Laravel 5.4：如何在不将一个 foreach 嵌套在另一个 foreach 中的情况下获得相同的结果？

Question

我打算以某种语言获取新闻$newif($new_lang->lang_id == $lang_id)，然后我查看与新闻相对应的图像表@foreach($data['images'] as $image)，这是主要的@if($image->imageable_id == $new->id && $image->main == '1')。

问题是嵌套 foreach 时，加载非常缓慢，因为它们包含 7,000 多条新闻和大约 70,000 张图片。

如何在不将一个 foreach 嵌套在另一个中的情况下获得相同的结果？

@foreach($new->langs as $new_lang)
@if($new_lang->lang_id == $lang_id)
    @foreach($data['images'] as $image)
        @if($image->imageable_id == $new->id && $image->main == '1')
            @php
                $mini = substr($image->path, 0, strrpos( $image->path, "/"));
                $name = substr($image->path, strrpos($image->path, '/') + 1);
                $image_mini = $mini.'/mini-'.$name;
            @endphp
            <div class="crop">
                <a href="{{ route('noticia', [$new->id, $new_lang->slug]) }}">{{ HTML::image(file_exists($image_mini)? $image_mini : $image->path, '', array('class' => 'img-responsive ancho_100')) }}</a>
            </div>
        @endif
    @endforeach
@endif
@endforeach

已编辑：添加了控制器和特征

这是控制器：

    use ListNoticias;

public function actualidad(Request $request)
{
    $data['section_id'] = explode(',', '1,2,3');

    $data['ruta'] = 'actualidad';
    $data['title'] = __('header.actualidad');
    $data['num'] = $request->num;
    $url = $request->url();

    $data = $this->listNoticias($data, $url);

    return view('web.actualidad.listado', compact('data'));
}

还有特点：

trait ListNoticias
{
public function listNoticias($data, $url)
{
    $now = date('Y-m-d');
    $time = date('H:i:s');

    (isset($data['num']))? $num = $data['num'] : $num = '15';

    $data['images'] = Image::where('imageable_type', 'App\Models\Noticia')->get();
    $data['sections']  = Section::all();

    $data['noticias'] = Noticia::with('langs')->where('date', '<', $now)
        ->where('active', '1')
        ->whereIn('section_id', $data['section_id'])
        ->orWhere('date', '=', $now)
        ->where('time', '<=', $time)
        ->where('active', '1')
        ->whereIn('section_id', $data['section_id'])
        ->orderBy('date', 'desc')
        ->orderBy('time', 'desc')
        ->get();

    $data['noticias-es'] = [];
    $data['noticias-en'] = [];
    $data['noticias-pt'] = [];

    foreach($data['noticias'] as $row){
        foreach($row->langs as $row_lang) {
            if ($row_lang->lang_id == '1') {
                $data['noticias-es'][] = $row;
            } elseif ($row_lang->lang_id == '2') {
                $data['noticias-en'][] = $row;
            } elseif ($row_lang->lang_id == '3') {
                $data['noticias-pt'][] = $row;
            } else null;

        }
    }

    // Manual paginate
    /*  Get current page form url e.x. &page=1
        Create a new Laravel collection from the array data
        Slice the collection to get the items to display in current page
        Create our paginator and pass it to the view
        set url path for generated links
    */

    $currentPage = LengthAwarePaginator::resolveCurrentPage();

    // ES
    $itemCollection = collect($data['noticias-es']);
    $currentPageItems = $itemCollection->slice(($currentPage * $num) - $num, $num)->all();
    $data['noticias-es'] = new LengthAwarePaginator($currentPageItems , count($itemCollection), $num);
    $data['noticias-es']->setPath($url);

    // EN
    $itemCollection = collect($data['noticias-en']);
    $currentPageItems = $itemCollection->slice(($currentPage * $num) - $num, $num)->all();
    $data['noticias-en'] = new LengthAwarePaginator($currentPageItems , count($itemCollection), $num);
    $data['noticias-en']->setPath($url);

    // PT
    $itemCollection = collect($data['noticias-pt']);
    $currentPageItems = $itemCollection->slice(($currentPage * $num) - $num, $num)->all();
    $data['noticias-pt'] = new LengthAwarePaginator($currentPageItems , count($itemCollection), $num);
    $data['noticias-pt']->setPath($url);

    return $data;

}
}

已编辑 2

第一个视图是部分视图，包含在此视图中，并且还有另外两个 foreach nestead。这是因为我需要三个显示记录。我已经评论了问题不需要的其他包含：

@foreach ($data['noticias-'.$lang]->chunk(3) as $chunk)

<div class="col-xs-12 col-sm-12 col-md-12 col-lg-12 pad_inf_2">

    @foreach($chunk as $key => $new)
        <div class="col-xs-12 col-sm-12 col-md-4 col-lg-4 pad_der_1">
            <article>
                //@include('web.index.partials.noticia_etiqueta')
                @include('web.actualidad.partials.noticia_image_listado')
                //@include('web.index.partials.noticia_date_section')
                //@include('web.index.partials.noticia_title')
            </article>
        </div>
    @endforeach

</div>
@endforeach

模型公告：

class Noticia extends Model
{
protected $fillable = ['section_id', 'active', 'date', 'time', 'author'];

public function images()
{
    return $this->morphMany('App\Models\Image', 'imageable');
}

public function tags()
{
    return $this->morphToMany('App\Models\Tag', 'taggable');
}

public function section()
{
    return $this->belongsTo('App\Models\Section');
}

public function langs()
{
    return $this->hasMany('App\Models\LangNoticia');
}

}

LangNoticia 模型：

class LangNoticia extends Model
{
protected $fillable = ['noticia_id', 'lang_id', 'title', 'lead', 'text', 'author_place', 'slug'];

public function noticia()
{
    return $this->belongsTo('App\Models\Noticia');
}
}

EDITED 3：在 abr

的建议下减少了 trait 中的代码

特征减少：

trait ListNoticias
{
public function listNoticias($data, $url)
{
    $lang = Session::get('lang');
    if($lang == 'en') $lang_id = '2';
    elseif($lang == 'pt') $lang_id = '3';
    else $lang_id = '1';

    $now = date('Y-m-d');
    $time = date('H:i:s');

    (isset($data['num']))? $num = $data['num'] : $num = '15';

    $data['sections']  = Section::all();
    $data['images'] = Image::where('imageable_type', 'App\Models\Noticia')->where('main', true)->get();

    $noticias = Noticia::with('langs')
        ->where('date', '<', $now)
        ->where('active', '1')
        ->whereIn('section_id', $data['section_id'])
        ->orWhere('date', '=', $now)
        ->where('time', '<=', $time)
        ->where('active', '1')
        ->whereIn('section_id', $data['section_id'])
        ->orderBy('date', 'desc')
        ->orderBy('time', 'desc')
        ->get();

    $data['noticias-'.$lang] = [];

    foreach($noticias as $row){
        foreach($row->langs as $row_lang) {
            if ($row_lang->lang_id == $lang_id) {
                $data['noticias-'.$lang][] = $row;
            }
        }
    }

    // Paginate
    /*  Get current page form url e.x. &page=1
        Create a new Laravel collection from the array data
        Slice the collection to get the items to display in current page
        Create our paginator and pass it to the view
        set url path for generated links
    */

    $currentPage = LengthAwarePaginator::resolveCurrentPage();

    $itemCollection = collect($data['noticias-'.$lang]);
    $currentPageItems = $itemCollection->slice(($currentPage * $num) - $num, $num)->all();
    $data['noticias-'.$lang] = new LengthAwarePaginator($currentPageItems , count($itemCollection), $num);
    $data['noticias-'.$lang]->setPath($url);

    return $data;

}
}

Answer 1

只是分享一些想法。从检索Noticias的内容开始：

您真的需要所有这 3 种语言吗？未来还会有更多吗？您只想展示这些“公告”的一部分吗？

回答您应该提出的这些问题：

1. 一种方法，即使添加另一种语言，您也不必更改函数；

2. 一种提高查询性能的方法，因为获取 7k 条记录不同于记录 7k x 154 种语言

3. 你真的需要全部 7k 吗？

例如，您可以将该查询拆分为多个（如果您确实需要所有语言）或使用 Eager Loading 语句中的高级函数对其进行验证。

Noticia::with(['langs' => function ($query) {
    //where this lang_id == 1, select it as whatever name you require
}])
.
.
.

其次，你确定你想要它们的原样吗？你没有用 orWhere 或 Where 过滤太多。如果您打算缩小搜索范围，我建议您在 where 语句中添加一个函数，就像上面显示的示例一样。 如果您想了解查询的全部内容，请写：

dd($data['noticias']->toSql());

如果您声称拥有 70k 多于 7k 条新闻，那么获取所有这些新闻的图片将会很繁重。您不需要真正从一开始就加载所有内容，您可以使用简单的->paginate(15); 来缩小范围，同时使用->skip(15);

Answer 2

我认为您可以像这样访问新闻主图像：

$new_lang->noticia->images()->where('main', true)->first();

您可以在 LangNoticia 模型中定义 accessor 以方便调用。

public function getImageAttribute()
{
    return $this->noticia->images()->where('main', true)->first();
}

在您看来，您可以删除 foreach() 并改为调用访问器。

@foreach($new->langs as $new_lang)
    @if($new_lang->lang_id == $lang_id)
        @php
            $mini = substr($new_lang->image->path, 0, strrpos( $new_lang->image->path, "/"));
            $name = substr($new_lang->image->path, strrpos($new_lang->image->path, '/') + 1);
            $image_mini = $mini.'/mini-'.$name;
        @endphp
        <div class="crop">
            <a href="{{ route('noticia', [$new->id, $new_lang->slug]) }}">{{ HTML::image(file_exists($image_mini)? $image_mini : $new_lang->image->path, '', array('class' => 'img-responsive ancho_100')) }}</a>
        </div>
    @endif
@endforeach

现在您可以在您的 trait 中移除对 Image 模型的调用。

在查询Noticia 模型时使用eager loading 以减少查询次数。

Noticia::with(['images' => function($query) {
    $query->where('main', true);
}])->get();