如何在这里获得查询的整个结果集?

function get_book_info() {

/*
 * SELECT b.isbn, b.title, b.publisher, b.date, b.thumb, b.filename, b.pages, t.tag
 * FROM books AS b
 * INNER JOIN books_tags AS bt ON b.isbn = bt.book_id
 * INNER JOIN tags AS t ON bt.tag_id = t.id
 * ORDER BY b.title, t.tag
 */

$this->db->select('b.isbn, b.title, b.publisher, b.date, b.thumb, b.filename, b.pages, t.tag');
$this->db->from('books AS b');
$this->db->join('books_tags AS bt', 'b.isbn = bt.book_id', 'inner');
$this->db->join('tags AS t', 'bt.tag_id = t.id', 'inner');
$this->db->order_by('b.title, t.tag');
$query = $this->db->get();
$result = $query->result();

$counter = '';
$record = $meta = $tags = array();
foreach ($result as $book) {
    // If this is the first appearance of this book
    if ($counter != $book->isbn) {
        // If the meta array already exists
        if ($meta) {
            // Add the combined tag string to the meta array
            $meta['tags'] = implode(', ', $tags);
            // Add the meta array
            $record[] = $meta;
            // Empty the tags array
            $tags = array();
        }
        // Reset the counter
        $counter = $book->isbn;
        // Grab the book from Amazon
        $amazon = $this->amazon->get_amazon_item($book->isbn);
        // Collect the book information
        $meta = array(
            'isbn' => $book->isbn,
            'title' => strip_slashes($book->title),
            'publisher' => strip_slashes($book->publisher),
            'date' => date('F j, Y', strtotime($book->date)),
            'thumb' => $book->thumb,
            'filename' => $book->filename,
            'pages' => $book->pages,
            'rating' => $amazon->Items->Item->CustomerReviews->AverageRating,
            'raters' => $amazon->Items->Item->CustomerReviews->TotalReviews
        );
        // Add the tag to the tags array
        $tags[] = $book->tag;
    } else {
        // All we need is the tag
        $tags[] = $book->tag;
    }
}

return $record;
}

这段代码只适用于最后一本书——它总是漏掉最后一行。我知道它为什么会这样,但我不知道怎么解决它。这里有一些我尝试过的方法,但是仍然没有将最后一本书包含在$record数组中。

function get_book_info() {

    /*
     * SELECT b.isbn, b.title, b.publisher, b.date, b.thumb, b.filename, b.pages, t.tag
     * FROM books AS b
     * INNER JOIN books_tags AS bt ON b.isbn = bt.book_id
     * INNER JOIN tags AS t ON bt.tag_id = t.id
     * ORDER BY b.title, t.tag
     */

    $this->db->select('b.isbn, b.title, b.publisher, b.date, b.thumb, b.filename, b.pages, t.tag');
    $this->db->from('books AS b');
    $this->db->join('books_tags AS bt', 'b.isbn = bt.book_id', 'inner');
    $this->db->join('tags AS t', 'bt.tag_id = t.id', 'inner');
    $this->db->order_by('b.title, t.tag');
    $query = $this->db->get();
    $result = $query->result();

    $counter = '';
    $record = $meta = $tags = array();
    $count = count($result);
    $i = 0;

    foreach ($result as $book) {
        // If this is not the last row
        if ($i < $count) {
            // If this is the first appearance of this book
            if ($counter != $book->isbn) {
                // If the meta array already exists
                if ($meta) {
                    // Add the combined tag string to the meta array
                    $meta['tags'] = implode(', ', $tags);
                    // Add the meta array
                    $record[] = $meta;
                    // Empty the tags array
                    $tags = array();
                }
                // Reset the counter
                $counter = $book->isbn;
                // Grab the book from Amazon
                $amazon = $this->amazon->get_amazon_item($book->isbn);
                // Collect the book information
                $meta = array(
                    'isbn' => $book->isbn,
                    'title' => strip_slashes($book->title),
                    'publisher' => strip_slashes($book->publisher),
                    'date' => date('F j, Y', strtotime($book->date)),
                    'thumb' => $book->thumb,
                    'file' => $book->filename,
                    'pages' => $book->pages,
                    'rating' => $amazon->Items->Item->CustomerReviews->AverageRating,
                    'raters' => $amazon->Items->Item->CustomerReviews->TotalReviews
                );
                // Add the tag to the tags array
                $tags[] = $book->tag;
            } else {
                // All we need is the tag
                $tags[] = $book->tag;
            }
        // If this is the last row
        } else {
            // If this is the first appearance of this book
            if ($counter != $book->isbn) {
                // Grab the book from Amazon
                $amazon = $this->amazon->get_amazon_item($book->isbn);
                // Collect the book information
                $meta = array(
                    'isbn' => $book->isbn,
                    'title' => strip_slashes($book->title),
                    'publisher' => strip_slashes($book->publisher),
                    'date' => date('F j, Y', strtotime($book->date)),
                    'thumb' => $book->thumb,
                    'file' => $book->filename,
                    'pages' => $book->pages,
                    'rating' => $amazon->Items->Item->CustomerReviews->AverageRating,
                    'raters' => $amazon->Items->Item->CustomerReviews->TotalReviews
                );
                // Add the tag to the tags array
                $tags[] = $book->tag;
                // Add the combined tag string to the meta array
                $meta['tags'] = implode(', ', $tags);
                // Add the meta array
                $record[] = $meta;
            } else {
                // All we need is the tag
                $tags[] = $book->tag;
                // Add the combined tag string to the meta array
                $meta['tags'] = implode(', ', $tags);
                // Add the meta array
                $record[] = $meta;
            }
        }
        $i++;
    }

    return $record;
}

有什么建议吗?我该怎么解决这个问题?