分类： Oracle
2022-01-21 17:13:53
18、Evaluate the following ALTER TABLEstatement:
ALTER TABLE orders SET UNUSED (order_date);
Which statement is true?
A. After executing the ALTER TABLEcommand, you can add a new column called ORDER_DATE to the ORDERS table.
B. The ORDER_DATE column should be empty for the ALTER TABLE command to execute succsessfully.
C. ROLLBACK can be used to get back the ORDER_DATE column in the ORDERStable.
D. The DESCRIBE command would still display the ORDER_DATE column.
Source ： cuug
