Getting sum of rows based on column in oracle

One way to do this is with rollup. However, because you want the original data, this approach does a "fake" aggregation by rownum for the rollup:

select Month, sum(Count),
       (case when rn is null then 'SUM' end) as status
from (select rownum as rn, t.*
      from t
     ) t
group by Month, rollup(rn)

I'm not sure what you mean by the A and B in the status column.

The original table:

CREATE TABLE test
(
    month CHAR(3), 
    num INT,
    status CHAR(3)
);

INSERT INTO test (month, num, status) VALUES
    ('Jan', 5, 'A'),
    ('Jan', 7, 'B'),
    ('Feb', 1, 'A'),
    ('Feb', 2, 'B');

The query:

SELECT month, sum(num) AS num, 'SUM' AS status
FROM test
GROUP BY month
UNION
SELECT month, num, status
FROM test
ORDER BY month DESC, status

Result:

MONTH   NUM   STATUS
Jan     5     A
Jan     7     B
Jan     12    SUM
Feb     1     A
Feb     2     B
Feb     3     SUM

Here is the SQLfiddle.

select month, sum(count) from table group by rollup(month, count);

It will give net total as well, if you want to avoid it use month is not null.

Oracle have MODEL clause for the above: If you've the column status in your table, you have simple query:

Model Clause Link Oracle Documentation:

SELECT month, count , status
FROM my_test2
MODEL
PARTITION BY (MONTH)
DIMENSION BY (status)
MEASURES(count)
RULES(COUNT['Sum'] = count['A']+ count['B'])
order by month desc, status;


MONTH                     COUNT STATUS             
-------------------- ---------- --------------------
Jan                           5 A                    
Jan                           7 B                    
Jan                          12 Sum                  
Feb                           1 A                    
Feb                           2 B                    
Feb                           3 Sum                  

 6 rows selected