外键属于选择框

Question

我有一个餐桌产品：

• ID
• 那么
• date_operation
• category_id（外键表格类别）

表类别：

• ID
• 那么
• 描述

在addProduct视图中，我想显示一个包含类别表中类别的选择框：

但我有这个错误

未定义的变量：类别（查看：C：\ xampp \ htdocs \ Blg \ resources \ views \ addProduct.blade.php）

addProduct.balde.php

    <div class="form-group">
      <label for="inputPassword" class="col-lg-2 control-label">Name</label>
        <div class="col-lg-10">
          <input type="text" name ="name" class="form-control" id="" placeholder="">
        </div>
     </div>

  <div class="form-group">
    <label for="textArea" class="col-lg-2 control-label">categorie</label>
      <div class="col-lg-10">
         @foreach($categories as $categorie)
           <option value="{{ $categorie->id }}">{{ $categorie->name }}</option>
         @endforeach
       </div>
   </div>

CreatesController.php

public function add(Request $request)
        {
            $categories = Categories::all();
            $products = new Product;
            $products->name = $request->input('name'); 
            $products->date_operation = $request->input('date_operation'); 
            $products->category_id = $request->input('category_id'); 
            $products->save(); 
            return view('addProdcut', ['categories' => $categories]);

        }

Answer 1

你的结构不正确。

你的方法一定是那个

public function create() {

   $categories = Categories::all();

   return view('addProdcut', ['categories' => $categories]);
}



public function add(Request $request)
        {

            $products = new Product;
            $products->name = $request->input('name'); 
            $products->date_operation = $request->input('date_operation'); 
            $products->category_id = $request->input('category_id'); 
            $products->save(); 
            return redirect('some page')->withMessage('your product has been added');

        }