Select rows until a total amount is met in a column (mysql)

Question

I have seen this issue in SF, but me being a noob I just can\'t get my fried brain around them. So please forgive me if this feels like repetition.

My Sample Table

Answer 1

How about this? Using two variables.

SQLFIDDLE DEMO

Query:

set @tot:=0;
set @sup:=0;

select x.id, x.supplier, x.ctot
from (
select id, supplier, qty,
@tot:= (case when @sup = supplier then
@tot + qty else qty end) as ctot,
@sup:=supplier
from demo
order by supplier asc, id desc) x
where x.ctot >=5
;

| ID | SUPPLIER | CTOT |
------------------------
|  2 |        1 |    5 |
|  1 |        1 |    7 |
|  3 |        2 |    5 |