baoshi-was/app/Station.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

use App\Traits\ModelLogChanging;

class Station extends Model
{
    use ModelLogChanging;

    protected $fillable=['name', 'code', 'station_type_id','sequence','parent_id'];

    public function stationType(){
        return $this->belongsTo(StationType::class);
    }
    public function parent(){
        return $this->belongsTo(Station::class);
    }
    public function child(){
        return $this->hasOne(Station::class,'parent_id');
    }
}