Question

我有一个名为＆＃34; QueryTotalGrades＆＃34;的查询它有三个字段（Group，StudentID和Mark）。每个studentID都有多个商标。我想要做的是创建另一个执行以下操作的查询：

1- Sum mark for each studentID as a sumOfMark (Descending order)
2- Display the top 2 of sumOfMarks per group.

示例：假设＆＃34; QueryTotalGrades＆＃34;具有以下值。我使用的是Microsoft Access 2013

Group    StudentID     Mark
1           1            8
1           1            7
1           1            8
1           2            7
1           2            7
1           2            7
1           3            9
1           3            9
1           3            9
2           4            5
2           4            7
2           4            5
2           5            7
2           5            7
2           5            7
2           6            6
2           6            6
2           6            6
3           7            8
3           7            7
3           7            8
3           8            7
3           8            7
3           8            7
3           9            10
3           9            10
3           9            10

，所以我想要的输出应该如下

Group    StudentID     SumOfMark
1           3            27
1           1            23
2           5            21
2           6            18    
3           9            30
3           7            23

我尝试了很多解决方案，但没有用。帮助

Answer 1

有点啰嗦但是：

select 
    t1.[Group], t1.StudentID, t1.SumOfMark
from

    (select [Group], StudentID, sum(Mark) as SumOfMark
    from QueryTotalGrades
    group by [Group], StudentID) as t1

where

    (select count(*) from

        (select [Group], StudentID, sum(Mark) as SumOfMark
        from QueryTotalGrades
        group by [Group], StudentID) as t2

        where 
            t2.[Group] = t1.[Group] and
            t2.SumOfMark >= t1.SumOfMark) <= 2

order by 
     t1.[Group], t1.SumOfMark desc

您可以在此处播放：SQL Fiddle

Answer 2

<强>查询

;with cte as
(
   select rn=row_number() over
   (
       partition by [Group]
       order by sum(Mark) desc
   ),
  [Group],StudentID,
  sum(Mark) as SumOfMark
  from student
  group by [Group],StudentID
 )
 select [Group],StudentId,SumOfMark from cte where rn in (1,2);

fiddle demo

按组显示前两个求和值

2 个答案: