have a table with some like this fields :

order, client_name, unit, type

1 - nobody - 1 - orange
2 - me - 2 - yellow
3 - another - 1 - black
1 - nobody - 1 - orange
1 - nobody - 1 - orange

I want to make a select that return GROUP by "type" field but at same
time the SUM or "unit". Ok, works fine, but now i want to "order" must
be UNIQUE.. i mean, the SUM in this case return 6 instead 4

What can i do ? I use MySQL 4.1.18

The select that i use in this case is :

select type, sum(unit) from table group by type

The expected result is :

orange, 1
yellow, 1
black, 1