php laravel eloquent 多級聯(lián)動循環(huán) laravel 視圖輸出 laravel 無限極分類改怎么寫循環(huán)呢

下面是 city 模型

namespace App\Model;

use Illuminate\Database\Eloquent\Model;

class City extends Model
{
    protected $table ='cities';

    public function parentCity()
    {

        return $this->belongsTo('App\Model\City', 'pid', 'id');
    }

    public function childrenCities()
    {

        return $this->hasMany('App\Model\City', 'pid', 'id');
    }
}

 /**
 * 內(nèi)容資源列表數(shù)據(jù)模型倉庫
 */
public function index()
{
    //$city = $this->city->all();
    $cities = City::with('childrenCities')->get();
    return $cities;

}

print 輸出的數(shù)據(jù)如下關(guān)聯(lián) 子分類 $this->childrenCities

如果有下級分類就會有 childrenCities 如果沒有 childrenCities 返回 null


[{"id":19,"pid":0,"name":"\u4e0a\u6d77\u5e02","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u9876\u7ea7\u57ce\u5e02","children_cities":[{"id":20,"pid":19,"name":"\u666e\u9640\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":21,"pid":19,"name":"\u5949\u8d24\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":22,"pid":19,"name":"\u8679\u53e3\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":23,"pid":19,"name":"\u5609\u5b9a\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":24,"pid":19,"name":"\u9759\u5b89\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":25,"pid":19,"name":"\u5362\u6e7e\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":26,"pid":19,"name":"\u95f5\u884c\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":27,"pid":19,"name":"\u6d66\u4e1c\u65b0\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":28,"pid":19,"name":"\u5b9d\u5c71\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":29,"pid":19,"name":"\u9752\u6d66\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":30,"pid":19,"name":"\u677e\u6c5f\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":31,"pid":19,"name":"\u5f90\u6c47\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":32,"pid":19,"name":"\u6768\u6d66\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":33,"pid":19,"name":"\u95f8\u5317\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":34,"pid":19,"name":"\u957f\u5b81\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"},{"id":35,"pid":19,"name":"\u9ec4\u6d66\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04"}]},{"id":20,"pid":19,"name":"\u666e\u9640\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":21,"pid":19,"name":"\u5949\u8d24\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":22,"pid":19,"name":"\u8679\u53e3\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":23,"pid":19,"name":"\u5609\u5b9a\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":24,"pid":19,"name":"\u9759\u5b89\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":25,"pid":19,"name":"\u5362\u6e7e\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":26,"pid":19,"name":"\u95f5\u884c\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":27,"pid":19,"name":"\u6d66\u4e1c\u65b0\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":28,"pid":19,"name":"\u5b9d\u5c71\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":29,"pid":19,"name":"\u9752\u6d66\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":30,"pid":19,"name":"\u677e\u6c5f\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":31,"pid":19,"name":"\u5f90\u6c47\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":32,"pid":19,"name":"\u6768\u6d66\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":33,"pid":19,"name":"\u95f8\u5317\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":34,"pid":19,"name":"\u957f\u5b81\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":35,"pid":19,"name":"\u9ec4\u6d66\u533a","tag":"shs,shanghaishi","status":0,"created_at":"2015-07-07 09:29:04","updated_at":"2015-07-07 09:29:04","pname":"\u4e0a\u6d77\u5e02","children_cities":[]},{"id":36,"pid":0,"name":"\u6c5f\u82cf\u7701","tag":"","status":0,"created_at":"2015-07-27 11:55:55","updated_at":"2015-07-27 11:55:55","pname":"\u9876\u7ea7\u57ce\u5e02","children_cities":[{"id":37,"pid":36,"name":"\u5357\u4eac\u5e02","tag":"","status":0,"created_at":"2015-07-27 11:57:48","updated_at":"2015-07-27 11:57:48"}]},{"id":37,"pid":36,"name":"\u5357\u4eac\u5e02","tag":"","status":0,"created_at":"2015-07-27 11:57:48","updated_at":"2015-07-27 11:57:48","pname":"\u6c5f\u82cf\u7701","children_cities":[{"id":38,"pid":37,"name":"\u7ebd\u533a","tag":"","status":0,"created_at":"2015-07-27 11:58:41","updated_at":"2015-07-27 11:58:41"}]},{"id":38,"pid":37,"name":"\u7ebd\u533a","tag":"","status":0,"created_at":"2015-07-27 11:58:41","updated_at":"2015-07-27 11:58:41","pname":"\u5357\u4eac\u5e02","children_cities":[]}]

/**
 * view - 視圖模板 循環(huán)輸出2級
 */
@foreach($cities as $key => $li)
  @if($li->pid == 0)
    <tr>              
        <td class="text-aqua">{{ $li -> name }}</td>
        <td class="text-green">{{ $li -> tag }}</td>
        <td> <a href="{{ route('admin.city.index') }}/{{ $li->id }}/edit"><i class="fa fa-fw fa-pencil" title="修改"></i></a>  </td>
    </tr>
    @foreach($li->childrenCities as $li2)
        <tr>                 
            <td class="text-aqua">  &nbsp;&nbsp; -- {{ $li2 -> name }}</td>
            <td class="text-green">{{ $li2 -> tag }}</td>
            <td> <a href="{{ route('admin.city.index') }}/{{ $li2->id }}/edit"><i class="fa fa-fw fa-pencil" title="修改"></i></a>  </td>
        </tr>
    @endforeach
  @endif
@endforeach

目前是這么寫的，感覺不應(yīng)該這么寫輸出，按照三級欄目聯(lián)動循環(huán)的數(shù)據(jù)展現(xiàn)；

拋棄城市的上萬條數(shù)據(jù)不講；

現(xiàn)在就是想輸出三級欄目分類；城市只是舉個列子；

三級欄目改怎么在視圖輸出呢？反復(fù)用 foreach 循環(huán)嗎

還是有其他方案輸出呢？

小白，迷茫了啊；

有大神指導(dǎo)一下嗎；怎么在視圖輸出呢

現(xiàn)在輸出如下樣式圖

圖片描述

回答

編輯回答

澐染

你需要用遞歸實現(xiàn)。

2018年1月29日 09:50

編輯回答

初心

供參考

public function children()
{
    return $this->hasMany(Category::class, 'parent_id');
}

/**
*  獲取子分類
*/
public function getChild($payload = null) {
    $payload = $payload ? $payload : [$this->id];
    $this->children->each(function($child) use (&$payload){
        $payload = array_merge([$child->id], $child->getChild($payload));
    });
    return $payload;
}
    
// 使用
$categoryIds = Category::find($request->category_id)->getChild();
$Book = $Book->whereIn('category_id', $categoryIds);

2017年2月4日 03:31

編輯回答

雨蝶

咋沒有回答的呢，樓主有沒有解決啊~~ ^-^

2017年12月17日 06:43

編輯回答

陌璃

我今天也在搞一個遞歸顯示的問題。

1. 在模型里面

public function childMessages(){
    return $this->hasMany('App\Message','replyId','id'); //->with('childMessages')
}

2. 控制器里面的方法

    use Illuminate\Database\Eloquent\Collection;
    
    /**
     * 遞歸獲取數(shù)據(jù)
     * @param Collection $a, Collection $b
     * @return null
     */
    public function childM(Collection $a,Collection &$b)
    {
        foreach($a as &$v){
            if(count($v->childMessages)>0){
                $b->add($v);
                $this->childM($v->childMessages,$b);
            }else{
                $b->add($v);
            }
        }
    }

3. 控制器調(diào)用

$all=Message::with('childMessages')->where('replyId','0')->get();

$all2=(new Collection);
$this->childM($all,$all2);
 
return view('messages/index',[
    'messages'=>$all2
]);

4. 之后視圖輸出就可以了

p.s. 在模型里面如果直接return $this->hasMany('App\Message','replyId','id')->with('childMessages');，
然后$all=Message::with('childMessages')->where('replyId','0')->get();調(diào)用，結(jié)果里面會直接返回所有遞歸，但是這里不用管。因為在遞歸中使用$v->childMessages時，會自己再次查詢。

2017年2月9日 05:07

編輯回答

影魅

我反對遞歸實現(xiàn)。從數(shù)據(jù)庫設(shè)計的角度去解決可以明顯解決程序負擔。
關(guān)系行數(shù)據(jù)庫在存儲多級數(shù)據(jù)的時候。最好不要單純做pid。id。這樣的。
要么加上每一層的路徑。要么換結(jié)構(gòu)。要是數(shù)學(xué)大神還可以用矩陣來直接計算。

2018年5月5日 15:05

編輯回答

撥弦

請看我的文章
https://segmentfault.com/a/11...

2017年7月10日 05:57