sql - How to find max over a category

Question

How do I get the output like this in sql. I tried group by but it is not giving months, is there an easier way to do this.

select * from t1 order by 1,2 ;
 id | month | amnt
----+-------+------
  1 | feb   |   50
  1 | jan   |   20
  2 | apr   |   30
  2 | feb   |   50
  2 | jan   |   30
  2 | mar   |   70
(6 rows)

Output
=========

 id | month | amnt
----+-------+------
  1 | feb   |   50
  2 | mar   |   70

Answer 1

If you have window functions

Select Top 1 with ties *
 From  YourTable
 Order By Row_Number() over (Partition By id order by amnt desc)

Returns

id  month   amnt
2   mar     70
1   feb     50