Php 您提供的关系字段不是所提供的Eloquent模型上的有效关系方法名称

我有两张表：选项和选项选择。 以下是模型：

use LaravelBook\Ardent\Ardent;

class Option extends Ardent
{
    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'options';

    // MASS ASSIGNMENT -------------------------------------------------------
    // define which attributes are mass assignable (for security)
    // we only want these 1 attribute able to be filled

    protected $fillable = array('name');    

    public function selections()
    {
        return $this->hasMany('optionselection');       
    }
}

use LaravelBook\Ardent\Ardent;

class Optionselection extends Ardent
{

    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'option_selections';

    // MASS ASSIGNMENT -------------------------------------------------------
    // define which attributes are mass assignable (for security)
    // we only want these 1 attribute able to be filled

    protected $fillable = array('option_id', 'name');   

    public function choice()
    {
        $this->belongsTo('option');
    }
}

我试图像以前多次那样在Laravel administrator中创建关系，但我不明白为什么会出现错误：您为optionselections提供的“选择”关系字段在所提供的雄辩模型上不是有效的关系方法名称

    return array(

     /**
     * Model title
     *
     * @type string
     */
    'title' => 'Option Selections',

    /**
     * The singular name of your model
     *
     * @type string
     */
    'single' => 'Option Selection', 

    /**
     * The class name of the Eloquent model that this config represents
     *
     * @type string
     */
    'model' => 'optionselection',

    /**
     * The columns array
     *
     * @type array
     */
    'columns' => array(     
        'choice' => array(
            'title' => 'Option',
            'relationship' => 'choice',
            'select' => 'name',         
        ),
        'selection' => array(
            'title' => 'Selection'
        ),
    ),

    'edit_fields' => array(
        'choice' => array(
            'title' => 'Option',
            'type' => 'relationship',
            'name_field' => 'name', 
        ),      
        'name' => array(
            'title' => 'Selection Name',
            'limit' => 30,
        ),
    ), 

    'action_permissions'=> array(
    ),

 )

我知道method/relationship字段确实存在，并且在Laravel Administrator之外被识别，因为这是有效的：

    $optsel = new Optionselection();
    // var_dump($svcloc);
    if (method_exists($optsel, "choice")) {
        echo '<br/>Recognizes!';
    } else {
        echo '<br/>Problem!';
    }

$optsel=newoptionselection（）；
//var_dump（$svcloc）；
如果（方法_存在（$optsel，“选择”））{
回声'
识别！'；
}否则{
回显“
问题！”；
}

---

为什么会出现错误？

在关系方法中缺少返回值。封闭的