我编写了以下CodeIgniter模型函数来获取并遍历MySQL查询结果。
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 $record;
}
该代码适用于除最后一本书之外的所有内容 - 它总是错过最后一行。我可以看出它为什么这样做,但我不知道如何解决它。这是我尝试过的东西,但我仍然没有把最后一本书包含在$ 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 $record;
}
有什么建议吗?我该如何解决这个问题?
答案 0 :(得分:0)
我明白了。我在第二个例子中几乎是正确的,我只需要将$ i计数器初始化为1而不是0
$i = 1;