将父模型的数据提取到 static::saving() 引导函数中

Question

我想使用父模型中的数据在子模型中运行saving()函数

以前，我将计算数据插入到模型"Loan"中的表中，但现在我需要将其插入子模型" InterestAmount

贷款.php

use IlluminateDatabaseEloquentModel;
class Loan extends Model
{
    protected $fillable ['amount','interest','status','duration','member_id','loan_type_id','interest_type_id','loan_payment_type_id'];
    //protected $appends = 'interest_amount
    protected static function boot()
    {
        parent::boot();
        static::saving(function($model) {
            $model->interest_amount = ($model->amount/100 )* $model->interest;
        });
    }
    public function interest_amount()
    {
        return $this->hasMany(InterestAmount::class,'loan_id','id');
    }
}

我想从贷款中删除储蓄功能.php并按如下方式使用。

兴趣.php

use IlluminateDatabaseEloquentModel;
class InterestAmount extends Model
{
    public function loan()
    {
        $this->belongsTo(Loan::class,'loan_id','id');
    }
    protected static function boot()
    {
        parent::boot();
        static::saving(function($model) {
            $model->interest_amount = ($model->amount/100 )* $model->interest;
        }); 
    }
}

如何在此函数中获取"金额"和"利息"？

Answer 1

模型中InterestAmount $model变量是指一个InterestAmount对象：

static::saving(function($model){
    $model->interest_amount = ($model->loan->amount/100 )* $model->loan->interest;
}); 

然后，您需要使用关系方法获取相关loan loan()然后获取属性amount/interest。

注意：正如@namelivia的评论所说，您缺少loan()方法中的return：

public function loan()
{
    return $this->belongsTo(Loan::class,'loan_id','id');
}