Which of the following options is not correct?
Answer options
A
ALTER TABLE emp DROP column_name;
B
ALTER TABLE emp DROP COLUMN salary;
C
ALTER TABLE emp ADD COLUMN salary NUMBER;
D
ALTER TABLE emp MODIFY salary VARCHAR(20);
Correct answer: ALTER TABLE emp DROP column_name;
Explanation
The correct syntax requires the COLUMN keyword: ALTER TABLE emp DROP COLUMN salary; — DROP column_name; is invalid.