Re: sum in mysql

[Phillip Ward]

If you're using SUM to generate multiple rows, then you must have a "group by" clause that generates each row.
To get the "grand total", remove the "group by" clause to get a single-row total.

select * from table1 ; 

+----+-----+-----+
| id | key | qty |
+----+-----+-----+
| 77 | a   |   3 | 
| 88 | a   |   6 | 
| 99 | b   |  12 |
+----+-----+-----+

select 
  key
, sum( qty ) qty 
from table1
group by key 

+-----+-----+
| key | qty | 
+-----+-----+
| a   |   9 |
| b   |  12 |
+-----+-----+

select 
  sum( qty ) qty 
from table1

+-----+
| qty | 
+-----+
|  21 |
+-----+

Regards, Phill W.