Eloquent的“select”方法在使用“with”方法时无法正常工作。

我的村庄模型；

<?php namespace App; use Illuminate\Database\Eloquent\Model; class Village extends Model { public function positions() { return $this->belongsTo(Map::class, 'id', 'field_id');
    }
}

我的地图类迁移；

Schema::create('map_data', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('field_type');
    $table->integer('field_id');
    $table->string('x');
    $table->string('y');
    $table->timestamps();
});

我的 \"VillageController\" 类的 \"villages\" 方法；

public function villages() {
    $villages = Village::with([
        'positions' => function ($query) {
            $query->select('x', 'y');
        }
    ])->get();
    return $villages;
}

结果；

{
  "villages": [
    {
      "id": 1,
      "name": "village 1",
      "created_at": "2016-10-26 18:36:34",
      "updated_at": "2016-10-26 18:36:34",
      "positions": null
    },
    {
      "id": 2,
      "name": "village 2",
      "created_at": "2016-10-26 18:36:34",
      "updated_at": "2016-10-26 18:36:34",
      "positions": null
    }
  ]
}

\"Select\" 方法只需要提到，但是列返回为空。

如果我删除 $query->select(\'x\', \'y\'); 代码，返回以下结果。

{
  "villages": [
    {
      "id": 1,
      "name": "village 1",
      "created_at": "2016-10-26 18:36:34",
      "updated_at": "2016-10-26 18:36:34",
      "positions": {
        "id": 1,
        "field_type": "1",
        "field_id": "1",
        "x": "21",
        "y": "21",
        "created_at": "2016-10-26 18:36:34",
        "updated_at": "2016-10-26 18:36:34"
      }
    },
    {
      "id": 2,
      "name": "village 2",
      "created_at": "2016-10-26 18:36:34",
      "updated_at": "2016-10-26 18:36:34",
      "positions": {
        "id": 2,
        "field_type": "1",
        "field_id": "2",
        "x": "0",
        "y": "0",
        "created_at": "2016-10-26 18:36:34",
        "updated_at": "2016-10-26 18:36:34"
      }
    }
  ]
}

但是我使用 $query->select(\'x\'); 代码，结果应该是以下内容

资源： https://stackoverflow.com/a/32185643/3287225