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;