GROUP BY and ..not a group by expression ERROR

Question

Hi, I have the following table
===========
STUDENTS
===========
ID NAME TESTDATE MARKS
=== ====== ========= ======
1 JOHN 2007-10-01 10
1 JOHN 2007-10-02 11
1 JOHN 2007-10-02 8
2 MARY 2007-10-01 10
2 MARY 2007-10-02 7
I want to list student with maximum mark he/scored immaterial of the test - date
The following query does it:
SELECT ID, MAX(MARKS)
FROM STUDENTS
GROUP BY ID
RESULT -
ID MAX(MARKS)
=== ===========
1 11
2 10
Now, I want to show the NAME and TESTDATE in the result (remember, only for the max marks)
So I write:
SELECT ID, NAME, TESTDATE, MAX(MARKS)
FROM STUDENTS
GROUP BY ID
XXXXXXX ERROR - not a group by expression - Agreed that TESTDATE & NAME are not in group by expression. I don't want to group by TESTDATE/NAME as it won't yeild the result I am looking for.
What I am looking for is the same result from above with additional fields.
How to get around this problem? any help is highly appreciated.
THANKS IN ADVANCE.

Answer 1

Try this (Not tested)
SELECT ID, max(NAME) keep(dense_rank last order by marks) name,
       max(testdate) keep(dense_rank last order by marks) testdate,
       MAX(MARKS) max_mark
FROM STUDENTS
GROUP BY ID;Or using a subquery...
select id,name,testdate,marks
from
   (select id,name,testdate,marks,
      row_number() over(partition by id order by marks desc) rn
    from students)
where rn = 1;