fdesk/app/common/model/VehMoneyValue.php

<?php

namespace app\common\model;

use support\Model;

class VehMoneyValue extends Model
{
    /**
     * The connection name for the model.
     *
     * @var string|null
     */
    protected $connection = 'mysql';
    
    /**
     * The table associated with the model.
     *
     * @var string
     */
    protected $table = 'veh_money_value';

    /**
     * The primary key associated with the table.
     *
     * @var string
     */
    protected $primaryKey = 'id';

    /**
     * Indicates if the model should be timestamped.
     *
     * @var bool
     */
    public $timestamps = true;
    
    
    protected $dateFormat = 'U';

    /**
     * 不允许自动填充模型字段
     */
    protected $guarded = [];


    protected $fillable = [
        'object_scene','object_id','field','currency','amount','exchange_rate',
        'remark','created_at','updated_at'
    ];

    protected $casts = [
        'amount'        => 'string',
        'exchange_rate' => 'string',
    ];

    /** 按本行汇率换到结算币；无汇率返回 null */
    public function amountInSettlement(int $scale = 2): ?string
    {
        if ($this->exchange_rate === null) return null;
        return (string) bcmul((string)$this->amount, (string)$this->exchange_rate, $scale);
    }


    /**
     * 关联订单
     */
    public function order()
    {
        return $this->belongsTo(StockOrders::class, 'object_id', 'id');
    }

    /**
     * 关联订单项（一个货币价值记录可能关联到订单项）
     */
    public function orderItem()
    {
        return $this->belongsTo(StockOrderItems::class, 'object_id', 'id');
    }

    /**
     * 限定查询特定对象类型的货币价值记录
     */
    public function scopeOfScene($query, $scene)
    {
        return $query->where('object_scene', $scene);
    }
}