Which constraint can be defined only at the column level?
A.
UNIQUE
B.
NOT NULL
C.
CHECK
D.
PRIMARY KEY
E.
FOREIGN KEY
Explanation:
the NOT NULL constraint can be specified only at the column level, not at the table level.
Incorrect answer:
AUNIQUE can be define at table level
CCHECK can be define at table level
DPRIMARY KEY can be define at table level
EFOREIGN KEY can be define at table level