Agile Web Development Question

This is a question about Integration Tests from Agile Web D.
book - 2nd Edition.
The integration test is contained in the file “user_stories_test.rb” and
given on page 208 of the book. I can run the test fine and it works.
One thing that puzzles me is that both the orders and line_items tables
are empty after running the test unlike unit and functional tests which
leave the fixtures data populated in the table. I make a point of
checking them after I run the test to see if the tests ran and populated
the fixture data into the table. Integration test does not seem to do
that.
I even commented out the following two lines at the beginning of the
test called “test_buying_a_product” :

LineItem.delete_all

Order.delete_all

but that still left the tables empty. Is this the default Rails
behavior?
Bharat