Delete duplicate rows and add the deleted rows values to one that remain

Question

I have a table like :

id      |    name    |  profit |  cost  
---------------------------------------
1       |  aaa       | 4       | 2 
2       |  aaa       | 4       | 3 
3       |  aaa       | 4       | 2 
4       |  bbb       | 4       | 1 

I want to delete from this table duplicate rows (according the name) but before do the delete add the value of the deleted rows to the remain row

so in this case I want that the table after run queries look like :

id      |    name    |  profit |  cost  
---------------------------------------
1       |  aaa       | 12      | 7 
4       |  bbb       | 4       | 1 

Is it possible to do it in mysql, without create another table and copy the data, because this is a big table (1 million rows but increase every day) ?

Answer 1

SQLFiddle demo

First update rows with min(id) for each NAME

UPDATE T a JOIN 
(
  SELECT min(ID) as minID,name,SUM(profit) as SP,SUM(cost) as SC 
  FROM T GROUP BY name
) b 
 ON a.id = b.minID 
 SET a.profit = b.sp,a.cost=b.sc;

And then delete rows except only those rows with min(id) for each NAME

DELETE T
FROM T
LEFT JOIN 
(
  SELECT min(ID) minid ,name FROM T GROUP BY name
) b  
ON t.id = b.minid
WHERE b.minid is NULL