Laravel cursorPagination 返回包含数组和对象的结果

Question

我在 Livewire 组件中实现了无限分页，我注意到在初始页面加载时它正在加载对象，但是当我滚动并加载更多数据时，它会将数组添加到集合中，所以我最终得到了一个集合具有数组和对象的混合值。知道如何解决这个问题，以便它唯一的对象吗？我希望拥有所有对象的原因是我在视图中使用了一个方法，如果它是一个数组，我就无法访问它。

/**
     * Loads more blog posts.
     *
     * @return void
     */
    public function loadBlogs()
    {
        if ($this->hasMorePages !== null  && !$this->hasMorePages) {
            return;
        }

        if ($this->category_id) {
            $posts = BlogPost::where('user_id', request()->user()->id)
                ->where('category_id', $this->category_id)
                ->with('category')
                ->orderBy('id', 'desc')
                ->cursorPaginate(16, ['*'], 'cursor', Cursor::fromEncoded($this->nextCursor));
        } else {
            $posts = BlogPost::where('user_id', request()->user()->id)
                ->with('category')
                ->orderBy('id', 'desc')
                ->cursorPaginate(16, ['*'], 'cursor', Cursor::fromEncoded($this->nextCursor));
        }

        $this->blogPosts->push(...$posts->items());

        $this->hasMorePages = $posts->hasMorePages();

        if ($this->hasMorePages === true) {
            $this->nextCursor = $posts->nextCursor()->encode();
        }
    }

dd:

Illuminate\Support\Collection {#1751 ▼
  #items: array:32 [▼
    0 => array:10 [▶]
    1 => array:10 [▶]
    2 => array:10 [▶]
    3 => array:10 [▶]
    4 => array:10 [▶]
    5 => array:10 [▶]
    6 => array:10 [▶]
    7 => array:10 [▶]
    8 => array:10 [▶]
    9 => array:10 [▶]
    10 => array:10 [▶]
    11 => array:10 [▶]
    12 => array:10 [▶]
    13 => array:10 [▶]
    14 => array:10 [▶]
    15 => array:10 [▶]
    16 => App\Models\BlogPost {#1775 ▶}
    17 => App\Models\BlogPost {#1776 ▶}
    18 => App\Models\BlogPost {#1777 ▶}
    19 => App\Models\BlogPost {#1778 ▶}
    20 => App\Models\BlogPost {#1779 ▶}
    21 => App\Models\BlogPost {#1780 ▶}
    22 => App\Models\BlogPost {#1781 ▶}
    23 => App\Models\BlogPost {#1782 ▶}
    24 => App\Models\BlogPost {#1783 ▶}
    25 => App\Models\BlogPost {#1784 ▶}
    26 => App\Models\BlogPost {#1785 ▶}
    27 => App\Models\BlogPost {#1786 ▶}
    28 => App\Models\BlogPost {#1787 ▶}
    29 => App\Models\BlogPost {#1788 ▶}
    30 => App\Models\BlogPost {#1789 ▶}
    31 => App\Models\BlogPost {#1790 ▶}
  ]
  #escapeWhenCastingToString: false
}

Answer 1

我使用Illuminate\Support\Collection，我改为Illuminate\Database\Eloquent\Collection，而不是使用collect()来设置我使用new Collection()的初始集合

结果是这样的：

Illuminate\Database\Eloquent\Collection {#1805 ▼
  #items: array:32 [▼
    0 => App\Models\BlogPost {#1789 ▶}
    1 => App\Models\BlogPost {#1790 ▶}
    2 => App\Models\BlogPost {#1791 ▶}
    3 => App\Models\BlogPost {#1792 ▶}
    4 => App\Models\BlogPost {#1793 ▶}
    5 => App\Models\BlogPost {#1794 ▶}
    6 => App\Models\BlogPost {#1795 ▶}
    7 => App\Models\BlogPost {#1796 ▶}
    8 => App\Models\BlogPost {#1797 ▶}
    9 => App\Models\BlogPost {#1798 ▶}
    10 => App\Models\BlogPost {#1799 ▶}
    11 => App\Models\BlogPost {#1800 ▶}
    12 => App\Models\BlogPost {#1801 ▶}
    13 => App\Models\BlogPost {#1802 ▶}
    14 => App\Models\BlogPost {#1803 ▶}
    15 => App\Models\BlogPost {#1804 ▶}
    16 => App\Models\BlogPost {#1786 ▶}
    17 => App\Models\BlogPost {#1787 ▶}
    18 => App\Models\BlogPost {#1788 ▶}
    19 => App\Models\BlogPost {#1717 ▶}
    20 => App\Models\BlogPost {#1764 ▶}
    21 => App\Models\BlogPost {#1755 ▶}
    22 => App\Models\BlogPost {#1813 ▶}
    23 => App\Models\BlogPost {#1814 ▶}
    24 => App\Models\BlogPost {#1815 ▶}
    25 => App\Models\BlogPost {#1816 ▶}
    26 => App\Models\BlogPost {#1817 ▶}
    27 => App\Models\BlogPost {#1818 ▶}
    28 => App\Models\BlogPost {#1819 ▶}
    29 => App\Models\BlogPost {#1820 ▶}
    30 => App\Models\BlogPost {#1821 ▶}
    31 => App\Models\BlogPost {#1822 ▶}
  ]
  #escapeWhenCastingToString: false
}

**编辑

使用Illuminate\Database\Eloquent\Collection 会带来性能问题。以下是查询的样子：

select * from
'blog posts' where 'blog_posts'. 'id' in (10103, 10102, 10101, 10100, 10099, 10098,
10097, 10096, 10095, 10094, 10093, 10092, 10091, 10090, 10089, 10088, 10087, 10086, 10085, 10084
10083, 10082, 10081, 10080, 10079, 10078, 10077, 10076, 10075, 10074, 10073, 10072, 10071, 10070,
10069, 10068, 10067, 10066,
10065, 10064, 10063, 10062,
10061, 10060, 10059, 10058, 10057, 10056,
10055, 10054, 10053, 10052, 10051, 10050, 10049, 10048, 10047, 10046, 10045, 10044, 10043, 10042,
10041, 10040, 10039, 10038, 10037, 10036, 10035, 10034, 10033, 10032, 10031, 10030, 10029, 10028,
10027, 10026, 10025, 10024, 10023, 10022, 10021, 10020, 10019, 10018, 10017, 10016, 10015, 10014,
10013, 10012, 10011, 10010, 10009, 10008, 10007, 10006, 10005, 10004, 10003, 10002, 10001, 10000,
9999, 9998, 9997, 9996, 9995, 9994, 9993, 9992, 9991, 9990, 9989, 9988, 9987, 9986, 9985, 9984, 9983,
9982.
9981, 9980, 9979, 9978, 9977, 9976)

每次您前进一个页面时，此查询都会变得越来越大，这就是性能问题所在。

我决定坚持使用Illuminate\Support\Collection 并使用数组，查询如下所示：

select * from `blog_posts` where `user_id` = 1 and (`id` < 9848) order by `id` desc limit 17

这似乎更高效。

Answer 2

不确定这是否是最佳或最优雅的解决方案，但您可以尝试将数组转换为对象...

foreach($posts->items() as $post) {
    $this->blogPosts->push(new BlogPost($post));
}

编辑：哎呀...我认为下面的逻辑更正确。

foreach($posts->items() as $post) {
    $this->blogPosts->push(BlogPost::find($post->id));
}

编辑：如果您对为每条记录运行查找查询感觉不好。这种方法可能更快。

$blog_post_ids = collect($posts->items())->pluck('id')->toArray();
$blog_posts = BlogPost::whereIn('id', $blog_post_ids)->get();
$this->blogPosts->push(...$blog_posts);