Which statement adds a constraint that ensures the CUSTOMER_NAME column of the
CUSTOMERS table holds a value?
A.
ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK customer_name IS
NOT NULL;
B.
ALTER TABLE customers MODIFY CONSTRAINT cust_name_nn CHECK customer_name IS
NOT NULL;
C.
ALTER TABLE customers MODIFY customer_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 MODIFY name CONSTRAINT cust_name_nn NOT NULL;
F.
ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK customer_name NOT
NULL;
I think none of the answers are right
->Check constraint should have parenthesis
After applying parethesis A would be the answer
As mentioned, option C is the correct answer..
ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK (customer_name IS NOT NULL); –done
ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK (customer_name NOT NULL); –not done
ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK (customer_name) IS NOT NULL; –notdone