70、(31-2)choose the best answer:

View the Exhibit and examine the structure of the Book table.

The BOOKS table contains details of 100 books.

Examine the commands executed and their outcome:

SQL>INSERT INTO books VALUES ('ADV112', 'Adventures of Tom Sawyer',null,null);

1 row created.

SQL>SAVEPOINT A;

Savepoint created.

SQL>DELETE FROM books;

101 rows deleted.

SQL>ROLLBACK TO SAVEPOINT A;

Rollback complete.

SQL>ROLLBACK;

Rollback complete.

Which statement is true?

A) The first rollback restores the 100 rows that were deleted and the second rollback commits only the changes.

B) Both ROLLBACK commands restore the 101 rows that were deleted.

C) The first rollback restores the 101 rows that were deleted and the second rollback causes the row that was inserted to be deleted and commits the changes.

D) Both ROLLBACK commands restore the 100 rows that were deleted.

Answer：C

 

(解析：答案很简单，考的是回滚操作)