laravel，从另一个表的下拉列表中显示数据，但保存在当前表中

// app/Models/Category.php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Category extends Model
{
    public function products()
    {
        return $this->hasMany(Product::class);
    }
}

// app/Models/Product.php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;

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

<!-- resources/views/products/create.blade.php -->
<form action="{{ route('products.store') }}" method="POST">
    @csrf
    <div>
        <label for="category_id">Category:</label>
        <select name="category_id" id="category_id">
            @foreach ($categories as $category)
                <option value="{{ $category->id }}">{{ $category->name }}</option>
            @endforeach
        </select>
    </div>
    <button type="submit">Save</button>
</form>

// app/Http/Controllers/ProductController.php
namespace App\Http\Controllers;

use App\Models\Category;
use App\Models\Product;
use Illuminate\Http\Request;

class ProductController extends Controller
{
    public function create()
    {
        $categories = Category::all();
        return view('products.create', compact('categories'));
    }

    public function store(Request $request)
    {
        $product = new Product();
        $product->name = $request->input('name');
        $product->category_id = $request->input('category_id');
        $product->save();

        return redirect()->route('products.index');
    }
}