Fetch data using group by but last updated record

I want to display records on the basis of last updated , if updated column is empty then create date

Id	SubjectId	MarksId	Entry date	Updated Date
1	3	3	2022-09-25	2022-11-25
2	3	3	2022-12-25	null

It should print:-

Id	SubjectId	MarksId	Entry date	Updated Date
1	3	3	2022-09-25	2022-11-25

If data is like below:-

Id	SubjectId	MarksId	Entry date	Updated Date
1	3	3	2022-09-25	null
2	3	3	2022-12-25	null

It should print:-

Id	SubjectId	MarksId	Entry date	Updated D开发者_如何学Cate
1	3	3	2022-12-25	null

I am writing below query but unable to fetch the same it everytime fetches the second thing even though I have updatedate present

     select Id,at.SubjectId,at.marksid 
from student at 
INNER JOIN (
      select MAX(Id) as StudentId from student  
       group by SubjectId,marksid
      ORDER BY COALESCE(UPDATEDATE,ENTRYDATE) desc 
      ) maxat ON at.Id=maxat.StudentId
        

Further info.

MySQL version 8.0

Entry date cant be null it will have data, Kind of auto generated when data inserts to this table

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Please include all the details in the question so it could help future readers as well.

As per the question using row_number is one option.

select Id,
       SubjectId,
       MarksId,
       Entrydate,
       UpdatedDate
from (  select *,
               row_number() over(partition by SubjectId,MarksId order by (case when UpdatedDate is null then Entrydate else Entrydate  end) desc) as rn
        from student
     ) tbl
where rn=1; 

https://dbfiddle.uk/di517ZLv