Oracle 18c

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create table need ( item, packid, amount )
as
select 1, 1, 10 from dual union all   -- item 1: we need 2 packs of 10 
select 1, 2, 10 from dual ;
2 rows affected

create table fill( item, binid, amount )
as
select 1, 1, 5 from dual union all   -- item 2: we have 4 packs of 5
select 1, 2, 5 from dual union all
select 1, 3, 5 from dual union all
select 1, 4, 5 from dual ;
4 rows affected

create or replace view need_vw
as
select
  item, packid, amount, single_item
, row_number() over ( order by item, packid ) row_
from need N cross apply (
    select 1 as single_item from dual connect by level <= N.amount
) SN
;
create or replace view fill_vw
as
select
  item, binid, amount, single_item
, row_number() over ( order by item, binid ) row_
from fill F cross apply (
    select 1 as single_item from dual connect by level <= F.amount
) SF
;
select  NV.packid, FV.binid, sum( FV.single_item ) 
from (
  select item, binid, amount, single_item, row_ from fill_vw
) FV join (
  select item, packid, amount, single_item, row_ from need_vw
) NV on FV.row_ = NV.row_ 
group by rollup ( NV.packid, FV.binid );


PACKID
BINID
SUM(FV.SINGLE_ITEM)


1
1
5

1
2
5

1
null
10

2
3
5

2
4
5

2
null
10

null
null
20

PACKID	BINID	SUM(FV.SINGLE_ITEM)
1	1	5
1	2	5
1	null	10
2	3	5
2	4	5
2	null	10
null	null	20