从 Laravel 的数据库中选择多个下拉列表

Question

在我的 Web 应用程序中，我使用多个选择选项从 json_encode 向数据库添加了多个数据。

在我的数据库列中，如下所示。

["Agriculture & Food Processing","Automobiles","Banking & Financial Services"]

现在我想检索这些数据以进行编辑和更新。我的观点就像附加的图片

我的代码如下所示

<div class="form-group">
<label for="industry">Intrsting Industry</label>
<select id="industry" name="industry[]" class="form-control" multiple>
    <option value="">Select Option  </option>
    <option>Agriculture &amp; Food Processing</option>
    <option>Automobiles</option>
    <option>Banking &amp; Financial Services</option>
    <option>BPO / KPO </option>
    <option>Civil &amp; Construction</option>
    <option>Consumer Goods &amp; Durables</option>
    <option>Consulting</option>
    <option>Education</option>
    <option>Engineering</option>
    <option>Ecommerce &amp; Internet</option>
    <option>Events &amp; Entertainment</option>
    <option>Export &amp; Import</option>
    <option>Government &amp; Public Sector</option>
    <option>Healthcare</option>
    <option>Hotel, Travel &amp; Leisure</option>
    <option>Insurance</option>
    <option>IT &amp; Telecom</option>
    <option>Logistics &amp; Transportation</option>
    <option>Manufacturing</option>
    <option>Manpower &amp; Security</option>
    <option>News &amp; Media</option>
    <option>NGO &amp; Non profit</option>
    <option>Pharmaceutical</option>
    <option>Real Estate</option>
    <option>Wholesale &amp; Retail</option>
    <option>Others</option>
  </select>

那么我如何从数据库中选择上面的列表。

Answer 1

其实你不需要手动对其进行json_encode，laravel可以选择castarray/json的任意属性：

我们假设您的型号名称是 Item。

//Model
class Item{
   protected $casts = [
      'industry' => 'array'
   ]
//snap
}
//Controller
class ItemController extends Controller{
   //snap   
   public function update($id,\Request $request){
      $item = Item::findOrFail($item);
      // no need to json_encode! laravel handle this magically!
      $item->industry = $request->industry;
      $item->save();
   }
   //snap
   public function show($id){
      $item = Item::findOrFail($id);
      return view('item.show',compact('item'));
   }
}

@php
   // just making an array of industry options, so later we will iterate on it.
   $industries = [
      'Agriculture & Food Processing',
      'Automobiles',
      'Banking & Financial Services',
      //list all the industries here
   ];
@endphp
<select id="industry" name="industry[]" class="form-control" multiple>
   <!-- default value -->
    <option value="">Select Option </option>
    @foreach($industries as $industry)
       <!-- if industry found in current item's industry field we add selected to it -->
       <option @if(in_array($industry,$item->industry)) selected @endif>{{$industry}}</option>
    @endforeach
  </select>