my $find_book = $dbh->prepare(qq{
SELECT title FROM book WHERE isbn = ?
});
####
my $isbn = "156884915X";
my $title = $dbh->selectrow_array($find_book, undef, $isbn);
####
my $isbn = 1565922433;
my $title = $dbh->selectrow_array($find_book, undef, $isbn);