You have an ORDERS table with the following structure:
The table has data in the ODATE column for all rows. Many orders are placed in a single day. You
need to ensure that the ODATE column must contain data for every order in future.
Which method would serve the purpose?
A.
Modify the column using the ALTER TABLE … MODIFY command.
B.
Add a UNIQUE constraint to the column using the ALTER TABLE … ADD CONSTRAINT
command.
C.
Add a NOT NULL constraint to the column using the ALTER TABLE … ADD CONSTRAINT
command.
D.
Add a PRIMARY KEY constraint to the column using the ALTER TABLE … ADD CONSTRAINT
command.
ALTER TABLE ORDERS MODIFY OID NOT NULL.
ALTER TABLE orders MODIFY (oid CONSTRAINT oid_nn NOT NULL);
Could you please clarify that; what is the relation between OID and ODATE; question is ODATE must contain data a.k.a must be not null but you say to modify oid column?
Thanks in advance