Question

我想从db中获取学生列表，他们在每个班级中都有学生姓名获得最大数量。使用MySQL DB。

我有以下表格，如学生，班级，结果（具有不同的年份结果）

表结构学生（student_id，student_name，class_id，地址），类（class_id，class_name），结果（result_id，student_id，year，marks）

我需要列表

Student Name   class   Marks
Jon            A-1      800
Steve          B-1      789

Answer 1

修改更正的代码，评论正确

尝试使用此SQL Fiddle link

上的代码

Answer 2

您可以使用子查询来过滤每班最高分的学生：

select  s.student_name
,       c.class_name
,       r.marks
from    results r
join    student s
on      r.student_id = s.student_id
join    class c
on      c.class_id = s.class_id
where   r.result_id =
        (
        select  r2.result_id
        from    student s2
        join    results r2
        on      s2.student_id = r2.student_id
        where   c.class_id = s2.class_id
        order by
                r2.marks desc
        limit   1
        )

Live example at SQL Fiddle.

Answer 3

select s1.student_name, c1.class_name, r1.marks 
from student s1, class c1, results r1,
  (select s2.class_id, max(r2.marks) marks 
   from results r2, student s2
   where r2.student_id = s2.student_id 
   group by s2.class_id) agg
where r1.marks      = agg.marks 
  and r1.student_id = s1.student_id
  and s1.class_id   = c1.class_id
  and s1.class_id   = agg.class_id

获取每个班级最多编号的学生列表

3 个答案: