test_app/app/Models/Audit.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Audit extends Model
{
    //定义表
    protected $table = "audit";
    //定义主键
    protected $primaryKey = "id";
    protected $fillable = ['user_id','amount','img_url','desc','status','activity'];
//    public $timestamps = false;
    public function user()
    {
        return $this->hasOne('App\Models\User','id','user_id');
    }
}