如何根据另一列的唯一ID获取一列的最大值，平均值，最小值，计数

Question

    SELECT  [Student ID]
      ,[Course ID]
      ,[Name]
      ,max[Marks]
      ,[Grade]
  FROM [CE].[dbo].[GradeCount]
  order by [Student ID]    

Answer 1

use aggregation and group by

 SELECT [Student ID]
      ,[Course ID]
      ,[Name]
      ,max([Marks])
      ,max([Grade])
  FROM [CE].[dbo].[GradeCount]
 group by [Student ID] ,[Course ID],[Name]

Answer 2

Just use GROUP BY fields you want to use aggregation functions such as MAX , MIN , AVG , COUNT :

  SELECT 
    MAX(course_ID) MaxCourse_ID
  , MIN(course_ID) MinCourse_ID
  , AVG(course_ID) AvgCourse_ID
  , COUNT(course_ID) CountCourse_ID
  FROM [CE].[dbo].[GradeCount]
  group by course_ID