如何在 Laravel 的 Eloquent ORM 中按数据透视表数据排

问题描述

在我的数据库中，我有:

In my Database, I have:

• tops 表格
• posts 表格
• tops_has_posts 表格.

• tops Table
• posts Table
• tops_has_posts Table.

当我在 tops 表中检索顶部时，我还会检索与顶部相关的 posts.但是如果我想按特定顺序检索这些帖子怎么办?所以我在我的数据透视表 tops_has_posts 中添加了一个 range 字段，我尝试使用 Eloquent 按结果排序，但它不起作用.

When I retrieve a top on my tops table I also retrieve the posts in relation with the top. But what if I want to retrieve these posts in a certain order ? So I add a range field in my pivot table tops_has_posts and I my trying to order by the result using Eloquent but it doesn't work.

我试试这个:

$top->articles()->whereHas('articles', function($q) {
    $q->orderBy('range', 'ASC');
})->get()->toArray();

还有这个:

$top->articles()->orderBy('range', 'ASC')->get()->toArray();

两者都是绝望的尝试.

提前致谢.

推荐答案

有两种方法 - 一种是指定 table.field，另一种使用 Eloquent 别名 pivot_field if你使用 withPivot('field'):

There are 2 ways - one with specifying the table.field, other using Eloquent alias pivot_field if you use withPivot('field'):

// if you use withPivot
public function articles()
{
  return $this->belongsToMany('Article', 'tops_has_posts')->withPivot('range');
}

// then: (with not whereHas)
$top = Top::with(['articles' => function ($q) {
  $q->orderBy('pivot_range', 'asc');
}])->first(); // or get() or whatever

这会起作用，因为 Eloquent 将 withPivot 中提供的所有字段别名为 pivot_field_name.

This will work, because Eloquent aliases all fields provided in withPivot as pivot_field_name.

现在，通用解决方案:

$top = Top::with(['articles' => function ($q) {
  $q->orderBy('tops_has_posts.range', 'asc');
}])->first(); // or get() or whatever

// or:
$top = Top::first();
$articles = $top->articles()->orderBy('tops_has_posts.range', 'asc')->get();

这将对相关查询进行排序.

This will order the related query.

注意:不要因为这样命名事情而使您的生活变得艰难.posts 不一定是 articles，我会使用一个或另一个名称，除非确实需要这样做.

Note: Don't make your life hard with naming things this way. posts are not necessarily articles, I would use either one or the other name, unless there is really need for this.

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