SQL Show most recent record in GROUP BY?

Question

I have a table that looks like this:

id    |    SubjectCode    |    Grade    |    DateApproved    |    StudentId  1            SUB123            1.25            1/4/2012            2012-12345  2            SUB123            2.00            1/5/2012            2012-12345  3            SUB123            3.00            1/5/2012            2012-98765    

I'm trying to GROUP BY SubjectCode but i'd like it to display the most recent DateApproved so it will look like:

  id    |    SubjectCode    |    Grade    |    DateApproved    |    StudentId  2            SUB123            2.00            1/5/2012            2012-12345  3            SUB123            3.00            1/5/2012            2012-98765   

I'm a little bit lost on how to do it?

EDIT:

Ok guys now im on my real PC, sorry for the poorly constructed question.

Here's what I'm actually trying to do:

SELECT GD.GradebookDetailId, G.SubjectCode, G.Description, G.UnitsAcademic, G.UnitsNonAcademic,  GD.Grade, GD.Remarks, G.FacultyName, STR_TO_DATE(G.DateApproved, '%m/%d/%Y %h:%i:%s') AS 'DateAproved' FROM gradebookdetail GD INNER JOIN gradebook G ON GD.GradebookId=G.GradebookId  WHERE G.DateApproved IS NOT NULL AND G.GradebookType='final' AND StudentIdNumber='2012-12345'  GROUP BY <?????> ORDER BY G.SubjectCode ASC 

Basically, I only want to display the most recent "DateApprove" of a "SubjectCode", so I don't get multiple entries.

Answer 1

Start with this:

select StudentId, max(DateApproved)  from tbl group by StudentId 

Then integrate that to main query:

select *  from tbl where (StudentId, DateApproved) in  (   select StudentId, max(DateApproved)    from tbl   group by StudentId ) 

You can also use this:

select *  from tbl join (select StudentId, max(DateApproved) as DateApproved        from tbl        group by StudentId) using (StudentId, DateApproved) 

But I prefer tuple testing, it's way neater

Live test: http://www.sqlfiddle.com/#!2/771b8/5