選擇具有2個級別（類別和子類別）的類別

Question

即時創建一個選擇類別與2 leves，一個類別和子類別，我已經創建和保存數據庫中的數據，唯一缺少的是在視圖頁面，使選擇字段顯示我的期望，但即時通訊有一些疑問，有人可以提供一個提示？

代碼示例：

categories: 
- id; 
- name; 
- parent_id; 

example data: 
1, Politics, null; 
2, Sports, null; 
3, World, null; 
4, Soccer, 2; 

Final result on Input Select: 
Politics 
Sports 
-- Soccer 
World 


my view: 
<select name="category" id="category" class="form-control"> 
           <option>Select...</option> 
            @foreach($categories as $category) 
            <option value="{{$category->id}}">{{$category->name}}</option> 

            @endforeach 
           </select> 

Answer 1

創建爲categories之間的關係：

類別型號

public function subcategories() 
{ 
    return $this->hasMany('App\Category', 'parent_id'); 
} 

public function parent() 
{ 
    return $this->belongsTo('App\Category'); 
} 

然後你就可以查詢它：

$Categories = Category::whereNull('parent_id')->with('subcategories')->get(); 

我n您的看法，你可以做：

@foreach($categories as $category) 
    <option value="{{$category->id}}">{{$category->name}}</option> 
    @foreach($category->subcategories as $subcategory) 
    <option value="{{$subcategory->id}}">{{$subcategory->name}}</option> 
    @endforeach 
@endforeach