num