select distinct invoice_no
from shipment A
where exists(select 1 from ship where invoice_no =A.invoice_no and supplier_no=A.supplier_no)

------解决方案--------------------

SQL code

select * from 
(
    select invoice_no,supplier_no,count(1) as a 
    from shipment group by invoice_no,supplier_no
) a left join 
(
    select invoice_no,supplier_no,count(1) as b  
    from ship group by invoice_no,supplier_no
) b 
on a.invoice_no=b.invoice_no and a.supplier_no=b.supplier_no and a.a<>b.b

------解决方案--------------------
SQL code
select distinct invoice_no
from shipment A
where not exists(select 1 from ship where invoice_no =A.invoice_no and supplier_no=A.supplier_no)