SQL Vis seneste post i GROUP BY?

Start med dette:

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

Integrer det derefter i hovedforespørgslen:

select * 
from tbl
where (StudentId, DateApproved) in

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

Du kan også bruge denne:

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

Men jeg foretrækker tupeltest, det er på den måde pænere

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