首页 > 解决方案 > Laravel:如何排序相关模型的结果?

问题描述

我提出了以下查询生成器,并且我得到了准确的结果,除非我需要根据论坛的喜欢和线程总数对结果进行排序并根据它进行分页。

下面是没有 sortby 的查询生成器:

$limit = isset($_GET['limit']) && !empty($_GET['limit']) && is_numeric($_GET['limit']) ? (int) $_GET['limit'] : 10;

$page = isset($_GET['page']) && !empty($_GET['page']) && is_numeric($_GET['page']) ? (int) $_GET['page'] : 1;

$offset = ($page - 1) * $limit;

$forums = Forum::where('status', 1);

if(isset($_GET['search']) && !empty($_GET['search'])) {

    $search = trim($_GET['search']);

    $forums = $forums->where(function($query) use($search) {

        $query->where('title', 'LIKE', '%' . $search . '%')->orWhere('content', 'LIKE', '%' . $search . '%');

    });

}

if(isset($_GET['category']) && !empty($_GET['category'])) {

    $forums = $forums->whereIn('category_id', explode(',', trim($_GET['category'])));

}

if(isset($_GET['sortby']) && !empty($_GET['sortby'])) {

    $sortby = trim($_GET['sortby']);

    if($sortby == 'newest') {

        $forums = $forums->latest();

    } elseif($sortby == 'oldest') {

        $forums = $forums->oldest();

    } elseif($sortby == 'popular') {

        // Sort By: Popular | Logic: Total no of likes and threads to a forum

    } else {

        $forums = $forums->latest();

    }

} else {

    $forums = $forums->latest();

}

$forums = $forums->offset($offset)->limit($limit)->get();

我在论坛模型中定义了雄辩的关系如下:

public function threads()
{

    return $this->hasMany('App\ForumThread', 'forum_id', 'id');

}

public function likes()
{

    return $this->hasMany('App\ForumLike', 'forum_id', 'id');

}

论坛表架构:

CREATE TABLE `forums` (
    `id` bigint(20) UNSIGNED NOT NULL,
    `category_id` int(10) UNSIGNED NOT NULL,
    `user_id` bigint(20) UNSIGNED NOT NULL,
    `title` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
    `content` longtext COLLATE utf8mb4_unicode_ci,
    `image` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
    `tags` text COLLATE utf8mb4_unicode_ci,
    `status` tinyint(3) UNSIGNED NOT NULL DEFAULT '1',
    `created_at` timestamp NULL DEFAULT NULL,
    `updated_at` timestamp NULL DEFAULT NULL,
    `deleted_at` timestamp NULL DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

论坛喜欢表模式:

CREATE TABLE `forum_likes` (
    `id` bigint(20) UNSIGNED NOT NULL,
    `forum_id` bigint(20) UNSIGNED NOT NULL,
    `user_id` bigint(20) UNSIGNED NOT NULL,
    `created_at` timestamp NULL DEFAULT NULL,
    `updated_at` timestamp NULL DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

论坛线程表架构如下:

CREATE TABLE `forum_threads` (
    `id` bigint(20) UNSIGNED NOT NULL,
    `forum_id` bigint(20) UNSIGNED NOT NULL,
    `user_id` bigint(20) UNSIGNED NOT NULL,
    `content` longtext COLLATE utf8mb4_unicode_ci NOT NULL,
    `created_at` timestamp NULL DEFAULT NULL,
    `updated_at` timestamp NULL DEFAULT NULL,
    `deleted_at` timestamp NULL DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

谢谢!

标签: phplaraveleloquentlaravel-query-builder

解决方案


计算相关模型
如果你想计算一个关系的结果数而不实际加载它们,你可以使用 withCount 方法,它会在你的结果模型上放置一个 {relation}_count 列。

因此,您可以使用withCount()然后按放置的列对结果进行排序。例如对于“喜欢”关系:

} elseif ($sortby == 'popular') {
    $forums = $forums->withCount('likes')->orderBy('likes_count', 'desc');
}

推荐阅读