Question

我使用不同类型的成绩并根据他们的分数对其进行排名：

select id,subject,semester,student,course,mark,grade
,dense_rank() over(PARTITION by course order by mark desc) as RANK 
from courses c 
LEFT JOIN course_enrolments b ON c.id=b.course;

结果是：

id  subject semester    student course  mark    grade   rank
5270    1001    126    1077055  5270    99        HD    1
5270    1001    126    1076079  5270    98        HD    2
5270    1001    126    1077334  5270    85        HD    3
5270    1001    126    1076920  5270    84        DN    4
5270    1001    126    1077443  5270    84        DN    5
5270    1001    126    1072135  5270    67        CR    6
5270    1001    126    1079997  5270    66        CR    7
5270    1001    126    1071034  5270    62        PS    8
5270    1001    126    1079993  5270    62        PS    9
5270    1001    126    1074070  5270    44        FL    10
5270    1001    126    1078409  5270    30        FL    11
5270    1001    126    1073006  5270    28        FL    12

然而，我想要实现的目标是根据成绩对这些人进行排名，而不是根据他们的标记：

所以我想要实现的是这样的：

id  subject semester    student course  mark    grade   rank
5270    1001    126   1077055   5270    99        HD    1
5270    1001    126   1076079   5270    98        HD    1
5270    1001    126   1077334   5270    85        HD    1
5270    1001    126   1076920   5270    84        DN    2
5270    1001    126   1077443   5270    84        DN    2
5270    1001    126   1072135   5270    67        CR    3
5270    1001    126   1079997   5270    66        CR    3
5270    1001    126   1071034   5270    62        PS    4
5270    1001    126   1079993   5270    62        PS    4
5270    1001    126   1074070   5270    44        FL    5
5270    1001    126   1078409   5270    30        FL    5
5270    1001    126   1073006   5270    28        FL    5

我怎样才能做到这一点？谢谢，

Answer 1

你应该能够在oracle和sql server中运行：

select id,subject,semester,student,course,mark,grade,
case when grade = 'HD' then 1
     when grade = 'DN' then 2
     when grade = 'CR' then 3
     when grade = 'PS' then 4
     when grade = 'FL' then 5
end as RANK 
from courses c 
order by mark desc

Answer 2

如果有帮助，我会在SQL Server中使用以下内容。也许你（或某人）可以翻译它？

DECLARE @GradeRankTVP Table (
  Grade Varchar(2),
  GradeRank int
);
INSERT INTO @GradeRankTVP (Grade, GradeRank) VALUES
  (HD, 1)
  ,(DN, 2)
  ,(CR, 3)
  ,(PS, 4)
  ,(FL, 5)
-- ,etc
;
select c.id, c.subject, c.semester, b.student, c.course, b.mark, b.grade
, d.GradeRank
from courses c 
LEFT JOIN course_enrolments b ON c.id = b.course
LEFT JOIN @GradeRankTVP AS d on b.grade = d.Grade

使用SQL / Rank / Dense_Rank（）根据表中的字母排名

2 个答案: