View the Exhibit and examine the ORDERS table. The ORDERS table contains data and all
orders have been assigned a customer ID. Which statement would add a NOT NULL
constraint to the CUSTOMER_ID column?
A.
ALTER TABLE orders ADD CONSTRAINT orders_cust_id_nn NOT NULL (customer_id);
B.
ALTER TABLE orders MODIFY customer_id CONSTRAINT orders_cust_id_nn NOT
NULL;
C.
ALTER TABLE orders MODIFY CONSTRAINT orders_cust_id_nn NOT NULL
(customer_id);
D.
ALTER TABLE orders ADD customer_id NUMBER(6)CONSTRAINT orders_cust_id_nn
NOT NULL;