mysql - 无法添加或更新子行: a foreign key constraint fails (Laravel)

Question

我有错误，并且我不知道如何正确处理 Eloquent 关系:c类别编号正确，但用户 ID 错误。我认为它是从表 models.id 中获取的，但需要 models.user_id这是我的表格:

photoset_categories(包含照片集类型的目录，例如: id = 1，name = 'Studio'；id = 2，name = 'Portrait')

Schema::create('photoset_categories', function (Blueprint $table) {
    $table->increments('id');
    $table->string('name')->comment('Category name');
});

模特(模特数据:眼睛颜色、高度、体重等)

Schema::create('models', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('user_id')->comment('Model id from users');
    $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade'); // Foreign key

    $table->timestamps();
});

model_photosets(拍摄模特的照片)

Schema::create('model_photosets', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('model_id')->unsigned()->index();
    $table->foreign('model_id')->references('user_id')->on('models')->onDelete('cascade'); // Foreign key
    $table->integer('category_id')->unsigned()->index();
    $table->foreign('category_id')->references('id')->on('photoset_categories')->onDelete('cascade'); // Foreign key
});

以下是数据库模型:

class PhotosetCategory extends Model
{
    protected $table = 'photoset_categories';
    protected $guarded = ['name'];

    public function modelPhotoset()
    {
        return $this->belongsToMany('App\Models');
    }
}

...

class Models extends Model
{
    protected $table = 'models';
    protected $fillable = ['user_id', 'd_birth', 'birth', 'm_birth', 'y_birth', 'hair_color', 'eyes_color', 'growth', 'weight'];
    protected $dates = ['created_at', 'updated_at'];


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

    public function photosets()
    {
        return $this->belongsToMany('App\PhotosetCategory', 'model_photosets', 'model_id', 'category_id');
    }
}

...

class ModelPhotoset extends Model
{
    protected $table = 'model_photosets';
    protected $fillable = ['user_id', 'category_id'];
}

Controller 模型 Controller

class ModelsController extends Controller
{
    public function editData(Request $request)
    {
        $title = 'Model data';

        $data = Models::where('user_id', Auth::id())->first();

        $all_types = PhotosetCategory::all(); // List of photo shoot catagories

        if ($request->has('save')) {
            $this->validate($request, [
                // ...
            ]);

            // UPDATE USER PRO SHOOTS DATA
            $data->photosets()->sync($request->get('ps_types'));
        }

        return view('model.edit', [
            'title' => $title,
            'data' => $data,
        ]);
    }
}

错误:

SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (delavour.model_photosets, CONSTRAINT model_photosets_model_id_foreign FOREIGN KEY (model_id) REFERENCES models (user_id) ON DELETE CASCADE) (SQL: insert into model_photosets (category_id, model_id) values (2, 2))

Answer 1

错误表明您正在尝试插入 model_id 为 2 的 model_photosets，但在 id 为 2 的模型中记录不会退出。