我在創(chuàng)建新產(chǎn)品時(shí)無法添加關(guān)鍵產(chǎn)品。我收到錯(cuò)誤，SQLSTATE[HY000]: General error: 1364 Field 'category_id' doesn't have a default value (SQL: insert into `products` (`activation_key`, `updated_at`, `created_at`) values (57394cd3-54f8-3e95-a951-e11f029fa0f5, 2020-05-27 17:09:08, 2020-05-27 17:09:08)) 我不知道為什么，它問我那個(gè)。我試過的：category_id是我要添加到表格中的第一列。如果我輸入->nullable()，category_id我會(huì)得到與表中下一列名稱相同的錯(cuò)誤。這是我的代碼：產(chǎn)品控制器  public function store(Request $request)    {        $inputs = $request->except('_token');        $quantity = $inputs['quantity'];        factory(KeyProduct::class, $quantity)->create(); foreach ($inputs as $key => $value) {            $home->$key = $value;        }        $home->image=$path;        $home->save();        return redirect('admin/gamelist');}產(chǎn)品表 Schema::create('products', function (Blueprint $table) {            $table->increments('id');            $table->integer('category_id')->unsigned();            $table->string('name');            $table->string('image')->nullable();            $table->string('activation_key')->nullable();            $table->timestamps();        });KeyProduct_table.php         Schema::create('key_products', function (Blueprint $table) {                        $table->increments('id');             $table->string('activation_key');             $table->timestamps();         });關(guān)鍵產(chǎn)品.php public function products()    {        return $this->HasOne('App\Product')->withPivot('quantity');    }產(chǎn)品.phpclass Product extends Model{    public function categories()    {        return $this->belongsTo('App\Category', 'category_id');    }        public function keyProduct()    {        return $this->HasOne('App\KeyProduct');    }    protected $fillable = ['quantity'];}KeyProductFactory.phpuse App\KeyProduct;use App\Product;$factory->define(KeyProduct::class, function (Faker $faker) {    $product = factory(Product::class)->create();    return [            'activation_key' => $product->activation_key,        ];});