Question

有3张桌子，一张是学生，第二张是主题，第三张是标记表。

student table:
    student_id  student_name

subject table:
    subject_id  subject_name

marks table:
    student_id   subject_id  marks

我写了这个查询：

select student_id, subject_id, marks, RANK() over (partition by subject_id order by marks desc rank 
from marks order by student_id, subject_id;

它正在给出正确的结果，但我希望student_name和subject_name代替student_id和subject_id。

如何加入这些表格？感谢。

Answer 1

只需添加几个join子句：

SELECT   student_name, subject_name, marks, 
         RANK() OVER (PARTITION BY subject_name ORDER BY marks DESC) rk
FROM     marks
JOIN     student ON marks.student_id = student.student_id
JOIN     subject ON marks.subject_id = subject.subject_id
ORDER BY student_name, subject_name

Answer 2

这可以通过简单的连接

来完成

    select student_name,  subject_name, marks, RANK() over (partition by subject_id order by marks desc) rank 
     from marks 
     inner join student on mark.student_id=student.student_id
     inner join subject on mark.subject_id=subject.subject_id
     order by student_id, subject_id;

如何查询得到这个结果？

2 个答案: