Which statement adds a constraint that ensures the CUSTOMER_NAME column of the
CUSTOMERS table holds a value?
A.
ALTER TABLE customers
MODIFY customer_name CONSTRAINT cust_name_nn NOT NULL;
B.
ALTER TABLE customers
MODIFY CONSTRAINT cust_name_nn CHECK customer_name IS NOT NULL;
C.
ALTER TABLE customers
MODIFY name CONSTRAINT cust_name_nn NOT NULL;
D.
ALTER TABLE customers
MODIFY customer_name CONSTRAINT cust_name_nn IS NOT NULL;
E.
ALTER TABLE customers
ADD CONSTRAINT cust_name_nn CHECK customer_name NOT NULL;
F.
ALTER TABLE customers
ADD CONSTRAINT cust_name_nn CHECK customer_name IS NOT NULL;