Shulou(Shulou.com)06/01 Report--

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 100rows that were deleted and the second rollback commits only the changes.

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

C) The first rollback restores the 101rows 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 100rows that were deleted.

Answer:C

(parsing: the answer is very simple, testing the rollback operation)

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