I have four tables (Customer, OrderTbl, OrdLine and Product). I have to list the customer number of customers who have ordered all of the products that a manufacture called ColorCorp have to offer.

describe customer;
CUSTNO

describe product;
PRODNO
PRODMANUFACTURE

describe ordertbl
ORDNO
CUSTNO

describe ordline
ORDNO
PRODNO

I tried very unsuccessfully using subqueries. I just can’t manage to get it going. Can anyone please give me any adivice or help, very much appreciated.