GY_zhishiku_admin/app/Model/QuestionHistory.php

<?php

namespace App\Model;

use Illuminate\Database\Eloquent\Model;

class QuestionHistory extends Model
{

    protected $table   = "jm_question_history";
    public $timestamps = false;
    public $primaryKey = 'id';


    /**
     * 答案属性
     */
    public function getAnswerAttribute($value)
    {
        if( ! $value) {
            return '';
        }
        $value = json_decode($value , true);
        return is_array($value) ? implode(',' , $value) : $value;
    }
}