mysql - hasMany和属于Laravel

我有3个模型。用户，通知和Lmo通知。该关系是一个用户具有多个通知，并且通知具有许多LmoNotification。

插入通知和lmoNotification我创建了两个模型和控制器，它们具有单独的数据库表。

我的问题是，当我在数据库中输入通知时，它会插入数据，而user_id作为外键没有任何问题。但是接下来，当我尝试输入lmonotification时，出现错误。

通知模型：

class Notification extends Model
{

  protected $table = "notifications";


  protected $fillable = [
    'unit_code', 'unit_name', 'project_title', 'project_ref_number', 'storage_location', 'keeper_name', 'user_id',
    ];

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

}

LmoNotification模型

class AddLmoNotification extends Model
{

/**
 * The attributes that are mass assignable.
 *
 * @var array
 */

protected $table = "lmo_notifications";

protected $fillable = [
    'lmo_name', 'lmo_risk_level', 'lmo_quantity', 'lmo_volume', 'notification_id',
    ];

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

}

通知控制器创建通知

public function create(Request $request)
{
    $notification = Notification::create([
        'unit_code'=>$request->unit_code,
        'unit_name'=>$request->unit_name,
        'project_title'=>$request->project_title,
        'project_ref_number'=>$request->project_ref_number,
        'storage_location'=>$request->storage_location,
        'keeper_name'=>$request->keeper_name,
        'user_id'=>Auth::user()->id
        ]);

        return redirect()-> route('show.lmo_form', $notification->id);

    // return view('ApplicationForms.notifi', $notification);
}

隆起控制器

 $notification = new Notification;

    /*this loop is because im adding rows dynamically to the table*/
    $count = count($request->input('lmo_name'));

        for ($i=0; $i<$count; $i++){

        $data = AddLmoNotification::create([
        'lmo_name'=>$request->lmo_name[$i],
        'lmo_risk_level'=>$request->lmo_risk_level[$i],
        'lmo_quantity'=>$request->lmo_quantity[$i],
        'lmo_volume'=>$request->lmo_volume[$i],
        'notification_id'=>$notification->id
        ]);
        return response($data);
    }

        //return response($notification);
        return redirect()->route('show.go_to_notification');
     }

web.php

Route::prefix('notification')->group(function(){
    /*show notification main page*/
    Route::get('/', 'HomeController@getNotificationPage')->name('show.go_to_notification');
    /*route to lmo_notification_form*/
    Route::get('/personal_information_notification_form', 'HomeController@getNotificationForm');
    /*route to biohazardous material notification form*/
    Route::get('/biohazardous_material_notification_form', 'HomeController@getotherNotificationForm')->name('show.biohazardous_material_notification_form');
    /*submit lmo notification route*/
    Route::post('/personal_information_notification_form/submit', 'NotificationController@create')->name('submit.personal_Info_Notification');
    /*Rtoute to lmo form*/
    Route::get('/personal_information_notification_form/add_lmo/{notification_id}', 'HomeController@getlmoNotificationForm')->name('show.lmo_form');
    /*Route to submit lmo list for notification*/
    Route::post('/personal_information_notification_form/add_lmo', 'LmoNotificationController@create')->name('submit.lmo_list');
});

通知表

Schema::create('notifications', function (Blueprint $table) {
        $table->increments('id');

        $table->integer('user_id')->unsigned();
        $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade')->onUpdate('cascade');

        $table->string('unit_code')->nullable();
        $table->string('unit_name')->nullable();
        $table->string('project_title')->nullable();
        $table->string('project_ref_number')->nullable();
        $table->string('storage_location');
        $table->string('keeper_name');

        $table->timestamps();


    });

Lmo通知表

public function up()
{
    Schema::create('lmo_notifications', function (Blueprint $table) {

        $table->increments('id');


        $table->integer('notification_id')->unsigned();
        $table->foreign('notification_id')->references('id')->on('notifications')->onDelete('cascade')->onUpdate('cascade');


        $table->string('lmo_name');
        $table->string('lmo_risk_level');
        $table->string('lmo_quantity');
        $table->string('lmo_volume');

        $table->timestamps();

    });
}

通知表包含一些个人详细信息字段，而lmonotification包含产品列表。

错误消息说


  SQLSTATE [23000]：违反完整性约束：1048列'notification_id'不能为空（SQL：插入lmo_notifications（lmo_name，lmo_risk_level，lmo_quantity，lmo_volume，notification_id，updated_at， created_at）值（asd，medium，2、2，2017-05-09 22:35:15，2017-05-09 22:35:15））


请帮忙。

最佳答案

关系设置没有任何问题。问题开始于将新notification_id的AddLmoNotification设置为实例化模型的地方：

$notification = new Notification;

请注意，只要$notification不能通过以下方式持久保存到数据库中：

$notification->save()

该通知将没有数据库分配的ID，因此，访问其id属性将返回null。因此，在创建任何依赖于其外键字段的id属性的模型之前，必须先保存$notification模型。

关于mysql - hasMany和属于Laravel，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/43880910/