向laravel 5.4添加子类别 [英] Adding subcategories to laravel 5.4

问题描述

我的应用程序中有类别表，它工作得很好，但我想知道如何也为此获得子类别?

I have categories table in my application and it works just fine but i wonder how to get subcategories for that as well?

目前我所拥有的是:

类别模型

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Category extends Model
{

  protected $fillable = ['name'];

  public function ads(){
     return $this->hasMany(Ad::class);
  }

}

类别迁移:

public function up()
    {
        Schema::create('categories', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->string('slug')->unique();
            $table->timestamps();
        });
    }

我的帖子模型:

public function category(){
       return $this->belongsTo(Category::class);
    }

PS:我知道我必须创建新表并为子类别调用category_id的外键，但令我感到困惑的是关系以及如何在前端选择它们，因此类别和子类别都显示在一个中下拉给用户(例如WP)?

PS: I know I have to make new table and call for foreign key of category_id for subcategories but what makes me confuse is the relationships and also how to select them in front-end so category and subcategories all shows in one drop down to user (like WP)?

推荐答案

我真的不太了解您要执行的操作..但是，如果您要在一个下拉列表中同时添加类别和子类别，我认为这就是你想要的:

i really don't understand well what you're trying to do .. but if you're trying to add both categories and subcategories in one dropdown i assume this is what you wanted:

假设您已经在控制器中建立了关系..

let's say you already have done the relationship .. in your controller

$categories = Category::with('sub_categories')->get();
return view('page',compact('categories'));

现在我们掌握了所有类别及其对应的子类别..您只需要做的

now we got all the categories and it's corresponding sub-categories .. in your blade all you have to do is

<select name="categories">
@foreach($categories as $categ)
    <optgroup label="{{ $categ->name }}">
        @foreach($categ->sub_categories as $sub)
            <option value="{{ $sub->id }}">{{ $sub->name }}</option>
        @endforeach
    </optgroup>
@endforeach
</select>

这将为您提供类似的输出

and that would give you an output like

<select>
  <optgroup label="Fruits">
    <option value="1">Apple</option>
    <option value="2">Banana</option>
  </optgroup>
  <optgroup label="Vegetables">
    <option value="3">Beans</option>
    <option value="4">Cabbage</option>
  </optgroup>
</select>

编辑

关系很容易理解英语..实际上您已经在类别广告中做到了..

relationship is easy as understanding english .. actually you've done it already in your category ads ..

类别模型

public function ads()
{
    return $this->hasMany('App\Ad');
    // return $this->hasMany('App\Ad','theforeignfieldtocomparetomyprimarykey')
}

hasMany-这意味着广告模型在数据库表中的字段中有category_id作为字段..

hasMany - this means Ad model has category_id in it's database table as field ..

在您的广告模型

public function category()
{
    return $this->belongsTo('App\Category');
    // return $this->belongsTo('App\Category','myfieldtocompare');
}

belongsTo-由于函数名称为category，它将在其字段中查找category_id，并将其与model category的primary key

belongsTo - since the function name is category it will look up on his fields for category_id and match it to the primary key of model category

因此，基本上，您要做的是首先制作具有如下迁移功能的模型:

so basically what you have to do is first make models with migrations like:

类别

• id
• 名称

子类别

• id
• category_id
• 名称

然后在您的模型中，您应该具有上面示例的脚本..

then in your model you should have a script as exampled above ..

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