Question

Is there any way to make first row be different then the rest, so it would show total sum of the appropriate columns?

For example:

      fruits|a|b|c
       total|3|4|6
      apples|1|2|3
     bananas|1|1|2
     oranges|1|1|1

Is it possible to make query like that or it is against the logic of sql?
It would be like this (ignoring the first row for now):

SELECT fruits, sum(a), sum(b), sum(c)
FROM basket

So the first row would be different. It would show word ‘total’ instead of fruit name, and would show total sum of a (1+1+1=3), b (2+1+1=4) and c (3+2+1=6). Is it possible to do like that? Thanks

Answer 1

You can avoid a second full scan of the table with a CTE:

PostgreSQL 9.2 Schema:

create table basket(fruits text, a integer, b integer, c integer);
insert into basket(fruits, a, b, c) values('apples', 1, 1, 1),
                                          ('apples', 0, 1, 2),
                                          ('bananas', 1, 1, 2),
                                          ('oranges', 1, 1, 1);

Query:

with w as ( select fruits, sum(a) a, sum(b) b, sum(c) c
            from basket
            group by fruits )
select * from w union all select 'total', sum(a), sum(b), sum(c) from w

Results:

|  FRUITS | A | B | C |
-----------------------
| bananas | 1 | 1 | 2 |
| oranges | 1 | 1 | 1 |
|  apples | 1 | 2 | 3 |
|   total | 3 | 4 | 6 |

SQL Fiddle here