Two foreign keys instead of primary

Question

I was wondering, is there any possibility to create a table without a primary key, but with two foreign keys, where the foreign keys pairs are always different? For example,

Answer 1

Like this:

create table stock
( item_id      references items(item_id)
, warehouse_id references warehouses(warehouse_id)
, quantity     number(12,2) not null
, constraint stock_pk primary key (item_id, warehouse_id)
);